posted on February 04, 2013 14:00
The FAA is adopting a new airworthiness directive (AD) for Bell Helicopter Textron, Inc. (Bell), Model 412 and 412EP helicopters. This AD requires creating a component history card or equivalent record and begin counting and recording the number of accumulated landings for each high aft crosstube assembly (crosstube). Also, this AD requires installing "caution" decals regarding towing of a helicopter at or above 8,900 pounds.
This AD also requires confirming the crosstube is within the horizontal deflection limits and replacing it if it is not. This AD also requires a recurring fluorescent penetrant inspection (FPI) of each crosstube and upper center support for a crack, any corrosion, nick, scratch, dent, or any other damage. This AD requires repairing damaged crosstubes and upper center supports that are within acceptable limits, reworking crosstubes by bonding on abrasion strips, and replacing each unairworthy crosstube with an airworthy crosstube.
This AD was prompted by analysis of the crosstubes conducted as a result of recent field failures and corrosion problems of the affected crosstubes. The actions are intended to prevent failure of a crosstube, collapse of the landing gear, and subsequent loss of control of the helicopter.