Understand I am not saying this plane encountered tail plane stall. I am saying the plane gave all the signs of tail plane stall. Read about the signs of a tail plane stall, and look at the recovery procedures. It is the exact opposite of a normal stall. These are the actions this crew did.
Their names are being drug through the mud
What is a stick pusher needed for anyway? Whatever happened to just a plain old stall warning horn and stick shaker?
No, pythos1, the tailplane was very effective. It had brought the nose up to 10 degrees when the automatic pilot was engaged, and up to 31 degrees when the pilot pulled it up. A tailplane that is stalled or nearly stalled couldn't have done that.
grandCentraldepot: The plane's pitch attitude was brought level and the descent almost stopped before 1920' MSL--after dropping from 2500' MSL. If the tail was so blanketed as to be ineffective the plane couldn't have done that.
But the automated system (stick pusher) made it seem as if the plane was encountering a tail plane stall. Remember the captain had just been tested on dealing with tailplane stall, was tired and was in conditions conducive to tail plane stall. If this plane just had a stick shaker and no damn pusher, I don't think this accident would have happened. The sign of a tailplane stall is the wheel moving forward by itself, with enough force to pull the yoke out of a weak grip.
I just listened to the report. The flaps were extended to 5. Then the gear was lowered, then the flaps were put to 10. As the flaps began their way to 15 degrees, there was an "upset". In the tailplane stall scenerio, upon lowering the flaps if there is a DRASTIC change in pitch, RETRACT THE FLAPS TO THE PREVIOUS SETTING, and apply back pressure. This is what he did. There was no discussion about the pitch up. There was an upset 29 seconds before the impact.
The "upset" was the pilot drastically pitched the deck angle from 9 degrees to 20 degrees. That was before the stickpusher activated.
The stick moved forward? When?
The back pressure applied in a tail stall is to get the nose back up where it belongs. They didn't have that problem. The nose began too high at 9 degrees, and the pilot pitched it up drastically to 31 degrees.
When the stick pusher activated was when the stick moved forward. Did you even listen to the report. The term "flaps set to 15" was mentioned at least twice. The flaps never reached that position due to them being quickly retracted at the moment of upset.
Why do you defend a stupid device as the stick pusher any way? I as a pilot need no such device. I need a stall horn, or stick shaker.
so what you are saying is there was a delay on the part of the pilots. You did hear the power was reduced, which is another action to be done for tailplane icing. You are not getting that I do not think it was actual T.P. icing. I am saying the pilots were fooled into thinking the plane was encountering this situation, due to this stupid and unnecessary system.
The power had been back at or near idle in order to slow down for the final approach, but after the stickshaker activated and the automatic pilot disengaged the pilot promptly powered up and pitched up drastically--before the stickpusher activated.
A stickpusher offers only about 30 pounds of force; the pilot was able to overpower it easily.
The stick pusher is a device that should be removed from all aircraft that are meant to operate in icing conditions. It is unnecessary. From what I have heard the stick pusher in fact provides a lot of resistance to being pulled back. It is a dangerous system and can give a pilot the wrong signal. Check out the Nasa video about tail plane icing. The stick pushes imitates these movements.
"They commanded flaps 15......The flap handle.....got back to the 10º notch--we think--because all we see on the flight data recorder is the flaps got to 10º. They didn't get to 15º."
As I have said, I do not think there tailplane icing or stall. But the plane gave all indications of such. The stick moved forward. There is no other indication of the stick pusher activating such as a light or horn. The pilots were tired after three legs. Their "recovery" was reduce power, return flaps to previous setting, and hauling the gear up. These are the recovery procedures for tail plane stall. They THOUGHT they had a tail plane stall.
Sounds like tailplane stall. This was probably due to the stupid stick pusher, which can look just like a tailplane stall. In said the controls push forward. The recovery is to haul the flaps up, and pull back on the wheel, while decreasing power.
Over automation killed the occupants of the plane.
But in this case they were not in a tailplane stall, they were in a regular stall. All their hauling the flaps and gear up and pulling back on the stick did was make the stall worse.
The stick pusher gave the indications of a tailplane stall.
That is exactly what they did. You don't have to be in level flight to have a tailplane stall, you can have it happen at an angle. The stick pusher gave the impression the tailplane was stalled. The system has no other indicating system dealing with the activation of the system. It is did, this may not have happened.
Understand I am not saying this plane encountered tail plane stall. I am saying the plane gave all the signs of tail plane stall. Read about the signs of a tail plane stall, and look at the recovery procedures. It is the exact opposite of a normal stall. These are the actions this crew did.
Their names are being drug through the mud
What is a stick pusher needed for anyway? Whatever happened to just a plain old stall warning horn and stick shaker?
pythos1 2 years ago
No, pythos1, the tailplane was very effective. It had brought the nose up to 10 degrees when the automatic pilot was engaged, and up to 31 degrees when the pilot pulled it up. A tailplane that is stalled or nearly stalled couldn't have done that.
grandCentraldepot: The plane's pitch attitude was brought level and the descent almost stopped before 1920' MSL--after dropping from 2500' MSL. If the tail was so blanketed as to be ineffective the plane couldn't have done that.
bethpage89 2 years ago
But the automated system (stick pusher) made it seem as if the plane was encountering a tail plane stall. Remember the captain had just been tested on dealing with tailplane stall, was tired and was in conditions conducive to tail plane stall. If this plane just had a stick shaker and no damn pusher, I don't think this accident would have happened. The sign of a tailplane stall is the wheel moving forward by itself, with enough force to pull the yoke out of a weak grip.
pythos1 2 years ago
The stickpusher didn't activate until he had pitched up to 29 degrees.
The plane had been holding altitude just fine, and pitched up even further after the automatic pilot disengaged. Elevator authority was excellent.
The plane had been maintaining altitude just fine;, the pilot pitched it up much more once the autopilot disengaged.
Before the stickpusher activated, the pilot had already pitched the nose up to 29 degrees--guaranteeing a stall.
bethpage89 2 years ago
I just listened to the report. The flaps were extended to 5. Then the gear was lowered, then the flaps were put to 10. As the flaps began their way to 15 degrees, there was an "upset". In the tailplane stall scenerio, upon lowering the flaps if there is a DRASTIC change in pitch, RETRACT THE FLAPS TO THE PREVIOUS SETTING, and apply back pressure. This is what he did. There was no discussion about the pitch up. There was an upset 29 seconds before the impact.
pythos1 2 years ago
Flaps 15 degrees was never selected.
The "upset" was the pilot drastically pitched the deck angle from 9 degrees to 20 degrees. That was before the stickpusher activated.
The stick moved forward? When?
The back pressure applied in a tail stall is to get the nose back up where it belongs. They didn't have that problem. The nose began too high at 9 degrees, and the pilot pitched it up drastically to 31 degrees.
bethpage89 2 years ago
Are you even a pilot?
What does a stick PUSHER do?
When the stick pusher activated was when the stick moved forward. Did you even listen to the report. The term "flaps set to 15" was mentioned at least twice. The flaps never reached that position due to them being quickly retracted at the moment of upset.
Why do you defend a stupid device as the stick pusher any way? I as a pilot need no such device. I need a stall horn, or stick shaker.
pythos1 2 years ago
A stickpusher pushes the yoke, but the yoke doesn't move forward if the pilot doesn't let it.
Flaps up was selected at 22:16:36. The upset began before at 22:16:29.
bethpage89 2 years ago
so what you are saying is there was a delay on the part of the pilots. You did hear the power was reduced, which is another action to be done for tailplane icing. You are not getting that I do not think it was actual T.P. icing. I am saying the pilots were fooled into thinking the plane was encountering this situation, due to this stupid and unnecessary system.
pythos1 2 years ago
pythos1:
The power had been back at or near idle in order to slow down for the final approach, but after the stickshaker activated and the automatic pilot disengaged the pilot promptly powered up and pitched up drastically--before the stickpusher activated.
A stickpusher offers only about 30 pounds of force; the pilot was able to overpower it easily.
bethpage89 2 years ago
I didn't defend the stickpusher.
bethpage89 2 years ago
The stick pusher is a device that should be removed from all aircraft that are meant to operate in icing conditions. It is unnecessary. From what I have heard the stick pusher in fact provides a lot of resistance to being pulled back. It is a dangerous system and can give a pilot the wrong signal. Check out the Nasa video about tail plane icing. The stick pushes imitates these movements.
pythos1 2 years ago
"Flaps set to 15" wasn't mentioned.
"They commanded the flaps to 15...."
"They commanded flaps 15......The flap handle.....got back to the 10º notch--we think--because all we see on the flight data recorder is the flaps got to 10º. They didn't get to 15º."
bethpage89 2 years ago
As I have said, I do not think there tailplane icing or stall. But the plane gave all indications of such. The stick moved forward. There is no other indication of the stick pusher activating such as a light or horn. The pilots were tired after three legs. Their "recovery" was reduce power, return flaps to previous setting, and hauling the gear up. These are the recovery procedures for tail plane stall. They THOUGHT they had a tail plane stall.
pythos1 2 years ago
Sounds like tailplane stall. This was probably due to the stupid stick pusher, which can look just like a tailplane stall. In said the controls push forward. The recovery is to haul the flaps up, and pull back on the wheel, while decreasing power.
Over automation killed the occupants of the plane.
pythos1 2 years ago
"Haul the flaps up and pull back on the wheel"? Isn't that what they did?
bethpage89 2 years ago
But in this case they were not in a tailplane stall, they were in a regular stall. All their hauling the flaps and gear up and pulling back on the stick did was make the stall worse.
The stick pusher gave the indications of a tailplane stall.
pythos1 2 years ago
That is exactly what they did. You don't have to be in level flight to have a tailplane stall, you can have it happen at an angle. The stick pusher gave the impression the tailplane was stalled. The system has no other indicating system dealing with the activation of the system. It is did, this may not have happened.
pythos1 2 years ago