Boeing and CFM International were due to begin flight tests of the Tech Insertion CFM56-7B27/3 engine on a 737-800 testbed at Renton, Washington on 11 August, marking the start of what is expected to be a two-month certification programme, writes Guy Norris.
The engine, mounted on a new Alaska Airlines aircraft ,YK438, incorporates several new features taken from the Tech 56 technology development effort, including high-pressure (HP) compressor, combustor, HP turbine and low-pressure (LP) turbine nozzle changes. Together these have been designed to increase time on wing with up to a 20°C (68°F) additional exhaust gas temperature margin provide up to 1% improved specific fuel consumption, as well as more margin over CAEP 6 emissions levels and improve durability.
Before the start of both the Boeing programme, and a follow-on Airbus A320 flight-test campaign set to begin in early 2007, CFM completed tests on six different engines as part of the certification programme. These engines underwent icing tests, compressor and turbine blade stress tests, hail ingestion, emissions, over-temperature tests, a 150h block test, and a 65h flight-test programme on General Electric's 747 flying testbed. Before the start of flight tests on the 737-800, CFM says the Tech Insertion development and certification effort had logged around 970h of tests. Eight engines have been delivered to Airbus and Boeing to support the flight-test programmes.
The Tech Insertion will also be the -7 and -5B standard for all new aircraft from around mid-June 2007, although the first production aircraft due to be delivered with the new engines will be the 2,196th Next Generation 737 around March next year.
Source: Flight International
