FAA Wednesday issued an emergency AD
for a Honeywell TPE331 main shaft bearing (P/N) 3108098-1WD) made by Dixie Aerospace under a PMA following what the agency called an "excessive" failure. Explained FAA:
The bearings were manufactured with inadequate inner ring guide flange clearance. The main shaft axial compressive loads combined with the inadequate clearance have a high probability of leading to a condition where the rollers are pinched between the inner ring guide flanges, leading to premature bearing failure and engine main rotor seizure. The bearing failure mechanism is severe and sudden.
Operators are required to swap out the part within 10 operating hours. Here's the full AD (.pdf)
. NOTE: post updated to fix full AD link.