Polluted Hydraulic Fluid Ruled Out as Cause of USAir Jet Crash

The rudder on USAir Flight 427 that crashed near Pittsburgh, Pa., apparently operated normally despite contaminated hydraulic fluid found in the rudder mechanism, federal air safety officials said Monday.

Rudder problems had originally been considered a possible cause of the Sept. 8 accident in which 132 died.

Dave Thomas, director of the Federal Aviation Administration office of accident investigation, said investigators are no longer concentrating on the contaminated fluid in the Boeing 737.

“It is a portion of the investigation we are putting aside,” said Thomas.

“The level of the contamination did not have an impact.”

But FAA officials stressed that the National Transportation Safety Board is conducting the probe and has not yet ruled out any possible cause.

Thomas said his office was assisting the independent National Transportation Safety Board in its investigation.

Speculation that the crash was caused by a rudder malfunction came up early in the investigation.

The jet rolled sharply to the left before nose-diving as it approached Pittsburgh International Airport.

Meanwhile, Federal Aviation Administrator David R. Hinson noted that the government is moving toward imposing tighter regulations on small, regional airlines.

Those airlines have come under some criticism for their safety records, a focus heightened after the crash last week of an American Eagle plane in Indiana.

Anthony J. Broderick, associate administrator for regulation and certification, explained that the first step will be to require regional airlines to meet the same crew training rules as larger operators, and similar flight and duty time rules will follow.