Originally posted by BlackWidow23
It came to me a few seconds ago that the USA and some other countries have a different style of aircraft maintenance, and I was curious to which one
is more effective.
1. Replacing parts as you go, replacing the parts that look like they are about to fail
2. Giving the aircraft a massive overhaul and replacing most of the burdened parts every 10 years or so (note this still includes replacing parts as
they break, so a wheel doesnt have to wait 10 years to be fixed)
what is your opinion?
Aircraft undergo a regime of service and maintenance through their life, ranging from line item maintenance brought up by check sheets filled out by
the flight crew (ie 'This is broken, if another one breaks we cant fly the aircraft, please fix') which are carried out as and when the airline has
the spare capacity to handle such a maintenance.
There are also periodic checks on aircraft:
A Check - done monthly, generally in regular downtime between scheduled flights
B Check - done quarterly, generally done in regular downtime between scheduled flights
C Check - done 18 monthly, requires aircraft removed from schedule for the duration
D Check - done roughly every 5 years, aircraft is practically taken apart and is removed from the schedule for the duration
E Check - rarely done, mainly its done to increase the number of hours or cycles an airframe can fly for
There are reasons why both of your options are done - aircraft parts are not set to one maintenance schedule, some *have* to be replaced after a set
number of cycles, some *have* to be replaced after a set number of hours, and some have to replaced as and when required.
A number of these parts cannot be accessed in routine maintenance, and thus the aircraft has to undergo a heavy check (C or D) periodically to replace
them, and also C and D checks cover inspection of the airframe etc, which you just cannot get to in enough detail during routine downtime.
A number of airlines break up the B and C checks into parcels which can be carried out during a heavier than normal A check each month (these are
typically carried out overnight at the gate, but in the case where you are doing a C check parcel, the aircraft will be removed to a maintenance base
for a day or so to complete it, this is why this approach is only really taken by those airlines with large maintenance bases, or have access to large
Aircraft maintenance is not just about allowing the aircraft to continue to fly based on whether anythings broken, its also about maintaining the
aircraft in such a manner that its both safe to fly (no hidden fatigue issues) and its also economical to fly (if you are replacing bearings every 3
months, during a C or D check you can replace the entire part which is causing the bearings to require replacement, regardless of whether it infact
needs replacing itself).