MASTERY Flight Training, Inc.

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Beechcraft A36 Bonanza Split Flap Event

submitted anonymously for the purpose of pilot education



I had a "split flap" situation on my A36 as a result of maintenance during an annual.  This facility had performed a five-year [check] on the flap actuators and somehow screwed up the re-installation. I discovered the problem as I was doing my post-annual flight check to make sure everything worked well before I went off for the Christmas Holiday. 


After an uneventful flight I put approach flaps out as I turned base leg*.  As soon as I did that, I started to roll left which subsequently required me to hold about a half deflection of right aileron to compensate.  I tried to raise the flaps but they were stuck in a split configuration (right down to approach, left up) To aggravate the situation, there was a crosswind from the right on landing requiring even more right aileron.  I kept my speed about 10 knots fast to enhance aileron authority and landed on a very long runway. It ended up being a non event as we got down fine but certainly did elevate my heart rate a bit. My passengers were not aware anything was up.


From it, I learned two things: 
One, check flaps as part of the preflight.  I confess, I didn't do it and in this case it was particularly important.  (As a side note, the maintenance facility said the did ops check the flaps, and it was the flight loads that surfaced the ultimate it is possible I wouldn't have caught the issue).      
Two, skip the passengers on any "test flight." There is no need to expose others unnecessarily.

[*This experience also serves as a reminder to delay extending flaps until all turns are complete and you are wing-level.  As anyone who has flown a "spiral demonstration" with me or other instructors can attest, a roll to the left while in a left turn and close to the ground can cause you to lose precious altitude very quickly, or set you up for a cross-control, accelerated stall from a relatively low pattern speed in your attempt to compensate.--tt]