Cracks Discovered On Main Gearbox Oil Hoppers In Several Aircraft

The FAA has issued an Emergency AD (EAD 2014-22-51) for Airbus Helicopters (formerly Eurocopter France) Model EC130T2 helicopters.

This EAD requires, before further flight and thereafter at intervals not to exceed 10 hours TIS, visually inspecting the hopper for a crack at the four attachment points. If there is a crack, this EAD requires replacing the hopper with an airworthy hopper. Replacing the hopper is not terminating action for the repetitive visual inspections required by this EAD.

According to the document, the EAD is prompted by several cases of a cracked main gearbox (MGB) oil cooler hopper. The cracks were found on the hopper at the fan attachment points.

If there is a crack, this EAD requires replacing the hopper with an airworthy hopper. These EAD actions are intended to detect a crack in the hopper at a fan attachment point to prevent failure of the fan attachment, interference of the fan with the control rod of the front servo-control or with the flight control bellcrank, and subsequent loss of control of the helicopter.

The FAA says the EAD is an interim action. The design approval holder is currently developing a modification that will address the unsafe condition identified in this EAD. Once this modification is developed, approved, and available, additional rulemaking may be forthcoming.

(Image from file)

FMI: www.faa.gov