EBACE Convention News

GE Runs Passport Engine on 100 Percent SAF

 - May 24, 2022, 1:00 AM
GE Aviation's Passport engine has achieved more than 80,000 flight hours and 30,000 cycles with better than a 99 percent dispatch reliability rate on the Global 7500 fleet. (Photo: GE Aviation)

GE Aviation recently completed successful first testing of its Passport long-range business aviation engine using 100 percent sustainable aviation fuel (SAF). Ground testing was conducted with one engine over the course of two weeks in March at GE Aviation’s Peebles Test Operations in southern Ohio. 

The type of SAF used in the testing, HEFA-SPK (hydroprocessed esters and fatty acids synthetic paraffinic kerosene), is the most widely available SAF today and can be made from cooking oil and other waste fats, oils, and greases. Preliminary test results showed the engine performed similarly to running on petroleum-based jet-A. Currently, the SAF approved for use is a blend of petroleum-based jet A or jet A-1 fuel and an SAF component with a maximum blend limit of 50 percent.  ASTM International, an organization that develops technical standards, has not yet qualified 100 percent SAF. GE Aviation (Booth S93) is working with an international task force to standardize industry specifications supporting the adoption of 100 percent drop-in SAF. 

“As our testing shows, the Passport engine, like all GE engines, can operate on approved sustainable aviation fuel today and in the future. Our customers can be confident that the Passport-powered [Bombardier] Global 7500 can help meet their sustainability goals to reduce CO2 emissions in flight, thanks to the Passport’s more fuel-efficient technologies compared to previous-generation business jets and ability to operate on lower-carbon fuels,” said Melvyn Heard, GE general manager, Passport engine program. Heard said the Passport’s performance on 100 percent SAF was “no surprise for us” and was done more to demonstrate that capability to customers. “We don’t see any limitations on the engine,” burning 100 percent SAF, he said. 

GE Aviation has been actively involved in assessing and qualifying SAF since 2007.  SAF can be made from a variety of substances, but, compared to fossil fuels, using alternative feedstocks and processes for SAF reduces lifecycle CO2 emissions during production, processing, and distribution. 

This is the latest in a series of 100 percent SAF tests by GE and CFM International, a 50-50 joint company between GE and Safran Aircraft Engines. Other tests with 100 percent SAF in 2021 included flying 100 percent SAF in one of two Leap-1B engines on a Boeing 737 Max 8 operated by United Airlines; ground tests and flying an Airbus A319neo with 100 percent SAF in one Leap-1A engine; and flying the Boeing ecoDemonstrator with 100 percent SAF. A FedEx Boeing 777F with GE90 engines flew with 100 percent SAF in 2018 as part of Boeing’s ecoDemonstrator program. 

GE’s Passport engine, which entered service in 2018, has 3 percent lower fuel consumption, compared with other engines operating in the 18,000-pound thrust class and 17 percent lower fuel consumption compared with the GE CF34-3 engine. It features blisk fan blades, high-efficiency compressor, rich-burn combustor, proprietary turbine system, and high efficiency mixer. 

Heard said the engine has 2-3 percent better specific fuel consumption than comparable new engines that will come to market in the next few years and that it has room for growth in terms of future increases in performance. “The engine is ready to grow,” he said. “We still do have capability that we have not completely unleashed in the engine yet.”

To date, the installed engine fleet on Bombardier Global 7500s has achieved more than 80,000 flight hours and 30,000 cycles with better than a 99 percent dispatch reliability rate. That number is expected to grow to 100,000 flight hours by year’s end with the lifting of more and more Covid restrictions.  “We’re finally seeing people utilize the legs of this [Global 7500] as it was designed to do,” Heard said, noting that one operator flew non-stop from Sydney to Detroit in 2019, a distance of 8,255 nm, and that such trips are again becoming more commonplace. 

Dispatch reliability is enhanced via the substantial enrollment of Global 7500 customers in GE’s OnPoint engine services program and the Passport’s Diagnostics Monitoring health and usage system that can transmit data in real-time to GE’s monitoring centers in Cincinnati, Ohio, and Shanghai and allows operators to download data once the aircraft returns to base. Heard notes that GE has a combined 30,000 engines under diagnostics and that it “gives us the breadth of creating those [maintenance monitoring] tools. 

The Passport was recently selected to test hydrogen combustion. In February 2022, CFM joined Airbus to announce a new hydrogen demonstration program with ground and flight tests to take place later this decade. CFM will modify the combustor, fuel system, and controls of the engine to run on hydrogen. Flight tests will be conducted aboard an Airbus A380 testbed equipped with an additional pylon for the Passport engine. 

Heard believes a combination of advanced engine design, such as in the Passport, and alternative fuels such as SAF and hydrogen will be needed to achieve GE’s and CFM’s overall goal of improving efficiency by 20 percent. 

“The [Passport] engine has been the core of all [our] new development programs” in cooperation with CFM including open fan, compact core, and hydrogen propulsion, Heard said.