vanirIt maybe noteworthy that the comparative assessment of the electro-optical aiming system appears to be related to the sapphire radars which were their first dopplers and a full generation behind western contemporaries. They’re known for poor target discrimination and lock failures, I’m not surprised the EOS is 10x more accurate for a gun solution. A ring, bead and abacus is probably twice as accurate.
vanirCase by case basis. The RD-33 runs very, very hot in the afterburner section, because it’s got afterburners in the bypass stream as well as the turbine exit. It’s pretty trick, but designed for a disproportionately high max thrust capability over sustainability (dry it’s just the same as a GE F404).
Some others like the PW fighter engines and Lyulkas also have very trick afterburners with lots of little cooling techniques built in to the design. Ones like your GE units have a straight afterburner section tacked onto a bypass turbojet, so these would get pretty hot too.
Then there is construction materials. A tell is titanium content here, plus maybe certain ceramics, and blade cooling methods. I like titanium for a tell about sustaining afterburners because the most significant thing about titanium is that it only draws ahead of other alloys in terms of integrity at extremely high temperatures, most of the time it is a lot of difficulty and expense for no real returns.
Also engine cooling complexity, around the blades and afterburner unit are a tell.
vanirBy the way see the thrust-ratings of the first F100-PW-100 compared to the lower ones of the later F100-PW-220 about that, despite the benchmark claims of the first one. 😎
I think you’ll find this disparity is related to a management override facility that was omitted from the 220. It was only ever put there in the originally to satisfy the 1965/68 FX 2.5M requirement, it was never used in service anyway so the actual Eagle top speed (all versions) is 1.78M at the lower rating.
vanirA couple of things caught my eye.
The supercruise capability comes not from the high installed thrust at first but from the digital control of air-flow from inlet to outlet system and the atmospheric conditions high-up.
This is the first point which has really made a whole lot of sense to me about the original post. Intriguing, something I hadn’t thought of.
That’s certainly correct that the RPM % is usually the given indicator of thrust, but that article about the F-35 spoke about the throttle setting in percent and if it is as you say and idle would be 65% (just a guess) then the 40% throttle setting would equal a RPM of 79%.
I think you’ll find quite a bit of throttle travel doesn’t relate to much increase in rpm. The engine idles from zero to about 6/10 throttle, so effectively the throttle where measured in percentage is a good representation of power/rpm keeping in mind you’ve got it slid more than halfway forward before you see any change in rpm. This is probably where % throttle and % rpm has almost become interchangeable during flight operations in jet engines.
But there is a distinction, setting say 60% throttle may give idle-rpm in an engine which idles at 60% max rpm, but it is not idling. It is still 60% dry thrust. Pulling the throttle all the way back idles the engine, even though it won’t really lower the rpm any more by very much. It will lower the thrust by reducing extraneous fuel being fed into that rpm for the purposes of producing thrust.
Disclaimer: at least if the popular flight sims are in any way accurate, which many professional pilots I’ve talked to say they are in simple aspects like these.
wrt engines operating on afterburner for extended periods. Some are designed to. The primary accomplishment of the Aviadvigatel (D30F6) over the Tumansky R15 series is demonstrated sustained 2.35M cruise. The engineering requirements were actually 2.8M cruise but 2.35 was achieved (2.8+ is the max speed).
One of these engines has yet to fail. Even in benchmark testing, after “several hundred thousand hours” according to PERM. They do however have an airframe integrated, rather elaborate control/management system (in line with FADEC), something the Russians are very proud of.
And of course as mentioned the J58 is designed to cruise on afterburner (thrust is controlled at high mach by the movable intake cones, which is why they have a tendency to flame out on the inboard engine in turns at high mach).
For the most part however, it is generally true that front line service warplanes aren’t built to cruise on afterburners, quite simply they’re too mass produced to be all made to such demanding requirements without inordinate expense.
An Eagle I’ve no doubt could cruise on afterburners all day, the restriction being fuel load and never touching the management override (fitted so that the original Eagle satisfied the FX requirement of 2.5M top speed, it burns out the engines and may not even remain on the F100/220 I don’t know).
In any case the PW is a tough engine also featuring FADEC.
That should also mean F-16 blocks with PW engines should be able to maintain afterburners without significantly affecting engine life. The F100 afterburner is a pretty trick unit.
Now the GE F404 and F110 I’m not so sure about. I think they might run into problems sustaining afterburner for too long. Same with the Russian RD-33.
But on the other hand the AL-31F is another very tough engine with high titanium content and a trick afterburner unit, I think it was designed for climb performance in service with the burner lit for extended periods.
vanirwow, temper hot trolling itt.
I just tried hunting for a reference among my library but I’m positive I’ve specifications of the GSh-301 as having a barrel life of around 350rds. This is the main reason it’s an air combat weapon only, the GSh-6-23 gatling fitted to Foxhounds and Fencers is good for aerial or strafing use (the 23mm shell has twice the impact of a 20mm so is very good for most targets).
GSh-6-30 on the MiG-27 I know was mostly intended for light armour (like SPG emplacements), the strike-Flogger doesn’t have an anti-armour role (no reason late version couldn’t improvise using Kh-29 but it doesn’t really have any other stores options suitable for anti-armour, they’re all light/soft target weapons).
I’ve heard Russian Frogfoot pilots characterise the twin barrel 30mm as “not as effective as the A-10 gun” and that it was mostly used for light targets, with rockets or guided weapons used for anti-armour work.
I’ve watched documentaries using qualified references talking about the GAU-8 being specifically developed for anti-armour against MBT’s used in service, like the T-62. Russian MBT’s haven’t significantly increased in weight since the T-34/85 as like the German Leopards their primary design requirement is mobility and firepower. Glacis armour has improved, mostly by design and reactive armour helps defeat shaped warheads but against good old fashioned, dedicated AP rounds the top, lower-side and rear armour is vulnerable.
Put simply the T-90 is ten tons lighter than any other MBT in service (but can literally get airborne leaping trenches, and isn’t slowed down by soft or marshy ground), whilst the T-55 is some twenty tons lighter, despite its maximum 205mm front glacis.
That weight saving has to be somewhere, considering their equipment is has to be in armour everywhere but directly on the front facing.
They’re assault tanks, like the Panzer IV, not true MBT’s like a Panzer III for a classical comparison in terms of structure. It’s how you get fantastic mobility from something with the combat value of a heavy tank in an assault scenario (ie. only from the front).
Get one from behind and you could probably take it out with a scout car and a 25mm.
Finally I’ve watched Gulf War gun camera footage on television where a line of what are clearly Russian-build MBT’s are being taken out, more than one at a time, on one pass using a GAU-8
vanirI would add that I suspect an international protest would be tabled by the Kremlin via Russian Parliament if Israel went hot on Iran.
add. they did manage to scare off the US adding security detachment to some advisors they sent to Tblisi in the 90’s. That was the closest CIS/NATO came to starting up the Cold War again, well aside from Bush et al in general.
vanirAlso something to consider is the Kremlin considers Iran to be their backyard because it’s right on the border of the Kuban-transCaucasus military district (CIS) and southern strategic district (RF-PVO). Those are the commanders who went into Georgia despite direct instructions from Russian Paliament against this (overridden by the Kremlin under Presidential authority, so Parliament changed its tune).
Not only that, but all the Russian drama over the Iranian border is to do with the Caspian oil table, which is also on Iran’s border and Russia/CIS considers theirs (where the Persian Gulf table is considered western).
So far the Russians have requested any policing operations in central asia should be with coalition of CIS forces or otherwise directly handled by CIS forces, ostensibly related to the area south of the Caucasus, or Georgia, Armenia, Azerbaijan and Iran, all of these nations with significant Muslim as well as Christian or Christian-friendly secular populations.
I just can’t see Russia being okay with an Israeli assault/invasion of Iran. I think the Kremlin is going to be exceedingly suspicious of any invasion of Iran by anyone not in coalition with CIS forces.
vanir@Levsha, the GSh-2-30 is used on the Su-25 for anti-armour. It’s not as effective as the GAU-8 so it’s really used for soft targets and rockets or other external munitions against armour…theoretically, I don’t think they’ve ever shot at armour in warfare, just in testing.
I think this gun was first developed for a specialised anti-armour variant of the Hind (Mi-24P). Newer Russian attack helicopters (like the Hokum) use a more advanced single barrel 30mm which I believe has better projectile performance. On these 23mm gunpods are used for soft targets suggesting the main gun has a usable anti-armour performance.
Similarly I believe the GSh-6-30 is best suited to soft targets, but I mean it’d do a job on an armoured scout car, ACV or typical SPG just not so much an MBT.
vanirM1.78-1.82 achieved supercruise(not under test conditions), and there are articles with references to even higher speeds.
>1600mph top speed
any chance of a reference to confirm?
@jackjack, thanks for the link, Norwegian eh, not bad. Small warhead though.
Also, point taken, still I was talking about unescorted mission radius, which was a concern published in RAAF magazine way back when (but also like I said I think they’re pretty satisfied with the SuperHornet replacement). Cheers.
vanirGot any specifications on it? Will F-35 customers have it available by service delivery?
What else does it carry internally, JDAM?
vanirYeah I’m still a little confused about the F-35. So far it seems like it may have a lot of transitional drag going supersonic but once there it should be good for supercruise at maybe 1.3M
I mean it makes a hell of a difference in the anti-shipping role if the internal bays are big enough to handle a couple of Harpoons?
vanirJackJack the ADF reserved force interdiction in the far north as Pigs without escort. Sure for the regular strike role they’d use coordinated force projection with tankers and Hornets, and wouldn’t do that without moving frigates into the area too. I’m talking about the penetration strike role, not fisticuffs in extended hostilities. This point was covered in the RAAF own published magazine back before the purchasing agreement was finalised (one of the options tabled was trying to update the Pigs).
Also I’m aware currently the RAAF is satisfied with the SuperHornet replacing the Pigs, they weren’t about an F-35 only purchase however.
@eagle afaik the demonstrated supercruise is 1.6M with YF-22 (which has more sweep), all other figures being speculation. Max speed on burners for the F-22A is varied claims from 1.8M to 2.5M with around 2M being likely. Advertised supercruise I’m aware is 1.7M for F-22A but then the advertised max level speed of the F-15A/C is 2.5+M when it is 1.78M in service (unless the engine management is overridden, which if it is the engines have to be fully torn down on landing). At this point I’m prepared to consider actual performance figures for the F-22 ~1.6M supercruise and ~2M on burners but it’s “classified” so we’ll never know for about thirty years unless you fly one.
vanirI’m not much of an expert on the A-10 but another point to consider might be complexity. The Su-25 has similar survivability benefits of a titanium bathtub and robust structure but most importantly it carries a full service kit on board and can run in the field on any ad hoc fuel type, including civilian grade diesel. You can literally park an Su-25 in a desert patch with nothing but a palm tree for logistical support and a truckload of munitions and sustain combat operations.
Can complex aircraft types achieve these kind of requirements? I suspect the A-10 is a very good rough field operator too, it makes sense for the type. Can’t see an F-35 lasting under similar conditions without being close to major supply/support infrastructure. Maybe in Marine landing operations but then you’ve got massive logistical support in harbour only kilometres away.
vanirsorry scorpion I mentioned 1.1M at alt for the Hornet but I shouldn’t have shortened “at altitude” for “at alt” because it might confuse our international (non-English first language) forum members, I apolegise. Yes I meant at optimal altitude the Hornet is supersonic at intermediate power as according to McDonnell Douglas.
Nice point there obligatory, although stub wings can get away with low sweep and good transition to supersonic (eg. F-104), so long as the cone angle from nose to wingspan is good for it. But the point being complexity of wing design plays a role in transitional drag to supersonic speeds, but given the F-35 can manage ~1.8M I don’t see why you couldn’t maintain supersonic speed dry, with its high thrust engine I’d suspect it shouldn’t be a problem to keep ~1.3M at altitude around dry max clean.
@Blue Apple, the MiG-29 RD-33 are 0.4 bypass compared to the 0.27 of F404 in the Hornet and 0.76 of the F110 in Vipers and 0.36 of the F100 in Eagles. The F135 is 0.57 which is pretty middle of the road here. The Flanker’s AL-31F is 0.6 and the Mach 3 rated D-30F6 in MiG-31 is identical at 0.57 (<- this has a sustained max cruise of 2.35M but that’s with I think two of its four flameholder rings lit).
@em745 it is perfectly fair and reasonable to hold points of view and opinion is open game, but technically supercruise is defined by supersonic flight without afterburners. It doesn’t even matter how you got there, hell if you used rocket packs to get supersonic and then cruised dry at 1.4M you’ve got a fantastic fast response interdiction radius for a given fuel load.
The term is really a tactical one for mission planning and not an aircraft technical specification per se, which is the real point about supercruise. It’s mostly about force interdiction in the penetration strike role, because you have to go fast, you’re going to have to get low at some point and there aren’t going to be any tankers available in the combat zone. Aircraft like Hornets and Vipers are severely restricted for this, even the Strike Eagle falls down because it has to carry so much external fuel for the mission it becomes a subsonic cruiser or it won’t even make it to the target without running dry. The role of the supercruising multirole is like the 21st century version of the F-111 mission doctrine.
Certainly the faster the supercruise all the better combat radius for specific missions and in particular it also represents increased loadbearing at lower supersonic speeds, or in thicker air which is awesomesauce for the penetration of modern defences. But ultimately where planners are concerned you’ll be placing supercruise and dedicated penetration strike aircraft (which carry a big enough internal fuel load to make supercruise occasionally superfluous) in one box, and then everything else in another. Supercruise effectively turns an F/A-22 wing into a B-1B one for many foreseeable missions, there are so many reasons the Raptor is better for it. And it can do things you just can’t with Hornets or Strike Eagles, mostly range related.
Mind you, in the regular strike role under air superiority and late stage continued warfare, subsonic and loaded up with external stores the Raptor isn’t any better than an Eagle or Hornet.
Where Supercruise for the F-35 is important to me is since we took these for the RAAF our existing problem retiring the F-111 fleet is it takes away our force interdiction capabilities north of Australia in territorial waters. Hornets don’t have the combat radius in supersonic hi-lo-lo-hi to get far out from the coast on fast response anti-shipping strike if modern enemy warships are used. Cruise fast enough to penetrate defences and you’ll never get to the target area, go too slow and they won’t be there when you arrive (it’s a maze of islands north of Oz, you could hide a whole country up there and I’m so not kidding, only decades ago they were still finding entire regional communities that had never seen or heard of the outside world and thought overflying aircraft were the gods).
Supercruise, for Australia doesn’t mean anything about aircraft performance marques and the RAAF couldn’t care less about that. What it means is force interdiction radius. The only alternative is massive internal fuel loads on supersonic craft, so the next best thing is a Flanker really but that’s unrealistic.
vanirScorpion the Eagle’s titanium section of fuselage skin is the dark metal you can see around the engines underside which is not painted. The rest is mostly graphite/epoxy with some al-honeycomb sections. Aside from this stipulation the description doesn’t depart from mine, though is certainly more detailed.
My point about the Flanker is that it is described by Sukhoi OKB as all-metal with no composites used. So firstly the skin has to be stressed metal, like a Tomcat and not like an Eagle.
Secondly I do not know of any Russian manufacture of aluminium honeycomb in aircraft production. Aluminium honeycomb is an advanced engineering procedure the US developed at ridiculous expense from the Valkyrie project (it was the only useful thing gained from it). It is extremely difficult to manufacture.
The Russians make a novel graphite-honeycomb, but I can’t find any example of aluminium honeycomb used by MiG or Sukhoi in aircraft construction, at all.
Given the size of the Flanker, this means titanium is the only other construction material that could give its relatively light weight, solid aircraft alloys would make it several tons heavier. It is mandatory that titanium must be a major structural component, simply due to a sheer absence of any alternative material given there are no composites or non-metal structure used.
Finally it is stated by Sukhoi OKB that the Flanker “has a high titanium content”
If you could find any relation of structural materials by weight for the Flanker I’d be interested, as I can’t find anything that specific.
Similarly if you can find any example of Sukhoi producing aluminium-honeycomb I’d be equally interested, since that offers the only titanium alternative that doesn’t contradict Sukhoi claims, which would keep the weight of the Flanker what it is (damn light).
Consider the point, the Flanker is a fair bit bigger than an Eagle and just over three tons heavier and doesn’t have any composites and doesn’t have aluminium-honeycomb. It should be more like 8 tons heavier…unless titanium.
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