Preflight & Misrigged Controls

[Norman]

Before both my boss and I retired we did pick up a lot of planes that had to be disassembled (wings and horizontal removed) before we could legally transport them to our home base. The potential for misrigging them on reassembly was always there and we took precautions to prevent such.

 

[MauleSkinner]

Ah - the amendment REMOVED the reference to assembling wings from part 43, preventative maintenance. . https://static1.squarespace.com/sta...2fe131f8fb14f4b7/1464113792897/05+06+1987.pdf
Also added words in glider pre-flight that have since evaporated and been replaced by just "preflight operations" near as I can tell.

Thanks.

I guess it's been a long time since I looked at that stuff.

 

[Dan Thomas]

It seems like one could easily design control cable or rod systems in such a way as to make misrigging like this impossible. Turnbuckles in different positions, male/female threaded portions set up so they can only go one way, different sized bolts and eyes, that sort of thing.

No?

That is already done in many systems, but there are also chains that can be run the wrong way over sprockets, cables can be crossed, and so on. TWICE I have found the trim cables in Citabrias twisted around each other, and yet the builder managed to get them hooked up right anyway. In one of those airplanes the cable pair were also run around one of the elevator cables. All three cables were frayed. That airplane was misrigged at the factory, and had been through at least 17 100-hour inspections and the flaw had not been spotted. That there is not good maintenance, folks. What are you paying for?

The real solution is attention to the job and double-checking everything. In Canada it's a legal requirement to have another technician check any control system that has been disturbed, and the maintenance release has to have two signatures proving it.

CAR Standard 571.10(4)(d):

(d) Work that disturbs engine or flight controls:
That the system has been inspected for correct assembly and correct locking of any parts disturbed by the maintenance performed, including an operational check for proper sense and range of motion of the engine or flight controls has been accomplished, by at least two persons, and the technical record contains the signatures of both persons.

 

[Ravioli]

Anyone else notice that the pilot continuously indicates the trim input with his thumb?

My CFI would have kicked my lily white ass if he caught me using the electric trim.