Hydra 70 Rocket: Recent Performance Has Improved

Published by the Government Accountability Office on 1999-04-15.

Below is a raw (and likely hideous) rendition of the original report. (PDF)

      United States

GAO   General Accounting Office
      Washington, D.C. 20548

      National Security and
      International Affairs Division


      April 15, 1999

      The Honorable Floyd Spence
      Chairman, Committee on Armed Services
      House of Representatives

      Hydra 70 Rocket: Recent Performance       Has Improved

      Dear Mr. Chairman:

      In fiscal years 1992-95, an unusually high incidence of a potentially dangerous
      problem occurred while the military services trained with and tested the Hydra 70
      rocket. This problem, which is known as early motor blow (EMB), prevents the
      rocket from reaching its target and can cause damage to or loss of the aircraft and its
      crew. Only 1 EMB occurred between 1984 and 1991, but 15 occurred during fiscal
      years 1992-95.

      The services have taken action to identify and eliminate the causes of early motor
      blows. At your request, we identified those actions and investigated the present
      performance of the Hydra 70 rocket.


      The services acted effectively to address the problem of early motor blows. 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. Subsequently, the Army industrial Operations Command, as
      program manager for the rocket, identified corrective actions. These actions

      (1) improving the inspection process,

      (2) identifying authorized procedures   for making changes to the rocket
          manufacturing process,

      (3) redesigning the die used to form the rocket’s propellant,

      (4) establishing criteria to remove from inventory any propellant grain dropped during
          handling, and

                                                                      GAO/NSIAD-QQ-126R   Hydra 70 Rocket

(5) inspecting rockets already in inventory to screen out those that contain defective
    propellant grain.

The services began to implement these solutions in 1995, and, as of March 1999,
they have reported only one EMB. Service officials estimate that the services fire
about 270,000 Hydra 70 rockets each year. Hydra 70 program officials told us that
the probability of an early motor blow occurring now meets the standard of one
chance in a million.


The Hydra 70 rocket consists of a motor and various types of warheads. The motor
uses a propellant grain that is currently manufactured by Alliant Techsystems.
Ordnance Group at the Radford Army Ammunition Plant in Radford, Virginia. Under
normal circumstances, the Hydra 70 propellant grain burns for about 1 second after
ignition; an EMB occurs when the grain explodes less than .5 second after ignition.
In an early motor blow, the rocket motor tube generally splits longitudinally, breaking
into a few large pieces or exploding into many fragments of unburned propellant. An
EMB is dangerous for the aircraft and crew because it occurs close to the aircraft.

Beginning in February 1991, Radford Army Ammunition Plant replaced its ,100
percent x-ray inspection plan of the Hydra 70 rocket propellant grain with a sampling
inspection plan. According to plant officials, a sampling process was implemented to
meet an increased demand for rockets during Desert Storm.

The Army, Special Operations Forces, the Marine Corps, the Navy, and the Air
Force fire Hydra 70 rockets from various platforms. The Army Industrial Operations
Command in Rock Island, Illinois, assumed full responsibility for program
management of the Hydra 70 rocket in September 1991. The Indian Head Division
of the Naval Surface Warfare Center is the design agent for the Hydra 70 rocket

Actions Taken to ldentifv and
Eliminate Causes of Earlv Motor Blows

At the urging of the Hydra 70 Program Management Office, the Indian Head Division
of the Naval Surface Warfare Center chartered an independent investigation team
that determined the probable causes of the 3 EMBs that had damaged aircraft in the
1992-i 993 period. In October 1994, following 10 more EMBs, the Army suspended
use of the training rockets with grain produced by the Radford plant..

 In May 1994, the investigation team reported that the probable causes of the three
 EMBs studied were propellant grain fissures and propellant grain cracks. Fissures
 occur during manufacturing as a result of poor consolidation of the propellant as it is

 Page 2                                                       GAO/NSIAD-QQ-126R   Hydra 70 Rocket

extruded through a die to form the rocket grain. Cracks are caused when a rocket is
dropped (dropping can occur during the manufacturing process or when the rocket is
handled in the field). To prevent such failures, the team recommended that an
independent review of the propellant grain manufacturing process be conducted to
determine the causes of fissures, cracks, and poor consolidation of the grain. The
team also recommended 100 percent rotational x-ray of the grain. A blue-ribbon
panel authenticated the findings of the investigation team in March 1995.

A System Safety Risk Assessment report prepared in February 1995 by the Army
Industrial Operations Command identified actions to eliminate the EMB problem.
These actions which have been implemented included,

(l)*improving inspections through a refined processof ultrasound inspection of 100
     percent of the propellant grain and further x-ray evaluation of suspicious grain,

(2) Identifying the authorized procedure for making changes to the manufacturing
    process for the grain by analyzing and then classifying each process,

(3) redesigning the die used to form the propellant   grain, and

(4) establishing criteria to remove from inventory any grain dropped during handling.

In addition, the services’ inventories of Hydra 70 rockets and motors are being         :
inspected to screen out those that have defective grain. The Navy and the Marine
Corps are screening all their existing inventory at Indian Head; as of February 1999,
about 90,000 remained to be screened. As of February 1999, the Air Force had
approximately 136,600 uninspected rockets, but the Army was in the process of
arranging for their inspection through an extension of its current inspection contract.

Officials at the Hydra 70 Program Management Office estimated that, as of March
1999, about 550,000 rockets for all users had been x-rayed. The Army estimates
that about 170,000 Hydra 70 rockets to be used by the Army remained to be
screened. They anticipate screening about 70,000 of these rockets before
completing the current screening contract. Of the nearly 100,000 Army rockets not
currently scheduled for screening, about 59,000 will be inaccessible before the
current contract ends in about November 1999. Of these inaccessible rockets, about
24,000 are prepositioned on ships and another approximately 35,000 are positioned
overseas. Also, about 40,000 training rounds are being stored in the United States.
Officials at the Hydra 70 Program Management Office said they expect that the
extension of the inspection contract to accommodate inspection of the Air Force’s
inventory will also allow for inspection of the Army’s 40,000 training rounds and for
some of the Army’s rockets prepositioned afloat. The current cost to x-ray inspect
the rockets is about $22 per rocket.

Page 3                                                        GAO/NSIAD-99-126R   Hydra 70 Rocket

According to Army officials the Army’s inventory contains enough screened rockets
to meet 100 percent of its war reserve requirement because that requirement is
currently about half of what it was in 1994. Army personnel claimed the unscreened
rockets pose little risk given that the probability of an EMB in one of these rockets is
about one in 57,000-which       represents the actual. rate of EMBs that occurred during
the fiscal year 1992-95 period. In addition, Army aviators with whom we spoke
expressed confidence in the Hydra 70 rocket and said they would not hesitate to fire
those rockets during combat.

Hvdra 70 Rocket Performance since
Actions to Eliminate Causes of
Earlv Motor Blows
Between January 1995 and March 1999, the Army reported one EMB. An
investigation of this incident determined that a pallet of Hydra 70 rockets had been
dropped and that the rocket involved in the EMB could have come from that pallet.
The Special Operations Forces, Air Force, Navy, and Marine Corps reported no
EMBs during this same period.

Officials of the Hydra 70 Program Management Office estimate that the
Army/Special Operations Forces fire approximately 216,000 Hydra 70 training
rockets per year, the Air Force estimates that it fires between 30,000 and 35,000
annually, and the Navy and Marine Corps estimate they fire a total of about22,OOO
annually. Hydra 70 program officials stated that the probability of an EMB for the
screened and newly manufactured rockets now falls within the standard of one in a
million, which is where it fell prior to the series of EMBs that occurred in the fiscal
year 1992 to 1995 period.

Aqencv Comments

In oral comments on a draft of this report DOD fully concurred with its contents.
DOD also provided technical comments, which we incorporated as appropriate.

Scope and Methodoloqv

To obtain information on the causes of the EMBs, the actions taken to address those
causes, and the recent EMB record of the Hydra 70 rocket, we conducted work at
the Hydra 70 Program Management Office at Rock Island, Illinois; the Radford Army
Ammunition Plant at Radford, Virginia; and the Army Safety Center and the Combat
Development Center at Ft. Rucker, Alabama. We also obtained.data regarding the
 Hydra 70 from the following entities: Air Force Air Logistics Center, Hill Air Force
 Base, Utah; Office of the Deputy Chief of Naval Operations (Resources, Warfare
 Requirements and Assessments) Air Warfare Division; and Headquarters Marine
 Corps Office of the Deputy Chief of Staff for Aviation, Aviation Weapons Systems

 Page 4                                                        GAO/NSIAD-99-126R   Hydra 70 Rocket

Requirements Branch. Further, if officials with whom we spoke during conduct of the
review were aviators we solicited their opinion regarding the Hydra 70 rocket. This
work was conducted during the period December 1998 to March 1999 and in
accordance with generally accepted government auditing standards.

We are sending copies of this report to Representative Ike Skelton, Ranking Minority
Member, House Committee on Armed Services; the Honorable William Cohen,
Secretary of Defense; the Honorable Louis Caldera, Secretary of the Army; the
Honorable Richard Danzig, Secretary of the Navy; the Commandant of the Marine
Corps, General Charles C. Krulak; and the Honorable F. W. Peters, Acting Secretary
of the Air Force. Copies will also be made available to others upon request. <Y..

Major contributors to this report are Carol R. Schuster; Reginald L. Fur-r, Jr.; and
Janet M. Keller. If you have any questions on this report, please call me at (202)
512-5140 or my Assistant Director, Reginald L. Furr, Jr., at (202) 512-5426. We
appreciate the opportunity to provide you assistance.

Sincerely yours,

Mark E. Gebicke
Director, Military Operations   and
Capabilities Issues


Page 5                                                       GAO/NSIAD-99-126R   Hydra 70 Rocket

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