Hydra 70 Rocket:
Recent Performance Has Improved
NSIAD-99-126R, Apr 15, 1999
Pursuant to a congressional request, GAO provided information on the Hydra 70 rocket, focusing on the: (1) problem of early motor blow (EMB); (2) actions the military services have taken to identify and eliminate its causes; and (3) rocket's present performance.
GAO noted that: (1) the services acted effectively to address the problem of EMBs; (2) after three EMBs caused damage to aircraft in 1992-93, the Naval Surface Warfare Center, as the design agent for the rocket, launched an independent investigation to determine their cause; (3) subsequently, the Army Industrial Operations Command, as program manager for the rocket, identified corrective actions; (4) these actions included: (a) improving the inspection process; (b) identifying authorized procedures for making changes to the rocket manufacturing process; (c) redesigning the die used to form the rocket's propellant; (d) establishing criteria to remove from inventory any propellant grain dropped during handling; and (e) inspecting rockets already in inventory to screen out those that contain defective propellant grain; (5) the services began to implement these solutions in 1995, and, as of March 1999, they have reported only one EMB; (6) service officials estimate that the services fire about 270,000 Hydra 70 rockets each year; and (7) Hydra 70 program officials told GAO that the probability of an EMB occurring now meets the standard of one chance in a million.