Engine hours

[vololiberista]

I have a question about engine hours. After how many hours would engines be changed "arbitarily". 100's, 1000's ??
vololiberista

[Laurieg]

Engines servicing is called up on either cycles, (stop/starts), or engine hours. It may be that the controlling item is a LP turbine disc with a specific life between overhaul, often referred to as TSO (Time Since Overhaul) or TTO (Time To Overhaul).

The engines also have a TTO in themselves, (often 5000 flying hours). They may get an overhaul whilst it is in for a disc change but if not, (and this was sometimes the case when money is tight and the engine will be repaired to fault), then the balance of the TTO then may become the controlling factor.

Engine hours are the same as aircraft flying hours so the change will be represented as due on a certain flying hour.

[Gsxr600]

That's very interesting. Could a jet such as the Conway theoretically be overhauled again and again giving it an infinite life, or it there an absolute maximum hours where it must be decommissioned - obviously barring a major mechanical failure would end its life abruptly.

[Laurieg]

In theory it could go on, subject to spares availability. The whole idea was to replace lifed items to allow continuous use but there is obviously a finite time you can continue this but there are engines out there that have gone through more than one or two overhaul cycles.

[vololiberista]

In theory it could go on, subject to spares availability. The whole idea was to replace lifed items to allow continuous use but there is obviously a finite time you can continue this but there are engines out there that have gone through more than one or two overhaul cycles.

Engines in general if well looked after can go on and on. I would say that a turbine (by its very nature) could have a very long life with regular and full maintenance.

And as you say they may even equate to the aircraft hours. Having to keep an engine type running for more than 50 years is quite a task!!
vololiberista