The Army announced 5 November 1999 that all its 660 AH-64A and 83 AH-64D models must be inspected before their next flight. The hanger bearing assemblies fore and aft house the drive train, which passes turbine engine power to the tail rotor. A failure in the flange area will result in loss of tail rotor thrust and such a failure could be catastrophic. Army investigators had identified the bearing assembly problem while looking into a January 1999 accident at Fort Rucker, Alabama, that destroyed an Apache and injured the 2-man crew. Army officials said stress corrosion fractures resulting from a hardness heat-treat process used during manufacture may cause the bearing assemblies to fail. Hanger bearing assemblies produced after the Army changed the manufacturing process in 1993 do not have the potential for such fractures. Army officials determined that at least 400 of 743 AH-64 Apache attack helicopters needed the new parts.In December 2000 the US Army grounded its entire AH-64 Apache helicopter fleet as a precautionary measure, following the discovery of a faulty tail rotor swashplate assembly. Failure of a tailrotor swashplate assembly, which produces yaw control, could result in the loss of an aircraft and crew injuries. The Army ordered an inspection of all 742 AH-64A and D aircraft to locate specific swashplate assemblies identified as being potentially faulty, which would be replaced.
In early 2001, the Apache community was operating under a shortage of M299 launchers and a HELLFIRE missile restriction. The M299 launchers, under contract to Boeing St. Charles, suffered a failure in testing and had been deemed unsafe. The power supply card had to be redesigned, which was estimated to take 7-8 months to complete and qualify. Reverting to the old design was not an option. Required components were no longer in production. DCSOPS had published a distribution plan. The PM-ARM was responsible for the development and fielding of the launchers and is working to correct the problems. The HELLFIRE restriction was driven by the new spacer in the motor impacting and damaging the stabilator and potentially the tail rotor.
Damage to 19 of 43 Apache Helicopters was detected following HELLFIRE missile firing during the USAREUR training exercise Victory Strike in Poland between 6 and 18 October 2000. Damage to AH-64A Helicopter horizontal stabilators was initially attributed to ground debris then later to the HELLFIRE missile. Two Apache units fired 385 AGM-114C model missiles and numerous 2.75 inch rockets and 30mm rounds without incident. PEO Aviation System Safety Risk Assessment (SSRA) assigned a Category I-A risk (Catastrophic Probable) if missiles were fired from any position other than position number 4 on right outboard pylon. The SSRA applied only to the AH-64D Helicopter. SSRA for other helicopters was a "due-out" from PEO Aviation. AMCOM IMMC worldwide suspension of HELLFIRE missiles with the deficient Alliant/Hercules motors remained in place as of mid-2001. All HELLFIRE missiles with this motor were in CC-N, emergency combat use only. This included the entire inventory of the Longbow HELLFIRE Millimeter Wave (AGM-114L) missile, and nearly 90% of the latest Laser production assets (AGM-144K & K-2).
