04-01-2008 Ask Mike! Archive
T-34 Flap on Debonair?

Mike;

I am looking at a Debonair in California that used to belong to a person who does an air show routine in a T-34.  This Debonair has a T-34 flap on the left wing.  Think that's ok?  It has been flying around like that for several years.  I also noticed some rippling in the upper left wing skin behind the rear spar.  Is that normal?  I sent a message to the previous owner to see if she knew the story on the flap.

Thanks,
Tad


Tad;

It's hard to get a visual from a photo as it is 2 dimensional.  There is a normal contour in this area, so the shadows/reflections don't necessarily depict what is there.  Unless the aircraft was recently painted, any abnormal stresses to the skin should show up in paint cracking, either at a flex point or around rivets, indicating looseness.  A 4 foot straight edge is helpful in determining excessive deformation, but interpret that result cautiously, as the skin to structure joints will have normal deflection (compare with other side, for example.)

A T-34 flap is physically the same size and shape as a Debonair or Bonanza flap; however it carries some additional structure on the inboard end for a wing-walk.  That said, it is not the correct part number, doesn't conform to the type certificate, and therefore renders the aircraft un-airworthy, unless there is a field approval in the aircraft documents.

(Incidentally, I don't recommend using any flap for stepping on; the rib in the flap where the actuator attaches is prone to failure after too much bouncing on.)

Gear Green,
Mike