I built the standard Vans alternate air door into the bottom of my standard FAB for my RV-9A with an IO-320. This door has been a constant source of trouble, I have found it to have failed almost every time I've taken my bottom cowling off during my condition inspection. At best it's worked its way open, several times it has pulled some of the rivets through the FAB. This time I found the door to be be completely detached, hanging by the actuator cable with the pivot plate nut pulled right though the floor of the airbox.
The notch that the tab on the door closes into is plenty tight, but I suspect it just vibrates out over time and the weight of the door on the single pivot point is too much given that vibration.
I was thinking I'd just build up the floor of the the airbox with some carbon fiber above and below and then reattaching as designed, but I wondered if anyone had an alternate approach to this that might be more reliable.
My plane is about to go into hibernation for 3-4 months as I'll be unable to fly due to shoulder surgery that I'm getting next week. I won't be fixing this problem until July or August, but I'm interested in hearing what the collective mind of VAF thinks.
The notch that the tab on the door closes into is plenty tight, but I suspect it just vibrates out over time and the weight of the door on the single pivot point is too much given that vibration.
I was thinking I'd just build up the floor of the the airbox with some carbon fiber above and below and then reattaching as designed, but I wondered if anyone had an alternate approach to this that might be more reliable.
My plane is about to go into hibernation for 3-4 months as I'll be unable to fly due to shoulder surgery that I'm getting next week. I won't be fixing this problem until July or August, but I'm interested in hearing what the collective mind of VAF thinks.