GUY NORRIS / LOS ANGELES
Pratt & Whitney cracks stator vane problems by stepping up inspections and supply of spare JT8D engines
Pratt & Whitney hopes to restore the majority of Japan Air System's (JAS) fleet of Boeing MD-80s to service by the end of the month after an intensive series of inspections and the provision of spare engines helped counter stator vane cracking problems that led to the grounding of all 25 aircraft.
"We have inspected the whole fleet and they now have 12 aircraft back in service. We have a 'line of sight' to getting around 17 in service by the end of the month," says P&W executive vice-president and large commercial engines president Bob Leduc.
Although the JT8D-217A/C-powered fleet of MD-81/87s was grounded on 19 January following the discovery of cracks and damage to the eighth-stage compressor vane in several engines, subsequent inspections of other large JT8D-200 powered MD-80 fleets in the USA and Europe revealed the JAS situation was "unique".
"This is not a safety of flight issue, it's a local fleet issue," says Leduc. "What I've got here is a customer whose standards of excellence is zero in-flight shutdowns [IFSD]."
The fleet-wide rate of shutdowns caused by the specific compressor fault experienced by JAS is 0.0002/1,000 flying hours across a global fleet of around 2,300 engines, says P&W. By comparison, IFSDs for all causes on the JT8D are 0.011.
"We have put an operators wire out to the rest of the world saying there is no need for intervention," says Leduc.
JAS, which is merging into Japan Airlines, grounded its MD-80s after a spate of high-profile incidents and accidents that began when an MD-81 suffered a landing gear collapse at Tokunoshima on 1 January. Five days later another MD-81 take-off at Fukuoka was aborted because of engine vibrations, and on the 7 January an MD-87 returned to Kagoshima following similar problems.
JAS says it is "carrying out an in-house investigation of possible causes for the engine problems", and is "investigating the possibility of leasing engines through P&W from other sources".
P&W says four engines have now been provided and others are being sought. The airline, which on 22 January operated 79 flights out of 138 MD-80-operated flights planned for the day, hopes to restore full service by the end of February.
Source: Flight International