Maintenance Cost Formula revisited

[joefremont]

Hi All, I am reviving a proposal I made many moons ago:

Right now the maintenance costs of an aircraft are based on a percentage of its market value. This can produce some unrealistic numbers especially when dealing with older out of production where the real world market value is very low compared to current production aircraft. Often these aircraft have a very low market price because the maintenance costs are so high, where flynet reverses this, where the newest aircraft with the lowest maintenance costs are penalized because of there high purchase price. I would therefore propose the following change to the maintenance calculation.

Instead of using the market value to calculate maintenance cost, we would calculate a 'maintenance value' that would be based on the dry weight of the aircraft (larger the aircraft the larger the cost) the formula would be.

500v$ per KG of the aircraft's dry weight
+10% per engine.
+5% per engine if piston powered (not turbines).
+10% if no longer in production (alternate +1% for each year since production stopped).

Some examples, for two aircraft of about the same weight)

A320, current production two engines, market value is 61m, using this formula the maintenance value would be 25.3m and an A level check would be 759.000v$ rather than the current 1.830.000v$.
B727-200, not in production three engines, market value 40m, using this formula the maintenance value would be 63.5m and an A level check would be 1.9m rather than the current 1.2m.

Another comparison would be the DC-3, current market price 300.000v$ an A level check is 9.000v$. Using this formula
(8030kg * 500v$ * 1.4 two piston engines plus out of production) a maintenance value of 5.621.000v$ so 168.630v$ for an A level check. Of course this could lead an airline to conclude its cheaper to scrap an airplane than fix it, which happens some times in real life.

Here are some comments Chris made in a recent discussion about this:

Joe, I still think we need to go to a time based maintenance system with a percentage based failure system is the way to go. Percentage based maintenance just doesn't work as well since your maintenance can be too easily minimized by maintaining it before you go through the threshold for the next level of maintenance.

Also, I think we still need to have 4 levels of aircraft - jet, turboprop, helicopter, and piston. Those levels would trigger modifiers that would (in that order) progressively increase cost to account for level of difficulty to maintain (and thus cost). Beyond that, your original proposal still holds the same merit I said before.

So some additional comments and questions I have:

- Turbo props: Are they more or less costly to maintain that jet engines.
- Helicopters: Would probably add 10% or 20% to the cost to maintain, is that enough?
- How would a time based maintenance system work. Right now its percentage based, and the percent decreases by how many hours you fly and how hard your landings are. If we did implement an hour based maintenance system, we would still have to have some way to deal with damage done to the aircraft.

No decisions have been made and everyone's input is welcome.

[flightsimer]

a few things i can currently think of/comment on...

* B727 is only 4mil not 40, so those numbers need to be redone...


now as to maintenance
* Turbos are more expesive than jets in engine maintenance, so i would say over all that would make them more.
* helis, they would need to have two type, jet and piston, which would very in costs with piston being more.

for the time, i think there would have to be a reduction factor. in RW they go by months/years or hours, but here there is no way that would work. the only way i could think of that would be easy to do would be to have it based on hours. but the amount of hours between the 4 would have to be scaled down greatly from RW. but how would be end up coming up with the hours? we each aircraft have different spans like in RW?


now some questions i have is how is this gonna aircraft the aircraft that are no longer in production? this goes back to my question on should the prices for everything be based on what they actually were (in todays money)or current value of the old plane? personally i think the values should be what they were back then rose up to what that would be in todays money. if that would be the case, then the +10% for being out of production shouldnt be added.

[Quantum]

Hi,

The FSA economy is geared to the operation of todays modern aircraft with their higher values and higher incomes. I am often hearing about the older, out of production aircraft being more expensive to maintain 'today'. The beauty of FSA is that there really is no 'today'. We are operating these older aircraft as if they were 'factory fresh' as they are flying the routes that they flew when they were 'factory fresh'. Rather than having different economic models for the different eras that the aircraft predominantly were operated, we have to get them to fit into one economy. To that end FSA is going some way to enable this with the ticket factor so that the sums work for an old and a modern aircraft. An older aircraft will still not get as much income as the modern type but it will at least have the ability to operate in the black. There is no way today that the older aircraft can compete with the more modern fuel efficient types which is why the airlines try to re-equip to the most modern that they can afford to reduce their costs. FSA is a game based economy that strives to embrace the operation of all types of aircraft old or new. If you operate the older aircraft, the income is going to be less, so they should be cheaper to buy. We have to be realistic about mainternance costs, I agree, but I don't think we should be comparing costs between different types as if they were being operated at the same time and saying the older aircraft will be more expensive to maintain, spares will be difficult to come by and when you do find the spares they will be as expensive as gold dust. All the CBFS fleet are factory fresh and have full manufacturers support!

So, to maintenance. Higher hull value, higher profits. Lower hull value, lower profits. Maintenance costs I think should be based on hull values to keep everything relative.

The question is, do we keep to maintaining aircraft on the maintenance % of the aircraft or to hours flown, or to time. I was a believer in the early days of FlyNET that the maintenance should be hours based. Two and a half years later I am happy with the % based maintenance. This has worked well for all users and I don't hear very many complaints as it fits all styles and modes of operation at FSA.. The client is being tuned to take into account the time flown and the landings which is interpreted as the % we see against each aircraft. The more you use your aircraft, the more frequent you have to maintain it, the more it costs. Everything remains relative. I am happy to continue with this maintenance regime.

Here is one idea based on a % maintenance regime which makes things a bit more interesting.

If FSA kept a maintencance record for each aircraft we could have a 'Maintenance check schedule' where regardless of aircraft % you pay for the next check A/B/C/D that is due on the aircraft. I'm not sure what the check cycle would be but it would be perhaps something like:-

A, A, A, A, B, (Cycle 1)
A, A, A, A, B, (Cycle 2)
A, A, A, A, C, (Cycle 3)
A, A, A, A, B (Cycle 4)
A, A, A, A, B (Cycle 5)
A, A, A, A, D (Cycle 6)

The costs for each check could have a price range depending on the airframe %.

Maintenance Check A (1 day) = 2 - 6 % Hull value
Maintenance Check B (3 days)= 10 - 20 % Hull value
Maintenance Check C (7 days)= 25 - 35 % Hull value
Maintenance Check D (14 days)= 35 - 40 % Hull value

The lower value is paid if you maintain the aircraft when it is at 100%, The higher value is paid when your aircraft reaches 90%. This still gives a 3% maintenance cost when your aircraft gets to 95%, without the big jump when you get to 95.1%. If the random failures start to kick in below 95% then CEO's will be reluctant to let aircraft become poorly maintained, which will force the aircraft into maintenance. The more Check A's that are done brings the B/C/D checks closer. This will stop everyone just doing Check A's all the time and never doing a check B, C or D. In line with this, any FSA induced random failure should disable the aircraft for a specific time period depending what the failure was and the failure should be recorded on the flight report as a (nice to know) FSA failure and not a pilot enduced operating error. I've had pilots report a 'FlyNET engine failure' but they managed to re-light the engine. A FlyNET/FSA engine failure will not enable a re-light.

So, with the above, your aircraft info page will have an entry for Next Check due = 3A. This will give you an indication of where it is in the maintenance cylce and there is a 'major' check due afterwards. When an aircraft completes a 6D check it's next check becomes a 1A.

Well, that's one idea and I am sure others will come up with different ones.

Regards

John

[IslandBum]

I like it John

It gives some meaning to maintenance cycles -- also means a little planning required instead of just sticking aircraft in
maintenance now and then -- I see a Director of maintenance in VHAs future to keep track of this -- Now what we need to
is have Joe or DK write some script so the time remaining to check appears in Ogee' statsheets

Leif

[CAPFlyer]

John, I like what you say, but a few suggestions -

1) An "A" check both in the real world and in FlyNET shouldn't regenerate the hull value and should only partially regenerate the engine value (say 50% increase over current).
2) A "B" check should regenerate most of the engine (say 75%) and part (50%?) of the hull value.
3) A "C" check should regenerate all of the engine, most of the hull (75%) and some of the landing gear (50%)
4) A "D" check should regenerate all 3 values.

Gear should reduce the least followed by hull and then engines.

Failures should begin at 80% of ANY value, not composite. Hull would relate to electrical failures, Gear to Hydraulic and/or brake failures, and engine to (of course) engine failures.

This would mean that you still need to do maintenance on the schedule like suggested (which I like as a compromise over hours or cycles) but it would also mean that there is potentially a small chance that the aircraft will deteriorate to the point that something might fail.

In addition, I think an option should be available for a "heavy maintenance" check in case of an accident or heavy landing that would let you fully repair the airplane out of schedule. However, this would not affect the rest of the schedules unless you selected a checkmark to also "Do Scheduled Maintenance" which would do the next "heavy" check which would be either a "C" or "D" check and then reset the schedules. This would mirror real life as even if you're fixing damage, you can only get credit for a scheduled check if you do the proper paperwork as well.

[flightsimer]

gonna add on to your last part about the heavy maintenance... also like how i suggested a few moons ago about being able to refit/refurbish aircraft would go on like the heavy maintenance. Being able to refurbish the aircraft and repair at the same time would be nice when that gets added in...

[vaccaro]

The mainteanance thingy is already bad (with current ticket prices and multipliers).
I am quite sure most of you won't be agree with me but FSAirlines shouldn't be a "Tycoon" game.
I simply use it instead of FSPassengers which I don't like so much because it interfere with key setup of my FS9.
Just my 2 yeni kuruş (turkish currency for cents)

[Quantum]

Hi Chris,

Well, I think we should try and keep things as simple as possible. The current maintenance is dead easy to comprehend and implement without any thought or parralel with the real world. My suggestion is a bit more complicated and makes CEO's and managers have to think about their maintenance a little bit more and makes things a little bit more interesting. It's very much simplistic to what may be happening in the real world of aircraft maintenance. What you suggest as an addition to my suggestions, I think overcomplicates things and makes it more difficult to understand the maintenance thing. At the end of the day we want to make things user friendly and that includes WTF people have to do about their maintenance. As I previously said, the current maintenance is a no-brainer to understand, this makes things a bit more interesting without frightening people away due to overcomplication. Little steps, I think for now. If we feel bigger strides are needed later then it can always be reviewed - which is what we are trying to do now I guess.

Arslan,

Completely agree, I also don't want FSA to become a 'Tycoon' type environment. Coming from an aviation employment background myself it is always nice to have some similarites to real world but without it becoming a board game as opposed to a simulator. I think FSA makes you a better sim pilot. Making people have to think about caring for their aircraft is part of that. As in my suggestion, the maintenance costs should be relative to earnings and aircraft values.

Regards

John

[CAPFlyer]

John,

The issue though is that if you maintain it as everyone does now, there 0 chance of a failure ever occuring. There has to be some chance of a failure as time goes on. It doesn't have to be big, but there should be some chance. By having each level not fully repairing all parts of the plane to 100%, then you introduce that possibility. By reducing the gate where that possibility begins in consequence to that, it allows for you to let the plane run a bit longer before having to do any maintenance on it, allowing a little more time between A checks and thus the plane have more of an opprotunity to make money before having to cost money and be unavailable for any period of time.

[flightsimer]

but isnt that wat the random failures is for? random, i would of expected it to happen at any level of status as it happens in RW. hell there have been brand new planes that have crashed...

[joefremont]

...
So, to maintenance. Higher hull value, higher profits. Lower hull value, lower profits. Maintenance costs I think should be based on hull values to keep everything relative.
...

While I agree with the first part of this, Higher hull value, higher profits. Lower hull value, lower profits, I don't agree that maintenance costs should be based on the hull values. You can't divorce the maintenance costs from the profits in fact its a major determiner of what the profits will be. Those aircraft with lower fuel costs and lower maintenance costs will produce higher profit and therefore have a higher hull value. I am not trying to turn this into airliner tycoon or make any aircraft type uneconomic to operate, just make some of the economics a little more realistic. So I do like the idea of calculating an independent repair value rather that using the purchase price for calculating the cost of repairs/maintenance.

I kinda like the maintenance cycle idea, maybe we move to separate the idea of maintenance from repairs. An aircraft may have to do repairs because of a hard landing, but may not need to do its next check yet. But at the same time if it does go in for a check, all repairs are going to have to be done before it passes inspection. So what is the time period between checks in terms of hours or flights. I assume we could figure out a base cost of repairs and if when doing a check, part of the cost of that could go toward the repairs. What is the penalty if someone does not do there check, do we ground the AC, fines, lower reputation, increase breakdowns?

And for failures, on FlyNET kept my aircraft above 97% and never had any failures, we could keep to that with say modifiers for engine type time since last check with extra added in if past check. So how about this for an idea, the % chance of an engine failure is something:

98 - status + engine factor (jet = 0, turbo = 1, piston = 2.1) + 0.1 per flight/hour past check.

So a jet would have have no chance until 98%, turbo 99% and piston engines would always have some possiblity.

[flightsimer]

i think that the failures should just be completely random... i have had aircraft down to low 90's, and in my year here, never had a failure. like i said above, failures or crashes happen on brand new planes too. now yes after a certain amount of wear, the chance will go up, but i dont think that jets/ turbo should have any period that no failures couldnt happen...

[alasizon]

One issue I see with the cycle idea is leasing aircraft.

Leasees could possibly lease an aircraft that requires a D check rather than a normal A check that they would pay for now. While costs do need to be reformed, I think that airlines that lease any of their aircraft should have the cycles reset at each lease but after 5 or so leases, require the leaser to perform an additional check before it can be leased back out. While that will put quite a damper on my profits as a leasing company its better than an airline randomly getting stuck with a D check.

[CAPFlyer]

Under normal lease terms, the leasee is responsible for any and all maintenance required while they have the aircraft unless it is on a "wet" lease where the leasor is providing the maintenance and crew (also called an ACMI lease). However, the leasor typically tries to complete the next scheduled "heavy" check (C or D) required prior to putting the plane up for lease to prevent what you're talking about.

I would suggest that (again) a checkbox be made available to allow for the next heavy maintenance performed out of sequence to allow for it to be performed along with accident/heavy landing repairs or like above. This would make things fair for everyone and at least put it where there's a known quantity of time before the next required "heavy" maintenance for airlines to be able to prepare for them.

[Quantum]

Hi,

Regards lease aircraft, if the next check due is on the a/c info page then the lessor and the lessee can see what maintenance will be due whilst on lease. If I wanted to lease an aircraft I'd go for the one with the most 'life' in her to avoid any high maintenance charges whilst in my care. I don't think an aircrafts maintenance should be set back to next check 1A until it completes it's cycle has been completed by performing a 6D or when a D check is performed out of its normal sequence. Lessors will have to factor into the lease costs the prospect of aircraft being returned to them early with a B, C or D check due.

Regards random failures, now that we have the 'emergency' button available, pilots can divert if they need to if a failure demands it. There is no penalty as such incurred. With that in mind, I would prefer failures to be optional. As in the sim itself you can turn failures off so why not at FSA. A lot of folk come here to relax and while away their time enjoying a nice flight somewhere. They get a failure and they'll head for the hills or just turn the client off, restart the client and try again and hope that random is random and they won't be unlucky enough to get two failures in a row. I think failures should be avoidable above a certain a/c %. Those that want the failures can let the % drop lower and hope they get one.

Re the 'Emergency' button, what are others opinion of it's name? I would prefer 'Declare diversion' as it's name. A diversion is not always an emergency.

Regards

John