Jim Cast
Headquarters, Washington, DC              January 7, 1997
(Phone:  202/358-1779)

Dom Amatore
Marshall Space Flight Center, Huntsville, AL
(Phone:  205/544-0031)

Release:  97-3

CLIPPER GRAHAM INCIDENT REPORT RELEASED

    An unconnected hose led to the destruction of the Clipper 
Graham technology demonstrator last summer.  The Clipper Graham 
(DC-XA) Incident Investigation Board has released its final 
report concerning the July 31 post-landing tip-over and fire 
which destroyed the 43-foot vertical takeoff and landing 
vehicle at White Sands Missile 
Range, NM.

    The Board, Chaired by former Astronaut Vance Brand, 
concluded "The primary cause of the vehicle mishap was that the 
brake line on the helium pneumatic system for landing gear #2 
was not connected.  This unconnected brake line prevented the 
brake mechanism from being pressurized to release the brake and 
resulted in landing gear #2 not extending.  The vehicle became 
unstable upon landing, toppled onto its side, exploded and 
burned."

    The July 31 flight demonstration was the fourth in last 
summer's series of tests with Clipper Graham by NASA and its 
industry partner, McDonnell Douglas.  The vehicle flew the 
planned flight profile successfully and uneventfully until 
landing.  With landing gear #2 failing to deploy -- there were 
four landing gears on Clipper Graham -- the vehicle tipped over 
and, according to the report, "The Clipper Graham DC-XA vehicle 
was totally destroyed by ground impact and ensuing explosions 
and fires."

    Contributing causes of the mishap were identified as 
follows:

    o  Design of the system for gear stowage required McDonnell 
Douglas technicians to break the integrity of the helium brake 
line after integrity had been already verified.  No other check 
was conducted to re-verify the integrity of the system after 
disconnection and reconnection of the line was completed;

    o  Landing gear stowage was never identified as a critical 
process.  No special steps were taken to ensure the readiness 
of this system for flight;

    o  During the gear stowage process, there was no record of 
checking off steps or evidence of cross-checking;

    o  Distraction or interruption of the mechanical technician 
during gear stowage operations may have contributed to the non-
connection of the brake line.

    Gary E. Payton, NASA's Director of Space Transportation, 
commended the Board's thorough review of the incident.  "Even 
though the Clipper Graham Program itself is now behind us, the 
technology demonstrations from last summer's four flights were 
outstanding.  ÔLessons learned' from the Board's report, and 
the observations and recommendations made will play an 
important role in the Agency's continuing Reusable Launch 
Vehicle activities.  In the X-33 and X-34 programs, for 
example, cost reduction and efficient reusability will continue 
to be our major objectives, along with safety and reliability 
that the proper mix of automation and human control can 
deliver."

    The five member Board consisted of Chairman Vance Brand, 
Dryden Flight Research Center, CA;  George Hopson, Marshall 
Space Flight Center, AL;  Charles E. Harris, Langley Research 
Center, VA;  Lt. Col. David Sharp, USAF Safety Center, NM;  and 
Warren Wiley, Kennedy Space Center, FL.

                        - end -

NOTE TO EDITORS:  The Report's two page Executive Summary plus 
a three page section dealing with Causes, Findings, 
Observations and Recommendations are available, electronically, 
via the Internet at URL:

ftp://ftp.hq.nasa.gov/pub/pao/statrpt/msfc/cgistatus/cg.txt

The full 160 page report, with appendices, is available for 
review in the NASA Headquarters and Marshall Space Flight 
Center newsrooms.