Pete Aldridge, undersecretary of defense for acquisitions, said while he still has "some serious doubts about the safety, reliability and operational suitability" of the V-22, flight tests on the helicopter-like aircraft are scheduled to resume in April 2002, in hopes of fixing the problems.
Four of the 20 Ospreys built so far have crashed.
The Osprey is designed to take off and land like a helicopter, but to cruise like an airplane. Each V-22 costs about $89.7 million.
The fleet was grounded indefinitely after four Marines were killed in December when their Osprey crashed and burned in the woods near Jacksonville, N.C., on the way back from a training flight. A crash in Arizona in April 2000 killed all 19 Marines aboard.
In September, two Marine officers received letters of reprimand amid allegations that they ordered Osprey maintenance records to be doctored to exaggerate the troubled aircraft's readiness.
Aldridge said the tests would be comprehensive and focus on combat maneuverability and low speed hover conditions.
The test flights will be "event driven, as opposed to schedule driven," Aldridge said. "We will not be driven by trying to accomplish something within a certain amount of time."
Aldridge said while he personally had some doubts about the program, he could not find "any fundamental reason why the airplane would not work" after looking at reviews independent panels had conducted on the Osprey.
"There are lots of questions we don't have answers to yet," he said.
Aldridge added that the future tests would not use any troops.
The Marines last month estimated that the Osprey V-22 could be put into service in a year or two if flight testing resumed in the spring.
Congress recently passed an authorization bill with $1.044 billion for 11 Osprey aircraft.
By EUN-KYUNG KIM
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