IFR Options, Pitot Static Problems, A flight to Astoria

On a flight from Kennewick to Astoria, Oregon; on an IFR flight plan. At the end of the flight, the Astoria airport was stuck under a low cloud deck while the surrounding area was in the clear. After a stint in the holding pattern, I was able to expedite a landing by requesting a contact approach to the exposed approach end of runway 26.

Then on the return flight we experienced a plugged pitot system, where the incoming dynamic air pressure was locked into the input tube to the airspeed indicator. Trouble wasn't apparent to us until we began our descent. Within 2,000 feet the ASI bled down from 120 KIAS to zero.

After descending below the freezing level, the ASI came back to normal then bled back down to about 60 knots for a time as the plug was thawing out. It finally gave us (apparently) good indications in time for the landing.

Category:

Travel & Events

Tags:

• N4322K Piper Saratoga

[rwbready]

Upon reflection, I think I had a 3rd option for the landing at Astoria: Just shoot the ILS approach. Even though the ASOS was reporting Wx below minimums, a Part 91 flight can begin the approach and may land since the visibility in the landing zone was obviously above minimums. See FAR 91.175 for requirements to continue below the decision height.

[rwbready]

read my responses to RayBlazer in reverse order. I exceeded the 500 word limit.

[RayBlazer]

I was going to say the aircraft looked like a Saratoga! Smooth landing and great ADM skills on your part. I do have one question though. Did the Pitot Heat not work or with the amount of ice accumulation it just wasn't enough?

[rwbready]

@RayBlazer We have been having an ongoing problem with the pitot and static systems with this airplane and the mechanics can't seem to find the cause. I think water is somehow collecting within the tubes that lead from the pitot-static mast into the cockpit. Whenever I fly it into a cloud the static system plugs and the altimeter freezes up, until we climb or descend more than 500- or a thousand feet. Then the altimeter repeatedly jumps to new values. Very disconcerting!

[rwbready]

I am in the habit of flying IMC with the alternate static source open. But this time, we had a full pitot system blockage (where both the ram-air and moisture drain openings were blocked; or the blockage was further up the pipe. Fortunately, the static source remained clear. The airspeed needle was stuck on 120 knots IAS at 11,000 feet and then bled down to zero within the first 1500 feet of our descent.

[rwbready]

Just below the freezing level, the ASI came back and indicated our high-speed descent, then bled back down to about 60 knots for the next 10 minutes until we were approaching our destination airport. Then it returned to normal operation. I am guessing that the frozen water melted, then puddle in the pipe before clearing out.  But I’m just guessing.

[RayBlazer]

This happened to my friend who owns a 170. Mechanics discovered he had over a 1/4" of water in his system which could of caused lots of damage. He has the older style system but, it may be worth looking at

[Carsongamer23]

Great video! Got to go home and fly this Christmas, check out my channel for the four new videos. Took to dad up for a flight from KEUG to Lebanon (s30), then over to Waldport, then flew south along the coast to Florence. Lots of fun!!