CFM International expects to close a delivery gap for the Leap-1 engine family by the second quarter of next year as the manufacturer works to address a spreading technical problem within the engine.
Speaking to FlightGlobal on the eve of the Dubai air show, executive vice-president Allen Paxson acknowledged that CFM remained behind schedule on deliveries, which is slowing planned production ramp-ups for the Boeing 737 Max and Airbus A320neo families.
But the engine maker has started to recover lost ground in recent weeks, he says. CFM reached a delivery pace of 20 engines per week during October – a rate of output not planned to be achieved until the second quarter next year.
The accelerated deliveries are needed, however, for CFM to catch up with the planned rate of deliveries after falling behind earlier this year, as the 737 Max 8 entered service in May about nine months after the debut of the Leap-powered A320neo.
Supply-chain shortages caused the Leap-1 delivery shortfall, Paxson says. But he emphasises that the shortages stem from routine parts, rather than the more exotic materials – such as ceramic matrix composites (CMC) and 3D-woven carbonfibre – introduced by the Leap engine family.
As the CFM joint venture races to catch up on Leap deliveries, it is also tackling a new problem with the coatings in the (CMC) shrouds of the Leap-1A high pressure turbine. So far, CFM has removed 12 engines from the operational fleet that exhibit signs of CMC coatings that are peeling prematurely.
The problem does not pose a safety concern, but it does increase the exhaust gas temperatures in the high-pressure turbine module by more than 10%, Paxson says. Such temperatures fall within CFM's temperature margin, but could cause the CMC materials to wear out faster over a period of several years.
CFM plans to introduce an improved coating for the shrouds into the production system starting in January, Paxson says. Five of the 12 engines already removed have been returned to service with a new application of the existing coating chemistry. CFM has reduced the timeline to complete the coating retrofit to five weeks, but is continuing to work on accelerating that pace.