North Pole / South Pole
To: Pilots and mechanics of Bell 412, 214 or any Bell with Elastomeric teeter bearings to include pilots and mechanics that work on or operate helicopters with composite rotorheads and elastomeric pitch and lead lag bearings.
Please perform the following check at your earliest convenience.
1 Get a magnetic field indicator (Gaussimeter) from your shop. If you have a Magna Flux machine and a degausser this instrument is used to detect the level of residual magnetism after degaussing a part.
2) Take the instrument and place it near the top of the rotor shaft just under the rotor head and measure the level of magnetism. Perform the same check on the Jesus Nut. Record the level of magnetism at each point.
3) Check the overhaul manual for the level of residual magnetism allowed after degaussing a part that has been tested in a Magna Flux or Magna Glow machine. This is in the Bell overhaul manuals but I do not know if these limits are a part of the Eurocopter helicopter manuals.
4) If there is a significant difference between the recorded level and the allowable level check with your local tech rep. If he tells you to remove the mast and degauss it tell him it won’t do any good as one hour of flight will re magnetize the mast. Now, ask him once again what action should be taken.
------------------
The Cat