Honeywell engines power in-development Gulfstream, Embraers next
Honeywell (Stand 7044) has completed certification of its HTF7250G engine, which powers the in-development supermidsize Gulfstream G250, and is progressing with the development of the HTF7500E for the midlight/midsize Embraer Legacy 450/500. The U.S.-based manufacturer is also working on upgrades for the HTF7000, in service on the supermidsize Bombardier Challenger 300.
The 7,445-pound HTF7250G turbofan was FAA certified for the G250 on March 18. One year ago, the company hoped it would meet this milestone in late 2010. “The engine meets Gulfstream’s requirements for the G250,” Ron Rich, Honeywell’s vice president for propulsion, told AIN. The engine manufacturer is now supporting the G250 flight tests. Next will be the beginning of the production phase. “In fact, it has already started–Gulfstream’s test engines were built according to our production processes,” Rich said.
The Legacys’ HTF7500E is in the same engine family. It will be rated at 6,080 pounds (takeoff thrust) on the Legacy 450 and 6,540 pounds on the Legacy 500. The engine program is in the flight-test phase. Honeywell is using a modified Boeing 757 (see photo) as a flying testbed.
“We are seeing very good progress,” Rich said. In-flight restart and operability testing were performed recently and have not prompted any design change so far, he said. Therefore, certification is “on track for 2012.” Last fall, Honeywell was still targeting late 2011 for the engine certification, but Rich said the 2012 objective is “consistent with our commitment to Embraer.”
Honeywell has assembled and is testing the first two HTF7500E engines that eventually will be shipped to Embraer. Engineers are continuing to flight-test the 757, notably for mechanical and performance trials. “We are building on the HTF7000 and some certification items are about verifying those of the HTF7000,” Rich added.
The Saber (single annular combustor for emissions reduction) 1 low-emission combustor was certified last year. It is schedule for entry into service this year on the HTF7000 fleet, as the beginning of a three-phase sequence. “We are first installing it in our fleet leaders–namely, Challenger 300s operated by Flexjet,” Rich explained. Then, Saber 1 will become available to other customers for retrofit. Finally, it will become a production standard on the HTF7000.
“Saber 1 will be standard from day one on the HTF7250G and HTF7500E,” Rich said. It is based on a rich-quench-lean scheme, where the combustion commences with a rich setting and is quickly leaned out to mitigate the formation of nitrous oxides (NOx), he explained. The technology enables a 25-percent reduction in NOx emissions and does not compromise the durability of the combustion system, he said.
The next generation Saber 2 is in development, with Honeywell using its Tech7000 demonstrator engine. “We have initiated Saber 2 trials in ground test cells and will conduct in-flight testing on our 757 in the near future,” Rich said.
In addition to Saber 1 and 2 combustors, the HTF7000 will enjoy upgrades in other modules. The company has tested a better fan on the Tech7000 demonstrator, and the HTF7500E’s high-pressure compressor could be adapted to the HTF7000, thus improving overall performance. Finally, new materials and thermal barrier coatings in the high-pressure turbine will boost durability.