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By: 13th May 2008 at 16:03 Permalink - Edited 1st January 1970 at 01:00
-Pretty good. :cool:
By: 13th May 2008 at 19:39 Permalink - Edited 1st January 1970 at 01:00
-If memory serves, its main limitation was in terms of defensive aids and hardpoints, meaning that in later life combat missions necessitated carriage of chaff/flare and ECM pods on the two wing hardpoints. This meant that the centerline hardpoint was the only one available on some missions. I suspect the slim fuselage caused some of these difficulties, i.e. not providing room for the added equipment.
Performance wise, however, it was a very good aircraft, albeit limited by its Atar engine, where something more modern like the Spey would have been a benefit. Add in room for the ECM gear and chaff/flare dispensers, and you have an excellent fighter.
By: 13th May 2008 at 19:49 Permalink - Edited 1st January 1970 at 01:00
-Performance wise, however, it was a very good aircraft, albeit limited by its Atar engine, where something more modern like the Spey would have been a benefit. Add in room for the ECM gear and chaff/flare dispensers, and you have an excellent fighter.
Could J79 be an alternative?
By: 13th May 2008 at 20:08 Permalink - Edited 1st January 1970 at 01:00
-Performance wise, however, it was a very good aircraft, albeit limited by its Atar engine, where something more modern like the Spey would have been a benefit. Add in room for the ECM gear and chaff/flare dispensers, and you have an excellent fighter.
The Mirage F1 was always meant to have the M53 for advanced derivatives, but the sales success of the YF-16 put paid to the F1-M53 and lead Dassault to develop the all new Mirage 2000. The ATAR was inferior to the J79, but superior in serviceability to all of the contemporary Soviet turbojets. In hindsight, the ATAR was a far better choice for a fighter engine than many first generation turbofans such as the early TF-30 and Spey 202.
The Mirage F1 was a very good multi-role fighter, a relatively cheap alternative to the late production F-4E, and altogether superior to any comtemporary Soviet fighter before the MiG-29.
By: 13th May 2008 at 22:14 Permalink - Edited 1st January 1970 at 01:00
-In hindsight, the ATAR was a far better choice for a fighter engine than many first generation turbofans such as the early TF-30 and Spey 202.
Please elaborate.
By: 13th May 2008 at 22:19 Permalink - Edited 1st January 1970 at 01:00
-If memory serves, its main limitation was in terms of defensive aids and hardpoints, meaning that in later life combat missions necessitated carriage of chaff/flare and ECM pods on the two wing hardpoints. This meant that the centerline hardpoint was the only one available on some missions.
ECM pods (Barax/Baracuda) and chaff/flare dispensers (Phimat/Corail) were fitted to the outermost hardpoints (or under a dedicated hardpoint for the Corail dispensers). This left three hardpoints for ordonance or fuel tanks (one under each wing and one on the centerline), plus two MAGIC II missile.
By: 13th May 2008 at 23:12 Permalink - Edited 1st January 1970 at 01:00
-Please elaborate.
I would refer you to the service history of the F-14A to relate just how unsuitable the TF-30 was for a high performance fighter. Similarly, the Spey 202 was very problematic in RAF Phantom.
By: 13th May 2008 at 23:29 Permalink - Edited 1st January 1970 at 01:00
-If memory serves, its main limitation was in terms of defensive aids and hardpoints, meaning that in later life combat missions necessitated carriage of chaff/flare and ECM pods on the two wing hardpoints. This meant that the centerline hardpoint was the only one available on some missions. I suspect the slim fuselage caused some of these difficulties, i.e. not providing room for the added equipment.
Actually, almost every European combat aircraft of the era lacked internal ECM and was forced to result to podded self defence measures, in contrast to American aircraft of the same era. In reality, European air forces lacked immediate experience with Soviet-style air defenses, unlike the Americans, and the obvious funding and industrial constraints worked in favor of podded, rather than built in defensive measures.
By: 13th May 2008 at 23:46 Permalink - Edited 1st January 1970 at 01:00
-I would refer you to the service history of the F-14A to relate just how unsuitable the TF-30 was for a high performance fighter. Similarly, the Spey 202 was very problematic in RAF Phantom.
Better take-off performance (weight & runway length), better range on same fuel, better climb & acceleration at low altitude . . .
But -
lower maximum speed, & worse performance at altitude. How much of the latter was due to the engine, & how much to the aerodynamic changes necessitated by fitting it (the cause of the top speed loss), I don't know.
If you wanted to build a 1960s high-altitude interceptor, I wouldn't recommend the Spey. For a 1960s tactical fighter-bomber, it looks like a better engine than the J79. Better T/W ratio (lighter & more thrust) at low/medium altitude, better SFC.
By: 14th May 2008 at 01:41 Permalink - Edited 1st January 1970 at 01:00
-Better take-off performance (weight & runway length), better range on same fuel, better climb & acceleration at low altitude . . .But -
lower maximum speed, & worse performance at altitude. How much of the latter was due to the engine, & how much to the aerodynamic changes necessitated by fitting it (the cause of the top speed loss), I don't know.
If you wanted to build a 1960s high-altitude interceptor, I wouldn't recommend the Spey. For a 1960s tactical fighter-bomber, it looks like a better engine than the J79. Better T/W ratio (lighter & more thrust) at low/medium altitude, better SFC.
The Spey that went into the Phantom was larger (heavier?) than the J79. This being one of the reasons its high altitude performance was degraded, Mach 2.1 vs 2.3?; as it required major reworks of the aft-fueslage.
Or perhaps the J79s static TWR wasn't the whole story? Perhaps in dynamic conditions, it enjoyed performance advantages in certain envelopes of flight?
I think its a bit of both. It would be interesting to see how modern western jet engines perform other than at static level. Id put my money on the F-119 being the most impressive in higher-end flight regimes. EJ200 following on and then the rest.
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By: 14th May 2008 at 06:29 Permalink - Edited 1st January 1970 at 01:00
-The Spey that went into the Phantom was larger (heavier?) than the J79. This being one of the reasons its high altitude performance was degraded, Mach 2.1 vs 2.3?; as it required major reworks of the aft-fueslage.Or perhaps the J79s static TWR wasn't the whole story? Perhaps in dynamic conditions, it enjoyed performance advantages in certain envelopes of flight?
Turbofans have different thrust at higher Mach numbers. Additionally the additional drag you mention. As the Phantom spent 90% of its life between Mach 0.7 and Mach 0.95, a region where the Spey excelled in SFC and available thrust, where it almost never touched the Mach 2 limit (which can only be exceeded with at max 4 Sparrows anyways), the Spey looks like the better choice. But problematic is the disadvantages that come from adapting an existing airframe to a new engine.
I would refer you to the service history of the F-14A to relate just how unsuitable the TF-30 was for a high performance fighter. Similarly, the Spey 202 was very problematic in RAF Phantom.
While I wouldn't reason this with the fact that the TF-30 was a turbofan. It was a good engine, but it lacked the robustness required for such an aircraft. Additionally, at least in case of the F-111, it was gifted with a quite miserable inlet design.
I guess the Mirage F.1 excelled by being the best compromise between capability and cost (at its time). It was supersonic, moderately agile, small, had a useful radar, could be used for ground attack. Compared to its American counterparts at that time (F-4, F-5) it was either clearly less expensive or clearly more capable.
It was no match for the F-16A.
By: 14th May 2008 at 08:50 Permalink - Edited 1st January 1970 at 01:00
-I have read that the Spey used for the Phantoms used inferior materials in production as a cost cutting measure, and therefore had limits imposed through construction, not design.
By: 14th May 2008 at 11:15 Permalink - Edited 1st January 1970 at 01:00
-The Spey that went into the Phantom was larger (heavier?) than the J79. This being one of the reasons its high altitude performance was degraded, Mach 2.1 vs 2.3?; as it required major reworks of the aft-fueslage. ....
My mistake, it was slightly heavier (a few percent). I had the wrong weight for the afterburner when I said it was lighter. However, that wasn't the cause of the rework The important difference was that it was fatter (also slightly shorter), which meant it didn't fit in the engine bays, & the aft fuselage had to be widened to make room. It also had higher airflow, necessitating bigger intakes. The aerodynamics of the airframe were therefore compromised, reducing top speed. The RN also modified it to give more lift for take-off from small British carriers, which may have also reduced the top speed slightly.
Basically, the airframe/engine combination meant the potential performance improvement from a more powerful & efficient (much better SFC, better T/W) engine was only partly realised, & in some aspects performance was actually degraded. But that doesn't mean the engine itself was problematic, as Tinwing suggests. The F-4K problems would not have materialised in an airframe designed for the engine. And in any case, as Schorsch says, it spent most of its life in the range where the Speys advantages outweighed its drawbacks. In practice, the UK got an aircraft with higher usable performance - but probably not worth the extra cost of the redesign & setting up a new production line.
By: 14th May 2008 at 11:48 Permalink - Edited 1st January 1970 at 01:00
-Agreed, hence I used the word larger, to explain the performance drop. I was just questioning if it wasn't also heavier and indeed it was.
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By: 14th May 2008 at 11:50 Permalink - Edited 1st January 1970 at 01:00
-Basically, the airframe/engine combination ment the potential performance improvement from a more powerful & efficient (much better SFC, better T/W) engine was only partly realised, & in some aspects performance was actually degraded. But that doesn't mean the engine itself was problematic, as Tinwing suggests. The F-4K problems would not have materialised in an airframe designed for the engine. And in any case, as Schorsch says, it spent most of its life in the range where the Speys advantages outweighed its drawbacks. In practice, the UK got an aircraft with higher usable performance - but probably not worth the extra cost of the redesign & setting up a new production line.
I always had the impression that the changes in performance that resulted from the different engine were misunderstood by the general aviation public (overrating top speed, not looking at more operational figures). In most books the Speys are not really looked at, just a word is given that top speed was reduced.
It surely received bad press as it was British, and at that time anything British in aircraft was apparently considered worse than anything you could get from America, at least in the UK.
Finally, I don't think the writers of the history of the F-4 Phantom (who are in their majority Americans) really have any real interest in the F-4/Spey.
You know how it works, write some crap into a book, attach a few nice pictures and people start thinking you actually know stuff about aircraft.
By: 14th May 2008 at 11:52 Permalink - Edited 1st January 1970 at 01:00
-I guess the Mirage F.1 excelled by being the best compromise between capability and cost (at its time). It was supersonic, moderately agile, small, had a useful radar, could be used for ground attack. Compared to its American counterparts at that time (F-4, F-5) it was either clearly less expensive or clearly more capable.
It was no match for the F-16A.
I once made a similar comment to a French Mirage F1 pilot, and you should have seen him laugh! Turns out, F16As were no match for Mirage F1s, even as recently as the early-1990s...
Why? Because electronics and weapons systems are usually more important than raw performance in air combat. And before the MLU/ADF update, F16As had no BVR capability. Meanwhile, the Mirage F1 had Matra Super 530Fs (comparable to AIM-7s). Additionally, he told me that in exercises the Mirage F1's ECM systems (presumably he was talking about the offboard Barax) would greatly disrupt Belgian F-16s, which rarely carried ECM systems.
So even though the F-16A had the better engine and FBW, it was often at a significant disadvantage. Don't believe the "conventional wisdom"...
By: 14th May 2008 at 12:09 Permalink - Edited 1st January 1970 at 01:00
-I always had the impression that the changes in performance that resulted from the different engine were misunderstood by the general aviation public (overrating top speed, not looking at more operational figures). In most books the Speys are not really looked at, just a word is given that top speed was reduced.
It surely received bad press as it was British, and at that time anything British in aircraft was apparently considered worse than anything you could get from America, at least in the UK....
Exactly right. The only exceptions are those rare aircraft (usually cancelled ones, e.g. TSR.2) that capture the imagination, then all our woes are due to not building them. :mad:
By: 14th May 2008 at 13:17 Permalink - Edited 1st January 1970 at 01:00
-I once made a similar comment to a French Mirage F1 pilot, and you should have seen him laugh! Turns out, F16As were no match for Mirage F1s, even as recently as the early-1990s...Why? Because electronics and weapons systems are usually more important than raw performance in air combat. And before the MLU/ADF update, F16As had no BVR capability. Meanwhile, the Mirage F1 had Matra Super 530Fs (comparable to AIM-7s). Additionally, he told me that in exercises the Mirage F1's ECM systems (presumably he was talking about the offboard Barax) would greatly disrupt Belgian F-16s, which rarely carried ECM systems.
So even though the F-16A had the better engine and FBW, it was often at a significant disadvantage. Don't believe the "conventional wisdom"...
Correct.
Although I wouldn't credit the F1 with real modern autonomous BVR capability (radar not automized enough, only monopulse in the beginning), but it has the ability launch a missile outside the missile envelope of an F-16A, especially when helped by a ground station. I would assume that within visual range the F-16A have an advantage, but as you say, raw performance rarely decides an engagement.
By: 14th May 2008 at 14:08 Permalink - Edited 1st January 1970 at 01:00
-The Iraqi F.1 largely neutralized the air superiority of Iran because it was too potent for either F-4 or F-14 pilots to risk a tangle with. The awg-9 was thwarted by the ecm pod. And the F.1 was too maneuverable for its Iranian counter parts. However, the F.1 was unable to escape Hawk missile batteries if it got into a missile trap. Therefore the Iraqi pilots had strict operational procedures for operations so that they did not wind up in bad situations they could not escape.
There is a good book on the conflict that covers the air war well.
By: 28th September 2008 at 15:36 Permalink - Edited 1st January 1970 at 01:00
-interesting aircraft , i always wondered why it did not capture more orders from f-16
how did it compare to Mig-23ML in air2air combat ? it was up against this type in angola
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By: LoofahBoy - 13th May 2008 at 06:10
Stemming from the perfect fighter discussion but not wanting to derail that thread...
I've always been under the impression that the Mirage F1 was comparable to the F-5 in performance, but lately I've been hearing it was much better; possibly even better than the Phantom, Viggen, or Mig-23 in some respects.
Just how good of a fighter was the Mirage F1?