A-4 Skyhawk bring back the concept for the 21st century

[kcran567]

The a-4 was absolutely loved by its pilots. Cheap and versatile (less than 600k ea when first introduced) Heinemann's hot rod was built for simplicity, ruggedness and performance. It was even more agile than the Mig-17s according to pilots. The last F404 powered version for Singapore (A-4SU) was spectacular in its performance.


Any thoughts on a next generation, rugged, simple, and cheap A-4 type aircraft built with the same things in mind that made the A-4 so great?


For the modern day add some stealth features, light weight materials, an f404 type engine, flyby wire, advanced shaping, etc. Have an air to air version, strike version and possibly a STOL version for the Marines. (I know, sounds like the JSF) BUT KEEP COST DOWN and the aircraft small like the A-4 was.


I talked to a person in the Navy who wasn't a big believer in the modern ever increasing complexity and cost in the new systems. He said many wanted more of a "numbers" philosophy that the A-4 represented, badly needed today. He also said many times on the ships the encrypted communications systems would fail or be jammed, and the simple morse code transmitters (80+) years old, would be able to punch thru the jamming for ship to ship and ship to aircraft communications. Just something to be said about simplicity in combat, and the things that work. That was the underlying philosophy of the A-4.


Anyway, back to the A-4. Would like to see some personal sketches of you're idea of a 21st century/modern A-4 would look like. I will add some of my sketches if others are interested, and are A-4 fans.


<iframe width="640" height="360" src="http://www.youtube.com/embed/BLMM_jf6Lwc?feature=player_detailpage" frameborder="0" allowfullscreen></iframe>

 

[Madurai]

Are the South Koreans not already building it, effectively?

 

[cluttonfred]

Here's my suggestion...

1) Have Boeing dust off their X-32 JSF design--not the proposed production model, but the delta-wing design that actually flew which didn't meet the revised maneuverability requirements but carried lots of fuel internally.

2) Strip out anything related to the STOVL variant and create a single CTOL/STOL version suitable for carrier use or, with double wheels/bigger tires, STOL use from short, rough strips.

3) Dial back the avionics to use instead off-the shelf, current-generation equipment from various aircraft in service right now, focused on a primary attack mission with secondary air-to-air capabilty for self-defense.

4) Offer the new Boeing F/A design as a capable, stealthy strike aircraft, an alternative to the F-35 at half the price.

;D

 

[2IDSGT]

Wouldn't be much point to the Boeing JSF without STOVL. Engine is in the front to accommodate direct lift.

 

[overscan (PaulMM)]

Northrop had some appropriate ideas... e.g. Cooperative Fighter, Missileer, Compact Efficient Fighter.


Co-operative fighter takeoff weight is 17,700lb which is squarely A-4 class. Add a bit more stealth shaping, single afterburning F-414 engine, and Bob's your uncle.

 

[cluttonfred]

Wouldn't be much point to the Boeing JSF without STOVL. Engine is in the front to accommodate direct lift

Absolutely right, I stand corrected on the JSF. Why not take it even further since smart weapons are getting smaller and lighter all the time? What we need is a 21st century Folland Gnat! But then I've already started two threads along those lines in the past. ;D In fact both of those and this one could well be merged into one.

http://www.secretprojects.co.uk/forum/index.php/topic,6123.msg50545.html

http://www.secretprojects.co.uk/forum/index.php/topic,14706.msg146797.html

 

[2IDSGT]

Wouldn't be much point to the Boeing JSF without STOVL. Engine is in the front to accommodate direct lift

Absolutely right, I stand corrected on the JSF. Why not take it even further since smart weapons are getting smaller and lighter all the time? What we need is a 21st century Folland Gnat!

You need to refine your KPPs a bit more than that. Let's say the CUDA missile and SDB II are ready to go. How many, how far, and how fast?

 

[Hobbes]

If you want an aircraft in the same cost bracket as the A-4, you'll have to design it using the same processes as the A-4. I.e. no advanced shaping, but whatever you can throw together in an afternoon with a slide rule. That means you'll get an aircraft in the same performance bracket as the A-4 as well.
Getting better performance means spending the time to create an unstable but flyable design, and adapting a flight control system to your new airframe. Both are time-consuming and expensive.

 

[kcran567]

If you want an aircraft in the same cost bracket as the A-4, you'll have to design it using the same processes as the A-4. I.e. no advanced shaping, but whatever you can throw together in an afternoon with a slide rule. That means you'll get an aircraft in the same performance bracket as the A-4 as well.
Getting better performance means spending the time to create an unstable but flyable design, and adapting a flight control system to your new airframe. Both are time-consuming and expensive.

Hobbes, i don't agree with that at all. With current supercomputers, modern smaller and more efficient engines, and materials, an A-4, Folland Gnat, F-20 type airplane would be easier to make and design than ever before. The Boeing Bird of prey was a good example of new manufacturing techniques.


The real issue is companies are not wanting a cost effective fighter/strike platform anymore and it is getting impossible to do for economic reasons.


I'm actually a fan of the F-35, its just too ridiculously expensive for many allies to afford. Manned and unmanned versions of an A-4 type future aircraft would be a way to go to get real numbers of aircraft and allies involved.


The economic loss of just ONE F-35 to attrition/combat is unacceptable for any airforce, at over 100 million or more apiece. (not to get off-topic, but the cost issue is relevant as an example for discussion)


the only option is more numbers of an A-4 for the 21st century, I'm convinced of that.

 

[kcran567]

Modern A-4 ?

 

[kcran567]

Here's my suggestion...

1) Have Boeing dust off their X-32 JSF design--not the proposed production model, but the delta-wing design that actually flew which didn't meet the revised maneuverability requirements but carried lots of fuel internally.

2) Strip out anything related to the STOVL variant and create a single CTOL/STOL version suitable for carrier use or, with double wheels/bigger tires, STOL use from short, rough strips.

3) Dial back the avionics to use instead off-the shelf, current-generation equipment from various aircraft in service right now, focused on a primary attack mission with secondary air-to-air capabilty for self-defense.

4) Offer the new Boeing F/A design as a capable, stealthy strike aircraft, an alternative to the F-35 at half the price.

;D

Mole, I liked the x-32 for a number of reasons too. The one-piece wing that was CHEAPER, easy to make (I think they molded it together like a Rutan design!) and held tons of fuel, I liked the lifting body shape of it too. It just wasnt popular and the brass thought it was UGLY. I think the STOVL would've worked too--as good as the Harrier--, but not as good as the F-35, even though it is a Billion times cheaper/simpler to build direct lift like the Harrier/ x-32 had.


Now, get it down to the size of the A-4 and I'm interested.

 

[cluttonfred]

Hobbes, i don't agree with that at all. With current supercomputers, modern smaller and more efficient engines, and materials, an A-4, Folland Gnat, F-20 type airplane would be easier to make and design than ever before. The Boeing Bird of prey was a good example of new manufacturing techniques.

The real issue is companies are not wanting a cost effective fighter/strike platform anymore and it is getting impossible to do for economic reasons.

I'm actually a fan of the F-35, its just too ridiculously expensive for many allies to afford. Manned and unmanned versions of an A-4 type future aircraft would be a way to go to get real numbers of aircraft and allies involved.

The economic loss of just ONE F-35 to attrition/combat is unacceptable for any airforce, at over 100 million or more apiece. (not to get off-topic, but the cost issue is relevant as an example for discussion)

the only option is more numbers of an A-4 for the 21st century, I'm convinced of that.

+1 on just about everything you said. I don't understand why none of the few big aircraft manufacturers left are doing something like this as a private venture. Something small and simple, engineered to be easy to fly and easy to maintain, taking advantage of modern manufacturing techniques and avionics to be inexpensive to buy and operate. Perhaps what we need is not an A-4 or even a Folland Gnat, but a stealthy modern version of the Cessna A-37 Super Tweet. Twin engines, a respectable load (substantially more than its weight in fuel and ordnance) and rock-solid reliability--even with 1970s technology they needed only two man hours of maintenance for each hour of flight time!

Great article from Air & Space magazine: http://www.airspacemag.com/military-aviation/Legends-of-Vietnam-Super-Tweet.html

 

[2IDSGT]

Modern A-4 ?

The Boeing Bird of Prey was a pure test-bed and wouldn't be any more combat capable than the X-1. You can't have a tiny VLO fighter because of the necessity for internal weapons and fuel... period. The principal Mr. Heinemann used for designing the A-4 was "take as much as possible out of the airframe." In order to do so, he actually contributed more than most people realize to the modern concept of external stores. With VLO platforms, the principal is opposite; everything that would normally hang out the outside (largely thanks to Heinemann's innovations) has to go back inside.

 

[cluttonfred]

Modern A-4 ?

The Boeing Bird of Prey was a pure test-bed and wouldn't be any more combat capable than the X-1. You can't have a tiny VLO fighter because of the necessity for internal weapons and fuel... period. The principal Mr. Heinemann used for designing the A-4 was "take as much as possible out of the airframe." In order to do so, he actually contributed more than most people realize to the modern concept of external stores. With VLO platforms, the principal is opposite; everything that would normally hang out the outside (largely thanks to Heinemann's innovations) has to go back inside.

True enough, but then again the trend toward smaller and lighter smart weapons also means that a modest internal ordnance load can be remarkably effective. Just 500 kg payload gets you:

--one 1,000 lb or two 500 lb bombs, smart or dumb, iron or cluster or napalm;
or
--four GBU-39 small diameter, GPS-guided bombs;
or
--14-19 70mm rockets in their launcher(s) (more or less, depending on warheads) with the option to go for compatible precision-guided rockets;
or
--two AIM-9 Sidewinders and two AIM-120s AMRAAMs;

You get the idea. So a total payload of 1,000 kg or even just 500 kg can still make for very effective light strike aircraft. VTOL or STOVL capability is not necessary for the majority of small air forces around the world, but simple STOL capability and rugged landing gear would allow for flexible, and when necessary, forward basing.

 

[2IDSGT]

True enough, but then again the trend toward smaller and lighter smart weapons also means that a modest internal ordnance load can be remarkably effective. Just 500 kg payload gets you:

--one 1,000 lb or two 500 lb bombs, smart or dumb, iron or cluster or napalm;
or
--four GBU-39 small diameter, GPS-guided bombs;
or
--14-19 70mm rockets in their launcher(s) (more or less, depending on warheads) with the option to go for compatible precision-guided rockets;
or
--two AIM-9 Sidewinders and two AIM-120s AMRAAMs;

You get the idea. So a total payload of 1,000 kg or even just 500 kg can still make for very effective light strike aircraft. VTOL or STOVL capability is not necessary for the majority of small air forces around the world, but simple STOL capability and rugged landing gear would allow for flexible, and when necessary, forward basing.

Those are some very reasonable KPPs (similar to what the Koreans want), but they wouldn't get you anything close to the A-4's simplicity. Perhaps we could limit the internal payload to 4 spaces for SDB IIs and/or CUDA missiles (as I mentioned earlier). How small could we make the thing then? Any engineers want to jump in here?

 

[cluttonfred]

The Indians developed the Folland Gnat into the HAL Ajeet which almost exactly fits the specs we have just described though it had very short range. An aircraft of similar size and weight but with all fuel and weapons internal and a modern, efficient turbofan, so optimized for range and perhaps giving up some speed, would be a good place to start.

Specifications (HAL Ajeet)
Data from Jane's All The World's Aircraft 1982-83 [6]
General characteristics
Crew: 1
Length: 9.04 m (29 ft 8 in)
Wingspan: 6.73 m (22 ft 1 in)
Height: 2.46 m (8 ft 1 in)
Wing area: 12.69 m² (136.6 ft²)
Aspect ratio: 3.56
Empty weight: 2,307 kg (5,086 lb)
Loaded weight: 3,539 kg (7,803 lb) clean take-off weight
Max. takeoff weight: 4,173 kg (9,200 lb)
Powerplant: 1 × TJE HAL/Bristol Siddeley Orpheus 701-01 turbojet, 20.0 kN (4,500 lbf)
Performance
Maximum speed: 1,152 km/h (622 knots, 716 mph) at sea level
Combat radius: 172 km (93 nmi, 107 mi) low level, with two 250 kg bombs
Service ceiling: 45,000 ft (13,720 m)
Wing loading: lb/ft² (kg/m²)
Climb to 12,000 m (39,375 ft): 6 min 2 s
Armament
Guns: 2× 30 mm ADEN cannons with 90 rounds each
Bombs: Up to 1985 lb (900 kg) of external stores on four underwing hardpoints

 

[kcran567]

Wow, the Gnat looks very small. Really like these types of aircraft though. Max ToW 9200 Lbs.


The A-4 empty was around 10,000 Lbs and fully loaded with fuel and weapons at 24,900+ Lbs Max ToW


I don't know if a modern Gnat is do-able at this time, maybe when anti gravity engines are available


But an A-4 type with smaller higher thrust engine, light materials, smaller weapons like Mole said seems a great idea!

McDonnell Douglas A-4 Skyhawk – single seat, carrier-based light attack bomber First flight – June 22, 1954 (XA4D-1) Total production – almost 3,000 over a 26-year span Powerplant – one Pratt and Whitney J52-408 - (A-4M version), 11,187 pounds thrust. Wingspan – 27 ft., 6 in. (8.38 m) Wing area – 260 sq. ft. (24.16 m2)

Length – 40 ft., 4 in. (12.29 m) Height – 15 ft., 10 in. (4.57 m) Weight – 10,800 lbs. empty Maximum takeoff weight – 24,500 lbs. Speed – 677 mph at sea level Ceiling – 40,600 feet Armament – two MK-12 20 mm cannons and up to 10,000 lbs of bombs.

 

[Michel Van]

bring the A-4 back
means to bring robust airframe, simple mechanic system and Instruments,
that imply also the flight computers !

oddly, there were US pilot very happy about this uncomplicated A-4 system.
The pilots of US Blue Angels, how switch from F-4 Phantom to A-4 Skyhawk.

nice side effect on future "A-4" would be fast R&D time, especial on complex computer software, simply there no need for it.

 

[lastdingo]

The "modern A-4" is really the AMX or the armed versions of various trainers such as the BAe Hawk 200.
Both have the principal problem of an at best adequate engine, though.

The AMX has a quite resilient, relatively modern fuselage (nothing too fancy, but a decade newer than the Hawk).

 

[pathology_doc]

True enough, but then again the trend toward smaller and lighter smart weapons also means that a modest internal ordnance load can be remarkably effective.

Absolutely. Even if you don't go internal, SDB and its ilk, and the microminiaturisation of guidance systems to the point where even a podded RP can have one, are a HUGE game-changer for COIN/trainer-strike aircraft capability. The US aircraft industry badly needs a military export market of the sort that's not unaffordable to almost all nations and unsellable to all but its closest allies.

 

[northerndancer2000]

Wasn't this already done?


The RNZAF did up the Kahu modified A-4. Wonderfully capable aircraft with HOTAS, glass cockpit, 1553B data bus, AN/APG-66 radar, INS, Maverick, and LGB. The wings were reskinned and the wiring replaced. The only things that were missing are OBOGS (A-4AR) and re-engining to the F404 (as done with the A-4SU Super Skyhawk).


It is interesting to note that A-4SU aircraft of 142 Squadron won the annual Singapore AF Hotshot competition in 2005, a month before retirement, against F-16s.

 

[lastdingo]

The A-4-like market is covered by armed jet trainers (Hawk series, L-149, MB.339 - even single seaters!).

The concept of a simple, agile and austere ground attack aircraft is not fit for a modern battlefield because such an aircraft would be too vulnerable to modern air defences. The A-4 already struggled badly in face of ZSU-23-4, SA-7 and SA-6 = 1960's threat systems.

The sales for such jet trainer-derived aircraft are few in part because the military niche is limited to bush wars, and even there you would do much better with a small cargo aircraft with plenty civilian peacetime uses plus a gunship kit for wartime use.


Don't grow a crush on sexy concepts based on sexiness; do a tactical-technical analysis and find the niches of practicality (tactical feasibility, fiscal feasibility, superior efficiency compared to alternatives).

 

[yasotay]

Since all of the other exciting threads are too politically charged today :
I offer what I think are two excellent canidates for the "New A-4"

 

[pathology_doc]

He also said many times on the ships the encrypted communications systems would fail or be jammed, and the simple morse code transmitters (80+) years old, would be able to punch thru the jamming for ship to ship and ship to aircraft communications.

OT but while we're at it, why not put IR or image-intensifying "glasses" on a long-base coincidence rangefinder and go back to completely passive concepts of naval gun fire-control systems, at least as pertains to surface targets? I'm sure with modern optics and even basic computers to do the number-crunching and send orders to the guns, the results could be impressive.


Getting back to a modern A-4 variant with modern ordnance, someone needs to do an updated version of Chris Chant's "Modern Aircraft Armament" and "Modern Air Weapons", given that those books came out when in-service fighters were still (just) carrying AIM-4 and Firestreak missiles - the shrinkage in size and weight and increase in effectiveness of modern (2014 as opposed to late 80's) air-launched ordnance would be difficult to credit for anyone reading those books as-new, but oddly enough, it may not necessarily translate very well into big increases in the number of weapons carried. Yes, even a smaller aircraft can now lift a significantly increased number of individual "shots" on a weight basis, but volume and aerodynamic issues start to predominate. These might not be quite as critical for external carriage, where fins etc. can poke out into empty space without bumping into the sides of a weapons bay, but multiple ejector racks are very "draggy" and those same volume issues mean that not all combinations of weapons can always be put on a rack with a given weight capacity. And that's before we even get into weapon release and airframe clearance issues, wiring for the support systems, etc. etc. etc.

 

[SSgtC]

For the modern day add some stealth features, light weight materials, an f404 type engine, flyby wire, advanced shaping, etc. Have an air to air version, strike version and possibly a STOL version for the Marines. (I know, sounds like the JSF) BUT KEEP COST DOWN and the aircraft small like the A-4 was.

All of this is really expensive. You don't get cheap and low observable in the same aircraft. And with all the other add ons. Cheap does not lend itself to those qualities.

(Side note: haven't read the thread yet so everything may have already been covered)

 

[_Del_]

You don't get cheap and low observable in the same aircraft.

You won't get broad band VLO cheap, but you can get a relatively low signature compared to conventional designs fairly cheap. Shaping and spot treatment with RAM is enough to get you much lower than the fourth gen birds. I don't at all subscribe to the idea that stealth is useless unless it is VLO and broadband.

 

[H_K]

Nice necro post!

I think the main thing that has changed since 2012 is a) the USAF’s T-X program, and b) Textron’s Scorpion (although the latter was more of a CAS/light attack aircraft for permissive environments).

The T-X designs do seem to have some potential, more than the Scorpion IMHO. Essentially the T-7 Red Hawk is a « T-50 equivalent » with very modern aerodynamics. But my favorite candidate would be Northrop’s N400NT... light and super simple with a non-afterburning F404. Takeoff weight clean is 15,400lbs, almost spot on compared to an A-4. I could totally picture adding some wingtip AAMs and a light bomb load.

View: https://youtube.com/watch?v=hLqfdcS5Z3k

 

[SSgtC]

You don't get cheap and low observable in the same aircraft.

You won't get broad band VLO cheap, but you can get a relatively low signature compared to conventional designs fairly cheap. Shaping and spot treatment with RAM is enough to get you much lower than the fourth gen birds. I don't at all subscribe to the idea that stealth is useless unless it is VLO and broadband.

Personally, I prefer the Navy's view on LO aircraft. In that they're useful, but not the be all, end all. Especially since a lot of missions will require external ordinance and fuel tanks to be carried, this ruining stealth. But at the same time, designing an aircraft to have good LO characteristics is going to massively increase costs since most stealth designs are unstable as hell.

 

[_Del_]

Personally, I prefer the Navy's view on LO aircraft. In that they're useful, but not the be all, end all

A lot depends on the role, and what you have to compromise to get it. Just like anything else.

RCS is directly related to RRE and detection range. If I reduce my frontal RCS by a factor of 10 over an F-15, I can get 44% closer to a radar before the detection threshold. So if the F-15 is detectable at 50 mi's, I can get with 30 before being detected.

RCS is also a factor of jamming wattage needed to prevent burn through. So I can get just as close using less wattage, or closer with the same wattage. For the case above, I need 10% of the wattage for the same effectiveness. And if the F-15 can get within 30 mi's with a given wattage, then I can get within 10 miles.

Particularly if we're looking at a light strike aircraft, then reducing frontal RCS is going to be a massive help in mission-planning and survival. A stricter bow tie signature would be even better, but just reducing the frontal RCS will help you safely get within standoff weapon range.

So even if you think stealth aircraft will be rendered detectable at great range in the near future, the LO aircraft still has significant operational advantages over conventional aircraft with much higher signatures. I know there are people here who think small RCS reductions are meaningless, but even small reductions give tactical advantages and making mission planning easier.

 

[steelpillow]

Seems very similar to the thread on how small can LO/stealthy combat aircraft designs get?

 

[TomcatViP]

The problem is that you can't have a small size VLO aboard a 1000ft aircraft carrier when the latter will be detected well outside the strike mission range of the former...
It's just like joining the today infantry fight with only a sword in hands.

 

[riggerrob]

"Speed, quality or low price? Pick 2." as seen on the wall of a parachute loft.
A light fighter/attack airplane only has to be better than the competition.
Is your biggest competition, poor, disgruntled citizens?
Is your biggest competitor a neighboring nation that wants to annex some of your land?
Is your biggest competitor a well-equipped, first-world nation?

Any attack airplane can kill local mal-contents. Even a Cessna Caravan with fancy sensors and side-firing machine guns.
The neighboring air force might be a serious threat.
You can forget about defeating the first-world air force.

 

[riggerrob]

Aircraft manufacturers do not want to bother with low-budget military airplanes because there are few opportunities for mark-up and even less potential for profit.

The challenge is designing an airframe that looks stealthy and has internal weapons bays that can carry a variety of latest generation ordinance ... BUT ... expensive accessories and avionics are only sold to wealthier nations that can afford them.
The fanciest ordinance and avionics are demonstrated by the few examples flown by the manufacturers' home air force, but are rarely sold to smaller air forces. They only have to create the illusion of flying the latest and greatest, but leave neighboring air forces guessing about how capable/advanced you really are.

 

[Pioneer]

"a modern A-4 variant with modern ordnance"

Why not a modern take on the Northrop N-102 Fang?
-a General Electric F414;
-fly-by-wire flight control system;
-diverterless supersonic inlet;
-AN/APG-80 AESA radar;
-composite materials incorporated into fuselage and wing.......





Regards
Pioneer

 

[chimeric oncogene]

So... a J-17 Thunder?

Cheap planes make no sense these days when pilots and hardened airbases and smart munitions and whatnot are so expensive. It's like giving a giant a spoon to fight with "because the spoon's cheaper". You've already paid for the giant. Might as well pay extra for a big, shiny sword.

 

[uk 75]

The big difference since the Skyhawk was designed has been the growing unacceptability in the West of seeing downed pilots killed or captive.
A modern Skyhawk sized platform would have to be remotely controlled or better yet autonomous.

 

[H_K]

@uk 75 I imagine the target market wouldn’t be Western air forces but smaller / poorer countries who can’t afford a supersonic multi-role fighter or who want mainly light attack / air-to-ground capabilities and are willing to risk some pilots.

e.g. Any Air Force still operating F-5s, Su-25s, light attack / trainers. Many of these can’t afford more than half a dozen aircraft or so, so not a great market…

I don’t think this would be a fighter aircraft… there’s already the FA-50, JF-17, Tejas for that.

 

[trose213]

So... a J-17 Thunder?

Cheap planes make no sense these days when pilots and hardened airbases and smart munitions and whatnot are so expensive. It's like giving a giant a spoon to fight with "because the spoon's cheaper". You've already paid for the giant. Might as well pay extra for a big, shiny sword.

I more view it as the job getting done by a runway independent attritable drone, that you don't have to pay for the pilot or ground maintainers, etc.

The big difference since the Skyhawk was designed has been the growing unacceptability in the West of seeing downed pilots killed or captive.
A modern Skyhawk sized platform would have to be remotely controlled or better yet autonomous.

Pretty sure it's just having the pilots to begin with.

 

[Fluff]

Wow, the Gnat looks very small. Really like these types of aircraft though. Max ToW 9200 Lbs.

you can see the cockpit instruments while standing on the ground, with a Gnat....

 

[Pioneer]

True enough, but then again the trend toward smaller and lighter smart weapons also means that a modest internal ordnance load can be remarkably effective. Just 500 kg payload gets you:

--one 1,000 lb or two 500 lb bombs, smart or dumb, iron or cluster or napalm;
or
--four GBU-39 small diameter, GPS-guided bombs;
or
--14-19 70mm rockets in their launcher(s) (more or less, depending on warheads) with the option to go for compatible precision-guided rockets;
or
--two AIM-9 Sidewinders and two AIM-120s AMRAAMs;

You get the idea. So a total payload of 1,000 kg or even just 500 kg can still make for very effective light strike aircraft. VTOL or STOVL capability is not necessary for the majority of small air forces around the world, but simple STOL capability and rugged landing gear would allow for flexible, and when necessary, forward basing.

Those are some very reasonable KPPs (similar to what the Koreans want), but they wouldn't get you anything close to the A-4's simplicity. Perhaps we could limit the internal payload to 4 spaces for SDB IIs and/or CUDA missiles (as I mentioned earlier). How small could we make the thing then? Any engineers want to jump in here?

On re reflection, in which case, wouldn't the Indian HAL Tejas be getting close to this requirement? After all you wouldn't realistically make your operational requirements so stringently tight that the design excludes itself very quickly or enforces a short operational lifespan, as realistically the Gnat/Ajeet was.

Regards
Pioneer