The United States Federal Aviation Administration has issued new airworthiness directives (ADs) affecting Bell 412 and Eurocopter AS350 B3 and EC130 B4 helicopters.
The first AD affects 412 and 412EP helicopters, and was prompted by analysis of the crosstubes conducted as a result of recent field failures and corrosion problems of the affected crosstubes. It is intended to prevent failure of a crosstube, collapse of the landing gear, and subsequent loss of control of the helicopter.
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). It requires installing caution decals regarding towing of a helicopter at or above 8,900 pounds, and 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.
The second AD, for Eurocopter AS350 B3 and EC130 B4 helicopters, requires revising the limitations section of the rotorcraft flight manual to reduce the starter generator operating current to 180 amperes and installing a placard in the instrument panel indicating the revised limitation. This AD was prompted by the determination that the manufacturer-installed Aircraft Parts Corporation starter generator has exceeded the shaft horsepower extractions allowed for Turbomeca engines. The actions of this AD are intended to prevent the engine surge margin being reduced, which can result in engine failure.
The AD differs from a similar AD issued by the European Aviation Safety Agency (EASA) in that it requires the AD be accomplished within 100 hours time in service, rather than 110 flight hours or 12 months as stated in the EASA AD.
The complete text of both ADs can be found on the FAAs website.
