Continued funding for the F136 alternate engine for the F-35 Lightning II fighter jet could reduce the number of jets the Pentagon can buy unless the program receives more money, according to a March 22 report by the Congressional Research Service.
"If alternate engine funds are allocated within the existing F-35 budget lines, other F-35 activities must be curtailed in favor of the alternate engine program," says the report, titled "F-35 Alternative Engine Programs: Background and Issues for Congress."
The document is meant to inform Congress on issues that must be considered when deciding funding levels for the JSF alternate-engine program.
The report cites U.S. Marine Corps Maj. Gen. David Heinz, a former manager of the Joint Strike Fighter program, as saying that keeping the alternative engine program alive could force the Pentagon to cut 80 jets from the planned U.S. order of 2,443.
The report also warns against simply increasing the amount of money in the JSF program in order to buy the General Electric-Rolls Royce F136.
"Increasing the F-35 top line to account for the effects of increased alternate engine funding without" a similar increase in the Pentagon's total budget "would force the transfer for funds from other defense programs to the F-35," it says.
The Pentagon zeroed funding for the F136 in its 2011 budget request, but lawmakers continue to fight for the production of the second engine, arguing that the competition will improve contractor performance and provide a safety net against problems with the Pratt & Whitney F135 engine.
Pentagon officials have said numerous times that the second engine would be a distraction to a program already beset with delays and cost overruns. They say there is no financial justification for buying a second engine.
Correction: An earlier version of this story said funding the alternative engine "was likely to" reduce the number of jets purchased. The report said that it "could" do so.