CRACKED SOLDER JOINT LED TO CRASH OF NASA CRAFT, REPORT SAYS.

Byline: Charles F. Bostwick Staff Writer

An unmanned NASA aircraft crashed on Interstate 40 near Barstow because of a cracked solder joint in a voltage regulator and a conduit that snagged the airplane's recovery parachute, an investigation concluded.

NASA officials recommended changing operating policies as well as modifying the parachute system that lands the unconventional craft, which is back in Virginia at the facilities of Aurora Flight Sciences, its manufacturer and operator.

``The aircraft is repaired. It's almost ready to fly again,'' NASA Dryden Flight Research Center spokesman Alan Brown said Friday.

The single-engine Perseus B, one of several high altitude aircraft being evaluated under NASA's Environmental Research and Sensor Technology program, crashed Oct. 1 onto the westbound lanes of Interstate 40 east of Barstow after escaping the control of a pilot on the ground at Edwards Air Force Base.

A tractor-trailer and a motor home had to swerve to miss the craft, but no vehicles on the ground was damaged. NASA officials described the damage to the plane as minor.

Microscopic inspection of a generator revealed a suspected crack solder joint in the voltage regulator circuit board, later confirmed by tests, NASA said. The cracked joint caused sporadic high voltage that burned out motors controlling five of the aircraft's six control surfaces, such as ailerons and rudder.

When it became clear the Aurora pilot could not regain full control, a NASA range safety officer activated the ``flight termination system,'' which shut off the engine and deployed a parachute.

The rocket that deploys the parachute fired, but the parachute didn't unfurl.

NASA said investigators quickly found out that the parachute had been hindered from deploying by a throttle-cable conduit. The conduit is flexible and had been routed in the path of the rocket, but was not discovered by pre-flight inspections.

The investigation committee recommended that NASA exercise greater oversight of flight tests operated by government contractors, like Aurora, and recommended that parachute ``flight termination systems'' be designed to make sure an airplane doesn't land outside government airspace.

Even if the parachute had deployed properly, Brown said, the plane was flying so high - 45,000 feet - that it could floated for miles away from Edwards before coming to Earth.

About the same length and weight as a Cessna 172 but with nearly twice the wingspan, Perseus was built to fly as high as 62,000 feet - nearly twice as high as a jetliner - and in production versions to stay aloft as long as 24 hours.