Cost per Flight Hour of Military Aircraft

It is the combination of fuel burned and the ground maintainence time per hour of flight.

A real example is the Mig-21 costs about $6,000 per flight hour. This is because parts are cheap and plentiful and maintainence is cheap and easy.

More modern aircraft have internal diagnostic systems and testing systems that will not only generate a little report saying what is working and what isn't, but the new systems will actually shut down a system with a problem and bypass the data going to that component to another system to try to do the job.

Prices will also change due to sanctions like Venezuelas F-16s, and of course as technology moves on the older stuff becomes harder and harder to get, which also means more expensive.

For instance... try to get a video tape recorder now... not as easy as one would think... or try to buy a 5 1/4th inch floppy disk.
A Mig-29 from the mid 1980s might need its software on a floppy disk that costs $10 a disk now even though it is completely obsolete for data storage.

Yeah, military airfields don't charge aircraft for operations.

Things that reduce costs include integrated software diagnostics systems that help technicians find and solve problems faster.
Things that are bad are high maintainence things like surface coatings... on a normal plane you undo the screws and take panels off to access the internals of an aircraft.
In a stealth plane you remove the stealthy coating and tape and other things covering the screws, then undo the screws and remove the panel... fix the problem and then put it all back on including tape and surface coatings... real pain and very expensive too.

It is off topic but one of the biggest reductions in operational costs for the MiG-29 was when they changed their maintenance procedures from communist to non communist so to speak.

For the Soviets the cost of maintenance was less important, and needing large numbers of men to maintain a plane or long hours were not a problem... the focus was that for 500-1,000 hours you just fill up the things that needed filling and got in and flew the plane without needing any checks or tests and without needing a university degree.

That meant during a war or conflict all the aircraft not in overhaul would be available and ready to go.

Obviously that came at a price.

Maintenance was strict and very safe in regard to tolerances, so for instance during testing it was found that 15 parts of an engine had wear and while each would wear out at a different rate the idea is that between overhauls there needed to be no testing or expert analysis of parts or components...

This meant that for a given engine one of the parts might last 2,000h before needing replacing and another part might need to be replaced every 2,500h, and 7 parts might need replacing every 2,000 to 3,000 hours depending on how the engine in used, and another 5 parts might need to be replaced after between 1,500 and 3,000 hours also depending on how the aircraft is flown.

To be safe then the overhaul and replacement schedule would be 1,000 hours... all the parts that can wear out are replaced every 1,000 hours.

That is very wasteful of parts and also means stripping down engines every 1,000 hours so it takes time but it means in a combat situation you only need to worry about battle damage.

Parts that might be perfectly fine were discarded.

The maintenance of the MiG-29 dramatically got cheaper with portable scanning equipment and onboard diagnostic equipment that would tell the ground crew if there was an electronic problem... computers and computer networks can have problems too of course... it is not just the engines.

The point is that once they started changing the maintenance policy for peace time costs then the requirements for the support crew increased... they needed to be able to use portable scanners to detect cracks in engine blades, and parts started to get replaced only when they actually needed to be replaced.

One thing that has not changed is that Russian pilots are not expected to "go easy" on the planes.

In the west there are limits to manouvers and speeds and altitudes etc that aircraft can be used to prevent excessive wear and tear on the aircraft and their engines.

Regarding that report about the Gripen... it repeatedly says it lacks the range and performance for their needs.. being the only single engined aircraft in consideration, that is no huge surprise.

On page 14 it mentions Saab recommends spare parts pooling amongst all users to keep down costs... reliability or availability the Gripen scores better than Eurofighter...

The fact that in pretty much every area the Rafale was best, Typhoon was second, and both were better than the base standard F-18 they currently operate and that the Gripen rated worse than the F-18 in every regard... even after being upgrade to its latest model type suggests that single engined fighters are also less capable than twin engined fighters perhaps?

There is nothing in that document even mentioning operational costs, so perhaps it was another report... or another part of the report that perhaps SAAB managed to block the public release of...

Well that seems a good strategy for wartime operations.

When you produce the spare parts and you want work for your people then it is good, but many aircraft spend 99% of their time in peace time and it makes it rather inefficient, and also makes it less desirable to more sophisticated countries who dont want simple and cheap.

When the parts you are throwing out after 1,000 hours contains complex titanium parts worth tens of thousands of dollars it is more of a problem... though they might be lasting 4,000 hours so you might save money by replacing them after every third overhaul...

It is even better if you can harmonize the life of the different parts, so you don't overspend in those that are always discarded even when in perfect conditions.

Or perhaps instead of discard, you inspect and analyse and repair if possible for reuse.

That lack of complex systems is why the MiG-21 was dirt cheap and could be repaired in field with screwdriver and hammer, but no modern plane is ever going to be "affordable"

The attempt of the F-16 was supposed to make things easier with modules, with modern computer systems where parts are added and removed, where software updates can fix problems and create more, or simply make the whole system stop working. The same problem is creeping into motor vehicles... John Deer make tractors but wont share information about their software and diagnostic systems, so if something is not working you have to send it to them to fix. Most of the time a laptop and a few minutes might find something is set up wrong or some component has failed, or is broadcasting rubbish which means other things are not working properly either.

I remember when installing a computer game on an IBM type computer meant low level access to all sorts of things you don't worry about now... the operating system handles IRQ channels and sound card settings and the like. Back then the operating systems let you access the hardware directly and set ups could be stuffed up pretty easily. Newer OS manage that sort of thing themselves meaning vastly fewer blue screens...

Well, it is hardly surprising that it has lesser capabilities than the two other. The plane is extremely small compared to the other two, how should it do the same?

But hang on... you are saying that a single engined fighter is better than a twin engined fighter because it is lighter and smaller and cheaper... why are you also not saying that it is less capable and with much reduced performance?

is that they tried to solve everything with medium fighters with the price of heavy ones but without their capabilities, and ended up with very reduced numbers, because they didn't have the cheap light fighters to fill the gaps... a massive flop if you ask me...

So what you are trying to argue is that the Gripen should be bought in addition to either the Rafale or the Typhoon and used together by the air forces of Europe, because while it is not as good as either aircraft in most parameters, it is cheaper.

What would happen if we adopted that concept in other places... this doctor is a woman... she is smaller and lighter and cheaper to pay than the male doctors... she is not as good but we can afford to have more of them... even if they are incompetent...

It is only logical that the Rafale came on top of that competition, since it is a modern fighter, very well conceived, and designed specifically as multirole (omni-role they say), which was what the Swiss were evaluating.

The Gripen is a modern fighter and we are talking about an upgraded model with over 90 changes from the standard model... was it poorly conceived... was it intended to replace lollypop ladies helping children across the road instead of being a modern fighter aircraft?

The Eurofighter is not multirole (BTW the report confirms cruise 1.4 M, which is a serious capability for air superiority) and the Gripen in simply tiny, it cannot carry the same fuel or the same payload, and logically in some aspects it will be even worse than the old F-18. It rates high in EW for instance, and they say that many of the improvements that Saab reported were not accepted because they needed capabilities which were current. Those capabilities were going to come at the expense of more weight and a more powerful engine.

But you go on to complain that the Eurofighter and Rafale are bigger heavier aircraft... their two engines means they should be high drag and therefore lower performance than the smaller lighter Gripen, but that is clearly not the case.

I am quite a big heavy person but I don't work out, I don't have powerful muscles, but I have experienced situations where a strong wind was blowing and smaller lighter people were having difficulty standing up... they ended up walking behind me.  Size has advantages.

Or at least I don't see a proof of the contrary. If you put two engines side by side you get more thrust but also more drag, in a single engine the same thrust will result in a longer aircraft but also a less draggy airframe.

Yes, but what is the value of that drag reduction... none of these planes are bricks... and I would suggest their extra size and weight actually make them rather more effective platforms. Small size has a value, but not at the cost of serious loss of performance...

That explains perfectly the respective characteristics of F-16 and MiG-29 that we have discussed. The first is excellent in energy conservation (very low drag), the other in climb and turning rate (thrust and lift at the expense of more drag). Which one is better? It depends on what you want, but for a small multirole plane the first approach makes more sense to me.

In training with German MiG-29s the F-16s lost every time... they didn't have AMRAAM and R-73 was, together with its helmet mounted queing system, a vastly superior missile to the then standard Sidewinders. The difference in drag was irrelevant... the extra fuel the MiG can carry compensated for the extra drag, and in terms of flight performance the body lift from the twin engine trunks effectively forcing air flowing over the body of the aircraft and generating extra lift gives it advantage in manouver and cruising.

2. A light fighter needs to have simpler requirements compared to heavier ones. It is not a fault of the Gripen to be small and relatively simple, it is simply wishful thinking on the part of Switzerland to hope for medium or heavy fighter performance for the cost of a light one...

So small cheap fighters are shit fighters.... so why bother with cheap when it will also be ineffective?

Sounds like the Heavy (Su-35/57) and Medium (MiG-29M2/-35), with cheap drones (S-70 and others) is a better solution than single engined light fighters.

BTW this graphic is coherent with what I said, smaller size leads to disadvantages on persistence, detection range and some others. At a fraction of the operational cost and with the right backing it may be a sound decision to use it though:

Yeah, but looking at that chart I see three different aircraft... the light one with one engine might be cheaper, but doens't come close to the performance of the bigger twin engined aircraft which seem to be rather more competitive where each is better than some things than the other... we don't see that competitiveness of the smaller cheaper one.

What you fail to prove is that a single engined Gripen is better than a twin engined aircraft also intended to be a cheap light fighter...

Never said that

So there is no advantage to single engine design?

I said as much... in fact I think they should be bigger!

Fitting two engines makes them bigger doesn't it?

Many countries still getting things done with MiG-21, MiG-23, JF-17, J-10, F-16, Mirage etc etc. Do you want to check the numbers? I am not making this up, it is a simple reality of the kind of compromises air forces choose to do.

Yeah, but how many of those countries got a real honest choice as to which aircraft they could buy in the first place?

... which has nothing to do with the different layouts and propulsion concepts

But you are claiming single engined fighters are smaller and more agile and cheaper... if they get shot down then it wont matter how cheap they were.

That was one its main problems, it had very little fuel... as said before, its role was quite narrow as a point defence fighter with focus in TWR and manoeuvrability in a short fight at the expense of pretty much anything else. With the new family of MiG-29 they have been smart to expand the roles of the plane and give it more fuel. We don't have critical values like empty weight though, we would need them to compare its current performance

So you are saying it is worse but you don't know....

It is not really clear it has an advantage across the board, it may be better in some low speed manoeuvring (twin keels) but it has worse L/D than the F-16 and that affects the way it can keep speed during combat.

It lost every engagement against an early model basic unupgraded German MiG-29...

Excess power of the F-16 while turning is outstanding:

But not outstanding enough to win in testing.

If you want to go into the details of comparing F-16 and MiG-29 I think we can do it, since there is a lot of information about those planes available, including flight manuals, EM charts and so on. Some calculations are needed though, since altitudes and fuel weights need to be accounted for and are not always the same for both in the charts.

The comparisons were done in the 1990s by HATO and the solution was that the F-16 got helmet mounted sights and BVR missiles and were not allowed to get close to MiG-29s in combat...

My point was that the layout of the F-16 is more suitable for a general purpose fighter than a very specific one like the original MiG-29 as it is more efficient. Today's requirements include high AoA performance which means two vertical stabilizers and stealth so the layout would not be directly applicable and the size should grow a bit, but it is still a good example of a very well optimised plane that performs well on many missions.

You can try all you like to sell the F-16 but the Russians have said the new light 5th gen MiG fighter will be a twin engined aircraft.

At some point they decided to change from single engine (MiG-21 - MiG-23) to twin engine (MiG-29) for the short ranged fighters too and that of course has an impact on what is available today to work with.

They could go back to flint lock muskets to see if they could improve their performance to modern levels by why go backwards?  

BTW back to the thread's topic, did you read the cost analysis by Jane's? Do you basically agree with their conclusions?

No... I am sorry, but I find such stuff tedious and often framed to promote their favourite product at the time... you don't want to just piss away money for nothing, but the twin engined MiG is cheaper to operate than the twin engined Flankers and really that is all that matters.

Of course, not every manufacturer wants to deliver data, air forces calculate differently etc etc etc. We can only gather information and see if there are trends. With the existing data, I think it is rather reasonable to take the values from the same service, as those we have from USAF. And hope that the guys from Jane's did a good job and their figures are more or less justified, I cannot interrogate air force bosses to get better numbers...

The problem is that different ideas about supporting aircraft effect the results too much.... the Indians used to complain about the serviceability of Russian planes, but that was mainly because they ordered parts when they needed them... and all the red tape and crap meant it could be a while to get them.

Politics in an air force is a thing too... some airfields getting better support or higher priority than others.

Plus the US can't do affordable.

If you can buy and maintain two or three for the price of one of the others it would still be an attractive plane.

Yes, because having lots of planes is always more effective than having good planes... that is why the Soviets won WWII because they had more Polikarpovs than the rest of the world combined had aircraft.... and it was the same with light tanks... they Soviets had tens of thousands of T-26 light tanks so of course they won WWII, because small cramped two man tanks with poor optics, a good gun, weak armour and no communications is always going to kick the arse of much smaller numbers of German tanks with ordinary guns, ordinary armour, good optics and well laid out crew roles and tactics and excellent communications and training...

I think it is fairly reasonable to think a small, light plane with little dead weight (small airframe and fuel tanks) has some advantage in manoeuvrability and acceleration, also visual footprint is relevant in combat. But the diagram does not explain much in that regard.

The problem there is that both sides had already adopted air defence systems that largely involved large radars being used to detect threats and command structures where interceptors were directed to engage those threats along paths that were the safest for those interceptors to positions where the interceptors could launch attacks on the targets at minimal danger to themselves... directed by AWACS or ground control... where acceleration and manouver don't really come in to it.

By the mid 1990s HATO had had their chance to practise against MiG-29s and R-73s and helmet mounted sights and they realised that dogfighting with the Soviets would be suicide and that launching longer ranged missiles from outside visual range was the way to go because if you got within visual range of the target then that was mutual and if they launched a missile at you before your missile took them out of the fight then there was a good chance you were both walking home... if you survived that is.

Manouver became Typhoon manouver... climb and accelerate and launch and then turn away... old model Sidewinders and their equivalents had narrow fields of view and slow tracking rates and could not turn particularly hard... R-73s and similar later missiles had wide fields of view and fast tracking rates and thrust vectoring engines so they could turn hard and follow even light fighters turning in eye watering turns...

As I mentioned the F-16s they tested against the downgraded export MiG-29Bs used by East Germany that were further lumbered with having to carry the centreline external fuel tank which reduced manouver performance (5g I seem to remember) managed to get on the tails for a shot about 62% of the time... but they didn't win any of the tests because the MiG-29 pilot was ruled in each case to have already taken a shot with their high offboresight R-73s and gotten a kill before the F-16 was ready to fire.

I am not trying to suggest manouver is of no use, but during WWI the game was to get on the targets tail to prevent your enemy from bringing to bare his forward firing guns on you while at the same time positioning your forward firing guns on him... the ideal situation... if your aircraft was more agile than his there are not many manouvers he can perform to get you off his tail... which makes his position dominant.

Right now however, a missile can manouver and cover distance much faster than a plane... so being able to fire a missile forward that turns 180 degrees and comes back at something behind you means your position isn't as dominant... and more importantly pulling back hard on the flight stick to rotate the nose of the aircraft up and over and to end up pointing backwards and then launching a missile that missile will burn all its energy accelerating towards the enemy plane and wont be wasting energy pulling a 180 degree turn in the first few seconds of its flight... the time when it has the most energy it is wasting it on a hard turn...

In WWI such a manouver would be suicide because you can't fire guns forward and have the bullets turn 180 degrees and hit a target behind you, and pulling back on the stick to face backwards would result in a super stall which would make you an easy stationary target and then you would fall uncontrollably... so you stop and drop with no control of where you guns are facing.

Today with thrust vector control engines you can turn your nose to point at the target and keep it there to launch a missile and then point your nose down and fly away in full control.... you will be a stationary target but if you do it when the enemy is 5km away on your tail, your missile should hit him before he gets in cannon range anyway, and you will be directing your nose at the next target to launch a missile at anyway.

The rules of maintaining energy are changed because you don't stall and lose control of your weapons...

If Jane's values are true and Gripen costs 5 k to operate vs 18 k on the Eurofighter for instance, then the whole argument "which is better" is pointless.

But the Eurofighter was never intended as a cheap to operate aircraft so the example is irrelevant... but even if we ignore that... if it takes three Gripens to get the job done then is it really cheaper in actual terms because owning and operating three times more aircraft is not really actually saving much money...

Why are you trying to make this a matter of black or white? You know aircraft design is a matter of compromising. I stated some natural consequences of the single vs twin engine on the general shape and characteristics of the airframe, not claimed one to be superior above the other.

Because you are demanding that the new stealth MiG be single engined because you claim it would make it cheaper aren't you?

- If you have twin engines side by side, you place mass and drag in parallel with the planes longitudinal axis, since two engines are wider and shorter than one of the same thrust. Agree?

I would agree but would argue if the single engine has the same thrust as the two engines in a twin then you have already lost because that single is going to be crap.

To even have a chance of being useful the single has to have at least 3/4ths the power of the two engines combined.... ie MiG-29 with two 8 ton thrust engines vs F-16 with an 8 ton thrust engine? More like 12 ton at the very least...

- You get more drag for the same thrust with that design, but also a shorter airframe that may be lighter and hence have some other advantages associated to it, like lower pitch moment.

Spaced engines also add fuselage lift and torque for roll control using TVC engines... and space for internal weapon bays...

Here it is easy to understand why a fighter like the MiG-29 has a short and wide fuselage, high TWR and low fuel. It was designed for being capable to keep up or defeat F-16 and F-15 in close combat. Its design characteristics were not specially good for range. In combat, it has worse energy conservation than the F-16, which is also easy to infer from both plane's design characteristics and fully consistent with the data I provided. Each approach has its pros and cons.

Every upgrade the MiG has ever had has included improvements in fuel capacity... but I wonder if the F-16 and F-15 are so fuel rich why are both getting conformal external fuel added to their designs?

- Economies of scale and ease of maintenance due to the fact that both aircraft share the same engine;

It is a false economy, because the heavy and light fighters will rarely operate together from the same base so commonality is irrelevant except at the strategic level where having a couple of different engine types is fine... for goodness sake at the moment the Su-27SM, Su-30, Su-34, Su-35, and Su-57 don't use the same engine... it is clearly not critical.

- Complementarity between the characteristics of those two planes: one should have long range, big payload and powerful systems & avionics while the other should be very agile, simple, cheap to operate and numerous.

They can already achieve that with the Su-57 and the S-70 drone combination...

One would control the BVR combat while the other would be a plane the enemy does not want to meet at close quarters.

With modern WVR missiles no one wants to meet at close quarters...

They could fit a Yak-152 with 10 weapon pylons and a helmet mounted sight... it would be smaller than any F-16 or MiG-21... it would be cheap...

They should be full blown heavy fighters, not half arsed hopeless attempts at making a big plane that costs like a small one.

You are the one suggesting that fitting one engine to an otherwise modern fighter will somehow make it cheap and simple.

It is pretty clear the Russians are not interested as they have already stated it will be a twin...

In the case of the new MiG-29 generation, they were so nice not to publish empty weights. That is the crucial data they can hide and difficult all the comparative analysis, because it influences everything, wing load, STR, acceleration, climb, fuel consumption and so on.

They are not obliged to reveal anything at all, but I don't understand why you think a plane with better wing load or STR or acceleration or climb rate or fuel consumption and so on makes any difference at all... the MiG-21 was one of the best examples of light fighters... small light cheap easy to operate and maintain, difficult to see in combat... according to you it would be the ideal replacement for the MiG-29... except it isn't... the MiG-21 design is great for size and cost, but its limit payload and range means you can have a lot, but you need a lot, and in most areas the F-16 is better simply because the MiG-21 was the benchmark that the F-16 design was based on, but that is not to say it can beat every time unless the F-16 has AMRAAMs and the MiG-21 has AA-2s...

The reality is that the air force that operates the aircraft and the missiles it will be carrying and of course training and tactics matter more than fuel efficiency.

I can provide also info on that, as well as comments from the pilots dealing with the details of the engagements. In short, in WVR the helmet and missile combo was far superior, not the manoeuvrability or dynamic performance of the plane.

So as new aircraft will be fitted with WVR missiles and helmet mounted sights doesn't that render agility less useful than altitude and speed?

Makes a lot of sense, if they felt they had a better BVR package but were not superior in close combat.

They didn't, but they didn't appreciate that either...

As to the costs of the MiG, the reality is that we don't know them, and their leadership's sales pitch "our MiG-35 is twice and a half times cheaper than the MiG-29" doesn't help either.

And who do you think they are fooling... the Russian Air Force know what their MiG-29s cost to operate and they know the costs of operating Flankers of all types too.

The relevant question is: how much cheaper the MiG-29 would be, if it was single engine? That I would really like to know. Don't you think the reduced maintenance and spare parts burden would help, even when not discussing how relevant in the total CPFH that would be?

Klimov doesn't have a suitable engine, it would be a pointless exercise... a bit like saying what sort of performance would a MiG-31 have if you take out the two jet engines it has and replace them with a single NK-32 25 ton thrust engine... being a single engined aircraft they could make it so much lighter so the loss of power with the single engine could be compensated by lower drag blah blah blah...

Or how about a twin engined B-52... wouldn't it be so much cheaper and simpler... they could double its range...

The problem is that the Russian Air Force is not interested in manned single engined fighters... as far as I can tell the only single engined aircraft they have are trainers.... Yak-152, L39, and the An-2 transport plane...

Of course. It is also very easy to falsify data for political gain, like when they talk big now about the availability rates of the F-35, without saying how much does it cost to keep them above 80%. I can have 100 guys nursing every plane at an astronomical cost and the warehouse full of pieces that are missing somewhere else, as far as such information is not publicised everything seems ok.

Not new... during Desert Storm there were issues with the availability rates of the Apache helicopters.... the solution was pretty simple... they tripled the budget and man hours in maintenance and the availability rates got close to normal...

BTW: I didn't realize when creating this thread, that Stealthflanker had already done one. Can we merge both?

Make it easier for me with a link....

Life cycle costs are from left to right and capability from bottom to top... where the further left you are the cheaper you are and the further right you are the more expensive you are, while lower down the chart is less capable and higher up the chart more capable.

So this chart is showing all the euro canards are ahead of the Su-35 in terms of performance and the Su-35 is more expensive than any of them...

It also makes the claim that the current model Eurofighter Typhoon, the Rafale, and the F/A-18 and the Gripen NG are all cheaper to operate than any model MiG-29 or Flanker... while the F-35 is more expensive than the Fulcrum, but cheaper than any model Flanker and more capable... in fact the only planes more expensive than the Flankers and the Fulcrums is the Su-57 and the F-22.

I am guessing that screen is probably nice and soft three ply to have that sort of shit on there... that is pure marketing bullshit that makes you wonder why they bother.

For instance India will look at that and say... well we got offers for MiGs which are not on that chart an we got offers for the Rafale which would be off that chart.

I would be interested in seeing the figures they used to compile the chart in the first place... the numbers I have heard for Su-35s and Su-57s suggest they should both be to the left of the F-16IN, but of course further forward of where they are in terms of capabilities too.

Makes you wonder how the Russians manage to operate the worlds most expensive fighters on 65 billion a year.