Monday, November 26, 2012

Pattern work

Sitting on my couch watching TWIT.Tv. Supposed to be sitting in a La Quinta hotel room in the middle of no where.

On day 2 of a 4 day.

Day 1 was long. First turn was 5 hours. I then had a two hour sit. The next turn was a short 1 hour 40 minutes. Then an hour sit. Final flight was 50 minutes block also with just 34 minutes air time. Three different Captains.

The last Captain of the day was new to my base. I played tour guide again. I don't mind it. He had never flown out of my base before so he needed a little extra guidance especially with local ramp procedures and such.

Arrived on time. Nice 10 hour overnight at a maintenance base.

This morning at breakfast my phone rang. Crew scheduling was calling. I thought "eat my fresh omelet or talk to scheduling."

I finished my omelet.

I use Google Voice for my voice mail. I read the transcribed voicemail. Seems as though the plane was written up last night and needed a check flight before flying revenue service. Ok.

My crew joined me at my table. We discussed the scheduling change.

We were supposed to do one leg to base, quick turn and one leg to the overnight.

With the check flight we were pulled from the overnight. We'd all be going home when done.

Arrived at the airport. Plane was parked on the ramp.

I used to do a lot of check flights when I was on reserve. I recalled the process. My Captain hasn't done one in 10 years.

Took a bit to get through the paperwork and fire up the plane.

The crew that brought the plane in wrote it up stating the plane yawed abruptly when the gear was lowered.

Dispatch filed us a round robin flight up to FL320. We discussed it and felt a few laps around the pattern would be best as it was just a landing gear issue.

I took the leg.

Mechanic was on board just in case.

With an empty airplane we hit V1 and VR within 2000 feet. Pattern altitude 1500 AGL.

We agreed we'd do one low pass and then a full stop.

It was fun doing pattern work again. The first time I lowered the gear , I asked for it in a turn. Didn't feel anything. Low pass.  Went around.

The next time I asked for the gear to be lowered on downwind. There was a 40 knot crosswind at 1500 AGL. The plane indeed yawed. We raised the gear and it yawed again. Hmmm.

Cycled again. Still yawed.

Turned base. yaw.

We assumed it was yawing due to the left gear coming down slightly faster than the right. When the gear caught the 40 knot crosss wind it yawed the plane a bit.

I turned final. Cycled again and it slightly yawed in the opposite direction.

Verdict...normal given the very high winds aloft.

Normal landing.

Paperwork and we boarded up for one leg to base.

Arrived an hour late.

Happy to be home. I still get paid for my flights.




  1. The only problem with that theory is that there's no such thing as a crosswind when you're in the pattern. Up there it's a wind correction angle, and the plane can't tell. All apparent wind (unless cross-controlled e.g., during the landing flare) is dead on the nose.

  2. Hmm. But if the landing gear causes the wind correction angle to change - by essentially presenting different "control surfaces" to the slipstream - it's reasonable to see how that could cause a yaw in reference to the ground. The wind correction angle must then be adjusted (although this should be temporary only as long as the imbalance between the gear exists).

    I guess what you're saying is the direction and speed of of the winds aloft don't impact the yaw if it's caused by asymmetric gear extension, which I agree with. He did say the yaw was in the opposite direction sometimes, would you attribute that to the opposite gear coming down faster on that instance?


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