Army Returns Helicopter Gunships To Service
WASHINGTON (AP) _ The Army has completed inspecting a grounded fleet of 750 AH-1 Cobra helicopter gunships and returned them to service after replacing more than 100 main rotor blade fittings, a spokesman said Tuesday.
The last inspection was completed Jan. 29 ″and all of the copters are back on line,″ said Jim Wittmeyer, a spokesman for the Army’s Aviation Systems Command.
″We ended up inspecting 739 main rotor blade fittings in all, of which 112 or 15 percent flunked the ultrasonic inspection and were replaced.″
Wittmeyer added that as a further precaution, the Army had issued a directive setting up a ″recurring inspection program every 120 days for these fittings.″
The Army announced Dec. 22 it had temporarily grounded 750 of its 1,084 Cobras, a Vietnam-era chopper that still forms the nucleus of the Army’s gunship force. The move was prompted by results of an inspection in November and focused on those that might be equipped with a certain type of ″main rotor blade root end fitting,″ the Army said.
The fitting, known as the ″K747 root end fitting,″ is made by a subsidiary of the Kaman Corp. for the copter’s prime contractor, Bell Helicopter Textron.
According to the Army, two cracks in K747 fittings were discovered during routine maintenance inspections in November. That discovery led to a Nov. 21 order for an inspection of all AH-1 Cobras equipped with new fittings of that type that had flown for 200 hours or less.
That inspection, in turn, led to the discovery of a third crack and prompted the order to inspect all such copters regardless of flight time.
The Army said the root end fitting is a key piece of the assembly by which the main blade of the copter is attached to the rotor spindle. If it failed in flight, a copter could lose its main blade.
The Army described the grounding as a safety precaution and said there have been no accidents or crashes attributed to the fitting.
Elaine Henrion, another Army spokeswoman, said Tuesday the service ordered a replacement installed ″even if there was a suspected (metal) weakness″ as opposed to an actual crack.
Neither she nor Wittmeyer could say immediately how many actual cracks were found during the inspections.
According to Wittmeyer, each of the Cobras has two root-end fittings, but it is not unusual for the copters to have one Kaman fitting matched with another made by a different company.