Ewards C-17A #87-0025 (T-1) taxis past the control tower
on Oct. 19. This marked the first flight of a C-17 using
a synthetic fuel blend in one of its engines.
Photo: Jim Shryne
10/25/2007 - EDWARDS AFB, CA -- The Global Reach Combined Test
Force began testing a C-17 Globemaster III using a Fischer-Tropsch
synthetic fuel blend here Oct. 18.
Flight tests began the following day and was the first time
a C-17 was flown using the F-T fuel blend.
Another test flight was conducted Monday as part of the Air
Force's plans to certify the C-17 with F-T blended fuel and
develop an overall process to certify all aircraft in the Air
Force inventory with F-T fuel.
"Our goal was to prove that the F-T fuel blend operates
the same as JP-8 fuel with no adverse effects," said Maj.
Scott Sullivan, 418th Flight Test Squadron, experimental C-17
test pilot. "We started out with ground testing, which
involved running the auxiliary power unit and the running engines
up to maximum take-off power. We then proceeded to flight tests
and performed throttle transients at varying altitudes and air
The natural gas blend of F-T fuel was mixed with JP-8, he said.
It was essentially the same fuel blend used in the B-52H tests
except for the manufacturer. The C-17 used a Shell blend, while
the B-52 used a blend from Syntroleum Corp.
"The only real difference between the B-52 tests and the
C-17 is that we have more confidence now," said 1st Lt.
Randy Anderson, 418th FLTS, propulsion engineer. "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."
During the first mission, the C-17 carried about 30,000 pounds
of F-T fuel blend in one tank, he said. The other tanks were
filled with standard JP-8. During the second mission, the C-17
carried a full load of F-T fuel blend, which weighed about 120,000
"In the first flight, we only operated one engine on F-T
fuel blend for safety reasons," said Lt. Col. Bob Poremski,
C-17 Integrated Test Team director. "This verified that
the fuel worked and gave us a direct comparison between engines
running JP-8 and F-T fuel."
Major Sullivan said one of the greatest challenges to the flight
testing was the test planning portion.
"It was very challenging because we had to cover the full
operational envelope of the C-17 in two flights and ensure we
would get the data needed to eventually lead to certification,"
he said. "However, the flight tests themselves went very
One of the benefits of certifying F-T fuel is operational utility
and flexibility to the warfighter, Major Sullivan said.
"Being able to land in other countries and have more fuel
sources available will greatly enhance the warfighter's use
of the C-17," he said. "It will also carry our fuel
reserves further into the future by being able to use alternate
energy sources now."
The C-17 has engines that are very similar to those used in
multiple commercial aircraft, which is another important reason
to certify the C-17 with the F-T fuel blend, Colonel Poremski
"Certifying F-T fuel blends on the C-17 creates the potential
that commercial carriers will look at alternative and synthetic
fuels to burn in their fleet," he said. "This will
ultimately reduce the amount of imported oil we burn in the
United States and open up venues for other synthetic fuels."
The Air Force plans to test and certify every airframe to fly
on a domestically-produced synthetic fuel blend by early 2011.
Source: USAF Edwards AFB Press Release by Senior Airman