The US Air Force has concluded analysis of the effects of using a natural gas-based synthetic fuel with its Lockheed Martin F-22, as work to trial the technology accelerates through its trainer, transport and fighter fleets.

No anomalies were detected in F-22 flight tests (below), or during ground tests of its F119 engines at Pratt & Whitney's West Palm Beach facility in Florida, says Jeff Braun of the synthetic fuel certification office at Wright-Patterson AFB, Ohio.

© US Air Force

Flight tests using the Northrop T-38 supersonic trainer have recently commenced, while a Lockheed C-5 transport (below) will conduct a demonstration flight on 9 December and ground tests of the Lockheed F-16's General Electric F110 engine will start in mid-January.

The C-5 demonstrations will be conducted from Memphis Air National Guard base in Tennessee. "We are currently planning one sortie with the aircraft operating a single engine on the 50/50 Fischer-Tropsch blend, followed by a second sortie with all engines utilising the 50/50 blend," says Braun.

© US Air Force

Planning for synthetic fuel trials with the Lockheed C-130 transport, Fairchild A-10 ground-attack aircraft and Northrop Grumman RQ-4 Global Hawk and General Atomics MQ-9 Reaper unmanned air vehicles are ongoing, and Braun adds: "We will hopefully fly all by summer 2009."

The USAF aims to certify its entire fleet for synthetic fuel use by 2011, and to meet half of its domestic fuel needs by 2016 from fuels converted from coal and natural gas through the Fischer-Tropsch process.

Less than 570,000 litres (150,000USgal) of fuel provided by Shell remains for testing. "We recently took possession of 60,000 gal of Sasol fuel [from South Africa], and will accept another 335,000 gal during fiscal year 2009," says Braun.

The office of the assistant secretary of the air force for installations, environment and logistics is expected to select a private partner during December to develop a Fischer-Tropsch production facility at Malmstrom AFB, Montana.

For more F-22 news and images, see Flight's aircraft profile

Source: Flight International