The first wind tunnel has gone back online and more are expected to follow
after a “stand-down” to review research test procedures of six facilities at
NASA Langley Research Center in Hampton, Va.

The 14- x 22-Foot Subsonic Tunnel hummed back to life on May 1, just eight
days after the stand-down went into effect. The April 23 action was taken
after an investigation of a Feb. 5 accident at the 16-Foot Transonic Tunnel
suggested there may be procedural problems at some of the center’s major
facilities that could affect safety and test results.

“This is good news all around,” said Delma Freeman, deputy director of NASA
Langley. “We have learned from this first review, and expect to learn much
more by the time all of the reviews are complete.”

The 14- x 22 was reopened after tunnel operators satisfied a list of
requirements for improving test procedures. “Those procedural changes are
significant, but obviously were not show-stoppers or anything of a huge
magnitude or the tunnel wouldn’t be back on line so quickly,” Freeman said.

Operation of each wind tunnel is resuming only after an in-depth review
establishes that operating procedures are sufficient to assure safe
operation and the integrity of test results.

About 85 civil servants and 20 contractors work in the six tunnels, and many
of them have been assisting in the review.

The facilities taken offline were the 16-Foot Transonic Tunnel, the National
Transonic Facility, the 14- x 22-Foot Subsonic Tunnel, the 8-Foot High
Temperature Tunnel, the Unitary Plan Wind Tunnel and the Low-Turbulence
Pressure Tunnel. They are among 25 active tunnels at NASA Langley.

Of the six facilities, the Low-Turbulence Pressure Tunnel already was
offline as part of its normal schedule. The 8-Foot High Temperature Tunnel
was not running because of improvements being made to the facility. And the
16-Foot tunnel was offline for repairs from the February accident.

The 16-Foot was damaged when a test model became separated from its support
and blew down the tunnel at Mach 0.8, or approximately 550 mph. Damaged were
fan blades and components of the facility, including a structure called a
turning vane that stabilizes and smoothes the air-flow at corners of the

The accident caused an estimated $1 million in damage, which is being

The accident also destroyed the test model, an aluminum engine inlet, or jet
engine intake, taken from a salvaged aircraft. The model had undergone a
total of about 50 hours of wind tunnel testing prior to the incident and was
nearing the end of the test program.

The last major wind tunnel accident at NASA Langley occurred in 1988, when a
chunk of metal broke from a piece of machinery and destroyed fan blades in
the 16-Foot Transonic Tunnel. After that, a “catcher screen” was installed
and foam tips were put on the fan blades to minimize damage. Both
improvements limited damage to the 16-Foot in the February accident.