SchorschI’ve seen a prototype which was fed water in a typically sized fuel tank. The engine did the rest.
10 years ago it occupied a 1 foot high space beneath the passenger compartment. And extended most the length of the vehicle between the axles. In all, it was not that much different from the space taken my a conventional cumbustion engine, just flattened out and placed in what would normaly be dead space.
What shows again that space and weight are much less of concern in a car. Most cars drive distances below 50km a day with an average occupation of below 2 pax/car. Any hydrogen/biofuel application is best used in cars.
SchorschBoeing is developing a fuel cell for an APU replacement. This will be fitted to a DA20 aiui so at least for light aircraft the future may change (depending on performance)
Light aircraft are less relevant than gas driven grass mowers, only in the perception of light aircraft owners and users their fuel consumption truly matters. Globally, it is fart in a tornado.
SchorschBoeing is developing a fuel cell for an APU replacement. This will be fitted to a DA20 aiui so at least for light aircraft the future may change (depending on performance)
Light aircraft are less relevant than gas driven grass mowers, only in the perception of light aircraft owners and users their fuel consumption truly matters. Globally, it is fart in a tornado.
SchorschI’m no scientist but had thought that the major by-product of burning hydrogen was water vapour, a product with which the environment is well used to coping. Admittedly, it would put this into the atmosphere in large amounts so the consequences would presumably be – clouds..?
… which have proven to have a serious effect on climate. At rush hour up to 3% of European sky is covered by contrails. After 9/11 (cease of all airline operations for 3 days) the temperatures were measurably colder than for comparable weather conditions with A/C-traffic. Additionally, the use of hydrogen will produce nitrogen oxide.
The discussion about jet fuel alternatives is an artificial one, hyped by the fact that air travel always earns more attention than other modes of travel. Most of the world’s railways still run on diesel, my car runs on “conventional fuel”, my heat does, and all ships on this globe do. So, considering that these vehicles/applications burn way more oil than aircraft do, that these vehicles/applications are less safety or weight critical, why don’t we put our efforts into replacing “conventional fuel” there?
If a B747 can run on biofuel, why can’t my heater or my car, or the railway? These applications are not safety critical and nobody cares if the engine fails with a 0.15% higher probability. Let’s face it: biofuels are no real alternative. At the moment they actually blind the general public as people really think that they can replace today’s fuel and that they are “environmentally friendly”. That is of course big bullock, as the airline fuel alone burned by aircraft going in and out Heathrow would need a substantial amount of UK’s agricultural area. You can rather plant trees there. Additionally, the energy and water needed to convert plants into fuel is substantial and equalizes a good proportion of the saved carbon dioxide.
The most interesting question is “bang for buck”: which proportion of CO2 emission can be saved at what cost and what side effects. Go to your next street corner and estimate the average vehicle weight per transported passenger (example: one guy in a VW Tuareg is 2.2tons per passenger; 3 people in a Golf III is 350kg per passenger). You immediately see where we have to work on.
SchorschI’m no scientist but had thought that the major by-product of burning hydrogen was water vapour, a product with which the environment is well used to coping. Admittedly, it would put this into the atmosphere in large amounts so the consequences would presumably be – clouds..?
… which have proven to have a serious effect on climate. At rush hour up to 3% of European sky is covered by contrails. After 9/11 (cease of all airline operations for 3 days) the temperatures were measurably colder than for comparable weather conditions with A/C-traffic. Additionally, the use of hydrogen will produce nitrogen oxide.
The discussion about jet fuel alternatives is an artificial one, hyped by the fact that air travel always earns more attention than other modes of travel. Most of the world’s railways still run on diesel, my car runs on “conventional fuel”, my heat does, and all ships on this globe do. So, considering that these vehicles/applications burn way more oil than aircraft do, that these vehicles/applications are less safety or weight critical, why don’t we put our efforts into replacing “conventional fuel” there?
If a B747 can run on biofuel, why can’t my heater or my car, or the railway? These applications are not safety critical and nobody cares if the engine fails with a 0.15% higher probability. Let’s face it: biofuels are no real alternative. At the moment they actually blind the general public as people really think that they can replace today’s fuel and that they are “environmentally friendly”. That is of course big bullock, as the airline fuel alone burned by aircraft going in and out Heathrow would need a substantial amount of UK’s agricultural area. You can rather plant trees there. Additionally, the energy and water needed to convert plants into fuel is substantial and equalizes a good proportion of the saved carbon dioxide.
The most interesting question is “bang for buck”: which proportion of CO2 emission can be saved at what cost and what side effects. Go to your next street corner and estimate the average vehicle weight per transported passenger (example: one guy in a VW Tuareg is 2.2tons per passenger; 3 people in a Golf III is 350kg per passenger). You immediately see where we have to work on.
SchorschGenerally the sizing parameters are besides the individual aircraft’s take-off performance:
– prevailing winds
– slope
– altitude of airport (shouldn’t be a factor for you examples, but explain why Denver has such long runways)
– prevailing temperatures
Generally, a 3200m runway is sufficient to bring any current aircraft in the air. But it doesn’t have a big margin. If you look at aircraft with rather bad take-off performance (e. g. a fully loaded B747-400) may have problems at temperatures above 25°C and has to decrease take-off weight. A take-off with maximum take-off thrust is also a big strain on the engine, and it makes sense to accept longer run if the engines can be spared a bit.
A longer runway is always better, safer, offers more flexibility. But it also costs a lot, and many airports simply lack the space. For a new airport in warm latitudes 3800 to 4000m seems best size, in colder regions a 3400m runway is fully sufficient.
For any normal operation of single aisle aircraft 2400m/8000ft are OK, 2800m for challenging conditions (hot&high). For widebody it is more like 2800m as lower limit, while 3200m is a good length.
Don’t forget that some airports are back-up military bases and a long runway is well suited to even be usable after it cashed in some bombs (a 4000x60m runway is actually 4* 2000x30m, so more or less 4 military runways).
SchorschSo, thanks to Scorpion I am now proud owner of 2 advertisement brochures. Some thing that were written here are true and some things I claimed seem not to be so, first of all the fuel capacity is given with 11.5 tons maximum and 8t combat.
In general I am a bit disappointed about the level of information provided and also a bit wondering how all these wild claims are reasoned. Stealth for example: Many design headaches were caused in the Typhoon and F-18E program to reduce RCS, now Suchoi comes along and states “low radar oberservability” by canopy coating and RAM. If it was so easy even an A380 would be low observable.
They also make no statement concerning (operating) empty weight.
I cannot see “care-free handing”.
In general I would say that the Su-35 is on eyesight with later F-15E derivatives, although the Su35 off course retains its very high maneuverability. How one can set it above aircraft like the Typhoon or Rafale (or even F-22/F-35), which still are in extended development process, is a mystery to me.
And never forget: It isn’t in service yet!
SchorschCan we called F-5A/B a “Fighter Bomber” 😀
Given its size and cost the F-5A was indeed a fighter bomber, actually a very cost effective fighter bomber, probably better bang per buck than most aircraft the USA produced at that time, although a single F-5A not really rains down a carpet of bombs. But compared to other aircraft it can fly 6 missions a day (demonstrated). An F-105 can’t, or only with 25 people maintenance crew and a shipload of spares.
SchorschI agree with Distiller (how could I disagree?) and think that aircrafts like F-105 or F-4 are much too complicated. Even the USAF was unable to operate the F-105 satisfyingly under SE Asian conditions. The A-4 was well suited. The F-100 probably lacked the range and punch (it had either one). Let’s also not forget that the NF-156 flew first in 1959 and was tailormade for third world air forces. It was available in 1961, although no running line was installed. Even the A-1 Skyraider looks suitable (actually: most suitable), but would have probably offended the Thais (“What, the US President only sends us outdated propeller aircraft, that is an outrage!”)
SchorschExactly my point. I was just refuting Schorch’s patronizing attitude and ridiculous statements of great internal fuel capacity being useless in combat Or that the Su-35 TVC is meaningless in combat.
Guessing the combat endurance from the pure fuel capacity is no serious business. I would accept useful figures for fuel fraction, but none except me did provide that. Fuel fraction is a delicate business but the aircraft and engines in question have similar technology standard (comparing a 1960′ F-4B against a 1990 F-16C would be misleading). Although I concede that I based my claims on partly wrong figures (which are quite difficult to get), I miss a clear and coherent counter argument.
SchorschWell, gyus, it is a little offtopic.
EFTs add a lot of drag (they are quite big), so decrease the range, and also occupie hang points (a bulky weaponry points where a heavy AAM or AGM/GBU may have been accomodated). EFTs are simply a “cheat” to build a fighter with great range capability (when using EFTs) and yet remain not very heavy.
When you talk about overall range I agree. But when it comes to combat performance the additional drag is not of concern … the tanks are gone then. Aircraft go on counter air mission and will then drop their tanks. The additional drag is accepted for the sake of having lesser weight in combat. Aircraft have been designed such way since the late 50ies and it is agreed standard (because it makes sense). Designs like F-22 omit external tanks for other reasons. You’ll see that even F-22s will go on combat missions with EFTs if the pylons can be dropped along the tanks.
SchorschThat is all open to debate. If the Eurocanards can supercruise with honking big EFTs, surely a flanker might achieve SC without the EFTs?
This litte statement shows your background on this issue and how you turn my writing into adsurdity by twisting words. I said clearly: can supercruise with one EFT. Why should the Su-35 be able to supercruise because the EF2000 can do with one EFT? I guess you’ll start with static thrust/weight ratios, … please don’t do it … 🙂
The Suchoi 35 will most likely not have a tactically useful supercruise capability. Too much changes necessary to achieve it. That it can – under some special conditions – supercruise is nice for advertisement, but not of relevance.
Above numbers I provided show that even Russian website credits the Su-35 with only fuel fraction of .29, which is the same as an F-16A for a normal a2a mission.
(P.S.: for those who don’t know, and I guess that will be close to 100% here, 0.3 is considered the optimum fuel fraction for conventional fighter aircraft)
SchorschThat kind of situation can be hard to come when two well equipped AFs with awacs meet.And that sane pilot will definitely have to hang around even if detected because he has a job to do.
So now you are saying carrying fuel internally is not a disadvantage because both of them are carrying similar fuel fraction? right?
both are clean but the amount of combat fuel load on the flanker is sufficiently more than the euro to allow for more combat persistance
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Not at all academic.Even after the fighting is over it still has to come back to base.There has been numerous instances in Indo-Pak wars where aircrafts had to suffer from the lack of fuel barely reaching their forward airbases.Prove it.
Not at all.It is getting more important in the days of increasing budget cuts and decreasing number of platforms.Particularly useful when your side had the technological advantages in the form of awacs and the like while your opponent lacks it.
Normal mission profile for a counter-air mission is take-off with external fuel and use that fuel for cruise into combat zone. The tanks are dropped before the fighter enters the arena. The theory is simple and true: sacrifice cruise performance on way to target but have lower weight in combat. In case of nasty surprise the aircraft can be cleaned up with hitting one push-button.
My numbers are there. Dispute it. On internal fuel the Eurofighter has better/equel fuel fraction.
The Russian wikipedia site states for Suchoi 35:
Empty weight: 18.4t (metric)
Internal fuel: 8t
Take-offf Weight: 25.7t
That means a wepons load of: -700kg
–> negative weapons load. 😮
Assuming 1.2t weapons load (roughly 8 AAMs), the take-off weight is 27.6t and the fuel fraction is 0.29. That is equal to that of a loaded Eurofighter without external tanks.
Note that Empty Weight is normally not equal to Operating Empty Weight. Assume at least 500kg for pilot, equipment and “stuff”. Same applies for the Eurofighter, too.
Schorschyou have to be kidding. 😮 Its appalling to read something like “not that fuel and payload is a disadvantage”. one of the most important criteria in modern BVR combat is fighter endurance. To be able to play “cat and mouse”, you need to be able to engage and disengage at will and thats where a flanker’s huge fuel load is a massive advantage.
I would rather go in, get the kill and get away. If I don’t get the kill, I also get the hell out of it. Most air2air combats were won when the enemy wasn’t aware of its danger. No sane fighter pilot would loiter after his presence hac been detected.
Secondly, carrying internal fuel allows the flanker total freedom from EFTs, which the eurocanards will have to be burdened with if they are to match the flanker’s range/endurance.
Hmm, when the Flanker goes into combat it has at least burned 1/3 of its fuel. When the Eurofighter comes with ETs, he’ll drop them and in best case he has fuel internal fuel. In terms of fuel fraction they start at a comparable basis.
Thirdly, lack of EFTs automatically means less drag and better manouverability.
Any aircraft will drop its tanks when going into air2air combat. A rather academical remark. The lack of ETs means longer loiter time and better range, but when it comes to combat both are clean from tanks. The Eurofighter with remi-recessed missiles has considerably less drag.
Fourthly, lack of EFTs also mean tons of free space for carrying more munitions. So no, huge fuel load is not there mainly for hauling the airframe, otherwise a flanker’s range wouldn’t be considered such an asset.
8 AAMs are enough. More muntion is more wasted weight.
Wrong and ridiculously so. The NTOW for a flanker is about 25500kg. In a pure A2A loadout, it could easily carry 6XR77 + 2XR73 + 8000kg fuel,which would give it insane range and endurance, Which the Eurobirds can hope to match only with large EFTs.
I take Wikipedia here as reference:
Empty weight of Su-35: 18.4t
Internal fuel: 7.5t
Weapons load: 1.5t
Makes: 27.4t
Fuel fraction is: 0.273
Eurofighter
EW: 11.2t
Fuel (internal): 5t
Weapons: 1t
Makes: 17.2t
Fuel fraction is: 0.29
The Suchoi has 50% more fuel capacity but 64% more empty weight. So what I say is essentially true.
Yes, and in the same breath lose its ability to turn and burn for any length of time.
Fuel fraction is what counts and if the Eurofighter enters the combat after using primarily the fuel from external tanks (with 3ETs it still can carry 10 AAMs). it has a much better fuel fraction.
hmm, no wonder the eurocanards advertise their ability to fly with huge amounts of AAMs every chance they get.
As I said, advertisement is just that.
Highly debatable. it would depend on what the situation warrants. In either case, the ability to carry huge amounts of fuel internally is a massive advantage.
Stop looking at shear numbers and start looking at it relative.
talk about absurd reasoning. in that case, why even carry radar? ever heard of first look, first kill? No flanker is going to emit continously if he can help it. Also, Irbis has a degree of LPI incorporated in it making detection that much more difficult. Also, in case of a team of flankers, if one emits and provides SA, he can easily act as a mini AWACs for 4-8 other flankers, which can remain passive and position themselves favourably. So while your RWR might give you a general bearing on 1 emitting flanker, you have no idea regarding its buddies.
Tactics. Can work the other way round. As both aircraft are not stealthy, there is no real advantage for either one.
Why? Esp. considering how large Russia is, it’d be nice to have a/c with great range. BTW, you are talking about a very specific scenario here.
The Eurofighter wasn’t designed to fight 500nm from the Eastern border of NATO.
My dear chap, TVC is very, very useful, even in BVR and supersonic flight regimes as it helps cut drag. wonder why even the F-22 has it and why the Ef-2000 guys experiment with it if it offers no advantage whatever. And in terms of WVR, the flanker is at a disadvantage thanks to its huge size, so any feature that can help (such as tvc) ought to be incorporated. And the Su-35 is supposed to supercruise.
The F-22 needs TVC because it also is pretty heavy. Additionally, the F-22 uses TVC for better supercruise capability. Of course TVC is of advantage, but it is also increased weight and complexity. If you build your aircraft small enough you achieve pretty much the same results without it.
Supercruise capability is a tricky business. Needs specially adapted engines, inlets and first of all drag reduction. I can hardly believe you can retrofit it, especially not in a tactically useful manner (the Eurofighter can reach M1.3 with 8 AAMs and one centerline tank). Just a look at how the missiles are carried by F-22 and Eurofighter (by now the only aircraft that have demonstrated tactically useful supercruise capability). the Flanker still carries them hanging in the wind.
SchorschHmm, have to agree with hexpop here. While the Eurojets may be “technologically” superior considering they were designed and built much later than a flanker, they’ll still have a very difficult task in taking on an Irbis equipped flanker derivative (su-35/MKI/mkm) with TVC, AESA or not. So technological superiority doesn’t automatically transalte to performance and combat superiority. By virtue of some amazing salient features such as huge fuel loads, large radars, huge payloads, massive sensors, engines and a solid aerodynamic design, the Su-35 competes quite favorably vis a vis the newer Eurocanards. And comes much cheaper.
I always like the Flanker fanboys. They state fuel load and payload as advantage … for air to air combat? Guys, have you any idea what you are talking about?
Not that fuel and payload is a disadvantage, but for air to air combat you want your aircraft as light as possible. The huge fuel load is in majority there to haul the huge empty weight. A Flanker takes off with ~32 to 35 ton weight for a normal air2air mission, that is close to 2 Eurofighters. In case an engagement occurs, the EF can reduce its weight by several tons in a matter of seconds (drop tanks).
Payload is great, but seriously more than 8 AAMs are wasted space, at least when you not engage in very odd situations. Flying circles with 12 AAMs is the best garantuee to get killed with 8 AAMs still hanging on your aircraft.
A “large radar” is at first a large emitter and enemy’s RWR best friend on long distances. If AWACS is not available, the guy who uses his radar is the guy who will lose, at least he will never score a kill (cause everybody knows where he is and gets away if his terms are not favorable). If AWACS is available, individual radar will be switched on short notice. Large long range radar might be advantageous for long range intercept, actually the mission the Flanker was designed for, but for a combat over limited distances with all the force multipliers it is primarily wasted weight.
For an air to air combat over Central Europe a Eurofighter (and even a modernized MiG-29) are much better options than the huge Flankers, which have a massive logistical footprint, too.
Your celebrated TVC will be useless weight in 9 out of 10 situations. Actually if the Flanker was such a superior BVR platform, why does it need TVC? It still can’t supercruise, which a Eurofighter can use to disengage at will by that in case he is frightened by the Suchoi.
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