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Technology · In the factory and the shop

Engine durability engineering

Turbine blade coatings, cooling geometry, time on wing

active across every current engine family 2 min read · updated 15 October 2026 · checked 15 October 2026

Two independent sources on every claim.

Why it is here

Time on wing is the number that decides engine economics, and both CFM and Rolls-Royce are rebuilding it.

At a glance

What it is

Time on wing is how long an engine stays installed before it must come off for a shop visit. It is the single number that decides engine operating economics, because a shop visit is expensive, slow, and consumes a spare engine while it happens.

In plain terms

The high pressure turbine sits immediately behind the combustor, in the hottest gas in the engine. Its blades survive because cooling air is bled through tiny holes in the blade surface, forming a film of cooler air over the metal. Almost every durability problem in a modern engine is a variation on that film failing.

Why it matters on the line

The two current programmes are instructive because they failed differently and were fixed differently.

On the LEAP, fine sand ingested in the Middle East, India and parts of Africa clogged the film cooling holes. The redesigned stage 1 blade uses revised internal cooling geometry so particulates pass through rather than accumulating, with reinforced nozzle structures to stop thermal warping. CFM reports the new blades held structural integrity twice as long as the original.

On the Trent 1000, the failures were in the intermediate pressure turbine and compressor, and the fix was a staged durability enhancement package: reduced weight high pressure turbine blade shrouds and new advanced coatings, approved in June, followed by a second phase adding roughly another 30 percent. Together they should deliver up to triple the original time on wing.

On the line

Both fixes reach the installed fleet gradually, at scheduled refurbishment rather than through a mandated campaign, so your fleet will carry a mix of build standards for a year or more. Track time on wing by build standard rather than averaging across the fleet, or the improvement will be invisible in your own data. When an engine is inducted, confirm which standard it will come out with, because that changes the interval you plan the next removal against. The LEAP gain is also concentrated in hot and harsh operations, so do not apply one expected interval across a mixed network.

Where to read more

The two programmes are on the CFM LEAP and Trent 1000 pages. The Trent 7000 was where Rolls-Royce proved its upgrades first.

Sources