|C-17 taxis out for first flight on synthetic fuel blend.|
A C-17 Globemaster III took off 22 October on a flight using a 50:50 blend of Fischer-Tropsch synthetic and JP-8 fuels in all four fuel tanks.
The fuel used was essentially the same fuel blend used in the earlier B-52H tests (earlier post) except for the manufacturer. The C-17 used a Shell blend, while the B-52 used a blend from Syntroleum Corp.
This is the first time a C-17 has flown using a Fischer-Tropsch/JP-8 blend as the only fuel on board. Air Force members successfully flew a C-17 19 October with the Fischer-Tropsch/JP-8 blend in one tank to validate engine performance.
The C-17 is the workhorse of the mobility airlift fleet and the biggest user of jet fuel. C-17 certification is the next big step by the Air Force, after the initial certification of B-52s, to certify synthetic fuel blends for its fleet. The four-hour flight was designed to assess how well the aircraft performed using the synthetic blend of fuel. The mission consisted of ground operation of the auxiliary power unit and evaluation of in-flight performance of the engines and fuel quantity measurement system throughout the C-17 operational envelope.
The only real difference between the B-52 tests and the C-17 is that we have more confidence now. We know it worked on the B-52. From the cockpit, the C-17 seemed to fly the same as it would with JP-8 fuel. Now we have to go back and look at the test data to confirm that.—1st Lt. Randy Anderson, 418th FLTS, propulsion engineer
The final steps for C-17 certification include a service evaluation out of McChord Air Force Base, Wash., completion of material compatibility tests and final supplier qualification of the engine, auxiliary power unit and fuel quantity measurement system with the Fischer-Tropsch/JP-8 blend.
Fleet-wide certification is planned for the first quarter of 2008, making the C-17 the second AF platform to be certified to use this synthetic fuel blend. The B-52 Stratofortress was the first, completing certification 8 August.
In accordance with the Secretary of the Air Force’s Assured Fuels Initiative, all USAF aircraft will be certified by 2011. An office has been created at the Aeronautical Systems Center, Wright-Patterson Air Force Base, Ohio, to manage this unparalleled effort.
The C-17 Globemaster III exclusively uses Pratt & Whitney’s F117-PW-100 engine—the military version of the PW2000 commercial engine. The PW2000 engine was designed for the Boeing 757, and covers the thrust range from 37,000 pounds to 43,000 pounds.
(A hat-tip to pda!)