The block one improvement will offer between a 7% and 10% improvement in thrust, as well as between 5% and 7% better mission fuel burn, and could be available around 2018. “So far, no one has decided they need the capability but we are making sure we are providing the options,” says Pratt & Whitney Military Engines President Bennett Croswell.

Although higher thrust and better fuel burn have obvious payload, range and mission advantages, Pratt expects the main benefit to come from trading the performance for lower operating temperatures and longer time on wing. “We are planning a life-extension for the F135, like we did on the [F100] -229 with an engine enhancement package where you had a 50% improvement in life.

"WASHINGTON — The US Air Force is deliberating if and how to replace its close-air support workhorse, the A-10, and may have a better picture of their path forward later this year, the service’s top civilian said Wednesday.

During an interview with Defense News, Air Force Secretary Deborah Lee James said she and other top service leaders — such as Chief of Staff Gen. David Goldfein — will be briefed on various options for replacing or augmenting the A-10 Warthog this fall, as the service begins to build its next five-year budget plan.

“Any of these types of possibilities would likely come up in the fall to me and the chief during this planning choices forum. And that's when we would discuss and we could make some recommendations,” which could then flow into the budget cycle, she said....