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part :- 3
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Is the Typhoon a Demon or a Lemon? :-
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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.
---------- Post added at 11:17 PM ---------- Previous post was at 11:16 PM ----------
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.
---------- Post added at 11:18 PM ---------- Previous post was at 11:17 PM ----------
conclusion.
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What conclusions can we draw about the
Typhoon? The notion that the aircraft is “almost
as good as an F-22” is not supportable, indeed
upgrading the F-15 with engines and a radar/
IRS&T/AAM package of the same generation as
that of the Typhoon would equalise almost all
advantages held by the Typhoon over older
F-15C/E variants. By the same token, no upgrades
performed on the F/A-18A/C would equalise the
performance advantages of the Typhoon over
these aircraft.
The strength of the Typhoon is its very modern
and comprehensive avionic package, especially
that in the RAF variant, and its excellent agility
when operated around its optimum combat
radius of about 300 NMI (a figure to be found in
older Eurofighter literature, which has since
disappeared with the export drive to compete
against the bigger F-15 and F-22).
The Typhoon’s weaknesses are its F/A-18C class
weight and thrust and the implications of this in
combat at extended operational radii, and the
longer term sensitivity of its BVR weapons
advantage to equivalent technological
developments in opposing fighters.
In terms of where to position the Typhoon in the
current menagerie of fighter aircraft, it can be best
described as an F/A-18C sized fighter with BVR
systems and agility performance better than older
F-15 models, similar to growth F-15 models with
same generation systems and engines, but
inferior to the F-15 in useful operating radius. The
Typhoon is not a stealth aircraft, despite various
assertions to this effect, nor is it a genuine
supercruiser like the F-22. Its design incorporates
none of the features seen in very low observable
types, nor does the EJ200 incorporate the unique
design features of the F119 and F120 powerplants.
The Typhoon is certainly not a lemon, although
the wisdom of mass producing a high
performance conventional fighter of its ilk in a
period where stealth is about to hit mass
production in the F-22 and JSF programs could be
seriously questioned. It represents what is likely
to be the last major evolutionary step in the teen
series design philosophy.
