AerFin told media that high-pressure turbine blades have become the single biggest constraint on CFM56 overhauls. New OEM blades are not arriving as fast as shops need them. Used serviceable blades with 10,000 or more cycles left are scarce on the aftermarket. The OEM can still turn a repairable blade in about 45 days. The engine waits for a replacement set. A full CFM56 shop visit that used to take about 60 days before the pandemic now runs 90 to 120 days. Light work is closer to 45. While that engine sits, the aircraft either borrows a spare or stays on the ground. Hobbs says short-term spare-engine leases are rising for exactly that reason. He thinks supply may ease toward the end of 2026 or early 2027. That is a calendar, not a spare engine on a wing in Delhi.
The CFM56 is not a museum piece. More than 14,000 aircraft still fly on it, mostly 737NGs and A320ceos that remain the workhorses of Asia, Africa and the Middle East. Those markets kept the old narrowbodies because new LEAP and GTF metal is late, expensive or both. A blade shortage on a mature engine therefore hits the airlines that can least absorb a parked jet. One missing set of HPT blades stretches the shop slot. The shop slot stretches the spare-engine pool. The spare-engine pool stretches the lease rate. The lease rate hits the cost of a Hajj extra or a domestic morning bank. If the carrier cannot find a QEC engine, the route is cut. That cascade does not require a powder-metal disk crisis. It requires a part that lives in the hottest section of the core and cannot be improvised from a teardown with no remaining life. GE Aerospace’s Greenville plant is the sole maker of new CFM56 HPT blades and has put tens of millions into the line, including a 2.5-times lift in the latest performance-improvement blades. Repair shops in Singapore are laser-welding older blades to keep metal in the loop. Output is rising. Demand from engines that should already have retired is rising faster.
Maintenance cost follows the wait. A longer visit means more lease days, more green-time shuffling and more pressure to accept a heavier workscope once the engine is finally open, because the slot itself has become the scarce good. Lessors price that into CFM56 values and into the fee for a three-month cover engine. Airlines that once pooled two spares across a 30-aircraft subfleet discover the pool is empty when three cores go in together. The industry conversation this year has been about new-generation shop congestion. The quieter story is that the engine family still flying most of the world’s short-haul seats is being rationed by a turbine blade. Until Greenville and the used-material market catch the induction wave, a 737NG in Lagos or an A320ceo in Jakarta can be grounded by a component measured in centimetres. The timetable does not care that the LEAP line is busy. It cares that the old engine cannot leave the shop.