General Electric/Rolls-Royce claims the F136 alternate engine for the Lockheed Martin F-35 Joint Strike Fighter will be introduced with a major power advantage over its rival propulsion system.
The F136 engine core has been sized to enter service with a maximum rating of about 43,000lb thrust (190kN), and could be further upgraded over time to 45,000lb, says Mark Rhodes, senior vice-president for the F136 joint venture Fighter Engine Team.
By contrast, the Pratt & Whitney F135 has demonstrated about 41,000lb thrust in hover pit tests for the short-take-off and vertical-landing (STOVL) variant in April. That system will be upgraded by 5% next year, raising the F135 to 43,000lb thrust.
Rhodes says the F136 was designed in the aftermath of the weight growth problem that delayed the F-35 development schedule by two years, so the company was able to size the engine core and fan to provide a higher level of thrust from the beginning.
That built-in advantage should make the F136 more desirable over the next decade as operators add more capabilities - and weight - to operational F-35 fleets, he says.
"The experience has been you always need more thrust," Rhodes says.
Further, an R-R executive last week also noted that the F136 would be in line for a dramatic thrust upgrade around 2020, when either his company or GE would be prepared to introduced variable cycle engine technology.
Those arguments could figure largely into the ongoing debate about the future of the F136 funding account.
In response to the Pentagon's decision to remove funds for the F136 for the fourth year in a row, Congress has again moved to restore the programme's budget, says Jean Lydon-Rogers, president of the Fighter Engine Team.
Last week, a House armed services subcommittee added $603 million to the DoD's authorisation bill, which includes $463 million to continue development and $140 million to buy the first four production engines.
It was not immediately clear if the added funding would require the F-35 programme to buy fewer jets next year.
Meanwhile, the process of clearing the F136 for first flight in February 2011 on the conventional take-off and landing AF-1 prototype has recently begun, Lydon-Rogers says.
A second test engine is scheduled to begin testing in July, and a third engine should run by the end of the year, she adds. By next July, the first six F136s should be delivered to Lockheed.