View Full Version : B737NG Elevator Balancing reasons.
elfinknight
5th May 2021, 18:46
Hi,
Can anyone give me direction as to where I can find a list of reasons that require the balancing of a B737 elevator.
Thanks
747 Requirement is in the SRM Ch. 51. Probably same location for 737.
Off the top of my head:
Painting
Repairs
Control flutter
Webby737
9th May 2021, 13:27
Have a look in the AMM around chapter 55-20, it should give you some info.
In general, you would balance a flight control surface after paint or if you carried out a large repair.
CV880 is correct, the balance procedure can be found in SRM 51-60-04. (I never thought to look in Chap. 51 !)
It states "This section presents the operational (in-service) balance requirements and rebalancing procedure for the elevator after a rework operation (repair or repaint)."
ericferret
9th May 2021, 17:38
I believe the elevator on the 737 is extremely sensitive and rigging set up with a DTI.
One uk carrier had a serious loss of control incident post maintenance.
One test is hydraulics off and only pilots trained to carry out the task in flight were allowed to conduct the test.
All said above have an effect so caution is required.
Cat Techie
6th Jun 2021, 23:50
I believe the elevator on the 737 is extremely sensitive and rigging set up with a DTI.
One uk carrier had a serious loss of control incident post maintenance.
One test is hydraulics off and only pilots trained to carry out the task in flight were allowed to conduct the test.
All said above have an effect so caution is required.
Yes the Esy Jet ATCL handback **** up. Tests not documented in a tech log, adjustments not recorded accurately by questionable LAEs (I knew the people involved) and a Dynamic captain that screwed up for a 21,000 feet per minute event.
elfinknight
7th Jun 2021, 17:50
Hi all, thanks for your replies. They were a big help
Bus429
30th Jun 2021, 19:19
Yes the Esy Jet ATCL handback **** up. Tests not documented in a tech log, adjustments not recorded accurately by questionable LAEs (I knew the people involved) and a Dynamic captain that screwed up for a 21,000 feet per minute event.
Not strictly balancing; it was a trim tab adjustment that requires a manual reversion check.
TURIN
30th Jun 2021, 19:52
Not strictly balancing; it was a trim tab adjustment that requires a manual reversion check.
A similar thing happened at Big Airways on a - 200. I believe the AMM was changed afterwards to clarify the procedure.
Bus429
30th Jun 2021, 20:39
A similar thing happened at Big Airways on a - 200. I believe the AMM was changed afterwards to clarify the procedure.
I've flown on a couple of those manual reversion tests. Has to be done (on the 737-400) at 17000' and 30000'. The amount of stab trim required depends on the rods on the trim tab (titanium or steel) and the hope they've been adjusted correctly!