Aileron balance

[signman130]

The srm 57-10 states that the tolerances are +2 to -48. I find this impossible. If using the Alt method and multiplying the net weight reading by the arm, there can never be a negative number. I can only conclude that the SRM has a misprint and the correct tolerance should be +2 to +48, otherwise we are in big trouble. both ailerons have had massive repairs done to them, skin replacements,frame repairs and such. If the SRM is misprinted is there anywhere that this is stated? The MRO that I work at does not have access to LockHeed.

[Steve1300]

Our SRM is fairly new and says the same thing. I don't think it is a mis-print. I do seem to remember that the aileron, when in the jig, tilts up while the others hang down.

[trev130eng]

I've just balanced Ailerons using the alt method. My SRM gives +2 to -48 but the table for calculating number of balance weights is +2 to +127. If the aileron tilts up then no balance weights are necessary. My ailerons were in good condition and only required 4 balance weights each. The SRM is quite confusing to read but the job is pretty straightforwad. Don't forget +2 to-48 is the manufactures tolerance. Field tolerance is +2 to -72.

[signman130]

We found the problem, seems we have hybrid ailerons now. the original skin was .016 and the new skins are .032, which added the extra weight, plus the repairs. This is according to the engineers. we had to send them out to be overhauled and hopefully not scraped. These are from 63-3940 and came in under-balanced.

[miamiair]

The key is using a protractor to get the correct angle to weigh the reaction.

We just received two that wouldn't balance. The L/H is definitely shot. The MRO used stainless steel for doublers for repairing the web at the tab cut-out. There were numerous rib repairs. Lots of Cheery-Max rivets. Lost cause. This one is getting replaced.

The R/H wouldn't balance either. We found one of the weights had been trimmed and didn't weight what it is supposed to. We replaced that, replaced a whole bunch of Cherries. Needed to add four adjustment weights total. It is now at zero.

But again, the angle has to be on the money, not doing so changes the reaction.

[signman130]

I believe you have the Ailerons from the a/c we are working. They were originally from LN3940. The ailerons from 3925 we good, but now have a home on 3940. Lucky me,I get the headaches from the other a/c. Thanks for repairing them.