He granted Kennedy's point that Pratt and Whitney had delivered engines several weeks late in 2011, but pointed to testimony by the Pentagon's point person on the Joint Strike Fighter, who told the House Armed Services Committee earlier this month that he projected remaining engine deliveries for 2011 would be on time.
Risseeuw also estimated that GE is six years behind Pratt Whitney, and has not yet put one of its engines in the air in a jet. "We first flew in December of 2006," said Risseeuw. "I expect the best they can do is 2012."
Both President Obama and Defense Secretary Gates are on record opposing the alternate GE engine, and the House voted in February to stop funding it. The Pentagon cited the House vote and the administration's opposition to the engine when it issued the stop work order.
"The Bush administration opposed this engine. The Obama administration opposes it. We have recommended for several years now against funding this engine, considering it a waste of money," Gates told reporters back in May 2010. "To argue that we should add another $3 billion in what we regard as waste ... frankly, I don't track the logic."
The competing engines are just one component of the F-35 Joint Strike Force program -- one of the most costly weapons programs in U.S. history. The original plan called for the development of 2,443 "fifth generation" planes of three different types: planes using conventional landings, planes capable of use by the U.S. Navy on aircraft carriers, and planes capable of vertical take-offs similar to that of the famed Harrier jet.
Each of the planes ordered from aeronautics manufacturer Lockheed Martin in 2002 was originally projected to cost just over $40 million. That figure has risen nearly 25 percent, according to Lockheed Martin, to closer to $49 million, accounting for inflation over the past nine years. With inflation added, as well as additional production, maintenance and spare parts costs, the total cost per plane tops out at $92 million.
The program has also been delayed several times and recently the contract with Lockheed Martin was extended from its original 2011 deadline to 2016.
"I think what you have to recognize is this is by far the most complex aircraft ever built," Lockheed spokesperson John Kent told ABC News. "We all acknowledge that we underestimated the complexity of developing the airplane. Hindsight is always very clear and I'm sure there are things we would've done differently.
"Yes, we're behind schedule. Yes, we're over budget on developing the airplane, but we exceeded flight test milestones last year. A lot of the problems that were dogging [the project] have been fixed," he said.
GE has pointed to the delays, and what it says are billions in cost over-runs with the Pratt & Whitney engine, as proof that an alternative is needed.
In addition to arguing that an alternate engine could eventually push costs down, analysts with the House Armed Services Committee have also pointed out that a back up could keep the aircraft program aloft even if the primary engine for the aircraft, which is being built by Pratt & Whitney, proves unreliable.