A federal audit agency said Wednesday that a Pentagon study used to justify shuttering the C-17 aircraft line in Long Beach was flawed and cautioned Congress about relying on the report to decide the cargo jet's fate.
In a scathing analysis that could breathe new life into the program, the General Accountability Office said the results of the study were based on questionable assumptions and data that could not be verified.
In its review of airlift requirements, the Defense Department concluded that a 180-plane C-17 fleet would give it adequate capabilities. The analysis has been used to justify not seeking additional C-17s beyond those already delivered or on order.
But the GAO, in assessing how the Pentagon's airlift needs were analyzed, said the study drew certain conclusions even though it lacked adequate data and in some instances came up with hypothetical scenarios when it could have analyzed the Pentagon's own "approved concepts of operation."
The GAO said some of the study results also were "incomplete, unclear, or contingent on further study," making them difficult to evaluate. The Pentagon has refused to publicly disclose the details of the study.
The study's methodology "raises questions about the adequacy and completeness of the study," the GAO concluded.
Boeing Co., maker of the $200-million aircraft, began taking the first steps toward closing the Long Beach plant last month after the Air Force said it would order no more planes, citing the Pentagon study.
Boeing has built 154 C-17s so far, but without additional orders, the Long Beach plant is scheduled to be shut down in 2009. About 5,500 people work at the plant, the last manufacturing line in Southern California for large aircraft. Before the Pentagon study, the Air Force had said it needed to buy 220 C-17s to meet its requirements.
"The Department of Defense has hung its decision to terminate the C-17 almost entirely on the flawed [study]," said Loren Thompson, defense policy analyst with the Lexington Institute. "At the very least the GAO report provides ammunition to critics of the C-17 decision."
"Basically, every C-17 that's available is in use every day, delivering supplies to troops in Afghanistan, providing humanitarian relief to refugees, evacuating wounded soldiers from Iraq," Thompson said.
The Pentagon's decision to halt purchases at 180 planes has ignited criticism in Congress, which is considering adding budget funds to buy more C-17s.
A Pentagon spokeswoman said she could not comment, pending the department's review of the GAO report.
David Bowman, Boeing's C-17 program manager, said Congress might request a more comprehensive study to look more precisely at military airlift needs. But he added, "We just hope that the C-17 line is still open when the new study is done."