A Marine Corps commanding officer ordered the falsification of important records on the controversial V-22 Osprey aircraft program, a Pentagon investigation found.
A small number of less senior officers knew of the falsifications and took no action to correct them, the report from the Pentagon inspector general's office said.
Moreover, the investigation found the commanding officer, Lt. Col. O. Fred Leberman, former commander of the Marines' only V-22 squadron, perceived pressure from his superiors to order the falsifications.
But investigators say they found no evidence Leberman's superiors directed or suggested he do so, after conducting hundreds of interviews and reviewing thousands of documents and more than 200,000 e-mails.
Leberman was relieved of duty and faces possible criminal charges.
The report's findings were described to ABCNEWS in an advance summary. The actual report and its detailed accounting of the evidence are expected to be provided to the Marine Corps in mid-July.
In unusually strong language in January, the senior Republican and Democratic leaders of the Senate Armed Services Committee, Sens. John Warner, R-Va., and Carl Levin, D-Mich., warned the Osprey program would be held back in Congress unless the Pentagon initiated the investigation independent of the Navy.
"[T]his program will not be able to move forward unless and until the Defense Department has restored confidence in the integrity of the V-22 program and the people managing it," they wrote Secretary of Defense Donald Rumsfeld.
Marine Corps Commandant Gen. James Jones ordered the inspector general assessment.
Important Mass Production Decision
Last December, Marine Corps investigators found evidence Leberman had ordered the falsification of maintenance and readiness records. The changes allegedly had the effect of making the aircraft appear to hold up better to everyday wear and tear.
A tip from one of Leberman's subordinates prompted the investigation. Evidence included a tape recording that suggested Leberman ordered the records falsified and told his juniors to lie about the plane until the Navy decided to begin mass-producing it.
A senior Navy official planned to make that decision in December, but a deadly Osprey crash that month delayed the issue.
Some members of Congress have charged the program is not ready for mass-production, and may not even be worth producing at all. Critics have cited several deadly accidents, increasing program costs, and a report by the Pentagon's top testing official which criticized the plane's maintenance and readiness record.
A total of four of the 12 Osprey purchased so far by the Marines have crashed, including the one in December, killing four Marines. The remaining eight have been grounded since that accident.
Senior Marine Corps officials have argued the V-22 is essential for replacing several types of troop transport helicopters currently in service, and offers important new capabilities. The Marines are hoping to buy 360 Ospreys by 2013, in the $40 billion program, with the Navy and Air Force also planning to purchase about 50 each.
Falsifications Not Responsible for Crashes
The inspector general's report found that the falsifications said to be ordered by Leberman were not a factor in the December crash or the April 2000 crash, which killed 19. The report said Leberman's orders occurred after those crashes, between Dec. 20, 2000 and Jan. 11.
Leberman's junior who provided the anonymous tip, a Marine mechanic, however, charged that "type of deception has been going on for over two years." But he said he believed the instance he documented in January was "the first time it will affect safety."
According to the advance summary, the inspector general's report concluded a number of Marine officers knew about the falsification and took no action to correct or report it. The summary does not identify those officers or their positions.
The inspector general's office said it arrived at its findings after conducting 700 interviews, examining 38 computer hard drives and examining 3,000 maintenance documents. It addition, it looked at 125 network data tapes, numerous computer files, and more than 219,000 e-mails and 84,000 attachments. — ABCNEWS' Barbara Starr contributed to this report.