Talk:Supercruise
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As a rule of thumb...
All aircraft capable of Mach 2+ speed in level flight at some altitude with afterburners can do Mach 1+ at the same altitude without. Just look at the F-104: Military thrust is 48kN, with AB it's 69kN, i.e. less than 60% more. Theoretically it could do Mach 2.2 with AB. Even if we assume supersonic drag to increase linear with airspeed (it's worse), this will give us > Mach 1.5 without AB. For other aircraft this is not much different. - Alureiter 22:37, 14 December 2005 (UTC)
- Wrong. I don't understand the aerodynamics, but it appears the thrust needed to cruise above the speed of sound is dramatically more than you need to cruise below it, so most fighters can't go supersonic without afterburners. As this Air Force press release on the F-22 says
- Mushala added that "Its ability to supercruise will allow the F-22 larger patrol areas, and permit the Raptor to enter and exit hostile areas in quick fashion, reducing the time a pilot spends over an enemy’s territory. The capabilities of an F-22 aircraft will be a great benefit to our warfighters."
- Virtually all other modern day fighters must use their afterburner either to sustain supersonic flight or to reach initial supersonic speeds.
- I'll take the USAF's word for it...--Robert Merkel 23:57, 14 December 2005 (UTC)
- I don't understand the aerodynamics, but it appears the thrust needed to cruise above the speed of sound is dramatically more than you need to cruise below it - This is exactly my case, since the thrust with afterburners is not dramatically more than without it. BTW: see also http://www.dcr.net/~stickmak/JOHT/joht12f-104.htm:
- Many of the Century Series fighters could supercruise, though most of those just barely. (As a rule of thumb, any plane which can exceed Mach 2 with afterburner can probably exceed Mach 1 without.) Starfighters with the J79-19 engine can - at altitude - maintain about Mach 1.1 in level flight in military power (maximum throttle without afterburner). This isn't surprising when you realize that the J79 engine was vastly improved during the long production lifetime of the F-104, with later versions producing nearly as much thrust without afterburner as early models did with.
- This is were I got that rule of thumb from. (But my simple calculations are obviously wrong). Alureiter 00:13, 15 December 2005 (UTC)
- I don't understand the aerodynamics, but it appears the thrust needed to cruise above the speed of sound is dramatically more than you need to cruise below it - This is exactly my case, since the thrust with afterburners is not dramatically more than without it. BTW: see also http://www.dcr.net/~stickmak/JOHT/joht12f-104.htm:
- I think the rule of thumb is correct, but there's a joker in the pack. For example Concorde used reheat (a/b) to go supersonic, but then supercruised. I read in a book on Concorde that it turns out that Concorde had enough thrust to go supersonic without reheat, but it took ages to push through the hi-drag transonic regime. Since drag is bad, you're just pissing away fuel. Net upshot was, Concorde used more fuel avoiding reheat, than with it, for distance over the ground, so they always used reheat in practice. I bet that many other supersonic planes are the same.WolfKeeper 19:37, 23 January 2007 (UTC)
This issue is far more about aerodynamics than engine power or design. Concorde could supercruise because it was designed to -- a long, slender fuselage with a relatively short wingspan. Militarily, this doesn't work, because such an aircraft would be ineffective as a fighter. All true fighters are very inefficient at supersonic speeds, but usually they are very good at subsonic high-g combat maneuvering. Concorde was so poor at slow-speed maneuvering that takeoffs and landings were performed primarily by reference to instruments. There is a book called "In the Cockpit" that describes takoffs and landings in Concorde by reference to pitch angle within one-half degree and stopwatch timing within one second, and of course almost religious airspeed control. Of course, Concorde did use straight turbojets because that is what works best at supersonic cruise. Most modern fighters use some kind of fan because that fits their normal operating envelope the best. It is also possible that an aircraft unable to break the sound barrier without AB can subsequently cruise above mach 1 without it, due to the high drag in the transonic zone. For this reason, most aircraft will engage AB between mach .90 and .95 and accelerate above mach 1.2 (figures approximate), then disengaging the AB. Srilm (talk) 21:08, 1 April 2010 (UTC)
- Concorde super-cruised across the Atlantic at Mach 2.0 on ~40,000lb of thrust, around the equivalent in power of a single early RB211. — Preceding unsigned comment added by 2.31.130.17 (talk) 14:35, 1 March 2015 (UTC)
- " ... Concorde was so poor at slow-speed maneuvering ..." - Video on YouTube of a BA Concorde 'greasing in' at Kai Tak back in 1996 here: [1] — Preceding unsigned comment added by 2.29.18.153 (talk) 20:18, 9 August 2015 (UTC)
- Just FYI, the reason the Concorde could supercruise was because the inlets operated as a hybrid ramjet. The compression ratio of the concorde was abysmal at subsonic speeds, just 15.5:1. This is a quarter of modern engines. The reason it was able to supercruise was because the hybrid ramjet intake produced a compression ratio of over 5:1. which boosted the total pressure ratio to roughly 80:1.
- So clearly the design of the intakes is the most important factor. Most fighters have ramps or shock cones that release or deflect excess air from the intake at supersonic speed. This is because the engines stall if they are fed supersonic air. The ramps and cones reduce intake pressure instead of increasing it as the Concorde intake does.
- The compression ratio of the engines may also be a limiting factor, as using a Concorde intake with most modern engines would result in pressure ratios above 200:1, which is not something that can be sustained with any materials I am aware of. Due to the intakes, the Concorde could not physically operate with engines of higher compression ratio. DbivansMCMLXXXVI (talk) 20:09, 26 December 2018 (UTC)
- I cannot agree with Alureiter. In the 1971 war vs Pakistan, IAF MiG-21s downed four F-104 Starfighters. One was a tailchase starting from Jamnagar on 12 Dec 71 [1] with Flt Lts BB Soni and MM Sehgal of 47 Sqn in MiG-21s chasing one F-104 flying at 200' which was shot down some 20 km into the sea. Soni said he was at ~1150 Kph, just below M 1.0.
--Moitraanak (talk) 13:23, 7 August 2019 (UTC)
References
MiG 1.44 dispute...
Did this aircraft EVER supercruise? It seems to be very similar to the Avro Arrow... From what little i can find, the aircraft had 1 or 2 tesflights before being shelved.
Mig 1.44 and Su-47 are designed for a supercruise using AL-41F engines. Mig 1.44 definitely did not have time to test supercruise during its two flights. Su-47 had much more flights, but information about its the results is limited. Single build prototype Su-47 was equipped with D30F6 engines, the same as on the MiG-31 which has no supercruise ability. Certainly, none of them flew supersonically on military thrust.Lorethan (talk) 20:34, 21 December 2018 (UTC)
Tu-144 detail
I was a bit baffled about the revert of my edit yesterday which added detail of the TU-144's supercruising capabilities. There was no detail anywhere about why it was reverted, so I have put it back. It was all accurate and correct, and any extra detail is clearly a good thing. If anyone wants to tell me what was wrong then please say so here. The edit was coupled with the addition of another aircraft to the list which admittedly was wrong, as i'd confused myself but the rest was good, so the good Tupolev stuff I have put back. Please do point out what is wrong with it if there is a problem. Thanks, vwozone 19:01, 23 January 2007 (UTC)
- I'm a bit baffled too, since your user name has not made any edits to the article for at least the last month. If you were not signed in, it might be helpful if you told us the IP address you were on. I think I can figure it out in this case, but it might be harder in cases where there are more than one revert on a given day. - BillCJ 21:53, 23 January 2007 (UTC)
Okay, fair play - forgot I wasnt logged in at the time. Edit was made under IP: 91.109.46.60. For information, revert was made on the same day by 'Wikimachine' vwozone 20:31, 24 January 2007 (UTC)
Tu-144D with the RD-36-51A engine was capable of a supercruise like the Concord, but it never been used in commercial operation.Lorethan (talk) 20:41, 21 December 2018 (UTC)
F-35 Lightning II doesn't supercruise
At least according to http://www.jsf.mil/contact/con_faqs.htm. --Edward Sandstig 09:52, 13 April 2007 (UTC)
- The original claim comes from a Lockheed Martin official but as far as I know has never been verified elsewhere. I can't prove what I'm about to say and Wiki doesn't allow original research but the claims for it are almost ridiculous. The official apparently said that it could supercruise at Mach 1.2, which is highly unlikely if you know anything about transonic drag. The drag peak for an aircraft of that configuration would be about M1.1 and would not stabilise at a practical level until at least M1.3. Realistically, there's no practical reason to do it unless you could get at least M1.4 out of it.
- The other issue is the engine, which has a significantly higher bypass ratio than the others. This engine was designed for favourable SFC at subsonic speeds so supercruising is pretty unlikely. Supercruising apparently also places a lot of stress on the HP turbine which, on an engine like the F-135, is already under some pretty significant pressure. You'll have to excuse me for not being able to back this up with a reference but there really isn't a lot out there. I only know from what I've read about transonic and supersonics over about 30+ years but its not easy to remember where it all came from. Flanker235 (talk) 13:29, 30 September 2017 (UTC)
- Why not blow the claim away since the original ref is busted and see if it resurfaces other than as echoes of this page. Not verifiable=not on wiki. See also http://www.jsf.mil/contact/con_faqs.htm Greglocock (talk) 21:36, 30 September 2017 (UTC)
- A bit more digging reveals that what was probably meant was that if it uses full A/B to reach M1.6, and then throttled back to switch the A/B off, it takes 150 nm to slow to M1, giving an average speed of M1.2 . LM PR up to their usual tricks. I suppose I could reverse engineer that hypothesis, but frankly why bother? Greglocock (talk) 22:16, 30 September 2017 (UTC)
- A quick calculation suggests someone made a factor of 10 error and the actual so called supercruise capability is more like 20 miles, not 200. Also, the LM definition would apply to any suspersonic aircraft, since they will all maintain M>1 for some time after the engine is switched off. Assumptions - mass=27000, vmax=472 m/s Tmilitary_thrust =.33*Tab. Tab=220000 N. Greglocock (talk) 02:50, 1 October 2017 (UTC)
- All interesting and totally believable hypotheses gentlemen. I like the idea of blowing the claim away and seeing what comes of it. Either the claimants can back it up or they can't. One of the claims doing the rounds at the moment is that it can supercruise at M1.2 with 10% afterburner! It seems some of these claims come from people who don't actually know what supercruise is! Flanker235 (talk) 11:11, 6 October 2017 (UTC)
This thread on f16.net http://www.f-16.net/forum/viewtopic.php?t=20559 quotes an F-35 pilot who says it can sustain supercruise at 1.2: "As I've mentioned in another thread, I chatted with "Hog" from the 461st and he confirmed that yes the F-35 can indeed supercruise. It takes afterburner to get past the sound barrier but once hes supersonic he can pull the power back to mil and it'll stay there around Mach 1.2." 50.247.253.194 (talk) 16:02, 20 June 2020 (UTC)
- no, a pilot is reporting a claim by another pilot. If we assume that pilots never exaggerate, tell tall tales, etc etc then we are still left the problem that a chat site is not an RS. Greglocock (talk) 22:19, 20 June 2020 (UTC)
MiG-31 in the 'Aircraft designed to cruise on afterburner'
MiG-31 should also be mentioned in that section, because it was designed to supercruise (e.g. cover large distances in relatively long time) with afterburners at Mach 2.35 with 4 semi-recessed R-33 missiles under it's body and it can cover some 700 km on this speed. I'll provide sources if needed. —Preceding unsigned comment added by 89.216.142.96 (talk) 16:39, 5 August 2010 (UTC)
- Supercruise means without afterburners so, although it's good at high speed cruise, it's not a super cruiser. Flanker235 (talk) 22:56, 30 September 2017 (UTC)
No it does not! This entire article is about justification of aircraft flying at supersonic speed with an afterburner ! and I work in the aerospace engine industry and that was NEVER what this term was originally intended to mean. I think that this entire article has twisted the meaning to allow people to justify their points of view. And just to be clear 'supercruise' only became a generally accepted term when it was used in the marketing material.
- Agree with your points but would you mind signing your posts please? Flanker235 (talk) 01:10, 20 April 2018 (UTC)
Saab Draken
I saw recently that this aircraft was removed from the list. There was a series on aircraft (I believe it aired on the History Channel but I could be mistaken) that featured the Swedish Airforce. I do recall the narrator announcing that the J-35 could cruise at mach 1.2 without using afterburner but I have been unable to find the video again. I believe the video was on Youtube for a period but then removed (most likely for copyright violation). If anyone else saw this video or has another source for the Draken it would be appreciated. -Nem1yan (talk) 02:16, 7 March 2011 (UTC)
Draken did the first supercruise 26 january 1956 when a prototype without afterburner broke the sound barrier. Later versions with stronger RM6C engine had no problems to reach supercruise without afterburner. 130.241.141.198 (talk) 07:37, 19 June 2013 (UTC)
- I don't doubt that. Any decent source for this? ––Nikolas Ojala (talk) 12:12, 24 March 2018 (UTC)
It's not entirely clear how single Avon engine could provide a supercruise for Saab 35. It is even more doubtful that it was possible with missiles loaded. Is Avon so unrealistically powerful on transonic or is the Saab 35 so unbelievably streamlined? — Preceding unsigned comment added by Lorethan (talk • contribs) 22:02, 14 December 2018 (UTC)
- Random googling came up with these numbers for the engine. J35D had "RM6C, which was a copy of the substantially uprated Rolls Royce Avon 300 "big bore" engine, fitted with the Swedish EBK 66 afterburner. The RM6C could provide 56.4 kN (5,750 kgp / 12,700 lbf) dry thrust, and 76.8 kN (7,830 kgp / 17,260 lbf) afterburning thrust." So, if Cd was unchanged and the thing is good for 1340 mph wet, then dry it would be 1148 mph . Now that seems too good to be true, perhaps the source for thrust figures is wrong. Greglocock (talk) 05:51, 15 December 2018 (UTC)
English Electric Lightning is capable to 1.2M supercruise because it has 2 Avon engines and 11Kn of dry thrust. Avon engine has a low overall pressure ratio, so it have a good excess of thrust on supersonic. But Saab 35 has a single Avon. — Preceding unsigned comment added by Lorethan (talk • contribs) 17:46, 15 December 2018 (UTC)
- I prefer your analysis to mine! But how do i reconcile 56.4 kN of thrust (my figure) with 10 kN (your figure)? oh, sign your posts! Greglocock (talk) 22:36, 15 December 2018 (UTC)
- Dry thrust to empty weight ratio is virtually identical for the two. Greglocock (talk) 23:06, 15 December 2018 (UTC)
Supercruise ability is determined not by thrust to empty weight ratio, much more important is thrust to drag ratio. I doubt that Saab 35 has 2 times less resistance than EEL. Is there at least one reliable resource about possibility of supercruise for Saab 35 with missiles? Not words in the documentary. There are many planes that can reach 0.99-1M with weapons, but not 1.2M. — Preceding unsigned comment added by Lorethan (talk • contribs) 10:00, 16 December 2018 (UTC)
- "I doubt that Saab 35 has 2 times less resistance than EEL" So do I, but I don't know, and haven't found a ref that says either way. Adding the requirement for missiles probably knocks out the Lightning, and Concorde, as well. Greglocock (talk) 19:47, 16 December 2018 (UTC)
Is there at least some source that Draken had the possibility of a real supercruise? I will give an example. The maximum speed without afterburner for the MiG-29 at 11,000 m is М 0.96 with 2 missiles. Maximum thrust of two engines at this moment is 2700kg. Engine thrust equals air resistance. If you run a full reaheat, then the thrust in the same situation is 6,300 kg and excess thrust is 6300 kg - 2700 kg = 3600 kg. It needs 4800 kg of thrust to run MiG-29 on М 1.1 at 11,000 m, its not a problem with full afterburner thrust 7500 kg in this situation, but without afterburner engines cannot produce 4800 kg at altitudes above 8500 m. The maximum wet thrust of two MiG-29 engines on the stand is 16,600 kg, but at a maximum speed of 1,500 km / h at sea level it increases to 23,500 kg. All these figures are from the MiG-29 manual. EEL has high dry thrust and relatively low drag, so it is capable to perform supercruise, but I'm not sure that this is a real cruise flight and not 8 minute acceleration like the on F-35.— Preceding unsigned comment added by Lorethan (talk • contribs) 10:00, 16 December 2018 (UTC)
- Jeez are you ever going to sign your posts? I looked in the flight manual at http://www.avialogs.com/index.php/en/aircraft/sweden/saab/j-35draken/hflv-685-121-flight-manual-f-rf-tf-35-draken.html#download and for a clean a/c at military power the maximum speed is M0.97 at 23000 ft roughly. That's on page 590 labelled as 10-41. So whatever the prototype might have managed whatever variant the manual is written for was not expected to supercruise. Of course this is WP:OR Greglocock (talk) 00:17, 17 December 2018 (UTC)
M 0.97 sounds like the truth, J-35 has no prerequisites for a supercruise ability. I just wanted to say that it is incorrect to compare dry and wet thrust measured on the stand at sea level. As the flight altitude increases dry thrust for MiG-29 drops from 5000 kg at sea level to 850 kg per engine at 14,500 m. The maximum wet thrust at 15,000 м is 4,000 kg per engine. Afterburner gives a dramatic increase of thrust, thats why so few airplanes capable to perform dry supercruise. Max mach number for MiG-21 on dry thrust is M 0.96, for MiG-25 it is M 0.98. Probably modern supercruise engines can burn a lot of fuel in the combustion chamber and withstand enormous thermal stress. In older engines fuel for supersonic flight is burned in reaheat. Here are some pages from book "Practical aerodynamics of the MiG-29" https://cdn1.radikalno.ru/uploads/2018/12/18/427a395ea6f19286f6ba19d1dcaec61c-full.jpg, https://cdn1.radikalno.ru/uploads/2018/12/18/c74d67144dfabf3a0a334526dfbbb186-full.jpg. The first graph on dry thrust, the second on full afterburner. Рр - engines thrust lines, Х - drag force lines, H = 0,5,14,5 (Хн=0,5,15) - line on sea level, 5000 m, 14500 m. Typhoon's dry thrust is not much greater than that on the MiG-29, but if the Typhoon is capable to supercruise, then this means that its engines do not lose thrust at high altitude. The fuel that is burned in the MiGs-29 afterburner in the Typhoon is burned in the combustion chamber, which means the Typhoon combustion chamber withstands extreme stress.Lorethan (talk) 20:52, 21 December 2018 (UTC)
So, in the end, the J35D is not able to supercruise, right? 176.221.170.199 (talk) 10:24, 10 August 2021 (UTC)
MIG-25 and MIG-31 ?
It need to tell something about these mach 3 planes
- Neither of these aircraft can supercruise. The MiG-31 can sustain high Mach flight but not without afterburners. Please sign your posts. Flanker235 (talk) 11:21, 6 October 2017 (UTC)
Aircraft designed to cruise on afterburner
Most of the statements in this section are incorrect.
1. "using afterburners with air that was diverted past the turbojet core of the engine". No air entering the J58 afterburner bypassed the core. 80% was turbine exhaust. About 13% was cooling air from the 4th compessor stage and 7% was also from the 4th stage but used, together with the turbine exhaust, for combustion. So, a turbojet with afterburning.
2. "did not radically modify the intake/exhaust geometry in order to achieve Mach 3 flight". The XJ93 intake was a Mach 3 'multi stage' air compressor so had to have all the same features as that for the J58. They were just different shapes. The exhaust was, just like that on the J58, a Mach 3 expander with the same pumping requirement for secondary air. Hence, both ejector nozzles with similat expansion ratios.
I will correct with credible refs. — Preceding unsigned comment added by Pieter1963 (talk • contribs) 18:41, 25 March 2014 (UTC)
TSR-2 super cruise claims
The article currently states "supersonic cruise at Mach 2.00 at 50–58,000 ft.[5] Supersonic cruise at lower levels was at Mach 1.1 at 200 ft". In all of my sources these are the maximum speeds with afterburner at those two altitudes. Does anyone have a source that states a maximum speed without afterburner? Maury Markowitz (talk) 16:13, 28 December 2014 (UTC)
- A Pilot Press cutaway drawing of TSR.2 with comprehensive specification figures as-of November 1962, here: [2] but no mention of whether reheat was used or not.
- I suspect that if reheat had been required for cruise then the range would have been much less than the ~2,000 miles on 5,588 gallons of internal fuel stated, but I could be wrong.
- The best resource is the Flightglobal Archive here: [3] with an excellent 1964 article here: [4]; including the sentence " ...at low altitude the aircraft will cruise without reheat ..."
- BTW, range figure above is from: Radius of action figures with one 2,000lb bomb internally are: '1,105 mls (1,850 km) with 10 per cent at Mach = 1.7 above 40,000 ft (12,200 m) and 20 per cent Mach = 0.9 at 200 ft (61 m), or 575 mls (925 km) at Mach = 2.0 at medium altitude or 800 mls (1,286 km) at Mach = 0.9 at 200 ft (61 m).'
- FWIW the basic design began life as the English Electric P.17 by the same company that designed the Lightning. They then merged with Vickers for the TSR2 contract and became BAC - BAC and Sud Aviation later produced Concorde. The latter aircraft's engines were based on the TSR2's Olympus. — Preceding unsigned comment added by 95.148.220.15 (talk) 11:37, 4 February 2015 (UTC)
- Not much use in answering your question I know. — Preceding unsigned comment added by 95.148.220.15 (talk) 11:06, 4 February 2015 (UTC)
deletion of B-58 by Greglocock
The B-58 meets the definition for supercruise given in the first paragraph of the article. It's a good one (see comment below) , although not cited, and does not preclude the use of afterburner. A crucial part of this definition is that the plane could/can spend some period(time unspecified) at some sustained steady-state supersonic speed without compromising its mission success.
I think the B-58 may have been the only plane to enter service that had two design cruise speeds, one supersonic in addition to the usual subsonic one, making it the first supercruiser (to enter service) by this definition (Mach 2 and Mach 0.91), until the Concorde came along (Mach 2 cruise and diversion cruise at Mach 0.93).
A B-58 flew 8,000 miles at an average speed of 938 mph. This is a fair indication of the prolonged periods at its supersonic design speed of Mach 2 between refuellings.
I've just noticed that this definition was deleted by Greglocock a while ago before being re-instated. There is an equivalent definition from an authoritative technical source.[1] This source specifically names the SR-71 as a supercruiser.
The current definition covers everything, yesterdays wet and todays dry supercruisers. Although a dry definition is popular it is unnecessarily restrictive and leads to confusion with regard to afterburning supercruisers. Pieter1963 (talk) 22:10, 14 February 2015 (UTC)
- You are misusing the definition of supercruise. Typical b58 mission was subsonic until 100-200 miles from target, then climb and M2, and subsonic on the way back. In the SAC charts there is no mention of supercruise. Greglocock (talk) 00:38, 15 February 2015 (UTC)
- Here's what NASA had to say "The limited range capability of the B-58 can be directly traced to the compromises required in its aerodynamic design. The Mach 2.0 dash requirement dictated the use of a delta wing with leading-edge sweep angle of 60° and a low aspect ratio of about 2. As a consequence, the value of the maximum subsonic lift-drag ratio, without the fuel and weapons pod, was only 11.3 (compare this with the value of 21.5 for the B-52G); an even lower value would be expected with the pod attached. The value of (L/D)max at Mach. 2.0 was slightly greater than 5. Thus, the aircraft was not capable of efficient cruising flight at either subsonic or supersonic speeds. " Greglocock (talk)
- Thank you for your reply. Interesting information and food for thought.Pieter1963 (talk) 14:43, 15 February 2015 (UTC)
- That statement has nothing to do with whether the B-58 could cruise long distances at supersonic speed, and is no basis for removing the B-58 from the article. It traveled from Los Angeles to New York City at an average speed of 1,214 mph. The crew was awarded the Distinguished Flying Cross for this achievement. The record stood for 28 years and was only bested by the SR-71: http://www.wvi.com/~sr71webmaster/b58.htm Whether B-58 operational doctrine used that proven sustained supersonic capability is beside the point. The F-22 itself (as mentioned in the article) is not capable of sustained supercruise without a significant fuel/range penalty, and operational plans envision restricting supercruise to a limited mission phase -- as was the practice with the B-58. Joema (talk) 12:01, 3 April 2015 (UTC)
- Re-instate it (but not as a supercruiser because the term hadn't been invented) As long as the right qualifying statements go with it (available from the NASA site) eg able to cruise supersonically for 450 mi with 1500 mi radius of action without flight refuelling, etc. no one is being misled and it can be compared to other, 'woefully deficient in range(NASA)', aircraft. As to what a typical mission was, where is that info available for a more complete entry? The Lightning entry is ripe for some qualifying words. I've not been able to find any statement that said it cruised anywhere supersonically, just numerous statements by pilots with one theme "it had no spare AVTUR". Combat air patrols cruised subsonically until SS interception and intercept missions were just that, no cruising at any speed. Perhaps its ability to fly supersonically for short periods w/o afterburner was only useful for doing stabilized performance to check dry-thrust/drag predictions?Pieter1963 (talk) 00:37, 12 April 2015 (UTC)
- I repeat, in the SAC charts there is no mention of supercruise. That is, in the standard mission profiles the thing was either subsonic or at M2 with afterburner. Neither of those conditions is supercruise. The wikipedia way is that you find a reliable source for one of these planes flying efficiently at >M1, or without afterburners at >M1, if you read this http://history.nasa.gov/SP-468/ch12-4.htm neither seems likely. http://www.ww2aircraft.net/forum/album/data/745/1959-T-O-1B-58A-1-Flight-Manual-USAF-B-RB-58A-Aircraft.pdf is also generally interesting, and http://www.alternatewars.com/SAC/B-RB-58A_Hustler_SAC_-_10_July_1959.pdf includes enough data that you could probably work it out, although that would be WP:OR. The problem with the simple calculation mentioned much earlier (that an a/c that can fly at M2 with a/b should be able to maintain m1 dry) is that it ignores the well documented increase in resistance in the transonic region, and assumes (thrust a/b)/(thrust dry) is not too great. Greglocock (talk) 02:46, 12 April 2015 (UTC)
- Here's the engine spec from the wiki page, Maximum thrust: 11,905 lbf (52.9 kN) dry; 17,835 lbf (79.3 kN) with afterburner
- Specific fuel consumption: 1.965 lb/(h·lbf) (200 kg/(h·kN)) with afterburner, 0.85 lb/(h·lbf) (87 kg/(h·kN)) at military thrust so it certainly fulfils the requirement for low (thrust a/b)/(thrust dry), but thus far I haven't been able to get much idea of the drag vs speed graph, as the nasa technical report server has been shut down. Greglocock (talk) 03:22, 12 April 2015 (UTC)
- P7, top ///RIGHT// graph in the SAC for mission planning probably tells you what you need to know, if not want you want to hear. If you do successfully work it out and it does supercruise and you present your working here I'll check it and if it is OK then I'll stop removing the B58 from this page (but without an RS anyone else is entitled to remove it), but at first sight it looks as though the incremental change in fuel consumption between M2 and M 1.2 is surprisingly small. I estimate the fuel consumption per nm is 2.6 times cruise for M1.2, 2.5*cruise for M1.6, and 2.9*cruise for M2.0 Greglocock (talk) 04:51, 12 April 2015 (UTC)
- Correction in above , top right, not left Greglocock (talk) 23:02, 12 April 2015 (UTC)
- P7, top ///RIGHT// graph in the SAC for mission planning probably tells you what you need to know, if not want you want to hear. If you do successfully work it out and it does supercruise and you present your working here I'll check it and if it is OK then I'll stop removing the B58 from this page (but without an RS anyone else is entitled to remove it), but at first sight it looks as though the incremental change in fuel consumption between M2 and M 1.2 is surprisingly small. I estimate the fuel consumption per nm is 2.6 times cruise for M1.2, 2.5*cruise for M1.6, and 2.9*cruise for M2.0 Greglocock (talk) 04:51, 12 April 2015 (UTC)
So for simplicities sake here's my estimates, errors are about +/-4%. There seems no sweetspot for fuel consumption (which is surely the raison d'etre for the supercruise concept) between M2 and M1.2
Speed | Fuel consumption lb/nm |
---|---|
Cruise | 18 |
M1.2 | 44 |
M1.6 | 45 |
M2.0 | 52 |
Greglocock (talk) 07:52, 13 April 2015 (UTC)
Late edit, NASA report SP-472 specifically mention the B58 and says it is designed for high subsonic cruise and supersonic dashes "In 1956, the Convair B-58, a medium range bomber also having Mach 2 "dash" capability, was brought into the Air Force inventory.All of these aircraft performed well in the transonic and supersonic speed regimes, but they all had rather short supersonic range and duration of flight. " "At the time of these preliminary B-70 studies, the Air Force perhaps expected little more than a larger version of the B-58. There was little to indicate that more than supersonic "dash" capability could be achieved, and "the only recourse available to the design engineer was the so-called brute-force concept -tremendous fuel capacity and an optimized aerodynamic shape for the target sprint." "Greglocock (talk) 00:10, 19 December 2018 (UTC)
References
- ^ "Practical Considerations in Designing the Engine Cycle" Philpot, RAE Pyestock, AGARD LS-183
English Electric Lightning
- "The Lightning entry is ripe for some qualifying words." - well the prototype P.1s weren't fitted with re-heated engines and they all exceeded Mach 1 quite comfortably, Beamont even doing so when in the climb. How much more obvious does that need to be. BTW, here's some video of Lightnings making transonic low passes at an airshow back in 1987 just in case you've never seen aircraft flying at around Mach 0.95 - 0.99 (from around 4:19) without using reheat: [5] - the visible shockwaves are from the thickest part of the wing and from the canopy. — Preceding unsigned comment added by 2.31.130.124 (talk) 16:36, 13 May 2015 (UTC)
- "On the performance side it is interesting to note that the Lightning has genuine supersonic performance capability in unreheated thrust, with stabilized level performance at the tropopause in the neighbourhood of Mach 1.2, the precise value depending on the temperature of the day ..." (the Lightning) " ... is still the only operational aircraft with this capability." - Roland Beamont in a 1963 Flight article here: [6] — Preceding unsigned comment added by 95.148.221.26 (talk) 19:05, 9 June 2015 (UTC)
- .. and here in a 1959 article it states that with a full load a Lighting maintains Mach 2 at a minimum reheat setting, i.e., with the lowest amount of reheat it's possible to demand; [7] — Preceding unsigned comment added by 95.148.221.26 (talk) 20:08, 9 June 2015 (UTC)
- "Transition from subsonic to supersonic flight can be achieved in maximum cold thrust from sea level to 45,000 feet, and up to 52,000 feet in reheat" - Pilot's Notes - Lightning F. Mk 1 & F. Mk 1A - 1962. — Preceding unsigned comment added by 95.149.173.74 (talk) 14:09, 23 May 2016 (UTC)
reasons for deletion of paragraph in article
"The key challenge in attaining supercruise... is a radical redesign of the engine because the air entering a jet engine must always travel at subsonic speeds, regardless of aircraft speed" The air always travels into the engine at subsonic speed so it doesn't have to be redesigned to make that happen for the special case of supercruise.
It's misleading to call the design changes in the mentioned engines "radical" as they are changes which have been going on for years to give lower weight/higher specific thrust/optimum bypass ratio. I think the only 'radical' features which have helped enable supercruise in todays engines are the vectored propelling nozzle and the diverterless intake.
"Otherwise compressibility waves (or shock waves) will create uncontrollable vibrations among the compressor vanes" Shock waves in the intake come nowhere near the compressor because all intakes have a subsonic part in front of the compressor. On the SR-71, for example, the closest they came was about 115 inches.
"uncontrollable vibrations among the compressor vanes" are not caused by shockwaves but by distortion in the subsonic airflow entering the compressor or by very high air temperatures, in which case the blades are operating in a stalled condition. (J-58 redesigned to avoid this)
"Engine inlet design therefore can effectively limit the speed of the aircraft, regardless of thrust" Inlet design is about making sure the incoming flight-speed air slows down in a way that gives the highest pressure possible to the engine and with acceptable distortion. This is not "regardless of the thrust" since the engine thrust is determined by the pressure and the distortion that the intake gives it.
"The SR-71 Blackbird's distinctive nosecone is designed to funnel air around the J-58 engine for that very reason" The nose cone is not designed to funnel air around the engine. The nosecone is designed to give the external (ie deflects flow into itself) and internal air passage the correct converging shape (area ratio)to make it into a supersonic compressor. A similar converging area ratio was required on the XB-70 as it was also a Mach 3 compressor. It used flat plates instead of cones.
Air is "funneled" around the engine because the intake is letting more air in at the front than the engine will accept, not to make sure it's subsonic or to stop blade vibrations. The air is passed around the engine by virtue of its pressure where it goes in (cowl boundary layer bleed slot/shock trap bleed)and the pumping action of the propelling (ejector) nozzle. Pieter1963 (talk) 01:30, 25 February 2015 (UTC)
reasons for deleting statements in article 2
If any one thinks the presumed intent of the deleted topics has a place in this article I will suitably reword with cites.
"using afterburners with air that was diverted past the turbojet core of the engine" The falsehood in this statement, popular with enthusiasts (it's appeared/been deleted before in this article), can be easily seen by looking on-line at the SR-71 Flight Manual, fig. 1-11. It shows 80% of what went into the afterburner was turbine exhaust and 20% was bleed air from the compressor.
"made use of specially designed turbojets" No cite. No value to the reader. That they were specially designed is a foregone conclusion, but how was it done?
"Unlike the J-58 engines powering the SR-71, the YJ-93 engines of the XB-70A did not radically modify the intake/exhaust geometry in order to achieve Mach 3 flight" Unfortunately the cite, the Jenkins/Landis book, stops short of explaining the intake, engine or propelling nozzle. I don't think that was because they weren't 'radical' enough. That something doesn't ring true with the 'did not radically modify' statement(apart from no cite) is apparent when we recognize that they both had to obey the same laws of physics (or more specifically aerothermodynamics). They used the same air, taking it in at the same speed and delivering it to the engine at the same speed and with the same low pressure loss and distortion. They both took in more air than required by the engine for the same reason and bypassed it to the propelling nozzle for the same reason. The propelling nozzles had to expand the same combination of engine exhaust and bypass air through the same pressure ratio. They both had to work everywhere between take off and cruise. They had to do all the same things but used different shaped parts so they looked different.
"the engines were specifically designed to be very efficient in afterburner" Again this statement is not cited , a personal viewpoint, presumably insightful to the writer, which conveys no meaning to the reader. How is an engine specifically designed to....etc?Pieter1963 (talk) 00:01, 3 March 2015 (UTC)
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XB-70
I am very pleased to have access to the flight manual supplement, which reveals the rather astonishing fuel consumption of the XB 70 at M3
If you look at the high speed charts at 75000 ft, at a constant weight, the fuel consumption per nm actually decreases with increasing speed.Greglocock (talk) 10:48, 31 August 2016 (UTC)
If I understand correctly the charts on pages 77 - 79, the XB-70 had a natural supercruise ability up to M1.4 at milirary thrust.Lorethan (talk) 08:30, 23 December 2018 (UTC)
The supercruising EE Lightning
Why is the Lightning in this article?
The article has 2 definitions for supercruise which I infer to mean supersonic cruising is part of a standard mission profile, not just the ability to go to M 1.1 for a few minutes, dry or wet. I see nothing in this article which says it had more than a supersonic dash capability.
So, is there another definition out there which needs to go in the article?Pieter1963 (talk) 00:34, 4 January 2017 (UTC)
- I'd have thought the first aircraft to supercruise without A/B in level flight deserves to be in the history section, whether it meets the strict definition or not. Greglocock (talk) 03:30, 4 January 2017 (UTC)
- I agree that it deserves a mention in this article as the first step towards supercruising but in deference to Wikipedia:Verifiability what published source says it was a supercruiser?Pieter1963 (talk)
- "whether it meets the strict definition or not" I think you either have to meet the definition, or explain, as this article is meant for those who don't already know. Pigeonholing, eg it's a supercruiser", only works effectively if everyone uses the same definition. My understanding is that the term "supercruise" was invented to cover a new capability for combat aircraft which included endurance at supersonic speed (It wasn't a new shorthand for "can do M1+ with no A/B". It included endurance). From "Lightning from the cockpit" we have, from the F3 tactical trials at CFE, "capability was dominated by its critically low fuel capacity" and "with one engine shut down.....increase of 37% in range". So you get either the "super" or the "cruise" but not together. Mission profiles shown in the same book show M0.95 and M0.9 cruise prior to engaging subsonic and supersonic targets. Again, no supercruising.Pieter1963 (talk) 01:54, 7 January 2017 (UTC)
- OK how does that look? Greglocock (talk) 06:05, 7 January 2017 (UTC)
- Good edit, much appreciated. I don't know any more about supercruise than the woman in the street which is OK. As this is a Wiki introductory article on supercruise I have elected myself on their behalf to try and make it less confusing. If there are any Lightning fans out there don't get me wrong. I've taken my share of photos.Pieter1963 (talk) 19:37, 8 January 2017 (UTC)
ramjet
I see in comedy corner (future proposed aircraft) there is a proposed high speed transport that will cruise using ramjets at M4. Now fair enough, that is not afterburners. Does this mean every non-gas-turbine engined plane that can cruise >M1 is a supercruise candidate? Greglocock (talk) 08:51, 9 January 2017 (UTC)
The F-35's long suppressed claim to supercruise
In about 2010 a breathless Lockheed PR dude (or dudette) claimed the F35 could supercruise. It turns out that what they really meant was that if it accelerate to M1.6 on afterburners, and then switched the afterburners, it would take some distance to slow down to below M1. This is of course true for all supersonic aircraft. The bogosity of the original claim was enhanced by a mathematical error by a factor of 10. Anyway when all this was pointed out to them several times by many people they shut up about it. AFAIK there is no current information provided by Lockheed or anyone else reliable claiming that the F35 can supercruise. http://www.jsf.mil/contact/con_faqs.htm etc. Greglocock (talk) 07:51, 1 May 2018 (UTC)
F-16N
I see the F16N has been proposed. Underneath this was basically a F16C/D. The flight manual shows that with the F110-GE-129 engine at all weights with a zero drag payload the F16 exceeds M1.0 at about 25000 ft and reaches M1.04 at low weights. Any significant drag from the payload reduces it to subsonic. The PW engine was always subsonic without a/b. Greglocock (talk) 03:24, 18 December 2018 (UTC)
- It makes as much sense as all the other marginal types you've been arguing about above. Although it's sourced to "The Drive", usually a sensationalist site in my experience, this story is by an actual pilot, so I presume he knows what he's talking about. The F-16N was a stripped-down version, and the whole point of the story is that it was a hotrod. - BilCat (talk) 05:10, 18 December 2018 (UTC)
- That's why I checked the flight manual. The N isn't really a hotrod, it didn't have the high thrust intake, and much of the weight saved by taking the gun out was replaced by ballast. Mainly they just flew pretty clean (I suspect the wingtip payloads were beneficial or neutral). Cheers Greglocock (talk) 06:45, 18 December 2018 (UTC)
- So basically you're saying the pilot's lying? That's not our determination to make. We report what reliable published sources say, and we don't do our own research using primary sources to determine whats true or not. - BilCat (talk) 06:52, 18 December 2018 (UTC)
- Not at all, from what I can see the F16 with the GE engine was good for M1.04 dry. Greglocock (talk) 10:40, 18 December 2018 (UTC)
- Does the F-16N flight manual detail all the weight changes over the C/D? - BilCat (talk) 06:56, 18 December 2018 (UTC)
- No, it's the flight manual for F16 C/D, the weight change comments were taken from the ref. Not too sure what your problem is. I don't have one, we have a primary source, a pilot, and confirmation from a published primary source, the flight manual. I'd like to see a robust case for each entry, not just a bloggy thing. If I were being wiki-picky I'd point out that the sources veer towards being primary, personally that doesn't bother me one little bit. Greglocock (talk) 10:40, 18 December 2018 (UTC)
- So basically you're saying the pilot's lying? That's not our determination to make. We report what reliable published sources say, and we don't do our own research using primary sources to determine whats true or not. - BilCat (talk) 06:52, 18 December 2018 (UTC)
If I were being wiki-picky I'd point out that the sources veer towards being primary, personally that doesn't bother me one little bit.
- So why post your question in the first place? That's my problem here. The article is full of primary source data being interpreted to prove that X aircraft was the first to "supercruise" at Mach x for x minutes, most which amounts to original research/synthesis in a national peeing contest. This one is a clear statement by a pilot, granted a primary source but still a clear statement, though without qualifying particulars. I'd like a robust case for each entry also, but very little of the article meets that standard already. So why question this one? - BilCat (talk) 21:30, 18 December 2018 (UTC)
M1.04 at maximum military thrust with a zero drag payload is definitely not that supercruise in the classic senseLorethan (talk) 16:32, 26 December 2018 (UTC)
- Much of what is in this article isn't supercrusising in the classical sense either, so how is this one any different? Also, we do not know what the F-16N's specifics are, as the source for the C/D variant doesn't specifically include the N model. It's synthesis to take specs for one variant and apply them as gospel to another one. - BilCat (talk) 20:23, 26 December 2018 (UTC)
- I think you guys are actually in agreement with one another. The OP appears to be saying the N model was only capable of supercruise because it had no armament, and became subsonic with even a minor payload. Every source I can find says it was just a standard Block 30. The replacement for the N model retained its original block number to avoid this confusion. — Preceding unsigned comment added by DbivansMCMLXXXVI (talk • contribs) 23:22, 26 December 2018 (UTC)
- No, we're actually not in agreement. The N- model was ordered specifically for the US Navy, with structural modifications as mentioned in The Drive article such as the use of titanium in the "lower wing attach fittings", not just a lack of a gun. Saying "the N model was only capable of supercruise because it had no armament" is an unwarranted assumption. The replacements were apparently stock aircraft as ordered by Pakistan, though the gun may have been removed after delivery to the Navy (I don't know). - BilCat (talk) 08:27, 27 December 2018 (UTC)
- The wingtip Sidewinders made no odds to the performance figures in the flight manual for C/D. I think for the aggressor squadron stuff they replaced one SW with a camera. I agree the performance of the N may have been different to C/D, but the changes seem small beer overall, and the documented performance of C/D adds credibility to the claim by the pilot for the N. Pilots have after all been know to um, stretch things a little. Greglocock (talk) 09:51, 27 December 2018 (UTC)
MiG-25
The official claim from the laugh a minute MiG 25 article is "Range: 1,860 km (Mach 0.9), 1630 km (Mach 2.35)[101] ()" The ref is to some unobtainable propaganda sheet. Even if the Cd is the same at M2.35 (in which case they should have obviously been put in charge of designing the Tu144), that implies the engines are 6 times as efficient on partial afterburner than optimal subsonic cruise. Greglocock (talk) 06:41, 18 December 2018 (UTC)
- Some digging suggests the air intakes were designed for supersonic cruise and the thing was horribly inefficient subsonically. The 31 added movable ramps etc. Greglocock (talk) 01:33, 19 December 2018 (UTC)
- This information is from a book for Soviet pilots, which was classified until 1998. Here is page at left side about flight range https://cdn1.radikalno.ru/uploads/2018/12/19/8e92ce69b3b264c886caafbb8863a561-full.jpg The compression ratio of MiG-25 engines is very low 4.74, so these engines are ineffective at subsonic speeds. These engines are designed for effective flight at supersonic speed, where the compression ratio and efficiency are significantly increasing. Mig-25 is an interceptor, it surpasses any fighter in cruising speed and altitude, it was designed to intercept the enemy as quickly as possible. Flying at a subsonic speed in economy mode does not fulfill its task. For example, a MiG-29 can fly M2.35 for no more than 5-10 minutes.Lorethan (talk) 19:29, 19 December 2018 (UTC)
- Thanks for the link, I see the numbers are there, but as you have confirmed the interesting thing is the poor performance subsonically. Greglocock (talk) 21:39, 19 December 2018 (UTC)
- This seems to indicate it uses a hybrid ramjet intake like the Concorde. The Concorde had a very poor 15.5:1 compression, but this was boosted to around 80 by the ram intake having a compression ratio of over 5.0. This only occured in supersonic flight, so its subsonic performance was not very good.
- If the Mig had any higher compression it would likely be temperature limited at a much lower speed, as the effective compression ratio at Mach 3 would be well over 100:1. So it almost certainly could not use an engine with higher compression. The Mig-31 has much higher compression ratio, and its top speed is significantly lower.DbivansMCMLXXXVI (talk) 23:29, 26 December 2018 (UTC)
The top speed of the MiG-25 was limited by the temperature of the skin, fuel and canopy, not by the engines Lorethan (talk) 20:52, 31 January 2019 (UTC)
- This is a common misconception. The fuel and airframe temperature limited the time it could maintain full afterburner, not its top speed. The top speed is limited by the turbine temperature. Whichever limitation comes first. It could exceed the turbine temperature and reach Mach 3.2, but this would damage the engine beyond repair. — Preceding unsigned comment added by DbivansMCMLXXXVI (talk • contribs) 01:43, 1 February 2019 (UTC)
- Those who have not seen this aircraft or heard about its operation first hand tend to make contentious statements. I'm glad that somebody finds it funny; the USSR types did have a whacky sense of humour. The Indian Foxbat (R) was a 20-tonne steel vehicle carrying 20 tonnes of hi-density avgas imported from the USSR and then Russia (Specific Gravity 0.84 vs the lighter version of the ATF used by the IAF) and transporting it across the skies. The landing approach of this ac was over 2.5 times the 'Radius of Action' of the MiG-21s of the 70s and flown at idle power. All other aircraft would either hold or leave circuit when this monster called "long finals". Flight durations were from 1 hr 15 min for operational missions to 1 hr 45 min for practice sorties. 1900/1600 km were a breeze, even with the gas guzzling engines. The large wings were not for agility- they were for Lift! The aircraft was made almost entirely of steel, with a little of the expensive, difficult to mould, weld and repair Titanium used only in heat-critical areas. Aluminium was reserved for the rare heat-free areas of the aircraft. In a fully loaded aircraft you couldn't exceed 60 degrees of bank, a stability limitation posed by the 5 huge cameras carried and the 1st generation Inertial Platform. The usual angle of bank was 45 degrees.
DbivansMCMLXXXVI is absolutely correct. This actually happened and the damage caused internally and externally rendered that aircraft a write-off. Moreover, max reheat simply burns flight time away at an alarming rate. - I feel that the definition of supercruise should include a sub-para: A phase of flight by aircraft that have their best SFC or TSFC at high Mach nos and in reheat. Do please read https://hushkit.net/2018/12/12/loneliness-at-mach-3-interview-with-a-mig-25-foxbat-pilot/ That post could come up soon as a reference.
- The author adds : The standard profile of the MiG-25 was at M 2.4 at altitudes 20 Kms+ (started around 20 Kms, then the aircraft cruise climbed as the fuel reduced. Generally one finished around 22 Kms or so. This was done at MINIMUM AFTERBURNER (and NOT(R) NOT AT MAX AFTERBURNER). Max afterburner was to get-away / escape & it could take you to 30 Kms / M 3.0.
At this point, I'm afraid there is no reference for this last statement, but expect it to come up soon when the full role of this aircraft in the Kargil War of 1999 is officially released in the public domain [1]; a reference of sorts is available on the Mikoyan-Gurevich MiG-25 page. However, this author states that best SFC of 2.45 was reached at M 2.35 at 21-22 km in minimum afterburner. - The Foxbat R was a reconnaissance version and did exactly that: photography and some ELINT. This aircraft was not designed for subsonic flight, except for the take off and landing phases of flight. Even with a huge ventral tank, the aircraft operated at M1.5. The max permitted Mach No was 2.83 for a sustained (and not cumulative) maximum of five minutes, [2][3] though you could also dash to M 3.0 for a very short time. All IAF pilots were expressly briefed as to how to join the Trisonic Club and authorised as such. They also climbed past 100,000', to clock two landmarks. The trainer was fully aerobatic, at 3.5 G for barrel rolls and 5.5 G for Rolls off the Top. The rollout was with cross-controls! Loops were banned as the elevator did not have enough authority to pull you out of the dive past 225 degrees of the loop. The limitation posed by the canopy was not entirely due to frame strength, but also because of the worry that its glue might melt away. Skin temp was around the 300 degrees C (572 deg F) mark. Moitraanak (talk) 14:04, 7 August 2019 (UTC)
- A number of issues are covered in the Mikoyan-Gurevich MiG-25 section. Looking back, this aircraft was never meant for close-in WVR combat, but for high altitude shoot and scoot tactics. Moitraanak (talk) 10:57, 8 August 2019 (UTC)
- Perhaps this sentence should replace that suggested: The definition of supercruise should include a sub-para: A phase of flight by aircraft that have their best SFC or TSFC when supersonic whether in dry power or in reheat.Moitraanak (talk) 11:16, 16 September 2019 (UTC)
References
- ^ http://www.bharat-rakshak.com/IAF/aircraft/past/963-mig25.html
- ^ "Intelligence: Big-Mouth Belenko." Time, 11 October 1976. Retrieved: 12 May 2010.
- ^ Gunston and Spick pp. 132–133.
Split the awful list, supersonic cruising vs supercruise
Perhaps it might be better to split the a/c designed/found to cruise supersonically with afterburner, from those that do not need afterburner. Greglocock (talk) 00:07, 19 December 2018 (UTC)
- On second thoughts I'd rather move all these non complying a/c to the section they already have. Greglocock (talk) 01:31, 19 December 2018 (UTC)
Three of four definitions, perhaps time to reorganise things
There are several different definitions of supercruise, leading to some rather silly pointless argy bargy. Examples given for each definition
1) able to maintain level flight >M1.0 without the use of reheat, afterburners or thrust augmentation (EEL) 2) as (1) with some non-clean configuration or useful load (how much?) (Rafale)(Concorde) 3) designed to cruise for a significant proportion (how much?) of a flight >M1.0 with some sort of thrust augmentation (MiG 25)(SR71) 4) able to maintain level flight >M1.5 without the use of reheat, afterburners or thrust augmentation with some non-clean configuration or useful load (how much?) (F22)
4 is not of much interest to me, it was a politically inspired redefinition of the term. 3 actually results in the most interesting designs. 2 is problematical as it relies on some definition of yet another subjective term. 1 is easier to document and includes more interesting historical a/c. At present we are claiming to be using (2) without defining useful load, in practice we use (1) and then have a section for (3), without defining how much of a mission needs to be >M1.0. I don't think that is awful, but would be interested to hear other suggestions. Greglocock (talk) 10:16, 28 December 2018 (UTC)
- There are a couple of types of sources where the term appears, for example sales literature/aviation journals, and technical papers written by engine cycle specialists. I have come across 3 different (British) technical sources on combat aircraft which make a distinction between cruising supersonically and cruising supersonically without using an afterburner, for which they reserve the term supercruise. And they use the term to refer to part of a mission profile, ie the aircraft is doing something useful, carrying the relevant fuel and weapons.
- The term is used for combat aircraft only in NASA Supersonic Cruise Research '79 which refers to commercial aircraft as supersonic cruise transports.
- So, following this sourced useage, it's incorrect/misleading to refer to EEL, Concorde, SR-71, etc. as supercruisers.
- Cheers.Pieter1963 (talk) 01:10, 1 April 2020 (UTC)
Military vs. non-military is a moot point, Concord can supercruise. ([User:JoshCC]) — Preceding unsigned comment added by 103.232.210.187 (talk) 07:38, 13 January 2021 (UTC)
- It's in the terminology. Civil aircraft don't need the term. They already had their own "supersonic transport" which says all that is necessary and hence satisfied all those experts who know far more about it than the rest of us. (hence also SSBJ supersonic business jet). Supercruise was a term invented to apply to combat aircraft new requirements.Pieter1963 (talk) 00:18, 13 February 2022 (UTC)
4th gen jets can faux-supercruise
It's true, as I put in the article, but sources are hard to find. An obvious example is from a SmarterEveryDay video which shows a 2-seater F-16 just breaking Mach 1 at ~29.5 kft. Other examples of sources are not reliable, but promising nonetheless (example claims to have a flight manual that states F-15C can just pass M1 in mil power - highly dubious source, though). There were plenty of examples of similar behavior listed that I removed or clarified.
I prefer a set of criteria that looks like this for being "real supercruise":
- Carrying combat-ready load (say, at least 2 AAM + 1 external fuel tank, or 4 AAM w/o fuel tank for stealth fighters? This is contentious alone, but it's still a practical measure)
- Can sustain it in level flight under 25 kft
Caveats may include stuff like "doesn't destroy engine", etc. These criteria exclude the Thunderbirds F-16 but include planes like the F-22. How can the wiki have clear criteria for "supercruise" when it seems to be more of a marketing term rather than scientific measurement like climb rate, thrust, etc? These criteria seem fair because most planes marketed as supercruise-able fit them, while planes that technically can (ie clean F-16) do not. It's more representative of what a manufacturer means when they use the term. I realize this is skirting NOR, but from a few hours of trying to find good sources, it seems there just aren't any. HarryKernow (talk) 18:34, 11 May 2021 (UTC)
Clarification on quality RS for supercruise ability and speed
I removed several planes that had citations that generally did not point to the plane having supercruise ability. Some said it was possible in a clean config (F-16N), others flat out stated that it wasn't supercruise (BAC TSR). The most interesting one is from this paper (page 123 (134 on the pdf)) that says "The F-16XL was intended to be capable of achieving Mach 2.2 at high altitude and Mach 1.2 at sea level. However, its maximum airspeed in some military thrust and in all augmented thrust (afterburning) conditions was never determined during the Air Force flight-test demonstration program." implying that they simply didn't test military power supersonic cruising. HarryKernow (talk) 05:22, 4 March 2022 (UTC)
More on F-16XL
The F-16XL has truly given me the run-around in terms of finding citations for its supercruise ability. This paper (same as linked above) states plainly: "Neither F-16XL flight demonstrator proved to be capable of true supercruise performance, as was later attained by the Lockheed YF-22A ATF prototype and the production Lockheed Martin F-22A Raptor. As defined by the Air Force, supercruise provided a capability for sustained supersonic flight without the use of afterburner." (p.116, or 127 on the pdf), specifying in an endnote that "Much later, during the NASA flight-test program (with the aircraft totally clean of any external stores, including armament pylons, and powered by the higher-thrust General Electric F110-GE-129 engine, F-16XL-2 demonstrated sustained Mach 1.1 flight in Military (nonafterburning) power at an altitude of 30,000 feet." I think this is substantial enough evidence to exclude the F-16XL from the list, even if the Langley report mentions "Langley was involved in research on several variants of the F-16, including the highly impressive F-I6XL, which was a derivative that can cruise efficiently at supersonic speeds without use of an afterburner." (p.147, 161 on the pdf). The F-16XL clearly does not match the capability of planes like the F-22, and even though originally supercruise appears to have been an important part of the program (SCaMP), they either didn't really establish the actual prototypes as having meaningful supercruise capability. In fact it even seems (to me) that GD didn't even try promoting the F-16XL as a true supercruise fighter. In any case, as I've said, this is more than enough evidence to exclude the -16XL. Let me know if you find anything I have missed. HarryKernow (talk) 06:40, 15 March 2022 (UTC)
Add Sukhoi Su-57
https://en.wikipedia.org/wiki/Sukhoi_Su-57#Specifications_(Su-57)