The factory sent me the main rotor shaft, main and tail rotor spindles, the bevel and pinion gears from the main transmission and the shaft from the TR gear box to perform nondestructive examination of the components prior to reassembling the transmissions. They also included several main and tail rotor spindles from other Safari's that had been involved in accidents. These parts were scrapped out and replaced with new parts.
It was nice to be able to get a close look at the quality of machining and finish of these very important parts. I paid particular attention to relief radii and how smoothly the transition was made from one diameter to another. Each radius I visually inspected on the parts I received looked fine. We also performed a fluorescent liquid penetrant (Zyglo) inspection on all of the titanium parts using ultra-high sensitivity penetrant materials. This is the same system used on rotating turbine components for GE and Pratt & Whitney. Our shop is qualified as a Flight Safety parts processor for Bell Helicopter and we also process fracture critical parts for the new F-35 fighter. We did not find cracks in any of the parts we tested (including the parts from crashed ships). We did find some slight erosion in a circular pattern where the seal contacts the main shaft. I specified that the factory install the new main shaft "Speedy Sleeve" modification upon re-assembly. In the future I'll be performing these checks each time the transmission is overhauled. I'll provide the applicable specification references for those of you who may wish to do the same: Liquid Penetrant inspect in accordance with ASTM E1417 Type I, Method B, Sensitivity level 4 (Ultra-High) using Form D nonaqueous wet developer. Acceptance criteria in accordance with MIL-STD-1907 Grade A. We did a magnaflux inspection on the main transmission bevel and pinion gears. No flaws were detected. The specification: Magnetic Particle inspect in accordance with ASTM E1444 utilizing wet horizontal FWDC equipment using Fluorescent particles
Spindles under going Fluorescent Penetrant (Zyglo) inspection