I previously thought maintenance cost was calculated on daily basis because it’s some indirect cost in the income statement. So I left some planes 2 maintenance windows per day. Now I check the bank account but find that in every maintenance window, my plane get maintenance cost and the total cost per day is twice of the proposed cost shown in the flight cost details. Should I set 1 long maintenance window or 2 short maintenance windows for my plane?
For example:
Actually I have a 332 fly from my hub to KUL, it’s a LH so I can only fly 2 flights per day. The first one departure at 2:35 and I get a maintenance cost of AS$28,780. The second departure at 14:01 and I get another maintenance cost of AS$29,018. But when I turn to the flight details window, I find that the maintenance cost under the indirect cost for each flight is AS$15,110. It’s really confusing…
for every single flight it’s indirect cost, because it is not deducted from your account after every flight, but of course it has to be paid. Therefore you will pay some amount of AS$ for every % the maintenance improves the status of the aircraft. The costs if you have one or two maintenance windows (assuming that in both cases your maintenance ratio is >=100%) are exactly the same, if you have two maintenance windows the maintenance cost will be split up in two pieces, but if you sum up this two pieces you will end up with the same amount as you have in one maintenance window.
The cost in each flight is calculated by dividing the total maintenance cost by the flight time of each flight (that’s the simple explanation, as far as I know there is some factor which results in shorter flights costing more maintenance ratio per time than longer flights, but I want to keep the example simple - in AS you would find some other values). For example: You pay let’s say 3000AS$ for maintenance each day for a given aircraft. You have four flights, A-B-A-C-A. The flight A-B lasts 9min, the flight B-A also 90min, flight A-C 60min, flight C-A 60min. Therefore: Total flight time is 300min(90+90+60+60), so 3000/300 is 10 (each minute flight time results in 10AS$ maintenance cost), so you will find a maintenance cost of 900AS$ for flight A-B and B-A, and 600AS$ for flight A-C and C-A.
Spliting maintenance window should not charge you more. Meanwhile, two maintenance windows generally help in improving your aircraft conditions. So I always attempt to split a long window when possible.
