How Long Can a Jet Engine Last — And Why Is It So Expensive to Keep One Flying?


A car with 200,000 kilometers on the odometer is considered old.

A 20-year-old Mercedes-AMG or BMW M can still run beautifully at that mileage. Maintain it well, replace worn parts and repair what breaks, and the car may keep going for years.

A commercial jet engine takes that idea much further.

It can remain in service for decades.

But aviation does not mainly ask how many kilometers an engine has traveled.

It asks different questions.

A jet engine has more than one clock

Two numbers matter enormously:

Flight hours — how long the engine has operated.

Flight cycles — how many flights it has experienced.

Consider two aircraft.

One takes off and flies for 10 hours.

Another makes five two-hour flights.

Both engines accumulate roughly 10 flight hours.

But one has completed one cycle, while the other has completed five.

That matters because an engine does not experience the same conditions throughout a flight.

Takeoff, climb, cruise, descent and landing create different temperatures, pressures and mechanical loads.

FAA guidance on critical engine parts therefore considers actual flight profiles when determining safe life.

So two engines with the same number of hours may not have lived the same life.

One engine flew 50,000 hours without a shop visit

There is a remarkable real-world example.

In 2012, CFM International announced that a CFM56-7B powering a TUIfly Boeing 737-800 had passed:

50,000 flight hours

without a single shop visit.

The engine had entered service in 1999.

Even more interesting, it was not removed because it had stopped performing properly.

CFM said it was still performing well when it was taken off the aircraft for replacement of life-limited parts.

That distinction matters.

The engine was not simply used until it broke.

Specific components inside it had their own approved lives.

And 50,000 hours was an exceptional record, not a normal expectation for every engine. CFM has separately reported roughly 30,000 hours as the average time on wing before a first shop visit for then-current-production CFM56 engines.

What does 50,000 hours actually mean?

Here's one simple way to understand the scale.

50,000 ÷ 24 ÷ 365 = about 5.7 years

That's equivalent to running continuously, 24 hours a day, for almost six years.

We can make another deliberately rough comparison.

At an illustrative 800 km/h:

50,000 hours × 800 km/h = 40 million km

A car with 200,000 km would have to cover that distance 200 times.

This is not an official aircraft-engine mileage figure. Aircraft do not travel at 800 km/h during every operating hour, and aviation does not measure engine life this way.

It is simply an OVIQQ calculation to make the scale easier to picture.

Why doesn't the airline just replace the whole engine?

Because an engine is not one part.

Inside are disks, shafts, hubs, casings and thousands of other components.

Some can be inspected.

Some can be repaired.

Some can be replaced.

And some critical components have strict limits.

FAA rules require approved maximum lives for engine life-limited parts whose failure could cause a hazardous engine event. These typically include components such as disks, hubs, shafts and high-pressure casings.

When one of those parts reaches its approved limit, it must be withdrawn from service.

That doesn't necessarily mean throwing away the entire engine.

The engine can be opened.

Parts can be inspected.

Some can be repaired.

Others can be replaced.

The engine can then return to the aircraft.

This is why asking:

“How many kilometers does a jet engine last?”

is not quite the right question.

A better one is:

“How long can its individual components be safely managed?”

And that leads to an enormous industry.

Keeping an old engine alive is a business

The industry has a simple acronym for much of this work:

MRO

Maintenance, Repair and Overhaul.

An airline buys or leases an aircraft.

The engine flies.

Eventually it needs work.

It goes to an engine shop.

Technicians inspect it, repair it, replace parts and return it to service.

Then it flies again.

This cycle can continue for years.

For the airline, maintenance is a cost.

For engine manufacturers, parts suppliers, repair shops and lessors, it is a business.

And the numbers show just how important that business can become.

Rolls-Royce makes most of its Civil Aerospace revenue from services

Rolls-Royce is a useful example.

In 2025, its Civil Aerospace division generated £10.38 billion in underlying revenue.

The split was:

31% — Original equipment

69% — Services

In other words, more than two-thirds of that division's underlying revenue came from services rather than original equipment.

That doesn't mean every engine company has exactly the same business model.

But it demonstrates something important about aircraft engines:

Selling the machine can be only part of the economics.

Once thousands of engines are flying around the world, they create years of demand for maintenance, parts, repairs and service agreements.

The installed fleet becomes an economic asset of its own.

But right now, there is a problem

Airlines need all this maintenance.

The industry does not currently have enough capacity, parts and spare engines to make everything move smoothly.

IATA says 648 aircraft powered by Pratt & Whitney GTF engines were grounded at the peak in March 2025, waiting for engine shop visits, spare engines or parts.

That represented 28% of the GTF-powered fleet at the time.

And maintenance demand is expected to rise sharply.

IATA and Emerton forecast annual shop visits for CFM LEAP engines increasing from roughly:

600–800 in 2025

to

more than 5,000 in 2040.

For Pratt & Whitney GTF engines, the forecast rises from roughly 1,000 to more than 2,000 over the same period.

That creates a bottleneck.

An airline may have a perfectly usable aircraft sitting on the ground simply because its engine is somewhere else being repaired.

So what does the airline do?

Sometimes, it rents another engine.

One engine can cost more than $6,500 a day to rent

Reuters reported in August 2026 that lease rates for some aircraft engines had climbed above:

$6,500 per day.

Engine-related maintenance spending by U.S. airlines increased 68% between 2019 and 2025, according to the same report.

Now do the simple math.

At $6,500 per day:

30 days = $195,000

If that daily rate theoretically continued for 365 days:

365 days = $2,372,500

More than $2.37 million.

Again, that is not an average annual engine lease price.

Actual contracts vary by engine type, duration, utilization and market conditions.

It is simply an OVIQQ calculation showing what a $6,500 daily rate means when a maintenance delay lasts months rather than days.

And delays matter.

IATA estimates that aviation supply-chain problems cost airlines more than $11 billion in 2025, including about $2.6 billion in excess engine-leasing costs because engines were spending longer in maintenance.

Suddenly, an engine waiting in a repair shop is not just an engineering problem.

It is a financial problem.

Why would an airline pay that much?

Because the alternative can be worse.

An airliner is an expensive asset designed to make money by flying passengers or cargo.

Without a usable engine, it may sit on the ground.

No flight.

No passengers.

No ticket revenue from that aircraft.

So an expensive temporary engine can still make economic sense if it gets an aircraft back into service.

This creates another market around the original machine:

spare engines, engine leasing, spare parts and MRO capacity.

The engine itself may be decades old.

The businesses surrounding it can keep generating revenue throughout that life.

There is another side to this story

High maintenance prices and scarce capacity are good for some parts of the aviation supply chain.

They are not good for everyone.

Airlines are paying more.

Aircraft can remain grounded longer.

Parts are difficult to obtain.

And newer-generation engines have faced durability problems that have increased demand for shop visits.

There is also pressure for more competition.

IATA has argued for greater access to independent MRO providers, alternative approved parts and repair options. In January 2026, IATA renewed an agreement with CFM designed to support more competition in the CFM engine aftermarket.

That means today's shortage should not automatically be treated as permanent pricing power.

More capacity can be built.

Repair technology can improve.

Alternative suppliers can enter.

Engine durability can improve.

The economics can change.

The machine is only the beginning

A 20-year-old performance car can survive because someone keeps maintaining it.

A commercial jet engine takes that idea to another level.

Its age is measured in hours and cycles.

Critical components have individual lives.

Parts are inspected, repaired and replaced.

The engine returns to the sky.

And every step creates economic activity.

For airlines, that can mean enormous costs.

For engine manufacturers, parts suppliers, MRO providers and lessors, it creates something valuable:

recurring demand.

That may be the most interesting thing about a jet engine.

It isn't simply a machine that gets sold once and slowly wears out.

In aviation, selling the engine can be only the beginning of the business.

BEYOND THE OBVIOUS.

Sources