PPRuNe Forums - View Single Post - Bristow S76 down in Lagos discussion (Not condolences)
Old 28th Sep 2015, 14:17
  #95 (permalink)  
helicopterkeys
 
Join Date: Jan 2008
Location: New Mexico
Posts: 3
Likes: 0
Received 0 Likes on 0 Posts
S76 Wizard wrote "My speculation is that when they rigged the input they misread the tape measure and made this an inch longer than it should be and then compensated by adjusting the pitch links to bring it in rig. The problem is that too much maintenance gets done to helicopters by engineers that don't have enough experience on type."
The input rods are not measured. With the controls set in a fixed position and rigging blocks installed in the servos, the inputs are adjusted to fit. Later in the process they maybe adjusted again for control clearance.

The S92 TR servo follow through linkage had a steel rod screwed into an aluminum block on early servos, with no jam nut. Vibration would cause the movement between the rod and block, steel won. No clue what that follow through linkage does, the servo will work when the steel rod falls out of the aluminum block. That steel rod augered that thing out like a drill bit, we didn't notice until it was in two pieces, we- in fact I didn't, a coworker spotted it while inspecting some unrelated work I had done. The design has been improved.
If the jam nut was loose for what ever reason, I can see the same type of wear occurring.
helicopterkeys is offline