Douglas A-4 Skyhawk Ideas and Inspiration

[GTX_Admin]

As this is a whiff site, why not a dry RB106?

Given the RB106 was supposedly designed as a drop in replacement for the Avon and thus of similar size (albeit more powerful), I still think it will be difficult to put into a A-4.  The diameter alone will be the killer unless you are happy with a fat arsed Skyhawk.

[M.A.D]

As this is a whiff site, why not a dry RB106?

Given the RB106 was supposedly designed as a drop in replacement for the Avon and thus of similar size (albeit more powerful), I still think it will be difficult to put into a A-4.  The diameter alone will be the killer unless you are happy with a fat arsed Skyhawk.

Not full bottle on engines mate! But I like a bit of arse

M.A.D

[M.A.D]

I found this snippet very interesting, especially as I'm looking at including an 'Improved' Foch class aircraft carrier in my 'Alternative ADF ORBAT' -
"As we increased the launch weights we started seeing some strange effects. The catapults were made by the Brits and not reinforced as frequently along the track as ours are. With the steep angle of the bridle and the heavier weights putting more and more downward pressure on the nose wheel and the track itself, the track deflected and didn't have time to flex back up by the time the shuttle got there. Metal was shearing off the underside of the track. At those heavy weights we could have had a bridle failure and gone off sideways or something equally unpleasant. The simple fix would have been to rotate the nose tire forward to give the track time to rebound. But since the French didn't buy the A-4.

Our impression when we flew out to the Foch and landed was the deck was small, really small. Also, that the lens setting put us a little short. Since they wanted to get closer and closer to the theoretical max engaging speed, we were given exact speeds to hit the wire. Because of having to fly within one knot on approach and the wind over the deck determining the actual engaging speed, it was only after landing that we knew how it went. Somehow we hit every point on every landing we did. Their own development folks onboard thought we walked on water... so they kept pushing us to go faster and faster. Twice we upped our own limits. Finally, we said, “That’s it. Buy the aircraft and you can do your own tests”."
(Source: Skyhawk Association: A-4's Forever!, France checking out the A-4M Skyhawk - France and the A-4M Skyhawk. http://a4skyhawk.org/content/france-checking-out-4m-skyhawk)

Wow I cant help but wonder what these yank pilots would have thought about landing on HMAS Melbourne then!

M.A.D

[elmayerle]

A reminder that one reason Singapore went with using J65-powered airframes as the basis for the A-4SU with the F.404 was that they had larger engine bays to accommodate the larger J65.  Wiki gives the following for the J65:
Diameter: 37,52 in.
Length: 122 in.

Definitely larger than the J52, if not quite as large as the Avon as noted.

[Old Wombat]

Wow I cant help but wonder what these yank pilots would have thought about landing on HMAS Melbourne then!

M.A.D

Well, mate, the RAN urban legend is that on a trip to the US our pilots flew ahead to land at a USN air field. On their way they flew over the USN carrier Enterprise & when at the bar that night suggested to the USN aviators present that they could land across the deck of the super-carrier. When mocked by the US Navy airmen the RAN pilots simply said "OK, you land along the deck of the Melbourne & we'll land across the deck of Enterprise." Next day USN & RAN pilots take to the air & over the docks where Melbourne was tied up alongside Enterprise. The US pilots took one look & said "OK, you guys win, no-one could land on that thing!"

My telling of the tale is pretty half-arsed but you get the picture.

[Weaver]

P&W J52s (variants used in A-4):

Thrust: 8500 - 11200 lb Dry thrust depending upon variant
Length: 118.9 inches
Diameter: 30.2 - 32.1 inches depending upon variant (latter more powerful models had greater diameter)
Weight: 2056 - 2318 lb dry depending upon variant (latter more powerful variants being heavier too)

RR Avon (aiming for roughly comparable models in terms of thrust):

Thrust: 7500 - 11250 lb Dry thrust depending upon variant (lower one is the Avon RA.7 Mk.26 as used in CAC Sabre whilst higher is the Avon RA.24R Mk 200 series as used in Scimitar and latter model Canberras)
Length: 126.9 inches for more powerful versions
Diameter: 40.2 inches for more powerful versions
Weight: at least 2,869 lb dry (hard to find exact number for this)

Either way, I think the RR Avon would have had trouble fitting into the J52 space plus it would have most likely been lower performing.

Since the A-4 was originally designed around the J-65/Sapphire, which was interchangeable with the Avon, it might not be as difficult as you think, i.e. the J-52 was a 'loose' fit in the space intended for a J-65.

[Weaver]

A reminder that one reason Singapore went with using J65-powered airframes as the basis for the A-4SU with the F.404 was that they had larger engine bays to accommodate the larger J65.  Wiki gives the following for the J65:
Diameter: 37,52 in.
Length: 122 in.

Definitely larger than the J52, if not quite as large as the Avon as noted.

Were the engine bay differences 'hard', i.e. smaller holes in the fuselage frames on the A-4E onwards, or were they 'soft' as in spacers and adaptors fitted to the earlier bays to take the J-52?

My Royal Navy Skyhawk project has them switching from Sapphires to Avons for commonality with Avon-engined Grumman Tigers, but then that's a late-1950s decision about new airframes.

Model: http://beyondthesprues.com/Forum/index.php?topic=5233.0

Profiles & full backstory: http://beyondthesprues.com/Forum/index.php?topic=3529.msg53106#msg53106

[M.A.D]

Hey, I like ya backstory Weaver
Although I don't know why I hadn't read it earlier

"My Royal Navy Skyhawk project has them switching from Sapphires to Avons for commonality with Avon-engined Grumman Tigers, but then that's a late-1950s decision about new airframes."

Its funny, I've been deliberating over weighing up either the simple and cost effective Skyhawk or the more advanced and slightly more costly Super Tiger for my Majestic class carriers in my 'Alternative ADF ORBAT'!
I wasn't aware until quite recently that Grumman offered a Avon-powered variant of their Super Tiger.
Do you have anything on this Avon/Super Tiger proposal Weaver? Please PM me if you do!!

P.S. what radar does your Royal Navy Skyhawks have?

M.A.D

[Weaver]

Hey, I like ya backstory Weaver
Although I don't know why I hadn't read it earlier

"My Royal Navy Skyhawk project has them switching from Sapphires to Avons for commonality with Avon-engined Grumman Tigers, but then that's a late-1950s decision about new airframes."

Its funny, I've been deliberating over weighing up either the simple and cost effective Skyhawk or the more advanced and slightly more costly Super Tiger for my Majestic class carriers in my 'Alternative ADF ORBAT'!
I wasn't aware until quite recently that Grumman offered a Avon-powered variant of their Super Tiger.
Do you have anything on this Avon/Super Tiger proposal Weaver? Please PM me if you do!!

Thanks!

Sorry, but all I've got on the Avon version is a line on the Super-Tiger Wiki page saying it was offered to the Luftwaffe in competition with the Starfighter.

P.S. what radar does your Royal Navy Skyhawks have?

M.A.D

Same AN/APG-53A as the standard A-4C, but they kept the full-size radome all the way through.

[M.A.D]

Thanks Weaver

The AN/APG-53A was predominantly a air-to-surface system wasn't it?
I was wondering if the Magnavox AN/APQ-94 fire control radar of the Vought F-8E Crusader would be able to be installed in the RAN's A-4G Skyhawk's? Im thinking incorporating its systems (black boxes) might deem the fitting of the camel hump (which the RAN had eliminated on its variant) to relocate systems and subsystem which would be displaced in the nose/forward fuselage area!
The thing I like about the Magnavox AN/APQ-94, is that its already an 'all-weather' tested and proven navalised system, and it would support the Aim-9C radar-guided Sidewinder variant - giving my RAN Skyhawk two 20mm cannon, 2 x Aim-9B (IR-guided) and 2 x Aim-9C (Radar-guided) Sidewinder AAM's!

I was contemplating including the F-8E's IRST sensor, thinking it would be an additional sensor (especially over vast open water), but from what I've read it was of limited reliability! So it might not have been worth the pain in the balls to incorporate into the little Scooter!

M.A.D

[elmayerle]

IRST's of that period were not too great - there's a reason they got removed early on in the Phantom II's development.  I could see fitting the f-8 radar or the F-11 radar as being of suitable size.  The larger radome would mean a redesign of the nose to move boxes and systems, or you could try keeping the antenna mounting plane the same and changing the lines of the radome forward of that, somewhat like the one pictured earlier in this thread with a F-11 radome.

[Weaver]

Thanks Weaver

The AN/APG-53A was predominantly a air-to-surface system wasn't it?

Yes indeed, but in my backstory the RN Skyhawks are primarily being bought as Sverdlov killing tactical nuclear bombers (small carrier Buccaneers, basically) so air-to-surface is what they need. The RN has it's Avon-Tigers with AI.23 for air defence.

I was wondering if the Magnavox AN/APQ-94 fire control radar of the Vought F-8E Crusader would be able to be installed in the RAN's A-4G Skyhawk's? Im thinking incorporating its systems (black boxes) might deem the fitting of the camel hump (which the RAN had eliminated on its variant) to relocate systems and subsystem which would be displaced in the nose/forward fuselage area!

Don't know about the relative volumes, but one oddball thing that's theoretically possible is having the actual radar black boxes, even including the transmitter, remote from the aerial and connecting the latter to the rest via long waveguides. This was one solution proposed for fitting a larger radar to the XF8U-3 Crusader III, whose radome shape couldn't be bulged or extended for aerodynamic reasons (because it functioned as part of the air intake system). How reliable it would've been is open to question since it was never actually tried. The next aircraft that I know of to have a distributed architecture radar like that was the Sea Harrier FA.2, but that came 30 years later and used a digital databus to make it work.

The thing I like about the Magnavox AN/APQ-94, is that its already an 'all-weather' tested and proven navalised system, and it would support the Aim-9C radar-guided Sidewinder variant - giving my RAN Skyhawk two 20mm cannon, 2 x Aim-9B (IR-guided) and 2 x Aim-9C (Radar-guided) Sidewinder AAM's!

As far as I know, the AIM-9C was pretty unsatisfactory and was hardly ever used.

[elmayerle]

I think this quote from the Directory of US Rockets and Missiles says it all:

"The SARH AIM-9C was only used with the Navy'S F8U Crusader fighters to provide these with an all-weather capability without having to fit a Sparrow-compatible radar. However, the AIM-9C was not very successful, and only 1000 were built by Motorola between 1965 and 1967. Many were later converted into AGM-122A Sidearm anti-radiation missiles. "

[GTX_Admin]

Just a colourful Skyhawk to inspire you:

[GTX_Admin]

More random A-4 inspiration:  Someone is about to have a bad day underneath this lot:

[elmayerle]

I suspect that's over a weapons range in the Southern California desert; the terrain looks quite right for that.  These might even be staging out of China Lake.

[kengeorge]

Bit of a thread revival here,
I'm wondering out loud IF a Skyhawk could be adapted as a Fleet Air-Defence Fighter. My idea is to use a common A-4 airframe with different mods for a dedicated combat/Strike escort/Fleet Air Defence/etc...version, as against the original light ground attack version
M.A.D. has asked a question here-http://beyondthesprues.com/Forum/index.php?topic=7213.0 to do with using an avon powered Skyhawk for his RAN 'Alternative ADF ORBAT', which was the basis of my inspiration.
What mods, would be needed to make the Scooter a fighter? A radar? If so what would be suitable? Armament...Sparrow & Sidewinder or other?
How about making the Fighter Scooter supersonic, an afterburning Avon, reskinned rudder, different intakes for instance.
I'm posting my version of an FMA Skyhawk/Mirage crossover as an example of what I mean.
This idea stemmed from a 'make do and mend' situation the Fuerza Aérea Argentina found themselves in during the Falklands war.
So any comments, suggestions, mild insults, gasps of incredulity, brickbats, whatever they are will be gratefully considered
Ken

[GTX_Admin]

Here's a real world A4 configured for Fleet Air Defence duties:

[finsrin]

Sweet looking A-4  :)

[M.A.D]

Interesting
Not wanting to give too much away with my backstory, but .....The RAN, in association with CAC and Douglas, incorporate the tested and proven Magnavox AN/APQ-83 radar and the Aim-9J Sidewinder AAM from the Vought Chance F-8 Crusader, to give it's CAC/Douglas A-4G+'s an all weather interception capability.........In addition to this, the RAN incorporates two 30mm ADEN cannons in place of the designs original two 20mm cannons - the RAN deeming the heavier 30mm round more effective against perceived enemy cruise missile carrying bombers, as well as shipping and ground targets.........

M.A.D

[elmayerle]

Bit of a thread revival here,
I'm wondering out loud IF a Skyhawk could be adapted as a Fleet Air-Defence Fighter. My idea is to use a common A-4 airframe with different mods for a dedicated combat/Strike escort/Fleet Air Defence/etc...version, as against the original light ground attack version
M.A.D. has asked a question here-http://beyondthesprues.com/Forum/index.php?topic=7213.0 to do with using an avon powered Skyhawk for his RAN 'Alternative ADF ORBAT', which was the basis of my inspiration.
What mods, would be needed to make the Scooter a fighter? A radar? If so what would be suitable? Armament...Sparrow & Sidewinder or other?
How about making the Fighter Scooter supersonic, an afterburning Avon, reskinned rudder, different intakes for instance.
I'm posting my version of an FMA Skyhawk/Mirage crossover as an example of what I mean.
This idea stemmed from a 'make do and mend' situation the Fuerza Aérea Argentina found themselves in during the Falklands war.
So any comments, suggestions, mild insults, gasps of incredulity, brickbats, whatever they are will be gratefully considered
Ken

I really can't see a supersonic Scooter without even more redesign for added cooling of the engine bay and some consideration of area rule in intake location.  A fighter variant of the Scooter I can see with a suitable radar fit and weapons fit, but a supersonic variant gets into way more redesign.

Just my two cents.

[kitnut617]

I've seen a what-if of an A-4 with a Sea Harrier FA.2 nose  ---- but do you think I can find where   

[M.A.D]

I really can't see a supersonic Scooter

I agree!

I've seen a what-if of an A-4 with a Sea Harrier FA.2 nose  ---- but do you think I can find where   

Would this be it??

[kengeorge]

elmayerle-
I had a feeling getting the scooter to go faster was a bit of a stretch, but it was interesting to read your reply.
Point being, if there was a way of squeezing in an appropriate radar, could the Skyhawk carry Sparrows? Would it be even practical?
What is the considered opinion on the Skyhawk being a dog-fighter? I know the US Navy used them in DACT, 'Top gun' being a prime example.
Then there is the Lockheed-Martin A-4AR Fightinghawk as used by the Fuerza Aérea Argentina.
Now the thing is, did the US Navy & Marines consider at any time using it as a fighter or only as a bomb truck?
But then again, it is whiffworld so anything is possible.........

[Rickshaw]

The A-4, if lightly loaded was quite a good dog-fighter.  It was how the Aggressors in the US Navy used to fly them.  It's major problem was it's lack of legs.   Away from DACT, in real life, the A-4 was used primarily as a fighter-bomber - primarily as a bomber and only secondarily as a fighter.   The A-4G of the RAN pictured above was optimised for air-to-air combat but could only carry four Sidewinders.   It lacked the radar to use BVR missiles.   However, it was forced on the RAN by necessity, rather than design.   HMAS Melbourne was to be retired when the RAN found a new use for her and then found that the only available new produced jet powered aircraft that could operate off a light fleet carrier with such a small deck was the A-4.

I've often wondered about the redesigned A-4 which Douglas proposed in the early 1960s IIRC.  It was a longer fuselage, with larger wings and a bigger engine.   It would have fixed many of the problems identified with the Scooter for speed, being able to achieve Mach 1 in level flight and would have had an adequate radar for BVR missiles (or room for one).   However, the US Navy wasn't interested and so it died on the vine.