For aircraft that have had the aileron counter balance weights removed, Service Memo 57 states that every 100 hours, aileron travel must be checked and cannot exceed 5/16". John Wright recently worked on a Coupe that the owners were complaining of a vibration at 90 mph and above. Inspection of the aileron travel revealed a difference of 3/4". The aircraft flew perfectly after new bearings and then properly rigged.
So Vne does not need to be exceeded for aileron flutter to occur and it can happen in straight and level flight! Other damage on the Sebring aircraft suggests that Vne was exceeded. The aileron control system on the Coupe has 6 MD36-14M bearings. (Current part number GMM-3M-670) What happens is in time there is normal wear on the rod end. But just a little play in a bearing is magnified by the length of the push rods. An engineer could compute that for you. A play of .002" at the bellcrank is therefore magnified at the aileron. If you have equal wear on your push rod bearings, you then double that play when taking into account both ailerons. That is the effect on just one bearing per side. Now, figure in the cumulative effect of 6 rod ends, assuming equal wear, in the aileron control system. This why we are so emphatic about the adherence to SM 57, 58 and 58A.
