Thursday, August 28, 2008

Pratt JT8D-219 Flight Test Program Gets Underway

The Pratt & Whitney 707RE FAA supplemental type certification flight test program for latest version of the popluar JT8D turbofan engine has finally gotten underway at the Mojave Air and Space Port. The JT8D-219 engine, a variant of the powerplant used on the MD-80 airliner, has been developed by Pratt in conjunction with Omega Air and Seven-Q-Seven as a re-engining candidate for Boeing 707s and the type's military derivatives. Seven-Q-Seven is a partnership between Dublin-based Omega Aviation and Ed Swearingen and Douglas Jaffe of San Antonio.

Civilian certification of the engine to the 707-series airframe is being accomplished by Mojave's Flight Test Associates (FTA) prior to military certification, which will be conducted by Northrop, according to a Northrop Grumman spokesman. The engine is initially being certificated at a derated thrust of 19,000 pounds, with follow-on certification at 21,000 pounds thrust expected. The FAA has required that the re-engined 707 - dubbed the 707RE - accrue 350 flight hours during this test program.

The testbed aircraft arrived in Mojave in November 2007, to first undergo an extensive inspection, known as a C-check, at FTA prior to initiation of the test program. The current program will eventually result in the issuance of an FAA Supplemental Type Certificate for civilian 707s. While the program was originally conceived by Omega as a cost effective method for updating the remaining civilian-operated 707s (with an original estimate of $16 million for the complete upgrade), it quickly found another application: providing modern, quiet and fuel efficient engines for the USAF E-8C JointSTARS aircraft. Other military 707 variants, such as the KC-135 fleet, have been re-engined with CFM-56 engines, but the 707RE conversion program is being marketed to the military in partnership with Northrop Grumman as a significantly cheaper alternative to the CFM-56-2, by some estimates as much as 50% less.

The initial phase of the flight test program began on August 9, 2001, operating from Seven-Q-Seven's San Antonio Texas operation. After the initial flight tests with a single -219 engine installed on the 707-300 testbed aircraft were completed, three more were installed and the predicted fuel savings were confirmed. In an unusual move, in 2001 Pratt sponsored a series of flights that were part of the flight test program but also took the 707RE on a world tour of airports and air bases to show off the program's advantages. While the -219 idea caught the eye of Northrop Grumman, who held the contract to upgrade the E-8 JointSTARS, a dirth of funding for the engine upgrades put the certification flight test program on hold.

The -219 will result in a 40dB reduction in noise over the existing TF33/JT3D engines, allowing the aircraft to meet current strict European noise standards. Additionally, flight tests have confirmed that the new engines will reduce fuel consumption by up to 22%. Besides direct savings in fuel costs, this feature translates into longer loiter times and improved operational utility for the aircraft. In 2001, Mike Lombard, then a Program Manager at Pratt, said, "We have now flown the JT8D-powered 707 on both the AWACS and JointSTARS mission profiles. We compared it not only to legacy engine data, but also our own performance models created for a JT8D-219 powered 707. The actual engines in flight have met or exceeded the projections of our models [and] provides a significant increase in power and range for the 707 while cutting fuel burn, noise, emissions, operating and maintenance costs. It fits neatly into any space where an existing TF33 resides, so there is virtually no aircraft modification required with re-engining. "

The engine modernization is being offered as an integrated "propulsion pod system" or PPS, in which the engines will be provided on a operational lease basis by Pratt, inlet and thrust reversers are being provided by Goodrich, and cowling is manufactured by Nordam.

For the JointSTARS, Northrop Grumman and the Air Force selected the -219 over competing engines as a "best-value source selection" after an open competition in 2002. It was hoped that the program could be initiated in 2003, but funding for the testing and upgrade program was not forthcoming. Finally, in the FY2006 budget, $12.5 million was allocated, starting the program rolling, and in June, 2008, it was announced that the USAF had awarded the team a $210 million contract to proceed with the E-8C project, with re-engining to begin in 2010.

In 2001, Europe's EADS partnered with Northrop Grumman, Pratt and Seven Q Seven to propose re-engining NATO's 17 E-3 AWACS and three Trainer Cargo Aircraft with the -219s. However, a Pratt spokesperson said that they currently have no plans to certify the engine for the AWACS aircraft.

1 comment:

Simon Gunson said...

I understand two testbed 707RE are parked up at Melbourne?

Does anybody know the fate of these aircraft and whether the product or STC is still on the market?