The Cessna 120-140 Association Forum

My door frames seal pretty well when I am on the ground, however the top rear part of window frame moves out during flight and I can see a gap there. I am guessing this can only be from pressure inside the cabin or negative pressure outside. Any ideas on which? Has anyone done anything to stop this happening?

Look on the inside skin of the door right around the door lock area for cracks. Cracks here allow the door to flex lengthwise. (Even if crack free they still tend to open in the top rear corner in flight.)

Thanks for your reply John.
I have strengthened around a crack on the pilots side, the passenger side is OK.
I realise they are weak in that corner but was wondering what actually causes the movement
Cheers
Michael