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Elevator bellcrank lateral movement
Posted: Mon Oct 29, 2012 10:00 pm
by Ratso
On preflight of a 1953 B model I noticed while standing at the tail and moving the elevator surface the elevator control tube was imposing a lateral movement in the elevator bellcrank. Reaching through the access hole I can move the bellcrank port/starboard approximately 3/8 inch. All hardware was secure and installed in proper order and there was not any binding in the control system. Searching of the forums I found numerous postings on rudder bellcrank issues, but could not located anything on this issue.
So, questions:
a) is this abnormal?
b) if the answer to (a) is yes, is there a replaceable bushing in the elevator bellcrank? (Did not see one in IPC)
c) last resort, where can I source a replacement elevator bellcrank.
Thanks, Steve
Re: Elevator bellcrank lateral movement
Posted: Mon Oct 29, 2012 11:58 pm
by Bruce Fenstermacher
Steve, is the part with play in this picture?
Fig 67 B model IPC.png
Fig 67 B model IPC item list.png
Re: Elevator bellcrank lateral movement
Posted: Tue Oct 30, 2012 2:34 am
by Ratso
Part #36, as it attaches to the bulkhead bracket via 36A, has the lateral movement. I believe it should only hinge fore and aft around bolt 36A with yoke elevator commands.
Re: Elevator bellcrank lateral movement
Posted: Tue Oct 30, 2012 3:26 am
by FredMa
That does seem excessive. It could simply be the wrong length bolt or improperly installed bolt/nut. I would imagine it would be a little difficult to measure the bolt length or see the part number.
Re: Elevator bellcrank lateral movement
Posted: Tue Oct 30, 2012 4:10 am
by c170b53
Well I know mine wobbles, if you search the thread elevator deflection, I placed a photo of the bell crank installed in my plane. If you look closely at the aft top portion, left side crank support bracket, you'll see the primer has been removed by the bellcrank. There 's no paint loss on the RH side, so it might be time for me to replace the bearing that is trapped between the riveted halves of the bellcrank on my plane. I don't think there's a worry if the crank is not damaging the brackets.