Honeywell has unveiled a new derivative of the TFE731 turbofan engine to power the Bombardier light Learjet 70 and super-light Learjet 75.
The 3,850lb (17.1kN) TFE731-40BR adds 10% more power compared with the 15.6kN TFE-731-20BR installed on the Learjet 40/45 series, says Mike Bevans, director - technical sales at Honeywell.
Honeywell has already delivered the first two examples of the upgraded powerplant to Bombardier for testing. Engine certification is scheduled by the end of the year, supporting certification of the Learjet 75 in the first half of 2013, says Bevans.
The TFE731-40BR's extra power is obtained using an identical fan and compressor sections to those of the previous model.
Honeywell limited the changes to the hot section of the engine. A software change allows the digital electronic engine controller to burn the fuel at a higher temperature.
To compensate for the increased heat, Honeywell is also adding a ceramic coating to the non-rotating shroud around the high-pressure turbine stage. The third-stage low-pressure turbine has also been modified to survive higher temperatures in the exhaust flow.
Bevans adds that he expects customers to inquire about retrofit possibilities for the Learjet 40/45 turbofan. However, Honeywell has no plans to launch a retrofit programme at this time, he adds.
Source: Flight Daily News
