Adour powered concepts

[red admiral]

I've been scratching my head and having a search without much joy.

Are there any concepts powered by a single Adour engine, either dry or reheated?

Besides the obvious HS Hawk and a few demonstrators then I'm drawing a blank.

Thanka

 

[GTX]

IIRC the CAC CA-31 was intended to be powered by a RR Adour.

 

[Archibald]

Jean François Hummel's Jaguar serial A91 returning from Al Jaber, January 17, 1991, with one destroyed engine by an Iraqi SA-7.

SEPECAT Jaguar A n°91 - Musée de l'Air et de l'Espace

Livré à l’armée de l’Air en 1977, le Jaguar A n°91 connaît, jusqu’en 1986, divers détachements au Tchad et plusieurs missions de guerre.

www.museeairespace.fr

Does that count ?

 

[klem]

McDonnell Douglas T-45 Goshawk and Mitsubishi T-2 both had an Adour engine.

 

[Archibald]

McDonnell Douglas T-45 Goshawk and Mitsubishi T-2 both had an Adour engine.

Alas... Goshawk is a Hawk derivative, and T-2 had two engines, just like the Jaguar.

Are there any concepts powered by a single Adour engine, either dry or reheated?

Besides the obvious HS Hawk and a few demonstrators then I'm drawing a blank.

 

[GTX]

The AA-107 (pictured below) was to have used the Adour:

 

[GTX]

Both the BAE Systems Taranis and the Dassault nEUROn use the Adour.

 

[GTX]

IIRC the MB-338 also planned to use the Adour.

 

[red admiral]

Jean François Hummel's Jaguar serial A91 returning from Al Jaber, January 17, 1991, with one destroyed engine by an Iraqi SA-7.
Does that count ?

Probably had better thrust/weight ratio than with two engines

 

[red admiral]

Thanks

Was AA-107 supposed to be supersonic too? Is that the fixed wing one or VG? Edit - ah yes VG wing. Hmm.

CA-31 looks neat but not sure it carried much very far

 

[H_K]

Would have been mighty interesting if someone had tried to develop a light fighter using the Adour. Kind of a Gnat/G-91 replacement and direct competitor to the F-5E.

Perhaps Dassault could have dusted off their Etendard VI and stuck the Adour inside instead of the Orpheus 12? The dimensions certainly fit. Would there have been any takers? Maybe as an alternative to the Alpha Jet (if Germany hadn’t insisted on twin engines and had asked for higher performance)…

And other potential candidates out there?

 

[red admiral]

Would have been mighty interesting if someone had tried to develop a light fighter using the Adour. Kind of a Gnat replacement and direct competitor to the F-5E.

That was kinda where I was coming from originally. I'm not sure why no one seemed to try to do this. Reheated Adour gives a lot more thrust than the Orpheus in Gnat.

 

[BB1984]

Would have been mighty interesting if someone had tried to develop a light fighter using the Adour. Kind of a Gnat/G-91 replacement and direct competitor to the F-5E.

Perhaps Dassault could have dusted off their Etendard VI and stuck the Adour inside instead of the Orpheus 12? The dimensions certainly fit. Would there have been any takers? Maybe as an alternative to the Alpha Jet (if Germany hadn’t insisted on twin engines and had asked for higher performance)…

And other potential candidates out there?

Couple versions of the Swiss Piranha project:

• Piranha 2C: 1 x Adour Mk 811 (RT172-58), 3900kgp thrust,
• Piranha 2D(1 and 2 versions): 1 x Adour (RT172-63), 4580kgp thrust,

Other versions looked at using the Larzac M-74/05, Garrett/Volvo TFE 1042-7, and RB.199

There's a thread on it here: https://www.secretprojects.co.uk/threads/alr-piranha.1279/

 

[isayyo2]

Would have been mighty interesting if someone had tried to develop a light fighter using the Adour. Kind of a Gnat/G-91 replacement and direct competitor to the F-5E.

Arguably that was the Jaguar? A supersonic lightish fighter-bomber capable of being forward deployed from grass strips and highways.

I think what happened was that European designers, both East and West, got hung up on designing a light plane that could perform the Attack and Trainer role equally well. By chasing perceived economies of we ended up with planes that could only do one role particularly well. Light planes like the Alpha Jet, L-39, and IAR 99 were excellent trainers but would get chewed up by tactical AA against a peer threat. The Jaguar was an advanced attacker, but too advanced/expensive for the trainer role as demonstrated by France and GB.

 

[H_K]

Couple versions of the Swiss Piranha project:

• Piranha 2C: 1 x Adour Mk 811 (RT172-58), 3900kgp thrust

There's a thread on it here: https://www.secretprojects.co.uk/threads/alr-piranha.1279/

Yes, yes, yes! Learn something every day…

I wonder what this would have looked like if designed a little earlier, say 1970-1975. The only Adours available would have been the Mk 102 / Mk 104, with somewhat less thrust (3,100 / 3,600 kg). But still should have been competitive with the F-5E and Mig-21.

 

[H_K]

Arguably that was the Jaguar? A supersonic lightish fighter-bomber capable of being forward deployed from grass strips and highways.

Jaguar was too big to be called light. More in the Mirage V / Mirage F1A category… except for being inferior in almost all respects lol. (IMHO)

 

[isayyo2]

Arguably that was the Jaguar? A supersonic lightish fighter-bomber capable of being forward deployed from grass strips and highways.

Jaguar was too big to be called light. More in the Mirage V / Mirage F1A category… except for being inferior in almost all respects lol. (IMHO)

A tad lighter than the F-16A and much lighter than the Mig-29 at empty weights, so “lightness” is a bit subjective. Though I don’t disagree with your viewpoints at all HK.

 

[Archibald]

Both the BAE Systems Taranis and the Dassault nEUROn use the Adour.

Yes. I browsed Dassault "Duc" family of drones yesterday, because I vaguely remembered french drones with Adours... couldn't find, so I gave up. Well done.

 

[Archibald]

Couple versions of the Swiss Piranha project:

• Piranha 2C: 1 x Adour Mk 811 (RT172-58), 3900kgp thrust

There's a thread on it here: https://www.secretprojects.co.uk/threads/alr-piranha.1279/

Yes, yes, yes! Learn something every day…

I wonder what this would have looked like if designed a little earlier, say 1970-1975. The only Adours available would have been the Mk 102 / Mk 104, with somewhat less thrust (3,100 / 3,600 kg). But still should have been competitive with the F-5E and Mig-21.

Well I have this idea in a corner of my mind, that doesn't want to go away...

In 1965 Sud Aviation (in a desesperate atempt at returning on the combat aircraft market against Dassault) proposed to licence-build F-5A in Toulouse.

The same year did start the Jaguar and AFVG, with Adour as a scaled-down M45...

Enlarged F-5 with Adours or M45s... = baby Hornet.

 

[Archibald]

Random thoughts related to Adour and M45
- M45 = RB.172, and Adour was a scaled-down RB.172
- M45 was SNECMA but Adour was Turboméca
- one of the few cases where Turboméca, specialized in helicopter turbines and turboprop derivatives, tried to compete with SNECMA on combat jet engines (other was the failed Gabizo a decade before, for NATO 1957 LWF)
- M45 lacked power for AFVG (VG wing are heavy, too)
- Adour Mk.102 lacked thrust for Jaguars

It's a pity a twin-Adour or a twin-M45 NOT Jaguar, NOT AFVG could not be designed. Something akin to a F-5A or F-5E: not strike like Jaguar, no VG like AFVG. A fixed wing LWF, kind of.

Both Adour and M45 were much more powerful than J85... and there, we are entering P-530 / F-17 / Hornet territory.

Sometimes I wonder whether Turboméca, building from their rather successful Adour expérience, should have taken M45 after SNECMA dumped it in 1968.

HS.1173, is that thou ? huge missed opportunity there. Imagine if it had been done instead of both Jaguar and AFVG...

Hawker Siddeley HS.1173

Projet d’avion monoréacteur d’entrainement avancé et d’attaque au sol britannique des années 1960.

aviationsmilitaires.net

Jaguar and Adour: French vs British opposite point of view.

The British added sophisticated avionics to their Jaguars, making them heavier.
I suppose this was related to the TSR-2 / F-111K disasters, with Buccanners as interim types before Tornados... the Jaguar filled the "interim / supersonic" gap (MRI) and as such as to grow more avionics and more powerful engines.
and so Adour had to follow: mk.104, then mk.106
Overall, the Adour / Jaguar couple ended as pretty powerful.

The French: Jaguar stuck with antiquated avionics until the very end in 2007. Also never got Adour upgrades: stuck with the 102s even in Africa harsh environment (hot and dry).

 

[Archibald]

Now that's one heck of an idea... Super Etendard with reheated Adour or M45G !
(M.45G specs attached)

 

[H_K]

Now that's one heck of an idea... Super Etendard with reheated Adour or M45 !

M45G might work (13,000lbf thrust), but the Adour would have been a step backwards in terms of thrust (only 8,000lbf) compared to a non reheated Atar.

Hence the need to shrink the Etendard… which brings us to the Etendard VI that I mentioned!

(Which however probably wouldn’t satisfy the French Navy’s needs, but might make a decent Gnat/G-91/F-5/AlphaJet style light attack aircraft with some supersonic fighter capabilities)

 

[Archibald]

M45G had 5500 kg of thrust... with reheat, while the Atar 8 had 5000 kg without reheat. Not sure it is a good idea in the end ! yours is probably better indeed...

 

[zen]

Thing is a reheated M.45 or 'large' RB.172 or RB.153 are much lighter than unreheated Avon or Atar. So the actual thrust-to-weight ratio is not significantly changed.
Furthermore the exhaust velocity/temperature is in reheat much higher relative to the older turbojets. Resulting in a higher achievable speed.
This is even better if mated with a variable shock inlet.
So while it seems retrograde to fit smaller lower total thrust engines, the benefits are clearly lower weight, higher achievable speed.

 

[zen]

HS.1173, is that thou

Absolutely!

 

[isayyo2]

Enlarged F-5 with Adours or M45s... = baby Hornet.

Between yours and HK's comment I was racking my brain on what a twin Adour fighter would look like. When you said Baby Hornet it hit me, It's Taiwans F-CK-1! The Honeywell F125 and reheated Adour are basically interchangeable in size and thrust.

If a Hawk 200 could be developed from the outset as a transonic light fighter with a reheat Adour, it'd be a great Gnat and G91 replacement. A twin engine Adour fighter would go after F-104 and Hunter users, but that would dig into sales of the F-1 and Jaguar?

 

[H_K]

If a Hawk 200 could be developed from the outset as a transonic light fighter with a reheat Adour, it'd be a great Gnat and G91 replacement. A twin engine Adour fighter would go after F-104 and Hunter users, but that would dig into sales of the F-1 and Jaguar?

Yes that’s why the single Adour fighter is more interesting IMHO as a “what if”.

Anyone can make a fighter given enough thrust, and there are plenty of real world historical designs with 15,000lbf thrust or more. The hard part is shrinking the available thrust to <10,000lbf and still getting good fighter performance out of the result!

How many designs did it successfully? F-5E? But… twin engined. The early Piranha 2C/2D seems closest.

 

[Trident]

Had it entered service, a reheated Adour would've made a nice upgrade for the HA-300. Probably going to require enlarged intakes though.

 

[Archibald]

Ching kuo ! of course it's a good idea.

 

[Archibald]

How about a F-5A with a single Adour Mk.106 ?

Rolls-Royce Turbomeca Adour - Wikipedia

en.wikipedia.org

Northrop F-5 - Wikipedia

en.wikipedia.org

Maximum thrust: 6,000 lb (27.0 KN) dry / 8,430 lb (37.5 KN) with reheat

Powerplant: 2 × General Electric J85-GE-21 afterburning turbojet engines, 3,500 lbf (16 kN) thrust each dry, 5,000 lbf (22 kN) with afterburner

https://www.secretprojects.co.uk/threads/improved-f-5-and-stol-f-5-from-1964.37675/

Sea level static thrust: 4080 lbf, J85-GE-13 engine

Note that I said F-5A, not F-5E. On the latter the twin improved J85s would bust any single Adour thrust.

Now that's an intriguing concept... Sud Aviation F-5A derivative with one Turbomeca "boosted Adour" (rather than SNECMA M45G, although that's equally interesting...)

SHAZAAAAM ! https://www.secretprojects.co.uk/threads/french-ecat-projects.1167/

SA-125

 

[red admiral]

My summary seems to be so far:

Dry engine for subsonic trainer e.g. Hawk

Dry/Reheated engine for single seat subsonic combat aircraft e.g. Hawk 200, some SABAs. Pretty short range and low avionics/weapons payload.

Reheated engine for some low supersonic trainers. Similar to concepts with the later BS Orpheus engines e.g. Gnat follow ons, AA-107

Reheated engine for some low supersonic combat aircraft with short range and basically day/visual combat only. e.g. some AST396, ALR Piranha. And basically all of these concepts ended up with a bigger engine e.g. RB.199.

So basically it looks like a single Adour was just a bit small for anything supersonic and "fighty"

 

[H_K]

Reheated engine for some low supersonic combat aircraft with short range and basically day/visual combat only. e.g. some AST396, ALR Piranha. And basically all of these concepts ended up with a bigger engine e.g. RB.199.

So basically it looks like a single Adour was just a bit small for anything supersonic and "fighty"

Interestingly though, in the late 50s the "second generation" NBMR-1 designs (Gnat F2, G-91S, Taon Br. 1003, Etendard VI A) were all planning to use what was essentially the Adour's predecessor in terms of thrust & size: the Orpheus B.Or 12SR. This engine produced 6,810lb dry / 8,170lb wet and weighed 650-700kg with an SFC of 0.97 dry / 1.62 wet.

These designs would all have been supersonic... in fact the Gnat F2's expected max speed was Mach ~1.5 (!). Also thanks to their light weight, they would have had good thrust-to-weight ratios... for example, the Etendard VI (3,835kg empty) would have been comparable in T/W to the Mirage III & Mirage F1, and only slightly less than an F-8E or F-5E. Internal fuel fraction was also competitive, so range should have been OK.

So if the Orpheus could do the trick (hypothetically... as none of the designs ever flew), then perhaps the Adour could too?

Attaching my info on the Etendard VI A below, to illustrate... (and a pic of the VI prototype).

 

[Archibald]

Well I answered that in another thread. Very interesting.

 

[red admiral]

So if the Orpheus could do the trick (hypothetically... as none of the designs ever flew), then perhaps the Adour could too?

The Adour 102 was about 10-20% down on thrust from the Orpheus 12, at sea level static... At the tropopause and above Mach 1 I'd expect even more of a thrust drop off due to the greater thrust lapse of the turbofan.

Against this the Adour has better SFC (in dry power), but none of these concepts carry much fuel anyway (volume and mass) so there's maybe little advantage from the lower SFC?

 

[H_K]

@red admiral Yes the Adour isn’t exactly ideal for a supersonic fighter due to the bypass ratio… really meant for low-level attack rather than cruise or combat at altitude, where a simple turbojet might actually be better in terms of all-round performance. In fact, the Adour is kind of disappointing in some respects... quite heavy (~700kg), with so-so thrust-to-weight (not uncommon for a high bypass engine). And the low dry thrust of the early Adours would lead to excessive reheat usage for take-off & climb... which in the Jaguar (at least) eliminated most of the benefits of the lower SFC!

So all in all for a light fighter it might be better to stay with an improved 1950s Orpheus-style turbojet and carry more fuel to offset the higher SFC...

 

[H_K]

the Adour has better SFC (in dry power), but none of these concepts carry much fuel anyway (volume and mass) so there's maybe little advantage from the lower SFC?

Maybe a topic for another thread, but small aircraft can still fly far... it's all about the fuel fraction. And given the same fuel fraction, a lower SFC will still be advantageous.

For example, the Etendard VI A with 2,250L (1,800kg) of internal fuel and ~4,000kg empty equipped weight has an empty fuel fraction of 0.45, which is very similar to larger fighter aircraft such as the F-8E (FF=0.46), Mirage F1C or F1A (FF=0.43/0.44). And also similar to its closest real world lightweight analog - the F-5A or F-5E (FF=0.46/0.44).

Basically one can think of the Etendard VI A as a half-sized Mirage F1 (!): half the weight, half the thrust, half the fuel. But same T/W, same fuel fraction, and in fact much better wing loading... which means it should have been quite maneuverable.

Of course, there are tradeoffs - one reason the NBMR-1 candidates were so light was the very simple avionics - basically aviate, navigate, point & shoot with the Mk1 eyeball. Not even a ranging radar or autopilot or gyro navigation computer! The other tradeoff is it wasn't optimized for high-supersonic flight (moving inlets, reheat nozzles etc). But for a cheap day fighter / tactical aircraft using guns / rockets / IR-guided missiles etc that's not unreasonable. It's not an interceptor or a precision strike aircraft.

I don't have much info on the other "second generation" NBMR-1 designs (Gnat F2, Taon 1003, G-91S), but they should have been similarly interesting. Maybe a little less for the G-91 since its aerodynamic formula was a little dated (higher drag).

 

[red admiral]

Maybe a topic for another thread, but small aircraft can still fly far... it's all about the fuel fraction. And given the same fuel fraction, a lower SFC will still be advantageous.

For range calculations (e.g. Breguet range equation) then you need to calculate the fuel fractions relative to the gross mass of the aircraft rather than empty.

W1 mass at start of mission leg i.e. empty + payload + fuel
W2 mass at end of mission leg i.e. empty (maybe +payload)

This hurts the relatively lighter aircraft if they are carrying the same payload. e.g. redoing your comparison Vs Mirage F1 etc produces different results. The same external AAMs also likely give relatively more drag on the smaller, lighter aircraft. It's the combination of these penalties which is one source for lower range from smaller aircraft.

They stuffed a lot of fuel in the Etendard IV compared to the Gnat. I'm not sure the Mach 1.3ish predicted performance of the MK2 can really be called useful supersonic performance either - that low Mach number generally means very low acceleration there, may be useful in escaping from a F-96/MiG-17 in a dive but not sure where else.

 

[H_K]

For range calculations (e.g. Breguet range equation) then you need to calculate the fuel fractions relative to the gross mass of the aircraft rather than empty.

This hurts the relatively lighter aircraft if they are carrying the same payload. e.g. redoing your comparison Vs Mirage F1 etc produces different results. The same external AAMs also likely give relatively more drag on the smaller, lighter aircraft.

I'm aware... that said the math doesn't change that much once loaded with a typical load of say 2x 1,000lb bombs + 2 AAMs (~1,200kg). The Etendard VI A's fuel fraction would now be ~0.38 vs. ~0.39 for a loaded Mirage F1C.

(FWIW, I like to use operating empty or zero-fuel weight for fuel fractions as it's easier to calculate... it doesn't change the results of the range equation).

Drag will have some impact, I agree, though less than one might think if the load is expended halfway.

Supersonic performance up to M 1.3-1.4 (similar to the Jaguar or F-5E) would be just fine in my book. Not meant to be an interceptor. The real benefit is less in top speed and more in combat turn performance.

Anyway, not saying that miracles can be achieved with a light fighter, but performance similar to the F-5 Tiger and competitive in a turning fight with a Mig-21 or a Mirage would be interesting.

 

[BB1984]

My summary seems to be so far:

Dry engine for subsonic trainer e.g. Hawk

Dry/Reheated engine for single seat subsonic combat aircraft e.g. Hawk 200, some SABAs. Pretty short range and low avionics/weapons payload.

Reheated engine for some low supersonic trainers. Similar to concepts with the later BS Orpheus engines e.g. Gnat follow ons, AA-107

Reheated engine for some low supersonic combat aircraft with short range and basically day/visual combat only. e.g. some AST396, ALR Piranha. And basically all of these concepts ended up with a bigger engine e.g. RB.199.

So basically it looks like a single Adour was just a bit small for anything supersonic and "fighty"

Adour is on the small side, especially for single engine designs, but another way to think of the steps is:

• Single, dry engine is small cheap trainer / multi-role, e.g., L-159
• Dual, dry engines is LIFT trainer / light attack, e.g., Yak-130 / MB-346
• Dual, dry/reheat engines is a light fighter, e.g, AIDC F-CK-1 Ching-kuo (as others have already pointed out)

It's worth remembering here that the F-CK-1 has about the same empty weight and thrust as a Gripen, it's just designed for a much lower max weight. There's no inherent reason a dual Adour design couldn't be capable of weights more comparable to the Gripen. This is still the the low end of the modern fighter spectrum, but it is at least competitive with larger, heavier designs in the F-16/F-18 class.

 

[H_K]

Dual, dry/reheat engines is a light fighter, e.g, AIDC F-CK-1 Ching-kuo

The question is… why would anyone want 2x small engines when you can have a single F404, RB-199 etc? Even an old Atar was better than 2x Adours in many respects (despite the higher fuel consumption).

2 engines will always be more expensive to buy and maintain, plus have a negative impact on overall aircraft design potential (extra drag etc).

Since the whole point of a lightweight aircraft is to be cheap… design around a single Adour (or F125, or even better the slightly larger M.45G) seems more appropriate… But no one seems to have really pursued this except for the ALR Piranha.