FBWPierre Sprey, the biggest proponent of FM, is specifically opposed to high tech sensors (radars) and radar-guided missiles. He doesn’t believe that BVR missiles have a place in the air battle, and thinks that only short range missiles and guns are useful. He uses his IFF argument to support his beliefs.
Sprey was a mouthpiece, he designed nothing, despite what some blogs claim. Harry Hilliker must want to roll over in his grave every time Sprey is called “designer of the F-16”.
@Obiligatory
You got that wrong, there was a thread here on this particular subject where Pierre advocates a beyond IFF missile,
hope someone is better at google than i, and in his book he advocates a supercruiser.
What F-22 didnt achieve according to Pierre is economy, he preferred a cheaper solution but with the performance
Sprey ( and Riccioni) did a similar hit job on the F-22 as on the F-35. I posted the piece over in the Su-27 thread awhile back. He claimed it would be inferior to the F-15 due to higher wingloading and lower thrust to weight. As usual, “cooking” the numbers to fit his claims. And Herp is right, his ideal aircraft was a light, IRST equipped fighter with minimal avionics fit.
FBWWrong. Conformal tanks were not added to have less drag compared to ETs. That do not differ really. The main purpose is to relief stations for other loads, be it weapons or pods.
That is not correct, they do have less drag, in subsonic flight they actually lower drag on F/A-18, and in some cases provide enough lift to offset increased weight:
http://defense-update.com/products/c/F-16-CFT.htm
http://www.f-16.net/f-16-news-article781.html
http://www.janes.com/article/31900/boeing-eyes-usn-s-growler-for-conformal-fuel-tank-upgrade
Quotes “The CFTs have very little adverse affect on the F-16’s renowned performance,” said Maj. Timothy S. McDonald, U.S. Air Force project pilot for CFT testing at Eglin. “The aircraft retains its full 9-g capability and flight envelope with the CFTs installed. The drag impact is very small – less than one percent in combat configuration at cruise conditions.”
“The conformal fuel tanks, which Boeing is building with its own money in partnership with Northrop Grumman, are capable of carrying 3,500 lb (1,587.7 kg) of fuel and are designed to reduce radar cross-section and minimise drag.”
FBWIn the last 10 years we have seen one fighter reach IOC the F-22, four fighters in development. They all share four characteristics : internal weapons, airframes shaped for reduced radar signature, embedded antennas, AESA radar. Presumably, at least, the F-35, J-20, and T-50, have large internal fuel capacity. I would mention integrated defensive avionics suites, but information on the Chinese birds is sparse.
The is no ambiguity in what are the design drivers for modern combat aircraft. It’s not just about radar “stealth” (hate that word) and no design since the now retired f-117 relied simply on passive defense. There is a reason why the EA-6 and the successor, the EA-18 are classified as defense assets for the DoD, not exclusive to the Navy. The USAF pursuit of MALD-J, continued funding of some parts of NJD, show a balanced approach. There is no reason to employ active EW on a LO airframe when you can use other assets. (though at least the APG-81 has electronic attack, APG-77 EW upgrade funded?)
FBWLooking at the “calculations” (rather a strong word) on the SLDInfo page, it is dazzlingly apparent that they assume that 30+ per cent more fuel = 30+ per cent more range; to wit, that the fuel tanks, whether empty or full, have neither mass nor drag.
That’s what one of my designer friends calls “Newton don’t allow”.
On the other hand, it’s a good piece to bear in mind when considering the quality of SLDInfo’s copious pro-JSF propaganda.
I don’t think media bias is unique to blogs, the words are from Michael W. Wynne. And yes he does state that “calculations, neglecting range drag”. I think he knows that 30% more fuel will not equate to equal increase in range. I think he is making the point that USAF is taking several different approaches to extend range.
FBWOne issue pointed out by the Super hornet drag index was that moving the tanks out lowered the drag. One issue affecting the F-35 with drop tanks on the inner two pylons is interference drag with the fuselage. The inner wet pylons are quite close to the aircraft, not ideal.
Here is the study on F-35 EFT: http://www.dodsbir.net/sitis/view_pdf.asp?id=AF141_076_Ref_5…pdf
Computational Optimization of the F-35 External Fuel
Tank for Store Separation-Eric F. Charltony and M. Bruce Davisz (if link to pdf does not work, put title in google.
Basically stores separation was the issue as previously noted by Low Observable, the was, however issues with airflow between fuselage and tank.
The USAF seems confident the range with external tank issue is well, going to be a non-issue.
Another link- http://www.sldinfo.com/what-are-the-next-concepts-in-air-warfare/
“Second, one could return to a drop tank design that was in vogue up to 2004 for the F-35 but set aside in light of the myriad hard problems being solved simultaneously to get through testing.
By that time they had settled on a extended pylon and tank design for a 426 gallon tank on each wing yielding a combined 852 Gallon range extension capability. The calculations, neglecting range drag, could yield an additional range of 372 Nautical Miles, which are directly additive to any other radius improvement; and therefore adds more value to the STOVL.”
…To further extend the F-35’s range, Lockheed Martin is exploring an innovative concept from Israel, of using unique drop tanks, developed by Elbit Systems Cyclone. Designed in a similar concept to the F-22 under-wing drop tanks, these tanks, each containing 425 gal. of fuel, will use special attachment pylons that would completely separate from the wing, regaining full stealth capability after separation. An additional 900 gal. of fuel will significantly extend the F-35I range, enabling the IAF to operate its new stealth fighter at the “outer ring” of operation without mandatory aerial refueling.”
In other words, I don’t think that the range on EFT was a result of some airframe aerodynamic deficiency as some have implied. As the article pointed out, the F-35 has had bigger issues to conquer as of late, the range with external fuel is probably not high on list of priorities with current software snafus dominating attention.
FBWI’m surprised that such liberal mixing of the terms “F-35” and “real world” doesn’t cause the offending posts to self-annihilate.
Flanker was designed around OCA, not DCA.
No, it was not. A clue of that would be which branch operated it first…. PVO. It did become part of frontal aviation by late 80’s.
FBWThe other faith-based piece is “internal fuel good, external fuel bad”. Not necessarily. My internal fuel tankage is stressed to max g and an 8000 hour life – that, the bomb bays and the STOVL penalty are reasons why the F-35A is heavier than Typhoon but has a smaller wing. It’s there all the time – in high-energy air combat, in transonic acceleration, and when it’s empty. I don’t have the choice of big “bomber” tanks and smaller, supersonic-cleared air combat tanks.
After reading through the recent posts, I’ve not seen anyone simplify the argument down to “internal fuel good. external bad” so I’m not really sure who you are addressing that to. There is no doubt that there is a penalty for large internal fuel fraction, but it would seem worthwhile for any strike aircraft. On the other side of the spectrum; there is the F/A-18 and the Mig-29, both were handicapped by small internal fuel capacity. Would you agree that the original F/A-18 A/C was handicapped by it’s reliance on refueling in the strike mission? The usage of CFT on the F-15E and F-16 block 60 would seem to point to the performance advantage of EFT when dropped is not as important as carrying large amounts of fuel efficiently for a strike aircraft. (F-15E rarely flown without CFT).
If you are conducting DCA or OCA missions, sure, EFTs would be superior on a smaller airframe. Of course, the very large fuel capacity of the Sukhoi aircraft would suggest that internal fuel capacity is also important for DCA missions for nations with a large amount of airspace to patrol.
FBWYou are forgetting one thing: war is expensive. You are planning to drop several bombs per sortie, each costing several thousand dollars. Do you really think the odd fuel tank dropped matters? How many bombs dropped over Irak, how many tanks?
As for logistics, sure, can be a problem. The solution: WRM tanks, as in war reserve material. They can be stored and built on site.
But what about carrier aircraft? Simple, don’t make them reliable on drop tanks. Has been done in the past (A-6, A-7 anyone?), not so much with the F-18 series…
Tanker scheduling? Yes, if your aircraft are being shot at, it tends to mess with your scheduling.
Not really going to respond to the “war is expensive”, as far as tankers: In most recent air campaigns, the limited number of tankers available requires a strict choreograph of who refuels when. I’ve posted the article from Libya about the Mirage-2000’s landing due to a fuel emergency. Tankers are not just circling up there like 24 hour gas stations open for all comers. Lastly, no air force want to expose their tankers to attack, and stage them as far from a threat as possible. The reality is a bit more nuanced:
yes you can drop the tanks which will most likely result in a mission kill, or emergency fuel situation on a deep strike.
The EFTs have a price to be paid in drag which is significant and compounded as you add more tanks (weight+drag), the impact on maneuvering performance is far greater than CFTs or large fuel fraction, and will present a problem with any pop up threat.
Every pylon carrying a tank cannot carry weapons limiting flexibility.
As I said in first post on page, there is no free ride, larger wetted area will increase drag on aircraft with large fuel capacities, yet EFTs impose a penalty that newer designs are attempting to avoid. Look at the F-18E/F, Rafale, Eurofighter, they are all experimenting with CFT.
FBWDon’t confuse the 5g maneuver graph from the book about the F-22 with Metz’s comments. To me that graph is a not very helpful due to no mention of load, fuel, etc. As far as the rest, of course there is no “special” physical laws that only apply to the Raptor. I would say that the unknowns about dry thrust/wet thrust figures of the F-119, inlet performance, drag, allow for only “ballpark” predictions of it’s performance envelope. Really, I don’t think I’ve made any longshot claims about it’s performance, I’ve just posted what has been released by the F-22 SAR and observations by the test pilot. Here is the other comment Metz made about the Raptor’s climb profile (APA interview- I know… but the words are Metz’s)
“The best subsonic afterburner climb speed in the Raptor occurs at 600 knots calibrated airspeed.
The fastest way to get to altitude in a Raptor is to accelerate to supersonic on the deck and climb all the way supersonically. Sorry, I can’t quote the numbers but suffice is to say that we are talking high supersonic climb speeds. The F-15, on the other hand, has its best climb rate when the climb is made subsonically to 30,000-35,000 feet and the aircraft is then dived to a supersonic speed before once again pulling up into a supersonic climb. The difference in time to climb using the Raptor versus the Eagle climb technique is dramatic but, again, classified.”
Interpret them as you will… As I am enjoying this thread, I will not be posting off-topic on this again.
FBWInteresting. I would somehow want to get my hands to its SEP graphs then 😀 There is a reason F-15 (or any other aircraft) climbs best in such way; while engine thrust stays mostly the same, incresed velocity steadily increases the available “power” due to Power =Force x speed; which increases climb rate. A large increase in drag at transonic/supersonic will automatically decrease available force, and drop the climb rate graph down. Despite less available “force” which is again steady after transonic drop, climb rate still increases. At sufficently high airspeeds it exceeds the subsonic one. subsonic climb is made at the “apex” before the wavedrag, and quickdive to “skip” the inefficient part, and continue climb at supersonic “apex” of the climb rate graph. This is not fully related to individual aircraft performance.
If F-22 is supposed to work best by going to supersonic at low alt, it needs to have very little wavedrag so that SEP not drops a little, or a huge thrust to provide a meaningful SEP at M1.3+. How fast F-22 can go at low altitude?
There used to be a post a f-16.net from an F-22 pilot DOZER (all his posts have been erased), ran into OPSEC issue. He had a story about accelerating in F-22 at low level. I wish it was still there. I’ve seen M 1.4 quoted at sea level but I would be very skeptical of that number. Metz may just have given the best answer for why F-22 climbs from supersonic on the deck :
F-22 Pilot Perspective.pdf 902KB Jan 04 2012 – DLIELC.edu
“The Raptor is always in a combat configuration, fully loaded and ready for war. The aircraft has no external stores, so drag remains low and Ps stays high. The specific excess power, or Ps, is a measure of the airplane’s ability to accelerate or climb at its current flight condition. Wing aerodynamics and overall drag are at a minimum near the design speed of 1.5 Mach at 40,000 feet. This airframe is actually at its best at supersonic speeds, with the best time to climb right off the deck. Conventional fighters have their best time to climb using a Rutowski climb profile. That is, they start with a subsonic climb to the tropopause (about 36,000 feet) and then perform a pushover to supersonic speed and climb supersonically from there. The Raptor can dispense with this complex profile and blast off supersonic from the deck. This machine just likes to go fast.”
FBWApparently according to him, F-22 fastest climb profile is to go supersonic at low level and maintain throughout climb. F-15 climbs best subsonic to 30,000 ft dive to supersonic then resume.
FBWOf course. Let me explain myself like this: While Su-27 is regarded has having superior turning, comperable climb and inferior acceleration to F-15, no one says the difference is beyond comparison. Su-27 is better, but still comperable.
Going from same example I’ve made above, Su-27 also has negative stability (or lifting tail as Basher54321 says), it has very minimal trim drag at supersonic (for example at 10-11 km altitude from M1.3 to M1.7, less than 0,5 deg angle is required on stabilizers; be it clean or armed with 10 missiles). F-119 may produce high (156 kN) thrust, but F-22 is heavier resulting in very comperable T/W and lack of variable inlets result in inferior T/W at supersonic speeds. It has huge wing area for good maneuverability, but heavy weight drops its wing loading. Large wings create greater drag, dropping T/D ratio despite great thrust…. etc etc etc etc.
I am not trying to trash F-22 thats not my intention at all, but I have two points:
1- all the qualities you wrote, which are supposed to give F-22 a HUGE edge over 4th gen fighters is also present on a very known 4th gen fighter; good old Su-27.
2- all the qualitative advantages (low trim drag, proportionally much higher thrust, large lifting area, negative stability) did not give any advantage to Su-27 over F-15 at the supersonic realm.So no, If F-22 will have kinematic advantages over legacy fighters, it won’t be a due to simple explainations like “its because it has X feature”.
Also whoever made the climb profile is misinformed; F-15 does not NEED to dive to go supersonic at 30k, if you look at the level flight envelopes of F-15E, it can go supersonic in level flight even when loaded with 4x AIM-9s, 12x Mk-82s, CFTs, centerline EFT, and Lantirn pod. However passing transonic regime as quickly as possible by diving is better for fuel efficiency, I am sure that applies to F-22 too. Going supersonic on level flight on an F-15 is problematic only around 55000 feet. As F-22 has similar service ceiling, its quite possible it will struggle too.
Paul metz -test pilot for f-22 program. And no f-15 does not NEED to dive/ go supersonic. That is fastest climb profile.
FBWRemember when US pressured Ukraine into giving up it’s nukes? Doesn’t bode well for non-proliferation negotiations.
same accord where Russia guaranteed the territorial integrity of Ukraine. Probably not productive to bring that up.
FBW@molnibalage; I agree on your post, except for two things; 1- to be honest, I don’t think even F-22A has tremendous or decisive maneuvering or climb performance compared to basic F-15. 2- I wouldn’t call PAK-FA sharing same aerodynamic concept as Su-27; even at the first looks, it has proportionally very tiny wings, but a huge lifting body, and has “LE flaps” for that lifting body. I would call Su-27 a tailled delta, MKI a canard-tailled delta, but I don’t know what to call PAK-FA.
There are several areas where the F-22 improves over the F-15- first, the very large horizontal stabs help unload the wing, coupled with TVC, reduces trim drag (especially supersonic). Also, the use of TVC increases roll/ pitch rates by controlling trim while the tail is used for roll maneuvers. F-119 produces more thrust (proportionally) in relation to the F-100 at high altitudes. There is a definite improvement on the left side of the envelope due to combination of FBW, TVC, and relaxed stability. As far as climb, there have been comments that the climb profile for the F-22 differs from the F-15 in that it’s best climb rate is supersonic without the need to dive at 30,000 feet, accelerate to supersonic, then continue the climb. If you are speaking of sustained turns, it may not be substantially better, but there is not a lot of data to use for comparison other than the 3.7 sustained g at 30,000 feet for the F-22 KPP. (F-22 is at “full-full” F-15 clean/ ~6,000lbs fuel/pylons is around 3.2 g at mach .8 30,000 ft)
FBWIf a specific high-priority mission required fighters to drop their tanks then of course they would do so, but the days of dropping tanks as a routine park of mission planning are long gone.
@Hopsalot
Absolutely, and it’s even more critical for nations without a robust air refueling capability. The Israeli raid on Osirak comes to mind. Had SAF scrambled to respond to Israeli incursion through their airspace, (denying any tacit understanding with Saudis that may have been present), that mission would have ended in failure.
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