Is the Typhoon a
Demon or a Lemon?
Given
the vigorous marketing effort of the Eurofighter consortium both in Europe and
Australia, and the often extremely hostile coverage the aircraft has received
in the international press, and moreso UK press, it is worth exploring the
aircraft's strengths and weaknesses against some established baselines.
The aircraft's counter air performance is cited as its major strength, and it is frequently cited to be “82% as effective as an F-22”.
The magic 82% number is derived from a mid nineties DERA simulation against a postulated Su-35 threat. The number is based upon the rather unusual metric of “probability of successful engagement” in BVR combat, rating the F-22 at 91%, the Typhoon at 82%, the F-15F (single seat E) at 60%, the Rafale at 50% and the F-15C at 43%.
The probability of a successful engagement can be translated into the more commonly used metric of a kill ratio by making some reasonable statistical assumptions, and doing this yields about 10.0:1 for the F-22A, 4.6:1 for the Typhoon, 1.5:1 for the single seat F-15E, 1:1 for the Rafale and 0.75:1 for the F-15C. So in the most common terms used, the Typhoon is by the DERA simulation about half as combat effective as the F-22A, about three times as combat effective as the F-15F, about five times as effective as the Rafale and 6 times as effective as the F-15C. If we compare this with cited USAF claims rating the F-22A as 10-15 times as combat effective as the F-15C in BVR engagements, this means that the DERA study roughly agrees with USAF assessments of F-22A vs F-15C combat effectiveness. The detailed assumptions applied to this study have not been disclosed.
The validity of this study in today's environment must be questioned. Since its compilation the Russians have developed the NIIP-011M and Phazotron Zhuk-Ph phased arrays for the Su-27/30, the R-77M ramjet Adder, the extended range R-74 digital Archer, 2D and 3D thrust vectoring nozzles, higher thrust AL-31 engine derivatives, and active radar seekers for the R-27 Alamo, as well as fielding an anti-radiation variant of the Alamo. The F-22A is likely to be shooting the ERAAM, and some USAF F-15Cs are being fitted with active phased arrays, with the likely prospect of getting ERAAMs as well, or even a ramjet AMRAAM variant. Therefore it is likely that most of the supporting assumptions used in the study are very stale, if not irrelevant. Until Typhoons are equipped with the AMSAR and Meteor, the projected 4.6:1 BVR kill ratio is by any measure optimistic, against an evolved Su-30 variant.
Clearly the Typhoon is robustly in the BVR lethality class of the F-15C/E, and the principal driver of relative effectiveness between these types will the radar and missile capabilities. Until the USAF field phased arrays and ERAAM or ramjet AAMs on the whole F-15 fleet (some aircraft are currently being retrofitted with APG-63(V)3 active phased arrays), the Typhoon will hold a decisive advantage. US longwave IRS&T technology is available off-the-shelf and would much reduce any advantage conferred by the PIRATE to the Typhoon.
The other important considerations in BVR combat are transonic and supersonic acceleration, persistence and sustained turn performance. While the latter are difficult to estimate, the former can be directly compared by looking at thrust/weight ratios.
The clean Typhoon, with 50% internal gas and 6-8 AAMs is firmly in the class of the F100-PW-229 powered F-15F, on dry thrust, and about 15% behind the F-15F on reheat. Where the Typhoon falls behind the F-15F is when its operating radius is stretched and additional external gas is being carried. If we take a Typhoon with 3 x 1000L external tanks, and an F-15F with 2 x 600 USG external tanks, we have configurations which deliver very similar endurance and operating radius for a point intercept. In the latter situation, approaching the target, the Typhoon is around 12% behind the F-15F in critical reheated thrust/weight ratio. If we compare a Typhoon with CFTs, 3 x 1000L external tanks against an F-15F with only CFTs, we get a shortfall of about 20% in thrust/weight ratio in addition to the drag penalty of the external tanks. These are very approximate estimates, not accounting for combat gas, but even doing a very accurate simulation would yield the inevitable conclusion - an F/A-18 sized fighter, no matter how agile when clean, cannot compete in thrust/weight ratio with an F-15 sized fighter at extended operating radii.
The argument that the smaller fighter can fly out in a less encumbered configuration, and rely upon a tanker, disregards the need for enough internal gas to safely if an AAR fails over water. By the same token, the use of higher thrust growth EJ200 engines in the Typhoon alleviates the problem, but it would still remain behind an F-15F fitted with the growth 32 klb F100-PW-232 or its GE equivalent F110 variant.
Clearly in any scenario where unrefuelled operating radius is not a major issue, the Typhoon is a highly competitive conventional fighter, and exceeds the capabilities of an F-15 variant without a phased array and extended range AAMs. However, a new build F-15 with current technology engines, and AESA/ramjet AAM package will maintain a healthy performance margin even over a growth variant of the Typhoon, and an operating radius advantage. The relative effectiveness would then boil down to issues such as tactics, and any relative advantages of the specific AAMs carried and radars fitted.
The comparative advantages of the Typhoon over the Su-27/30 family exhibit similar sensitivities to technology upgrades in the Sukhoi fighters. Fitted with a phased array, longwave IRS&T, carrying ramjet R-77M missiles, supported by SuAWACS, and using growth engines we must seriously question how great a lethality margin the Typhoon would hold against such a fighter. The Sukhoi, inevitably, exhibits the same thrust/weight ratio advantages the F-15 does in extended range combat, which was a design objective for this type as it was for the F-15.
In comparing the Typhoon against the only other fighter in its weight class, the F/A-18A/C, the benefits of using later generation technology show very clearly. The Typhoon outperforms the F/A-18A/C in BVR weapon system capability as well as aerodynamic performance. While much better than the F/A-18A/C in operating radius and agility, its optimal operating radius is not in the class of the F-15 and Su-27/30.
The aircraft's counter air performance is cited as its major strength, and it is frequently cited to be “82% as effective as an F-22”.
The magic 82% number is derived from a mid nineties DERA simulation against a postulated Su-35 threat. The number is based upon the rather unusual metric of “probability of successful engagement” in BVR combat, rating the F-22 at 91%, the Typhoon at 82%, the F-15F (single seat E) at 60%, the Rafale at 50% and the F-15C at 43%.
The probability of a successful engagement can be translated into the more commonly used metric of a kill ratio by making some reasonable statistical assumptions, and doing this yields about 10.0:1 for the F-22A, 4.6:1 for the Typhoon, 1.5:1 for the single seat F-15E, 1:1 for the Rafale and 0.75:1 for the F-15C. So in the most common terms used, the Typhoon is by the DERA simulation about half as combat effective as the F-22A, about three times as combat effective as the F-15F, about five times as effective as the Rafale and 6 times as effective as the F-15C. If we compare this with cited USAF claims rating the F-22A as 10-15 times as combat effective as the F-15C in BVR engagements, this means that the DERA study roughly agrees with USAF assessments of F-22A vs F-15C combat effectiveness. The detailed assumptions applied to this study have not been disclosed.
The validity of this study in today's environment must be questioned. Since its compilation the Russians have developed the NIIP-011M and Phazotron Zhuk-Ph phased arrays for the Su-27/30, the R-77M ramjet Adder, the extended range R-74 digital Archer, 2D and 3D thrust vectoring nozzles, higher thrust AL-31 engine derivatives, and active radar seekers for the R-27 Alamo, as well as fielding an anti-radiation variant of the Alamo. The F-22A is likely to be shooting the ERAAM, and some USAF F-15Cs are being fitted with active phased arrays, with the likely prospect of getting ERAAMs as well, or even a ramjet AMRAAM variant. Therefore it is likely that most of the supporting assumptions used in the study are very stale, if not irrelevant. Until Typhoons are equipped with the AMSAR and Meteor, the projected 4.6:1 BVR kill ratio is by any measure optimistic, against an evolved Su-30 variant.
Clearly the Typhoon is robustly in the BVR lethality class of the F-15C/E, and the principal driver of relative effectiveness between these types will the radar and missile capabilities. Until the USAF field phased arrays and ERAAM or ramjet AAMs on the whole F-15 fleet (some aircraft are currently being retrofitted with APG-63(V)3 active phased arrays), the Typhoon will hold a decisive advantage. US longwave IRS&T technology is available off-the-shelf and would much reduce any advantage conferred by the PIRATE to the Typhoon.
The other important considerations in BVR combat are transonic and supersonic acceleration, persistence and sustained turn performance. While the latter are difficult to estimate, the former can be directly compared by looking at thrust/weight ratios.
The clean Typhoon, with 50% internal gas and 6-8 AAMs is firmly in the class of the F100-PW-229 powered F-15F, on dry thrust, and about 15% behind the F-15F on reheat. Where the Typhoon falls behind the F-15F is when its operating radius is stretched and additional external gas is being carried. If we take a Typhoon with 3 x 1000L external tanks, and an F-15F with 2 x 600 USG external tanks, we have configurations which deliver very similar endurance and operating radius for a point intercept. In the latter situation, approaching the target, the Typhoon is around 12% behind the F-15F in critical reheated thrust/weight ratio. If we compare a Typhoon with CFTs, 3 x 1000L external tanks against an F-15F with only CFTs, we get a shortfall of about 20% in thrust/weight ratio in addition to the drag penalty of the external tanks. These are very approximate estimates, not accounting for combat gas, but even doing a very accurate simulation would yield the inevitable conclusion - an F/A-18 sized fighter, no matter how agile when clean, cannot compete in thrust/weight ratio with an F-15 sized fighter at extended operating radii.
The argument that the smaller fighter can fly out in a less encumbered configuration, and rely upon a tanker, disregards the need for enough internal gas to safely if an AAR fails over water. By the same token, the use of higher thrust growth EJ200 engines in the Typhoon alleviates the problem, but it would still remain behind an F-15F fitted with the growth 32 klb F100-PW-232 or its GE equivalent F110 variant.
Clearly in any scenario where unrefuelled operating radius is not a major issue, the Typhoon is a highly competitive conventional fighter, and exceeds the capabilities of an F-15 variant without a phased array and extended range AAMs. However, a new build F-15 with current technology engines, and AESA/ramjet AAM package will maintain a healthy performance margin even over a growth variant of the Typhoon, and an operating radius advantage. The relative effectiveness would then boil down to issues such as tactics, and any relative advantages of the specific AAMs carried and radars fitted.
The comparative advantages of the Typhoon over the Su-27/30 family exhibit similar sensitivities to technology upgrades in the Sukhoi fighters. Fitted with a phased array, longwave IRS&T, carrying ramjet R-77M missiles, supported by SuAWACS, and using growth engines we must seriously question how great a lethality margin the Typhoon would hold against such a fighter. The Sukhoi, inevitably, exhibits the same thrust/weight ratio advantages the F-15 does in extended range combat, which was a design objective for this type as it was for the F-15.
In comparing the Typhoon against the only other fighter in its weight class, the F/A-18A/C, the benefits of using later generation technology show very clearly. The Typhoon outperforms the F/A-18A/C in BVR weapon system capability as well as aerodynamic performance. While much better than the F/A-18A/C in operating radius and agility, its optimal operating radius is not in the class of the F-15 and Su-27/30.
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