Re: Aileron bellcrank bearing
Posted: Thu Aug 13, 2015 2:23 pm
This is detailed in part 2 of the rigging manual which should be release as draft soon.
I call out that the side without the flange be inserted in the center hole of the bellcrank. However, in the case of the bellcranks, they are captured on both sides by the mounting brackets and doesn't make much difference. If anyone has them mounted differently, I wouldn't drill the rivets out to change it.
Where this makes the most difference is in places where the bearing only has a mount on one side. Examples are the aileron joiners "Paddles" and the elevator reversing arm. In these cases the flange goes towards the mounting structure. Reason being is the flange is a stronger retaining mechanism than the staking used on the other side.
On all single sided mounting locations, we use an AN970-4 Large washer to act as a safety just in case for some extremely rare event where the bearing might come loose from the mounting flange. The washer will retain the bearing and control. While there will be a lot more friction in the controls, it should get you back safely. You always want backups to the backups on control systems.
I call out that the side without the flange be inserted in the center hole of the bellcrank. However, in the case of the bellcranks, they are captured on both sides by the mounting brackets and doesn't make much difference. If anyone has them mounted differently, I wouldn't drill the rivets out to change it.
Where this makes the most difference is in places where the bearing only has a mount on one side. Examples are the aileron joiners "Paddles" and the elevator reversing arm. In these cases the flange goes towards the mounting structure. Reason being is the flange is a stronger retaining mechanism than the staking used on the other side.
On all single sided mounting locations, we use an AN970-4 Large washer to act as a safety just in case for some extremely rare event where the bearing might come loose from the mounting flange. The washer will retain the bearing and control. While there will be a lot more friction in the controls, it should get you back safely. You always want backups to the backups on control systems.