Maintenance Schedules

[GEnxsux]

Hi.

Could anyone give me a short description of the time intervals between A,B,C & D checks for a typical civil airliner, 777 for example?

Also, time between shop visits for a typical engine, RR T800 for example. Is it done in terms of hours & cycles or time?

Any input would be appreciated.

Thanks.

[Marvo]

It has been a year since I put overalls on for the last time and signed into work in the hangar but here goes.

A checks, mostly done on the ramp are performed every 28days. They are broken down into A1/A2 etc and consist of lubrication, filter changes etc.


B checks tend to occur every three months and are also split into manageable chunks B2/B3 etc and are more in depth needing a hangar. Some airlines can roster these over several night shifts allowing the aircraft to operate during the day.

C checks are required every two years (approx - depends on flying hrs etc) and are done in the hanger.The last one I did was 10 days for a 737 14 days for a 777.

D checks occur every 4-5 years and are a deep strip down. If you can knock out a D check plus service bulletins in 28 days you are doing well.

This all depends on the flying schedule/hrs flown etc. Engines are monitored very closely (naturally) and can be removed on condition (borescope) or due components life expire called time ex. Engines can remain on wing for years if they remain serviceable. Hope this helps. Nowerdays I sit up front and complain if there are any inop items!

Marvo

[GEnxsux]

That's great, cheers.

I think the typical length for 1st shop visit for an engine seems to be 4-5 years (similar to D check).

The 500's off the A340-500/600 have started to come in, so that matches up.

Thanks again!

[BlueEng]

For LM checks most airlines will operte a flying hour control iso calender days. Although having said that the 777 you mention does have both, ie 500hrs or 75days. B's are at the operators preference.
The current trend for heavy checks now is to move to flying hours as it can extend the life of the C check to save the airline some more pennies.