General Electric Passport Engine Nears First Test
General Electric is preparing its new Passport engine for a first test run next month. Intended to power the Bombardier Global 7000 and 8000 jets, the Passport 20 is scheduled for certification in 2015. Assembly of the first engine began in March, and the low-pressure turbine was installed last week. The 52-inch fan section, one of five blisk (single-piece blade disk) stages, is fitted next, followed by the composite fan case. The engine forms an integrated propulsion system with a slimline nacelle designed in partnership with Nexcelle, itself a joint venture between GE and French engine manufacturer Snecma. The lightweight, low-drag nacelle has an outward-opening cowl for easy access.
Passport has been developed from General Electric’s eCore technology, which is also used in the CFM Leap engine for narrowbody airliners. Two eCore units have been running for more than 250 hours to assist with Passport certification, and a total of eight complete engines will be used in the test and validation process. After assembly is completed, the first test engine will be installed next month in the outdoor rig on Site 3B at GE’s Peebles, Ohio, facility. Next year a Passport engine will begin flight-testing using the company’s Boeing 747 testbed.
Developed for GE Aviation’s Business and General Aviation division, the Passport is a 16,500-pound thrust engine offering an 8-percent reduction in specific fuel consumption (sfc) and a margin over CAEP/6 emission and Stage 4 noise regulations. To achieve these figures it employs numerous advanced technology features, two of which were revealed at EBACE:
First was that GE has developed a durable engineered super-finish applied to the compressor blades and blisks resulting in a mirror-like surface that is four times as light-reflective as standard blades, leading to a smoother airflow and consequently greater engine efficiency.
The second new technology is the use of conformal, rail-mounted surface coolers that line the engine’s aft fan case. GE has developed a unique fin technology that can be formed into heat-exchanger shapes that can be molded to fit complex three-dimensional shapes. Such surface coolers were first applied to the Boeing 787’s GEnx-1B engine. At present this technology supports air-to-liquid applications, but liquid-to-liquid capability is being studied.