Story updated with clarification on number of shop visits versions of the CFM56-7B will see during an increased peak of maintenance.
Southwest Airlines expects to see a significant increase in shop visits for its CFM International CFM56-7B engines starting in 2014, says Amanda Gower, the airline's manager, power plant supply chain.
“On the -7 fleet starting next year, we will go into a bow wave that will last until 2017,” says Gower in an interview with Flightglobal. “So, our volume for shop visits is going to increase drastically.”
Shop visits for low-thrust engines powering Southwest’s 737-700 fleet are expected to increase 20% year-over-year from 2014 to 2017, she says.
The low-cost carrier uses the CFM56-7B engines to power both its 737-700 and 737-800 models, but the thrust rating for the engines on each aircraft type differs.
Lower-thrust engines powering Southwest’s 428 737-700s are rated at 24,000lb-thrust and will generally be seeing their second major shop visit during this wave of overhauls, says Gower.
High thrust versions of the CFM56-7B that power Southwest’s 50 Boeing 737-800 aircraft are rated at 27,000lb-thrust and will not see major shop visits during the increased maintenance period because of their young age.
The Dallas-based low-cost-carrier has a long-term maintenance and services agreement with GE Aviation for the repair and overhaul of its CFM56-7B engines. The low thrust and high thrust engines are covered under two different agreements that last through 2021 and 2031, respectively, says the airline.
Southwest Airlines’ maintenance spend decreased by $29 million, or about 9.7% in the third quarter from the same three months of 2012, regulatory filings show. About 45% of the decrease came from lower expenses tied to maintaining the 737-300, 737-500 and 717-200 engine fleet as the aircraft types leave the airline’s operations. The balance of the cost savings came from retrofitting a fewer number of aircraft with the new Evolve interior compared to 2012.
The fourth quarter is also expected to bring significantly lower year-over-year maintenance costs due to lower engine shop visits as the 717-200s leave the fleet. Southwest is subleasing 88 of the aircraft to Delta Air Lines as the latter carrier removes its 50-seat regional aircraft. Twelve of these aircraft were removed from Southwest’s fleet in the third quarter, according to regulatory filings.