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WB-57 Grounded This Year

by Robert Henson
UCAR Communications

The NCAR Research Aviation Facility's two-year effort to prepare the NSF/NCAR WB-57F aircraft for high-altitude research has been put on hold following a series of recent setbacks. NCAR has no plans for scientific use of the WB-57 during fiscal year 1997.

Since its arrival at NCAR in 1994, the aircraft has suffered from structural cracking, difficulties with avionics and engine gauges, uncertain supplies of spare parts, and problems with flight controls and brakes. Research Aviation Facility manager Paul Herzegh explains that "the recent history of problems we've faced alerted Jim Ragni [NCAR pilot], Dave Carlson [director of NCAR's Atmospheric Technology Division, which operates RAF], and me that we were trying to move too quickly to make the aircraft operational. Despite extraordinary scientific demand for the aircraft, we need to step back and reassess our status and plans."

In August, Carlson and Herzegh grounded the former Air Force reconnaissance aircraft indefinitely after an in-flight failure of the trim adjustment for the horizontal stabilizer (the small horizontal wing on the tail of an aircraft). Ragni and scientist Cindy Twohy were flying at around 16 kilometers when Ragni found that the trim adjustment was not working. Without it, he had to rely wholly on his own strength, exerting as much as 50 to 70 pounds (23-30 kg) of pressure to operate the elevators on the aircraft to bring the nose down. When the aircraft reached warmer temperatures at 5 to 6 km, Ragni could again adjust the stabilizer and was able to land the aircraft without incident at Denver International Airport, where the WB-57 is now being housed. During their descent, Ragni and Twohy coped with an unrelated surprise: sudden loss of radio and intercom communications from the pilot's position in the aircraft. The team communicated with each other by passing notes while Twohy handled radio communication with air traffic control.

"Although we've solved each of the specific problems faced to date," says Carlson, "we need to better anticipate those problems that future operations will bring, and we need to understand how we'll cope with them." He has launched a six-month evaluation that will exhaustively reexamine the feasibility and cost of operating the aircraft.

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Last revised: Tue Apr 4 10:18:15 MDT 2000