On one flight the pilot said I've got the Dogs covered they are nice and warm down there not to worry when you hear them bark while taxing to and from the gate lol.
its the hydraulic valve and pumps that control the rudder i think.. and why it's exclusive on A320s, that's because their parts are different from other planes.
Why is this exclusive to the A320 family? Well, I never heard anyone mention it happening on A330/340/380, so I assume it is. Boeing planes don't seem to have this "feature" either . :P
@joshieperson777 The PTU will work when there is either a 500 PSI difference between green and yellow systems, low reservoir pressure, low reservoir fluid contents and high fluid temperatures. You shouldnt really hear it during flight control movements, but obviously when the gear is operated as its a heavy system user.
LAOTG: The PTU can start anytime during startup,taxi,takeoff;flight; descent,landing and engine shut down. Have heard alot of times on takeoff,with A320 and A321. The PTU is a power transfer unit,that build up the pressure when it drops blow a certain point. If left hyd.system drops below its needed point PTU transfer power from right system to the left system. So its quite common to hear the PTU at all stages during a flight :D PTU on airbus A320 family have this "barking dog" sound.
My Cousin is a pilot and has told me the hydraulic system causes this barking sound. When the PTU is running overtime it causes the hydraulics to compensate. I hope this helps.
Yes this is very interesting. the PTU usually kicks in if one of the hydraulics systems goes below 500 psi (normally 2500-3000 psi). That usually only occurs during engine start up or shut down. Never heard in on finals.
Yes this is very interesting. the PTU usually kicks in if one of the hydraulics sytems goes below 500 psi (normally 2500-3000 psi). That usually only occurs during engine start up or shut down. Never heard in on finals.
@LegendxHD I've heard it just after taking off while climbing. It was back when I only just started to get interested into aircraft, so I was a bit worried.
If you've ever actually run these things, you would know that system pressure comes up almost immediately as the starter rotates the engines. THAT's how powerful the engine driven pumps are. So, during normal operation it is unlikely that the PTU will be heard in flight. What Sterlingjob may not know is that even when the engines are at idle in flight....they are turning faster than they do while on the ground. It's called "Flight Idle". Pumps put out more volume in flight than on the ground.
@JetMechMA The pumps pump more at flight idle? Are they not constant pressure? The volume moved depends on demand not speed of the engine, at flight idle with little demand the volume moved will be tiny,put the gear down and the demand is high and volome is high, You just shot yourself in foot there
@Sterlingjob: VOLUME...not pressure. Volume moved depends on demand...and you just contradicted yourself. It's about VOLUME, not prerssure. If demand requires too much volume, that results in a drop in pressure which triggers the PTU. Something's got to give. You can't keep up pressure if the volume output is too low. But the EDPs are designed to supply adequate volume for all normal use. As I said, if you knew anything about running these engines you would know that PSI comes on immediately.
@JetMechMA What kind of pump and how does the pump work? The EDP supplies the system with fluid at 3000 psi ( 206 bar ) and changes its output to that which is necessary for the system. A pressure switch 3074GD and a check valve 3050GM are installed downstream of the EDP. The pressure switch monitors the output pressure of the pump . The reason the pressure is high is so that pipes can be smaller therefore saving weight. But you just said the EDP's can supply all the demand? Now they cant?
@Sterlingjob: The reason the pressure is high is so that pipes can be smaller therefore saving weight. But you just said the EDP's can supply all the demand? Now they cant?
JM: You didn't make a connection between statements. Now you are acting irrationally.
@JetMechMA again you were not there so stop assuming. Sometimes the PTU can come on in flight with no ecam message. So unless you were there stop assuming. It can be anything and if you knew anything about aircraft you would know it could be any part of the system that is at fault. Use the TSM, 99% of all rectifications are in the TSM
@Sterlingjob As I said, if you knew anything about running these engines you would know that PSI comes on immediately after the starter turns the engine, let alone at idle or above. In flight when the engines are no slower than "flight idle" the volume output is even more assured and it is even less likely that the PTU would be needed. Anyway, as was said, there is very little demand when the PTU is heard running constantly in this video. You keep ducking that fact.
@Sterlingjob: What is the angle of the swash plate when idle?
JM: When "idle"? You mean with no demand? By your terminology I can tell you looked this up on Wikipedia. I think you got ahold of some Airbus manuals and come on Youtube trying to sound like an expert or something. By the way, the swash plate is neutral with zero demand on the pump. But any ten year old could look that up on the Internet now days. Besides, I don't overhaul hydraulic pumps in the back shop.
@JetMechMA Lets establish one thing here i am a EASA B1 type rated engineer, i dont have an easy to get A&P licence which i can get in 3 weeks where i learn questions and answers.
The angle of the swash plate when idle, (Idle (idling) is a term which generally refers to a lack of motion and/or energy) is at maximum because there is zero pressure being generated. It is in no way neutral position, this is hydraulic question from years ago.
@Sterlingjob: You are WRONG again, "idle" means running but not engaged. In other words, no demand. It is running and ready, but no demand. When the pump is running but idled, the swash plate is neutral. As far as you "engineers" go, you ain't no real engineer. Get over yourself. YOU'RE A MECHANIC....PERIOD. EASA, my foot. Funny how our aircraft operate safely every day just like yours...and it didn't take an engineer to get it airborne.
@JetMechMA Did i say engine idle? No i didn't. There is no neutral position, the swash plate is either at maximum deflection when stopped or it is at minimum angle producing 3000psi. When load is increased then the angle of the swash plate will increase to regulate 3000psi to keep up with demand. Oh and you forgot to mention the CASE DRAIN, fluid is always being pumped around the circuit. Even with no demand fluid is still passing through case drain and the system is still at 3000psi
@JetMechMA Lets see now....i am quoting directly from airbus manuals and course notes and im making things up? Erm ok, your knowledge level at best is poor and at worst shocking. When i was grilled by a CAA surveyor it was also a judge of character, did i know what i was talking about and quite clearly I DO. In the UK we would call someone like you a gobshite
@Sterlingjob: Lets see now....i am quoting directly from airbus manuals and course notes and im making things up?
JM: That's right, you're making things up. I got my training at the Airbus training facility in Miami Florida. I'm not altering what they told me, like you are. You aren't quoting the Trouble Shooting Manual or the Flight Crew Operating Manual any other manual.....you're MIS-quoting them. What's your beef anyway? We all make mistakes. Why have you gone ballistic over this thing?
JM: I never said I'm an expert. I only wanted to comment on what I observed happening in this interesting video. Some abnormal malfunction of the hydraulic system...most likely low presure in the green system at a time when there should have been very little demand on the system....and the PTU coming on over the threshold of the runway during what appears to be a CAT III landing. You want the plane "being all that it can be", during CAT III.
You're wasting your time Sterlingjob. Go watch several other A320/319 landing videos. The PTU doesn't come on until they pull up to the gate after engine shutdown. Know why?....because as system pressure bleeds off, the PTU goes back and forth between systems coming on for a split second at a time. That's what gives the A320 it's personality. That's normal....on the ground, at the gate, engines spooling down. Go watch other videos. This one is an abnormal situation. You're wrong Sterlingjob.
If the PTU came on because of an engine inflight shut-down....believe me, the passengers would never know, unless the person sitting in row #1 in First Class happened to look out and saw it spinning slower...or "windmilling". Yes, the autopilot is THAT good....you'd never know the engine shut down in flight unless the pilot told you. I've seen it first hand on several test flights. The FAC (Flight Augmentation Computer) responds to an engine failure very rapidly. Bless it's heart.
Once the PTU comes on in this video, it is heard running continuously...which means the PTU is supplying ALL the power to the green system.... main green system engine driven pump has failed....or the engine has failed in which case it's engine driven hydraulic pump might put out low pressure....especially if the pilots pulled the engine disconnect fire switch which closes all connections to and from the dead engine. This is a unique and relatively rare video.
Watched it again and decided that it is definitely an abnormal condition when the PTU comes on. The PTU isn't heard until they are over the runway thereshold. The flaps aren't moving...they were set to their final position long ago. The gear aren't moving, they were lowered way before the threshold. The PTU seems to come on when there is a very low demand on the system. Definitely abnormal in this case. Maybe a main pump failure.
@dannycis461 You have one of the few correct answers. The Yellow system has two pumps and Green has just the engine driven pump...so hearing the PTU like this means the green system engine pump is low on pressure and that is an ABNORMAL condition. It is not normal at all. Landing is a bad time for a hydraulic system to malfunction. I've never heard the PTU run with both engines running and I've run a lot of Airbuses. The pilots got an amber Master Caution for sure on that one and ECAM message.
@JetMechMA How do you know? The PTU works both ways not just one way. The PTU will work regardless if both engines are running if there is a difference of 500psi between systems. You will hear it on gear up or down for example. The whole point of 3 hydraulic systems is redundancy, that is if one goes down you have 2 spare so loosing a system is not bad. You still have full control of all control surfaces.
@Sterlingjob It would be highly unlikely for both the yellow engine pump AND the yellow electric pump to fail. You're right, it could be the green powering the yellow, but highly unlikely. But you are wrong about it being normal in any way. I have 21 years experience working on the A320 and I've never heard the PTU come on with both engines running....unless the green engine pump was low on pressure. The green engine driven pump should have MORE than enough volume to handle normal ops.
@JetMechMA What are the flow rates of the engine pumps and the electric pump? What conditions would cause the PTU to work in flight? What would cause a hydraulic system overheat? What about certain conditions in the MEL?
JM: The engine driven pumps should handle all demands...unless they are malfunctiioning and not providing enough pressure....which happens all the time. As I said, yellow system has two pumps, the engine and the electric...highly unlikely that the yellow systen is gonna need the PTU. The green system (engine pump) should be able to handle ALL demands, even at idle. Pressure comes up to max before the ignitors even light off. Ever run an A320?
@JetMechMA Ive never seen an EDP go down and have never changed one. The yellow system may have the the electric pump MEL'd. Both EDP's have the same fluid rates unlike the electric pumps which has much less. Yellow electric pump is mainly for auxiliary use. Yellow system would drive PTU during heavy load use, ie gear up and down, as i said, any difference of 500 psi would activate the PTU. What about hydraulic overheat? Pump failure? Reservoir pressure loss?
@Sterlingjob You've never seen an EDP go down because you are young and inexperienced, or just plain inexperienced. It happens all the time. They get worn out and don't hold pressure. It gets changed and sent to a shop to get rebuilt. I walk past that shop every day on the way into work. And what about those other things?....what are you, quiz boy?
@JetMechMA I work on a fleet of over 150 a319's im also type rated on a320 v2500 and cfm56. Other things are what any typed engineer would know, im going to TSM it tonight
JM: Good boy. You do that. I've been operating acft for 20 years and never heard the PTU come on with both engines running....and I've been an employee stand-by passenger for the same amount of time and never heard it come on in flight. If it does, it's because the EDP is wearing out. The manual MIGHT say that the PTU comes on....but that doesn't mean the EDP isn't worn out. The manual is only describing the operating parameters of the hydro system.
@JetMechMA You said that EDP's wear out all the time? You have never heard it in flight? Every time ive flown airbus ive heard the PTU on gear up and gear down. Ive heard it on brand new aircraft, its normal on retraction as the gear is a major user of hydraulics. Checking the TSM the PTU can come on for many reasons, not because a pump is worn out, it either works or it doesn't
@Sterlingjob The TSM doesn't address worn out pumps when describing the operating parameters of the PTU.....and yes, by coincidence I have never heard the PTU come on in flight. Of course I WORK on many more planes than I fly on, in any given year, so yes I have seen main pumps fail to maintain pressure during maintenance visits. They are worn out.The main pumps are designed to have more than enough pressure and volume for normal use.
@Sterlingjob: have you not noticed the size of the gear actuators?
JM: The odd thing here is that you think the designers didn't notice the size of the gear actuators. Don't you think they would design the main pumps to handle normal loads? Of course they would, and they did.
@Sterlingjob: Think about it, what sense would it make for the yellow system pump to have to lose some power through the PTU to help the green system raise the gear, when the yellow pump is a main pump just like the green pump? What sense does that make?...unless there is a malfunction. If a malfunction, then you are willing to live with half your hydraulic power being used by the PTU to run the malfunctioning green system...or in a rare circumstance, the green helping the yellow system.
@JetMechMA Sorry but i really get the impression you dont know much about the A320 type. The whole point of the PTU is transfer power between green and yellow, either when there is a 500psi difference or an EDP/ engine malfunctions. Its called system redundancy. The PTU will be working on gear up and gear down, if you have never heard it you have never flown on a320 type. As i said have you ever seen the size of the actuators on the gear?
@Sterlingjob Well I mis-spoke....but I bet you don't even know where I mis-spoke. My analogy was wrong because only green system powers the landing gear actuators. You see, that's the point, you didn't even catch that. Anyway, you keep dodging the fact that the main pumps are designed to have MORE than enough pressure and volume to handle their users. The PTU should not have to help in normal use...it's a back-up.
@JetMechMA A bidirectional Power Transfer Unit enables the green system to be powered by the yellow system or vice versa, without fluid transfer. In flight, with only one engine running, the PTU is automatically activated when the the differential pressure between the green and yellow system is higher than 500 psi (34 bar).
On ground, when the engines are shut down, the PTU allows the green system to be pressurized using the yellow electric pump.
@JetMechMA Look at ecam when you operate flight controls and guess what? the pressure of green and yellow fluctuate, funny that and it will always work on gear use
@Sterlingjob ....but in the case of this video it is clear that the PTU coming on over the runway threshold when there was very little demand on the hydraulic system is an abnormal situation. It also happened during a CAT 3 Approach. Something like that could be a reason to abort a CAT 3 approach and go to an alternate airport. So that means that in this case they had progressed beyond the point where they had to execute missed approach and go to another airport.
@JetMechMA Abort landing and go to another airport? Why? Engine throttles at idle, maybe there was too little pressure in one of the pumps.How do you know its cat3?
@Sterlingjob: Abort landing and go to another airport? Why?
JM: If the aircraft becomes compromised by mechanical fault during a cat 3 approach, you must abort the approach. The airport you are trying to land at, is in cat 3 status due to weather...simple logic tells you, you must go to an alternate airport that has weather within the aircraft's LEGAL ability to land in it. I used to certify the aircraft's CAT 3 systems. My qual expired on that recently though.
JM: Oh it's easy, I just used my Mk-1 Eyeballs to determine that.
"Category III B – precision instrument approach and landing with: a decision height lower than 50 feet above touchdown zone elevation, or no decision height." In this case the DH was less than 50 feet above the touchdown zone. They were well past the thereshold before we could see the runway in this video.
@JetMechMA I actually forgot to mention that when we were departing DUB on this flight just after engine startup on pushback the pilot announced we would be delayed by about ten minutes as they had to "restart the computer" engine 1 then spooled down for a minute or two then they restarted it. This barking was also head on departure to about 2000 feet then it stopped. Any insight to this?
@LAOTG FADEC 1A and 1B circuit breakers would have been pulled then reset.It should have only been heard on gear up and gear down, perhaps there was not enough juice in the system. TBH you would really need the trouble shooting manual and driver report, it might not even have been noticed.
@Sterlingjob: it might not even have been noticed.
JM: Not true. The PTU was heard running continuously at a time when it really shouldn't have been running at all. It was supplying 100% of the hydraulic power to the green system. That means that Green EDP was inop. They would have gotten a Master Caution and a message on the ECAM and also it would show up as a discrepency on the PFR, Post Flight Report which is kicked out on the printer after Door 1L is opened after engine shut-down.
The engine computer has two seperate but identical halfs. It's really two computers side by side in the same box mounted on the side of the engine. One side is A and the other B, for reference. The engine has it's own little generator that powers this EEC (Electronic Engine Control) so the EEC is independent of the main aircraft power system for added redundancy.
@LAOTG In order to "burn in" the circuits of these engine computers evenly during day in and day out use, each time the engine start switch is thrown, the computer switches to the "other" side. It is possible for one side to develope a fault. The trouble shooting for this is to do at least two engine runs (using both A and B side) and see if the fault follows. If the fault only shows up on every other engine run then it exists in only one half of the EEC and a change of the unit is required.
@Sterlingjob You don't even work on these things, do you? You've embarrassed yourself enough here....don't you think? The fact is, for some engine related faults you DO run the engine. The MCDU Multipurpose Control and Display Unit is an excellent tool for many ops checks, but even it doesn't tell all. Lots of induced faults show up on maintenance tests run through the MCDU and if a mech didn't know better ...like you...they would run in circles, chasing their tail.
@JetMechMA Yeah right ok whatever you say, like i said read the MEL if you know what it is. MOC can advise pilot to reset certain systems and he can put it in the tech log and sign for a successful reset. As i said before the PTU works both ways not just one way. We run test through the MCDU all the time, you dont have to run an engine at all.
@Sterlingjob You are speaking in non-sequiturs now. You are talking to yourself. You keep chanting nonsense about "read the MEL." The MEL doesn't have squat to do with this video and our conversation regarding it. The Minimum Equipment List is NOT a trouble-shooting manual. It only tells the pilots and maintenance persons what is legal to defer or as they say now...to "carry forward" CF. That's all. But you are stuck on chanting that term MEL...MEL. You're speaking non-sequitur responses.
@JetMechMA IF you knew the MEL you would know that 2 EDP's are required for dispatch otherwise your AOG, LAOTG quoted the PTU ran till 2000 feet ish, if a pump was down the PTU would have ran continuously during flight, hence why there is a PTU. You would not turn off green or yellow if you had a pump failure but use the PTU throughout flight
@Sterlingjob: Well I suspect that any aircraft YOU work on is Aircraft On Ground status. The PTU could have indeed been turned off so it wouldn't bark through the entire flight. Yellow and Blue stsem are adequate for a safe flight....although as I said, I don't know if that is legal to knowingly disable the third system if it is available. But they COULD have silenced the PTU by turning it from the automatuc mode to the O.F.F mode.
@Sterlingjob You saying the PTU works both ways is a non-sequitur response. It has no meaning. Running tests through the MCDU means NOTHING to this conversation. As I said, sometimes engine runs ARE required for certain troubleshooting procedures. If you knew anything more than what someone else told you or that you looked up on Wikipedia....you'd know that. What's the point in you coming back here to infinity just to embarrass yourself? That's not what this is about.
@LAOTG So bottom line, it's possible that in order to legally dispatch the aircraft, they shut down the engine using the faulty side of the EEC and restarted it causing it to switch to the side that did not display a fault warning. I'm not sure if that is legal because the two halfs are there for redundancy. It almost certainly downgraded the CAT III landing status but we clearly saw this aircraft land in CAT III conditions. Just saying.
@LAOTG: As far as you hearing the barking stop after about 2000 feet, I can't be sure. They could have de-selected the PTU switch out of automatic mode so it wouldn't be barking through the entire flight. Then proceeded with the flight on yellow and blue sytems. Again, that's probably a functional procedure, but I'm not sure if it's legal. Definitely not CAT III certified with that many faults existing.
@LAOTG In accordance with the MEL the PTU can run constantly as long as certain conditions are met. So hearing the PTU in flight is not the sign of a major problem. The pilot can reset the FADEC computers via phoning maintenance control.
@Sterlingjob You're completely wrong. The main pump should be adequate for ALL normal use. The fact that the PTU is heard runing c9onstantly right before touchdown means that it was supplying 100% of green system pressure and the main pump was supply ZERO pressure. That's a major malfunction. You couldn't be more wrong. And your FADEC comment is not even worth responding to. A PHONE call?
@Sterlingjob It means nothing SJ. Nothing. This video shows the green system malfunctioning because NEITHER the flaps NOR the gear is in operation. Since there was almost ZERO demand on the system and yet the PTU is running continuously, that means it is definitely a major malfunction. Nobody set out to embarrass you..but you INSIST on embarrassing yourself. What's WRONG with you? That's an OBSERVED fault SJ. IT'S NOT COVERED IN THE MEL !
@JetMechMA On ground with electric pump running the PTU still runs with no demand on the system, so if either green or yellow pumps are inop the ptu would still run either way. Zero demand? So the control surfaces do nothing on landing? ok whatever...As i quoted directly from the FAA MMEL the PTU can run continuously, unless you were there after the event how can you surmise what is wrong with the A/C?
JM: Key word being, "on the ground"...and likely only with the other pump still off. You are lying when you say that I said "zero demand", I said almost zero demand. Not nearly enough to cause the PTU to run contonuously...especially if as you say, it was only coming on to supplement a normally functioning EDP. You mis-quoted the MEL and took it out of context.
@Sterlingjob Whether or not the MEL describes how the PTU operates...has NOTHING to do with the subject of this video or the fact that I said it is not normal and is in fact a malfunction. What I said is true and you saying that it is normal is WRONG. I am right and you are wrong. Whether or not the MEL tells us that the PTU will back up the main pump on gear use....THE GEAR WASN'T IN TRANSIT ! ! ! ! !!!!!...in this case. In fact the PTU was NOT heard coming on during gear extention !
@Sterlingjob In fact the PTU was NOT heard coming on during gear extention ! The PTU only comes on at the very last moment before touchdown when there is very little demand on the system...and then runs continuously. In fact that could indicate that a hydraulic fluid line has BURST! What is heard in this video is not normal in ANY way shape or form. It is the sound of a major hydraulic malfunction on an A320 jet.....at the WORST possible moment......right at touchdown during a CAT III landing.
JM: You keep changing the topic. ....that you're wrong about this. And again, the Flight Crew Operating Manual only address operating modes, it does not address observed faults. All you're doing here is embarrassing yourself by talking in non-sequitur responses. Nobody is trying to embarrass you, that's not why we come to Youtube.
JM: That's right. The aircraft could be in a "safe to operate condition"...in other words, the back-up system has taken over and the safety of flight is not in question.... yet the aircraft is malfunctioning. That situation is observed by the pilots. The pilots must use their critical thinking and reading skills to determine, with the aid of the MEL, if they must take action. They wouldn't need to take any action with the PTU and would report it.
@JetMechMA If you read FCOM then you would see what would cause the downgrading of the autoland system. Perhaps you should read the course notes on the a320, i have lufthansa and airbus notes including VACBI. You have said nothing that is constructive including your first comment that airlines werent doing maintenance properly. Your assuming everything you say is correct. If you knew anything about aviation you would know its wise never to assume anything.
@Sterlingjob You are wrong in everything you say here...and that's the only reason I respond. People like you are what...I don't know. You were simply in error here...we all make mistakes...but for whatever reason you are too stubborn to admit that you are simply wrong about this incident. The PTU comes on continuously when there is very little demand. I am right and you are wrong. You have emotional issues if you are incapable of letting it go when you are as wrong as you are in this case.
@JetMechMA Yeah of course i am wrong. I have quoted from air nav, i have quoted from training notes i have quoted from the FCOM and i have quoted from the MEL and i am still wrong? The PTU works continuously with little demand? WTF? SInce when? The PTU operates when there is a 500 psi difference between systems which you forget. Look at my videos and if you work on A320 series i suggest you post some videos of your work cos you talk complete crap
@Sterlingjob: The PTU works continuously with little demand? WTF? SInce when?
JM: Now you are acting irrationally. YOU are the one who said that, not me. In THIS video we see that the aircraft is DONE with the heavy demand portion of the flight when the PTU comes on. The gear were extended LONG ago. Flaps extended LONG ago, yet the PTU comes on when you wouldn't expect it to come on. That's abnormal but you won't admit it...or don't understand the operation of the system.
@JetMechMA I never said this was not abnormal now did i? You would know being a A&P mechanic that trouble shooting the system can be anything. It might not be the PTU at fault, it might not be an EDP but your so cock sure of yourself. Unless you were there with your head in the techlog you cannot assume you know what the defect, if there is a defect, is. You have not quoted at all from the FCOM, MEL, TSM or the AMM and you would know being just a mechanic that all work c/o is done IAW the AMM
@JetMechMA I fly A320 all the time and ive always heard it. In the states your a mechanic, in the UK we are ENGINEERS. I forgot to mention im also dc10 type rated. You would never get an EASA ticket because we dont get given licence's on a plate like the FAA hand them out, you have to work hard to achieve it and when i did mine i was grilled for 2 hours by a CAA surveyor.
Oh yes are you going to answer the questions i asked you about the TSM and what it says?
@Sterlingjob: You aren't an engineer, you're a mechanic. Our aircaft fly just as safely and efficiently as yours do....no difference. You were grilled for two hours?....only two? The Airframe and Powerplant written and practical tests are an all day affair. Am I going to answer your questions about the TSM?......NO.
@JetMechMA You can get an A&P licence in a day? How easy is that.? For a B1 from scratch you would have to take 16 modules then take a written exam. You wont answer the TSM question because you do not know whats in the TSM, your answer about functionality is complete bullshit for a start. Try quoting like a proper engineer then the world might slightly believe you.
@JetMechMA I said i sat in front of a surveyor for 2 hours, that is only a small part of the process of getting what was Aeroplanes 2 and gas turbines or as it was A&C licence. Why on earth would i want an A&P licence? Only use of an A&P is working on N reg aircraft, bu then again i can sign off N reg aircraft under company approval
@Sterlingjob: i have lufthansa and airbus notes including VACBI.
JM: You indicate that you've studied the course material including Airbuse's "Video And Computer Based Instruction", but you don't fully understand what you read. Pride goeth before the fall. This video shows an abnormal condition. You are wrong to say that it is normal and nothing to worry about. Not only is it a malfunction...it happened during a CAT III landing.
@JetMechMA I know what it means, and you still cant assume what is wrong, only guess at what could be wrong. Why then in the TSM is there a section on continuous PTU working? I don''t think you even read any Manuals at all.
@Sterlingjob: I don''t think you even read any Manuals at all.
JM: The difference bewteen you and me is that even if you read the manual, you don't comprehend what you read. I didn't assume anything about what we see and hear in this video. The PTU shouldn't come on right over the threshold on landing. By simple system knowledge, it doesn't add up if everything is supposed to be operating normally. You should know that.
@Sterlingjob: The TSM covering continuous PTU operation is only describing its functionality. The EDPs should be able to supply all normal demand....as it does in every other video we see of A320 landings....except this one. In this video, THIS particular aircraft is malfunctioning when the PTU comes on.
@JetMechMA Ok, tell me what the TSM says about continous operation of the PTU? I want to see exactly what the TSM says regarding this. What part of the system can be at fault. You have access to the TSM you will be able to replicate what it says. The green edp cannot supply all demand for the gear FACT, hence why you hear the PTU.
@Sterlingjob: Hardly would have been CAT III C now would it.
JM: Currently no aircraft lands in Cat III C conditions....zero visibility down to the runway with zero visibility runway visual range. Why, you ask?....because while the aircraft is capable of making a 100% blind landing, there would be no safe way to find your way to the gate at the terminal in zero visibility, thus, nobody actually does Cat III C landings. It's currently not possible. Actual "Cat III C" conditions are seldom.
@Sterlingjob The PTU coming on when it shouldn't have to.....if it happens frequently enough, it becomes an "observed" discrepency. That is, it will not show up in the automatically generated post flight report (PFR) as a discrepency, it is classified as an observed fault because the pilots know it's not right even though the PTU is operating "normally" as it was designed. However the main pump was NOT designed to be constantly supplemented by the PTU. They know this and will gripe it.
@Sterlingjob The main green pump shouldn't need the PTU to lift the gear because positioning the gear can be done between flap detents. It's somewhat likely that while on a stabilized approach, they will select the gear down at the specified time....and few users are then using green system pressure. So the gear has green system to itself while in transit. Extending doesn't use a lot of pressure. Gear can free-fall with ZERO pressure. Don't need PTU to extend.
@JetMechMA Which system? The PTU works when there is a difference of 500 psi between systems, come on you have done the course you should know this. If there is low system pressure the TSM will aid you in trouble shooting. As i have said ive never known a pump failure, ive changed many PTU's and manifolds but pumps dont fail
@TiffanyJ1985 It's definitely nothing to worry about for the passengers because as Sterlingjob said, the planes are designed for minor malfunctions like this., but it should be fixed in this case. It might be totally normal on your friend's private jet. Lucky you.
PTU........POWER TRANSFER UNITS Makes the Barkin noises.....it transfers eletrical power into the engines........usually hear it when the igintion swtches are set ti ING or Crank.....
I know there is no problem aboard the aircraft and it is certainly not a dog. I should ask the full details again, but I can assure that it is normal. You don't hear it on every A320 though ;)
My god! thats a very bad weather in AMS, by the way, maybe it could be a failure on one of the hydraulics system, because the PTU only runs in startups and shutdowns to regulate and pressurize hydraulic fluids
During startup and shutdown it's normal, yes. But not during flight. It's evidence to suggest there may be a slight loss of hydraulic pressure in one of the systems.
normally the ptu shouldn't have been on. in this case there could be hydraulic pump problem in one of the hyd systems. if you always hear this kind of sound during flight that means the airlines never bother maintaining their aircraft.
whats your problem dude, if you dont like what i wrote just ignore it, dont be a childish uneducated jerk. is this what british people like?? what a shame.
Childish and uneducated? Perhaps youd like to change your comment regarding airlines not maintaining their components. And its not always a pump that causes the PTU to run, there are other faults that will cause the PTU to run in flight.
@JetMechMA That is complete bullshit. Components fail all the time, its nothing to do maintenance and you would only report it unless it was a result of incorrect maintenance which you have to prove.
@Sterlingjob The statement was....that the PTU was heard running all the time like this...which means they aren't fixing the discrepency at maintenance opportunities. If they aren't fixing their broken aircraft, then someone needs to drop a dime on them.
Nothin' special, it's power transfer unit, which transfers power to other hyfraulic systems. In this case the "problem" was probbably in a difference of pressure...
i was on an A319 flight awhile ago that the barking occurred every time the flaps where adjusted. I think it occurs when several hydraulic systems are being used at once and it transfers pressure to equalize them.
@jimmyp42002: I think it occurs when several hydraulic systems are being used at once and it transfers pressure to equalize them.
JM: If the PTU needs to come on that much, it means the engine driven pump is weak or inoperative and needs to be fixed. The PTU shouldn't come on in normal operation. The engine driven pumps are the main hydraulic pumps. The main pumps should be able to handle normal operations. If the back-up is coming on, there is something wrong with the main pump.
That "barking" sound is the so called PTU, the Power Transfer Unit. The PTU trnasfers power between the yellow and the green hydraulic system without exchange of liquids by means of two pistons. If one system has a lower pressure then the other one, then this piston starts working and pressurizes the other system. So if the yellow system is on, but the green is off, and you want to operate smth which is powered with the green system, the PTU translers power from the yellow to the green one.
The barking noise is of course that of the dog in the cockpit, the dog is in the cockpit to ensure that the flight crew do not touch the controls during landing...
I believe the PTU is active because changes in throttle settings on the engines and extensive usage of hydraulics, as is normal at take-off and landing, is causing a pressure difference between the two hydraulic systems.
The wheels should already be down by the time this was shot. Could it have been an actual dog with sore ears barking in the hold? And please don't call me all the names under the sun for this. I lose faith in humanity reading some of the replies on here. We all exist in one universe. (By whoever gods grace...) Peace love
My dad's an A320 pilot: the barking, known by the pilots as the "whining dog" haha, deals with the hydraulics and regulating their flow when the engines are not fully on (starting up or shutting down).
We always hear this sound when the A320 is on the ground, when the engines start. It's normal, but my question here is why do we hear it here during the approach ? Is it because of the landing gear ? Can you please ask your father ? Thank you !
When gear moves the ptu usually kicks in because there is more than a 500psi difference in pressure between the green and yellow sytems or #1 and #2 engines
That's actually really really weird. The PTU shouldn't be working in the air at all. Probably one of the hydraulic circuits clogged or malfunctioned during descent, or maybe even an engine stopped pumping (or was off!)
The PTU can work in the air when the is a difference of more than 500 psi between the green and yellow systems, you will hear it on gear up and gear down. If you want i can dig out the reasons why the ptu would work in the air, one is a loss of air pressure in the hydraulic reservoirs.
On one flight the pilot said I've got the Dogs covered they are nice and warm down there not to worry when you hear them bark while taxing to and from the gate lol.
travelplus1 2 weeks ago
The only necessary explanation why these hydraulic pumps "bark" is: "It's French."
besmith51 1 month ago
Hydraulics probably
TheAbc1234512345 1 month ago
Looks like an autoland
thegreatRDU 2 months ago
its the hydraulic valve and pumps that control the rudder i think.. and why it's exclusive on A320s, that's because their parts are different from other planes.
HeroshiKurashiwa 3 months ago
Why is this exclusive to the A320 family? Well, I never heard anyone mention it happening on A330/340/380, so I assume it is. Boeing planes don't seem to have this "feature" either . :P
ballebanan 5 months ago
@joshieperson777 The PTU will work when there is either a 500 PSI difference between green and yellow systems, low reservoir pressure, low reservoir fluid contents and high fluid temperatures. You shouldnt really hear it during flight control movements, but obviously when the gear is operated as its a heavy system user.
Sterlingjob 5 months ago
@joshieperson777 Hydraulic fluid does not move from system to system, they are all separate.
Sterlingjob 5 months ago
LAOTG: The PTU can start anytime during startup,taxi,takeoff;flight; descent,landing and engine shut down. Have heard alot of times on takeoff,with A320 and A321. The PTU is a power transfer unit,that build up the pressure when it drops blow a certain point. If left hyd.system drops below its needed point PTU transfer power from right system to the left system. So its quite common to hear the PTU at all stages during a flight :D PTU on airbus A320 family have this "barking dog" sound.
ollo1982 8 months ago
My Cousin is a pilot and has told me the hydraulic system causes this barking sound. When the PTU is running overtime it causes the hydraulics to compensate. I hope this helps.
travelplus1 9 months ago
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Yes this is very interesting. the PTU usually kicks in if one of the hydraulics systems goes below 500 psi (normally 2500-3000 psi). That usually only occurs during engine start up or shut down. Never heard in on finals.
LegendxHD 9 months ago
Yes this is very interesting. the PTU usually kicks in if one of the hydraulics sytems goes below 500 psi (normally 2500-3000 psi). That usually only occurs during engine start up or shut down. Never heard in on finals.
LegendxHD 9 months ago
@LegendxHD I've heard it just after taking off while climbing. It was back when I only just started to get interested into aircraft, so I was a bit worried.
scotplane 7 months ago
ptu wuff wuff wuff
HDFlightSim 10 months ago
this sound is airbus PTU i don't know how i can explain that but if you type airbus ptu you will find your answer ;)
flymilad93 11 months ago
lets run over justin bieber at landing lol
theanthony345 1 year ago
If you've ever actually run these things, you would know that system pressure comes up almost immediately as the starter rotates the engines. THAT's how powerful the engine driven pumps are. So, during normal operation it is unlikely that the PTU will be heard in flight. What Sterlingjob may not know is that even when the engines are at idle in flight....they are turning faster than they do while on the ground. It's called "Flight Idle". Pumps put out more volume in flight than on the ground.
JetMechMA 1 year ago
@JetMechMA The pumps pump more at flight idle? Are they not constant pressure? The volume moved depends on demand not speed of the engine, at flight idle with little demand the volume moved will be tiny,put the gear down and the demand is high and volome is high, You just shot yourself in foot there
Sterlingjob 1 year ago
@Sterlingjob: VOLUME...not pressure. Volume moved depends on demand...and you just contradicted yourself. It's about VOLUME, not prerssure. If demand requires too much volume, that results in a drop in pressure which triggers the PTU. Something's got to give. You can't keep up pressure if the volume output is too low. But the EDPs are designed to supply adequate volume for all normal use. As I said, if you knew anything about running these engines you would know that PSI comes on immediately.
JetMechMA 1 year ago
@JetMechMA What kind of pump and how does the pump work? The EDP supplies the system with fluid at 3000 psi ( 206 bar ) and changes its output to that which is necessary for the system. A pressure switch 3074GD and a check valve 3050GM are installed downstream of the EDP. The pressure switch monitors the output pressure of the pump . The reason the pressure is high is so that pipes can be smaller therefore saving weight. But you just said the EDP's can supply all the demand? Now they cant?
Sterlingjob 1 year ago
@Sterlingjob: The reason the pressure is high is so that pipes can be smaller therefore saving weight. But you just said the EDP's can supply all the demand? Now they cant?
JM: You didn't make a connection between statements. Now you are acting irrationally.
JetMechMA 1 year ago
@JetMechMA again you were not there so stop assuming. Sometimes the PTU can come on in flight with no ecam message. So unless you were there stop assuming. It can be anything and if you knew anything about aircraft you would know it could be any part of the system that is at fault. Use the TSM, 99% of all rectifications are in the TSM
Sterlingjob 1 year ago
@Sterlingjob As I said, if you knew anything about running these engines you would know that PSI comes on immediately after the starter turns the engine, let alone at idle or above. In flight when the engines are no slower than "flight idle" the volume output is even more assured and it is even less likely that the PTU would be needed. Anyway, as was said, there is very little demand when the PTU is heard running constantly in this video. You keep ducking that fact.
JetMechMA 1 year ago
@JetMechMA Explain to me how an EDP works. What is the angle of the swash plate when idle? If you cant answer this then your a bullshitter. Simple
Sterlingjob 1 year ago
@Sterlingjob: What is the angle of the swash plate when idle?
JM: When "idle"? You mean with no demand? By your terminology I can tell you looked this up on Wikipedia. I think you got ahold of some Airbus manuals and come on Youtube trying to sound like an expert or something. By the way, the swash plate is neutral with zero demand on the pump. But any ten year old could look that up on the Internet now days. Besides, I don't overhaul hydraulic pumps in the back shop.
JetMechMA 1 year ago
@JetMechMA Lets establish one thing here i am a EASA B1 type rated engineer, i dont have an easy to get A&P licence which i can get in 3 weeks where i learn questions and answers.
The angle of the swash plate when idle, (Idle (idling) is a term which generally refers to a lack of motion and/or energy) is at maximum because there is zero pressure being generated. It is in no way neutral position, this is hydraulic question from years ago.
Sterlingjob 1 year ago
@Sterlingjob: You are WRONG again, "idle" means running but not engaged. In other words, no demand. It is running and ready, but no demand. When the pump is running but idled, the swash plate is neutral. As far as you "engineers" go, you ain't no real engineer. Get over yourself. YOU'RE A MECHANIC....PERIOD. EASA, my foot. Funny how our aircraft operate safely every day just like yours...and it didn't take an engineer to get it airborne.
JetMechMA 1 year ago
@JetMechMA Did i say engine idle? No i didn't. There is no neutral position, the swash plate is either at maximum deflection when stopped or it is at minimum angle producing 3000psi. When load is increased then the angle of the swash plate will increase to regulate 3000psi to keep up with demand. Oh and you forgot to mention the CASE DRAIN, fluid is always being pumped around the circuit. Even with no demand fluid is still passing through case drain and the system is still at 3000psi
Sterlingjob 1 year ago
@Sterlingjob: I didn't forget anything. You have Munchousen''s syndrome where you need to make things up to sound like the expert.
JetMechMA 1 year ago
@JetMechMA Lets see now....i am quoting directly from airbus manuals and course notes and im making things up? Erm ok, your knowledge level at best is poor and at worst shocking. When i was grilled by a CAA surveyor it was also a judge of character, did i know what i was talking about and quite clearly I DO. In the UK we would call someone like you a gobshite
Sterlingjob 1 year ago
@Sterlingjob: Lets see now....i am quoting directly from airbus manuals and course notes and im making things up?
JM: That's right, you're making things up. I got my training at the Airbus training facility in Miami Florida. I'm not altering what they told me, like you are. You aren't quoting the Trouble Shooting Manual or the Flight Crew Operating Manual any other manual.....you're MIS-quoting them. What's your beef anyway? We all make mistakes. Why have you gone ballistic over this thing?
JetMechMA 1 year ago
@JetMechMA Yeah ok your the expert....
Sterlingjob 1 year ago
@Sterlingjob: Yeah ok your the expert....
JM: I never said I'm an expert. I only wanted to comment on what I observed happening in this interesting video. Some abnormal malfunction of the hydraulic system...most likely low presure in the green system at a time when there should have been very little demand on the system....and the PTU coming on over the threshold of the runway during what appears to be a CAT III landing. You want the plane "being all that it can be", during CAT III.
JetMechMA 1 year ago
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@Sterlingjob: Lets see now....i am quoting directly from airbus manuals and course notes and im making things up?
JM: Here's a quote for you, from you. "You wont hear this inflight because the engines are powering the yellow and green systems,..."
JetMechMA 1 year ago
You're wasting your time Sterlingjob. Go watch several other A320/319 landing videos. The PTU doesn't come on until they pull up to the gate after engine shutdown. Know why?....because as system pressure bleeds off, the PTU goes back and forth between systems coming on for a split second at a time. That's what gives the A320 it's personality. That's normal....on the ground, at the gate, engines spooling down. Go watch other videos. This one is an abnormal situation. You're wrong Sterlingjob.
JetMechMA 1 year ago
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Sterlingjob: Yellow electric pump may be in inop, thats allowable
JM: That's true.
JetMechMA 1 year ago
If the PTU came on because of an engine inflight shut-down....believe me, the passengers would never know, unless the person sitting in row #1 in First Class happened to look out and saw it spinning slower...or "windmilling". Yes, the autopilot is THAT good....you'd never know the engine shut down in flight unless the pilot told you. I've seen it first hand on several test flights. The FAC (Flight Augmentation Computer) responds to an engine failure very rapidly. Bless it's heart.
JetMechMA 1 year ago
Once the PTU comes on in this video, it is heard running continuously...which means the PTU is supplying ALL the power to the green system.... main green system engine driven pump has failed....or the engine has failed in which case it's engine driven hydraulic pump might put out low pressure....especially if the pilots pulled the engine disconnect fire switch which closes all connections to and from the dead engine. This is a unique and relatively rare video.
JetMechMA 1 year ago
Watched it again and decided that it is definitely an abnormal condition when the PTU comes on. The PTU isn't heard until they are over the runway thereshold. The flaps aren't moving...they were set to their final position long ago. The gear aren't moving, they were lowered way before the threshold. The PTU seems to come on when there is a very low demand on the system. Definitely abnormal in this case. Maybe a main pump failure.
JetMechMA 1 year ago
@JetMechMA Come on then what else would cause the PTU to work in flight?
Sterlingjob 1 year ago
That PTU should not be barking at that position if should only for Takeoff Pushback And Shutdown
dannycis461 1 year ago
@dannycis461 You have one of the few correct answers. The Yellow system has two pumps and Green has just the engine driven pump...so hearing the PTU like this means the green system engine pump is low on pressure and that is an ABNORMAL condition. It is not normal at all. Landing is a bad time for a hydraulic system to malfunction. I've never heard the PTU run with both engines running and I've run a lot of Airbuses. The pilots got an amber Master Caution for sure on that one and ECAM message.
JetMechMA 1 year ago
@JetMechMA How do you know? The PTU works both ways not just one way. The PTU will work regardless if both engines are running if there is a difference of 500psi between systems. You will hear it on gear up or down for example. The whole point of 3 hydraulic systems is redundancy, that is if one goes down you have 2 spare so loosing a system is not bad. You still have full control of all control surfaces.
Sterlingjob 1 year ago
@Sterlingjob It would be highly unlikely for both the yellow engine pump AND the yellow electric pump to fail. You're right, it could be the green powering the yellow, but highly unlikely. But you are wrong about it being normal in any way. I have 21 years experience working on the A320 and I've never heard the PTU come on with both engines running....unless the green engine pump was low on pressure. The green engine driven pump should have MORE than enough volume to handle normal ops.
JetMechMA 1 year ago
@JetMechMA What are the flow rates of the engine pumps and the electric pump? What conditions would cause the PTU to work in flight? What would cause a hydraulic system overheat? What about certain conditions in the MEL?
Sterlingjob 1 year ago
@Sterlingjob:What are the...
JM: The engine driven pumps should handle all demands...unless they are malfunctiioning and not providing enough pressure....which happens all the time. As I said, yellow system has two pumps, the engine and the electric...highly unlikely that the yellow systen is gonna need the PTU. The green system (engine pump) should be able to handle ALL demands, even at idle. Pressure comes up to max before the ignitors even light off. Ever run an A320?
JetMechMA 1 year ago
@JetMechMA Ive never seen an EDP go down and have never changed one. The yellow system may have the the electric pump MEL'd. Both EDP's have the same fluid rates unlike the electric pumps which has much less. Yellow electric pump is mainly for auxiliary use. Yellow system would drive PTU during heavy load use, ie gear up and down, as i said, any difference of 500 psi would activate the PTU. What about hydraulic overheat? Pump failure? Reservoir pressure loss?
Sterlingjob 1 year ago
@Sterlingjob You've never seen an EDP go down because you are young and inexperienced, or just plain inexperienced. It happens all the time. They get worn out and don't hold pressure. It gets changed and sent to a shop to get rebuilt. I walk past that shop every day on the way into work. And what about those other things?....what are you, quiz boy?
JetMechMA 1 year ago
@JetMechMA I work on a fleet of over 150 a319's im also type rated on a320 v2500 and cfm56. Other things are what any typed engineer would know, im going to TSM it tonight
Sterlingjob 1 year ago
@Sterlingjob: im going to TSM it tonight
JM: Good boy. You do that. I've been operating acft for 20 years and never heard the PTU come on with both engines running....and I've been an employee stand-by passenger for the same amount of time and never heard it come on in flight. If it does, it's because the EDP is wearing out. The manual MIGHT say that the PTU comes on....but that doesn't mean the EDP isn't worn out. The manual is only describing the operating parameters of the hydro system.
JetMechMA 1 year ago
@JetMechMA You said that EDP's wear out all the time? You have never heard it in flight? Every time ive flown airbus ive heard the PTU on gear up and gear down. Ive heard it on brand new aircraft, its normal on retraction as the gear is a major user of hydraulics. Checking the TSM the PTU can come on for many reasons, not because a pump is worn out, it either works or it doesn't
Sterlingjob 1 year ago
@Sterlingjob The TSM doesn't address worn out pumps when describing the operating parameters of the PTU.....and yes, by coincidence I have never heard the PTU come on in flight. Of course I WORK on many more planes than I fly on, in any given year, so yes I have seen main pumps fail to maintain pressure during maintenance visits. They are worn out.The main pumps are designed to have more than enough pressure and volume for normal use.
JetMechMA 1 year ago
@JetMechMA Every A320 series aircraft will have the PTU work on gear up and gear down, have you not noticed the size of the gear actuators?
Sterlingjob 1 year ago
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@Sterlingjob: have you not noticed the size of the gear actuators?
JM: The odd thing here is that you think the designers didn't notice the size of the gear actuators. Don't you think they would design the main pumps to handle normal loads? Of course they would, and they did.
JetMechMA 1 year ago
@Sterlingjob: Think about it, what sense would it make for the yellow system pump to have to lose some power through the PTU to help the green system raise the gear, when the yellow pump is a main pump just like the green pump? What sense does that make?...unless there is a malfunction. If a malfunction, then you are willing to live with half your hydraulic power being used by the PTU to run the malfunctioning green system...or in a rare circumstance, the green helping the yellow system.
JetMechMA 1 year ago
@JetMechMA Sorry but i really get the impression you dont know much about the A320 type. The whole point of the PTU is transfer power between green and yellow, either when there is a 500psi difference or an EDP/ engine malfunctions. Its called system redundancy. The PTU will be working on gear up and gear down, if you have never heard it you have never flown on a320 type. As i said have you ever seen the size of the actuators on the gear?
Sterlingjob 1 year ago
@Sterlingjob Well I mis-spoke....but I bet you don't even know where I mis-spoke. My analogy was wrong because only green system powers the landing gear actuators. You see, that's the point, you didn't even catch that. Anyway, you keep dodging the fact that the main pumps are designed to have MORE than enough pressure and volume to handle their users. The PTU should not have to help in normal use...it's a back-up.
JetMechMA 1 year ago
@JetMechMA A bidirectional Power Transfer Unit enables the green system to be powered by the yellow system or vice versa, without fluid transfer. In flight, with only one engine running, the PTU is automatically activated when the the differential pressure between the green and yellow system is higher than 500 psi (34 bar).
On ground, when the engines are shut down, the PTU allows the green system to be pressurized using the yellow electric pump.
Sterlingjob 1 year ago
@JetMechMA Look at ecam when you operate flight controls and guess what? the pressure of green and yellow fluctuate, funny that and it will always work on gear use
Sterlingjob 1 year ago
@Sterlingjob ....but in the case of this video it is clear that the PTU coming on over the runway threshold when there was very little demand on the hydraulic system is an abnormal situation. It also happened during a CAT 3 Approach. Something like that could be a reason to abort a CAT 3 approach and go to an alternate airport. So that means that in this case they had progressed beyond the point where they had to execute missed approach and go to another airport.
JetMechMA 1 year ago
@JetMechMA Abort landing and go to another airport? Why? Engine throttles at idle, maybe there was too little pressure in one of the pumps.How do you know its cat3?
Sterlingjob 1 year ago
@Sterlingjob: Abort landing and go to another airport? Why?
JM: If the aircraft becomes compromised by mechanical fault during a cat 3 approach, you must abort the approach. The airport you are trying to land at, is in cat 3 status due to weather...simple logic tells you, you must go to an alternate airport that has weather within the aircraft's LEGAL ability to land in it. I used to certify the aircraft's CAT 3 systems. My qual expired on that recently though.
JetMechMA 1 year ago
@Sterlingjob: How do you know its cat3?
JM: Oh it's easy, I just used my Mk-1 Eyeballs to determine that.
"Category III B – precision instrument approach and landing with: a decision height lower than 50 feet above touchdown zone elevation, or no decision height." In this case the DH was less than 50 feet above the touchdown zone. They were well past the thereshold before we could see the runway in this video.
JetMechMA 1 year ago
@JetMechMA I actually forgot to mention that when we were departing DUB on this flight just after engine startup on pushback the pilot announced we would be delayed by about ten minutes as they had to "restart the computer" engine 1 then spooled down for a minute or two then they restarted it. This barking was also head on departure to about 2000 feet then it stopped. Any insight to this?
LAOTG 1 year ago
@LAOTG FADEC 1A and 1B circuit breakers would have been pulled then reset.It should have only been heard on gear up and gear down, perhaps there was not enough juice in the system. TBH you would really need the trouble shooting manual and driver report, it might not even have been noticed.
Sterlingjob 1 year ago
@Sterlingjob: it might not even have been noticed.
JM: Not true. The PTU was heard running continuously at a time when it really shouldn't have been running at all. It was supplying 100% of the hydraulic power to the green system. That means that Green EDP was inop. They would have gotten a Master Caution and a message on the ECAM and also it would show up as a discrepency on the PFR, Post Flight Report which is kicked out on the printer after Door 1L is opened after engine shut-down.
JetMechMA 1 year ago
@JetMechMA Yellow electric pump may be in inop, thats allowable
Sterlingjob 1 year ago
@LAOTG: Any insight to this?
The engine computer has two seperate but identical halfs. It's really two computers side by side in the same box mounted on the side of the engine. One side is A and the other B, for reference. The engine has it's own little generator that powers this EEC (Electronic Engine Control) so the EEC is independent of the main aircraft power system for added redundancy.
JetMechMA 1 year ago
@LAOTG In order to "burn in" the circuits of these engine computers evenly during day in and day out use, each time the engine start switch is thrown, the computer switches to the "other" side. It is possible for one side to develope a fault. The trouble shooting for this is to do at least two engine runs (using both A and B side) and see if the fault follows. If the fault only shows up on every other engine run then it exists in only one half of the EEC and a change of the unit is required.
JetMechMA 1 year ago
@JetMechMA You dont run the engine do you? You BITE check via the MCDU
Sterlingjob 1 year ago
@Sterlingjob You don't even work on these things, do you? You've embarrassed yourself enough here....don't you think? The fact is, for some engine related faults you DO run the engine. The MCDU Multipurpose Control and Display Unit is an excellent tool for many ops checks, but even it doesn't tell all. Lots of induced faults show up on maintenance tests run through the MCDU and if a mech didn't know better ...like you...they would run in circles, chasing their tail.
JetMechMA 1 year ago
@JetMechMA Yeah right ok whatever you say, like i said read the MEL if you know what it is. MOC can advise pilot to reset certain systems and he can put it in the tech log and sign for a successful reset. As i said before the PTU works both ways not just one way. We run test through the MCDU all the time, you dont have to run an engine at all.
Sterlingjob 1 year ago
@Sterlingjob You are speaking in non-sequiturs now. You are talking to yourself. You keep chanting nonsense about "read the MEL." The MEL doesn't have squat to do with this video and our conversation regarding it. The Minimum Equipment List is NOT a trouble-shooting manual. It only tells the pilots and maintenance persons what is legal to defer or as they say now...to "carry forward" CF. That's all. But you are stuck on chanting that term MEL...MEL. You're speaking non-sequitur responses.
JetMechMA 1 year ago
@JetMechMA IF you knew the MEL you would know that 2 EDP's are required for dispatch otherwise your AOG, LAOTG quoted the PTU ran till 2000 feet ish, if a pump was down the PTU would have ran continuously during flight, hence why there is a PTU. You would not turn off green or yellow if you had a pump failure but use the PTU throughout flight
Sterlingjob 1 year ago
@Sterlingjob: Well I suspect that any aircraft YOU work on is Aircraft On Ground status. The PTU could have indeed been turned off so it wouldn't bark through the entire flight. Yellow and Blue stsem are adequate for a safe flight....although as I said, I don't know if that is legal to knowingly disable the third system if it is available. But they COULD have silenced the PTU by turning it from the automatuc mode to the O.F.F mode.
JetMechMA 1 year ago
@Sterlingjob: You would not turn off ...
JM: You SHOULD not turn it off, but that doesn't mean that they didn't do it.
JetMechMA 1 year ago
@Sterlingjob You saying the PTU works both ways is a non-sequitur response. It has no meaning. Running tests through the MCDU means NOTHING to this conversation. As I said, sometimes engine runs ARE required for certain troubleshooting procedures. If you knew anything more than what someone else told you or that you looked up on Wikipedia....you'd know that. What's the point in you coming back here to infinity just to embarrass yourself? That's not what this is about.
JetMechMA 1 year ago
@LAOTG So bottom line, it's possible that in order to legally dispatch the aircraft, they shut down the engine using the faulty side of the EEC and restarted it causing it to switch to the side that did not display a fault warning. I'm not sure if that is legal because the two halfs are there for redundancy. It almost certainly downgraded the CAT III landing status but we clearly saw this aircraft land in CAT III conditions. Just saying.
JetMechMA 1 year ago
@LAOTG: As far as you hearing the barking stop after about 2000 feet, I can't be sure. They could have de-selected the PTU switch out of automatic mode so it wouldn't be barking through the entire flight. Then proceeded with the flight on yellow and blue sytems. Again, that's probably a functional procedure, but I'm not sure if it's legal. Definitely not CAT III certified with that many faults existing.
JetMechMA 1 year ago
@JetMechMA I think you might like to look at the MEL
Sterlingjob 1 year ago
@Sterlingjob I never doubted that the electric pump could be inop'd. You're responding to the wrong person.
JetMechMA 1 year ago
@JetMechMA As i said read the MEL
Sterlingjob 1 year ago
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@Sterlingjob: As i said read the MEL
JM: It's good that you read the Minimum Equipment List deferal list.
JetMechMA 1 year ago
@JetMechMA Read the MEL yet?
Sterlingjob 1 year ago
@LAOTG In accordance with the MEL the PTU can run constantly as long as certain conditions are met. So hearing the PTU in flight is not the sign of a major problem. The pilot can reset the FADEC computers via phoning maintenance control.
Sterlingjob 1 year ago
@Sterlingjob You're completely wrong. The main pump should be adequate for ALL normal use. The fact that the PTU is heard runing c9onstantly right before touchdown means that it was supplying 100% of green system pressure and the main pump was supply ZERO pressure. That's a major malfunction. You couldn't be more wrong. And your FADEC comment is not even worth responding to. A PHONE call?
JetMechMA 1 year ago
@JetMechMA The main pump will be backed up by the PTU on gear use. The PTU May be inoperative (PTU runs continuously) provided:
a) System pressure indication on ECAM operates normally,
b) Power transfer can be stopped when PTU p.b sw is placed OFF, and
c) Operation of the PTU in both directions is verified before first flight of each day.
Sterlingjob 1 year ago
@Sterlingjob It means nothing SJ. Nothing. This video shows the green system malfunctioning because NEITHER the flaps NOR the gear is in operation. Since there was almost ZERO demand on the system and yet the PTU is running continuously, that means it is definitely a major malfunction. Nobody set out to embarrass you..but you INSIST on embarrassing yourself. What's WRONG with you? That's an OBSERVED fault SJ. IT'S NOT COVERED IN THE MEL !
JetMechMA 1 year ago
@JetMechMA On ground with electric pump running the PTU still runs with no demand on the system, so if either green or yellow pumps are inop the ptu would still run either way. Zero demand? So the control surfaces do nothing on landing? ok whatever...As i quoted directly from the FAA MMEL the PTU can run continuously, unless you were there after the event how can you surmise what is wrong with the A/C?
Sterlingjob 1 year ago
@Sterlingjob: On ground with ...
JM: Key word being, "on the ground"...and likely only with the other pump still off. You are lying when you say that I said "zero demand", I said almost zero demand. Not nearly enough to cause the PTU to run contonuously...especially if as you say, it was only coming on to supplement a normally functioning EDP. You mis-quoted the MEL and took it out of context.
JetMechMA 1 year ago
@Sterlingjob Whether or not the MEL describes how the PTU operates...has NOTHING to do with the subject of this video or the fact that I said it is not normal and is in fact a malfunction. What I said is true and you saying that it is normal is WRONG. I am right and you are wrong. Whether or not the MEL tells us that the PTU will back up the main pump on gear use....THE GEAR WASN'T IN TRANSIT ! ! ! ! !!!!!...in this case. In fact the PTU was NOT heard coming on during gear extention !
JetMechMA 1 year ago
@Sterlingjob In fact the PTU was NOT heard coming on during gear extention ! The PTU only comes on at the very last moment before touchdown when there is very little demand on the system...and then runs continuously. In fact that could indicate that a hydraulic fluid line has BURST! What is heard in this video is not normal in ANY way shape or form. It is the sound of a major hydraulic malfunction on an A320 jet.....at the WORST possible moment......right at touchdown during a CAT III landing.
JetMechMA 1 year ago
@JetMechMA CAT III Single or dual? With 2 pumps running CAT iii single is still available, check your FCOM
Sterlingjob 1 year ago
@Sterlingjob: CAT III Single or dual?
JM: You keep changing the topic. ....that you're wrong about this. And again, the Flight Crew Operating Manual only address operating modes, it does not address observed faults. All you're doing here is embarrassing yourself by talking in non-sequitur responses. Nobody is trying to embarrass you, that's not why we come to Youtube.
JetMechMA 1 year ago
@JetMechM It does not address observed faults? Are you taking the piss? So a pack regulation or hydraulic fault would not appear in it?
Sterlingjob 1 year ago
@Sterlingjob: would not appear in it?
JM: That's right. The aircraft could be in a "safe to operate condition"...in other words, the back-up system has taken over and the safety of flight is not in question.... yet the aircraft is malfunctioning. That situation is observed by the pilots. The pilots must use their critical thinking and reading skills to determine, with the aid of the MEL, if they must take action. They wouldn't need to take any action with the PTU and would report it.
JetMechMA 1 year ago
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@JetMechMA Ok you have proved you have never read the FCOM, tell me what is in the FCOM?
Sterlingjob 1 year ago
@JetMechMA If you read FCOM then you would see what would cause the downgrading of the autoland system. Perhaps you should read the course notes on the a320, i have lufthansa and airbus notes including VACBI. You have said nothing that is constructive including your first comment that airlines werent doing maintenance properly. Your assuming everything you say is correct. If you knew anything about aviation you would know its wise never to assume anything.
Sterlingjob 1 year ago
@Sterlingjob You are wrong in everything you say here...and that's the only reason I respond. People like you are what...I don't know. You were simply in error here...we all make mistakes...but for whatever reason you are too stubborn to admit that you are simply wrong about this incident. The PTU comes on continuously when there is very little demand. I am right and you are wrong. You have emotional issues if you are incapable of letting it go when you are as wrong as you are in this case.
JetMechMA 1 year ago
@JetMechMA Yeah of course i am wrong. I have quoted from air nav, i have quoted from training notes i have quoted from the FCOM and i have quoted from the MEL and i am still wrong? The PTU works continuously with little demand? WTF? SInce when? The PTU operates when there is a 500 psi difference between systems which you forget. Look at my videos and if you work on A320 series i suggest you post some videos of your work cos you talk complete crap
Sterlingjob 1 year ago
@Sterlingjob: and i am still wrong?
JM: Yes.
JetMechMA 1 year ago
@Sterlingjob: The PTU works continuously with little demand? WTF? SInce when?
JM: Now you are acting irrationally. YOU are the one who said that, not me. In THIS video we see that the aircraft is DONE with the heavy demand portion of the flight when the PTU comes on. The gear were extended LONG ago. Flaps extended LONG ago, yet the PTU comes on when you wouldn't expect it to come on. That's abnormal but you won't admit it...or don't understand the operation of the system.
JetMechMA 1 year ago
@JetMechMA I never said this was not abnormal now did i? You would know being a A&P mechanic that trouble shooting the system can be anything. It might not be the PTU at fault, it might not be an EDP but your so cock sure of yourself. Unless you were there with your head in the techlog you cannot assume you know what the defect, if there is a defect, is. You have not quoted at all from the FCOM, MEL, TSM or the AMM and you would know being just a mechanic that all work c/o is done IAW the AMM
Sterlingjob 1 year ago
@Sterlingjob: I never said this was not abnormal now did i?
JM: Here's you, "Every time ive flown airbus ive heard the PTU on gear up and gear down."
JetMechMA 1 year ago
@JetMechMA I fly A320 all the time and ive always heard it. In the states your a mechanic, in the UK we are ENGINEERS. I forgot to mention im also dc10 type rated. You would never get an EASA ticket because we dont get given licence's on a plate like the FAA hand them out, you have to work hard to achieve it and when i did mine i was grilled for 2 hours by a CAA surveyor.
Oh yes are you going to answer the questions i asked you about the TSM and what it says?
Sterlingjob 1 year ago
@Sterlingjob: You aren't an engineer, you're a mechanic. Our aircaft fly just as safely and efficiently as yours do....no difference. You were grilled for two hours?....only two? The Airframe and Powerplant written and practical tests are an all day affair. Am I going to answer your questions about the TSM?......NO.
JetMechMA 1 year ago
@JetMechMA You can get an A&P licence in a day? How easy is that.? For a B1 from scratch you would have to take 16 modules then take a written exam. You wont answer the TSM question because you do not know whats in the TSM, your answer about functionality is complete bullshit for a start. Try quoting like a proper engineer then the world might slightly believe you.
Sterlingjob 1 year ago
@Sterlingjob: You can get an A&P licence in a day?
JM: You said you got yours in two hours. I guess you couldn't pass the FAA Airframe and Powerplant test. Pity.
JetMechMA 1 year ago
@JetMechMA I said i sat in front of a surveyor for 2 hours, that is only a small part of the process of getting what was Aeroplanes 2 and gas turbines or as it was A&C licence. Why on earth would i want an A&P licence? Only use of an A&P is working on N reg aircraft, bu then again i can sign off N reg aircraft under company approval
Sterlingjob 1 year ago
@Sterlingjob: i have lufthansa and airbus notes including VACBI.
JM: You indicate that you've studied the course material including Airbuse's "Video And Computer Based Instruction", but you don't fully understand what you read. Pride goeth before the fall. This video shows an abnormal condition. You are wrong to say that it is normal and nothing to worry about. Not only is it a malfunction...it happened during a CAT III landing.
JetMechMA 1 year ago
@JetMechMA I know what it means, and you still cant assume what is wrong, only guess at what could be wrong. Why then in the TSM is there a section on continuous PTU working? I don''t think you even read any Manuals at all.
Sterlingjob 1 year ago
@Sterlingjob: I don''t think you even read any Manuals at all.
JM: The difference bewteen you and me is that even if you read the manual, you don't comprehend what you read. I didn't assume anything about what we see and hear in this video. The PTU shouldn't come on right over the threshold on landing. By simple system knowledge, it doesn't add up if everything is supposed to be operating normally. You should know that.
JetMechMA 1 year ago
@Sterlingjob: The TSM covering continuous PTU operation is only describing its functionality. The EDPs should be able to supply all normal demand....as it does in every other video we see of A320 landings....except this one. In this video, THIS particular aircraft is malfunctioning when the PTU comes on.
JetMechMA 1 year ago
@JetMechMA Ok, tell me what the TSM says about continous operation of the PTU? I want to see exactly what the TSM says regarding this. What part of the system can be at fault. You have access to the TSM you will be able to replicate what it says. The green edp cannot supply all demand for the gear FACT, hence why you hear the PTU.
Sterlingjob 1 year ago
@JetMechMA Hardly would have been CAT III C now would it.
Sterlingjob 1 year ago
@Sterlingjob: Hardly would have been CAT III C now would it.
JM: Currently no aircraft lands in Cat III C conditions....zero visibility down to the runway with zero visibility runway visual range. Why, you ask?....because while the aircraft is capable of making a 100% blind landing, there would be no safe way to find your way to the gate at the terminal in zero visibility, thus, nobody actually does Cat III C landings. It's currently not possible. Actual "Cat III C" conditions are seldom.
JetMechMA 1 year ago
@Sterlingjob The PTU coming on when it shouldn't have to.....if it happens frequently enough, it becomes an "observed" discrepency. That is, it will not show up in the automatically generated post flight report (PFR) as a discrepency, it is classified as an observed fault because the pilots know it's not right even though the PTU is operating "normally" as it was designed. However the main pump was NOT designed to be constantly supplemented by the PTU. They know this and will gripe it.
JetMechMA 1 year ago
@Sterlingjob The main green pump shouldn't need the PTU to lift the gear because positioning the gear can be done between flap detents. It's somewhat likely that while on a stabilized approach, they will select the gear down at the specified time....and few users are then using green system pressure. So the gear has green system to itself while in transit. Extending doesn't use a lot of pressure. Gear can free-fall with ZERO pressure. Don't need PTU to extend.
JetMechMA 1 year ago
@Sterlingjob: Checking the TSM the PTU can come on for many reasons, not because a pump is worn out, it either works or it doesn't.
JM: The PTU comes on for only one reason, low pressure in ther main system.
JetMechMA 1 year ago
@JetMechMA Which system? The PTU works when there is a difference of 500 psi between systems, come on you have done the course you should know this. If there is low system pressure the TSM will aid you in trouble shooting. As i have said ive never known a pump failure, ive changed many PTU's and manifolds but pumps dont fail
Sterlingjob 1 year ago
I hear that sometimes on one of my friends private jet's, it's the hydraulic pump it what i was told, nothing to worry about
TiffanyJ1985 1 year ago
@TiffanyJ1985 It's definitely nothing to worry about for the passengers because as Sterlingjob said, the planes are designed for minor malfunctions like this., but it should be fixed in this case. It might be totally normal on your friend's private jet. Lucky you.
JetMechMA 1 year ago
I've heard the barking sound on startup and sutdown, but never on landing....Hmmm thats interesting...
airplanecrazy1989 1 year ago
PTU........POWER TRANSFER UNITS Makes the Barkin noises.....it transfers eletrical power into the engines........usually hear it when the igintion swtches are set ti ING or Crank.....
gurubaba95 1 year ago
@gurubaba95 Complete rubbish
Sterlingjob 1 year ago
Sound is supposed to be while on the ground...never heard it before while actually in the air...
1037pm 1 year ago
I know there is no problem aboard the aircraft and it is certainly not a dog. I should ask the full details again, but I can assure that it is normal. You don't hear it on every A320 though ;)
Caellest89 1 year ago
man that's some low visibility, lol it really does sound like a big dog
Deadmeat996 1 year ago
My god! thats a very bad weather in AMS, by the way, maybe it could be a failure on one of the hydraulics system, because the PTU only runs in startups and shutdowns to regulate and pressurize hydraulic fluids
fernando13e 1 year ago
@fernando13e Complete rubbish
Sterlingjob 1 year ago
@Sterlingjob Hydraulic pressure is important for braking!!
ArticMuse 1 year ago
omg the dog is stuck in the wing!
nah, its normal.
funkyassholes 1 year ago
It is apparently the PTU (Power Transfer Unit). Someting to do with the aircrafts hydraulic system. Fairly loud but perfectly normal.
scoobyevo 2 years ago
During startup and shutdown it's normal, yes. But not during flight. It's evidence to suggest there may be a slight loss of hydraulic pressure in one of the systems.
WarthogMist08 1 year ago
it may be the engines.
SWATutorials 2 years ago
lol, good Doggy, it couldn't wait to touch down to play in Amsterdam lol. cool vid
brooklynlulu 2 years ago
normally the ptu shouldn't have been on. in this case there could be hydraulic pump problem in one of the hyd systems. if you always hear this kind of sound during flight that means the airlines never bother maintaining their aircraft.
ArticMuse 2 years ago
You talk shit
Sterlingjob 2 years ago
ok.. what the fuck?
whats your problem dude, if you dont like what i wrote just ignore it, dont be a childish uneducated jerk. is this what british people like?? what a shame.
ArticMuse 2 years ago
Childish and uneducated? Perhaps youd like to change your comment regarding airlines not maintaining their components. And its not always a pump that causes the PTU to run, there are other faults that will cause the PTU to run in flight.
Sterlingjob 2 years ago
@ArticMuse: if you always hear this kind of sound during flight that means the airlines never bother maintaining their aircraft.
JM: That's correct. Very dangerous and should be reported to the Federal Aviation Authority.
JetMechMA 1 year ago
@JetMechMA That is complete bullshit. Components fail all the time, its nothing to do maintenance and you would only report it unless it was a result of incorrect maintenance which you have to prove.
Sterlingjob 1 year ago
@Sterlingjob The statement was....that the PTU was heard running all the time like this...which means they aren't fixing the discrepency at maintenance opportunities. If they aren't fixing their broken aircraft, then someone needs to drop a dime on them.
JetMechMA 1 year ago
@JetMechMA And what defects would they be? What would be broken?
Sterlingjob 1 year ago
Huh, I never noticed this sound when I was flying on the A320. Maybe because I sat up front most of the time?
tiadaid 2 years ago
Nothin' special, it's power transfer unit, which transfers power to other hyfraulic systems. In this case the "problem" was probbably in a difference of pressure...
Chatefucio 2 years ago
this seems to occur on occasion in A320's.
i was on an A319 flight awhile ago that the barking occurred every time the flaps where adjusted. I think it occurs when several hydraulic systems are being used at once and it transfers pressure to equalize them.
jimmyp42002 2 years ago
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@jimmyp42002: I think it occurs when several hydraulic systems are being used at once and it transfers pressure to equalize them.
JM: If the PTU needs to come on that much, it means the engine driven pump is weak or inoperative and needs to be fixed. The PTU shouldn't come on in normal operation. The engine driven pumps are the main hydraulic pumps. The main pumps should be able to handle normal operations. If the back-up is coming on, there is something wrong with the main pump.
JetMechMA 1 year ago
That "barking" sound is the so called PTU, the Power Transfer Unit. The PTU trnasfers power between the yellow and the green hydraulic system without exchange of liquids by means of two pistons. If one system has a lower pressure then the other one, then this piston starts working and pressurizes the other system. So if the yellow system is on, but the green is off, and you want to operate smth which is powered with the green system, the PTU translers power from the yellow to the green one.
Waldfuerst114 2 years ago 7
i don't think i've ever noticed that before but i've only flown on the A320 a couple of times
ELChriss0 2 years ago
The barking noise is of course that of the dog in the cockpit, the dog is in the cockpit to ensure that the flight crew do not touch the controls during landing...
ThePlanesmith 2 years ago
Probably a miserable hosty who thinks the sun shines out her arse because shes aircrew!
Sterlingjob 2 years ago
love your comment hahaha!!
gazer88 2 years ago
I wonder if some people think there are dogs in the cargo holds?
Aviat92 2 years ago 2
I believe the PTU is active because changes in throttle settings on the engines and extensive usage of hydraulics, as is normal at take-off and landing, is causing a pressure difference between the two hydraulic systems.
TehMG 2 years ago
The wheels should already be down by the time this was shot. Could it have been an actual dog with sore ears barking in the hold? And please don't call me all the names under the sun for this. I lose faith in humanity reading some of the replies on here. We all exist in one universe. (By whoever gods grace...) Peace love
Terryzarzoff 2 years ago
that being said, ive never heard it in the air before...
tomcatpilot1 2 years ago
My dad's an A320 pilot: the barking, known by the pilots as the "whining dog" haha, deals with the hydraulics and regulating their flow when the engines are not fully on (starting up or shutting down).
tomcatpilot1 2 years ago
We always hear this sound when the A320 is on the ground, when the engines start. It's normal, but my question here is why do we hear it here during the approach ? Is it because of the landing gear ? Can you please ask your father ? Thank you !
Nicomurgia 2 years ago
Yeah I have no idea why it's in the air lol...I'll ask him, but he just left for a trip-expect an answer maybe tomorrow or the next day.
tomcatpilot1 2 years ago
When gear moves the ptu usually kicks in because there is more than a 500psi difference in pressure between the green and yellow sytems or #1 and #2 engines
Sterlingjob 2 years ago
OK, I understand better now. Thank you !
Nicomurgia 2 years ago
Great Video. I love that sound.
SABoeing 2 years ago
Nice video but it should be pointed out that there's no barking dogs until 2:06.
flybynightvideo 2 years ago
As per description "The "barking" starts at 02:06.". Read it next time before you comment!
LAOTG 2 years ago 2
oh ok.. you're right, I needed to click the "more info" tab. Thanks for posting the video... it was well done.
flybynightvideo 2 years ago
That's actually really really weird. The PTU shouldn't be working in the air at all. Probably one of the hydraulic circuits clogged or malfunctioned during descent, or maybe even an engine stopped pumping (or was off!)
patrik667 2 years ago
The PTU can work in the air when the is a difference of more than 500 psi between the green and yellow systems, you will hear it on gear up and gear down. If you want i can dig out the reasons why the ptu would work in the air, one is a loss of air pressure in the hydraulic reservoirs.
Sterlingjob 2 years ago
That's very interesting, thanks! I assume you have an A320 FCOM with you.
I'd love to get my hands on one, but they're a bit expensive.
Thanks again
patrik667 2 years ago
Theyve taken my other comment off! Nah ive got airbus and lufthansa training manuals, mail me your msn and we can try and send the various chapters!
Sterlingjob 2 years ago