‘North American General Purpose Attack Weapon’ - NAGPAW to Vigilante

[Pioneer]

Hello gents
I am looking to find some information on possibly one of the most advanced and powerful strike aircraft designed for its time, and yet possibly one of the least known and un-utilised designs in military aviation history –
The design I am speaking of is the North American A3J (A-5) Vigilante supersonic, carrier-based nuclear strike-bomber.
But saying this, the design that I am most interested in though, is the original project with the name ‘North American General Purpose Attack Weapon’ (NAGPAW), that the A3J (A-5) would be developed from.
Unlike the A3J (A-5) Vigilante, the NAGPAW was a privately-funded design project by North American Aviation, for a carrier-based aircraft that would be a more capable platform for the delivery of a nuclear weapon than the Douglas A3D Skywarrior. The company gave its project the internal name of North American General Purpose Attack Weapon (NAGPAW). The aircraft was to be capable of delivering a nuclear weapon at speeds of up to Mach 2. In 1954, the NAGPAW was offered to the Navy in an unsolicited proposal.
The Navy was suitably impressed, but added some conditions. The original NAGPAW proposal called for a low-altitude penetrator which dictated an aircraft with a small wing area with a high loading to give an acceptable low-altitude ride at high speeds. However, the Navy wanted the aircraft to have the ability to launch from a carrier even in a (ridicules) zero wind conditions, which requires a larger wing area, for it had decided that it would be a better idea to abandon the low-altitude penetrator mission in favour of better carrier landing and takeoff characteristics. Consequently, in January of 1955, the Navy changed the requirements, making a high-altitude Mach 2 dash capability primary and a low-altitude penetration capability only secondary.
The original NAGPAW design had twin vertical stabilizers, and this was actually how the mock-up was configured when it was reviewed in March of 1956. However this was changed to a single vertical stabilizer shortly thereafter (the USN getting cold feet with this revolutionary design idea of smaller twin-vertical stabilizers). The vertical tail was sufficiently tall that it had to be fitted with a hinge so that the top could be folded to the left for stowage aboard aircraft carriers.
Its primary offensive weapon, the Mk 28 IN nuclear weapon stored in an internal weapons bay. The weapons bay did not have a conventional bomb bay with doors opening underneath the bottom of the aircraft, since this would make it impossible to release the weapon at supersonic speeds. Instead, the was mounted at the end of a long duct which extended rearward between the two engines and was ejected to the rear during release.
Saying this does anyone have anything on the original NAGPAW design in the way of Pictures, drawing, 3-view drawing, artwork and specifications?
I think the original NAGPAW if developed in its original form could have been a very effective aircraft. It could even have been viable as an aircraft for the USAF, as a replacement for the English Electric / Martin Canberra and the Douglas B-66 Destroyer!

I am still a big fan of the fact, that the Vigilante could also have been developed still further into a more versatile and conventional strike aircraft (both carrier-based and land-based), if its linear-bomb bay design had been replaced by a Martin-type rotary bomb bay arrangement (eg as used on the Martin B-57 Canberra, the Martin XB-51 and the Blackburn Buccaneer!), plus its four wing pylons to carry conventional bombs and missiles, it would have made for a cheaper F-111 or TSR.2 replacement i think!

Regards
Pioneer

 

[Antonio]

The mock-up from 1957

 

[Skybolt]

The mock-up from 1957

This was already A3J. NAGPAW as conceived by NAA was a very different beast. First it had a single crew; second, more importantly, it was subsonic and smaller than the A3J. Actually an image of the original NAGPAW haaven't been published, AFAIK. Apart ot the differences, it had two engine and a linear bomb bay. When NAA tendered it in 1954, BuAer thought a little and then requested : 1) a Mach 2 aircraft capable to fly at 70,000 feet, and 2) a plane able to take-off from a carrier with a full complement of fuel and weapons without wind on deck (this to allow to launch a retaliatory strike with minimum warning and without manouvering the fleet to turn the bow to the wind). NAA tried first to simplify the task by studying a mixed propulsion aircraft: to Mach 1.5 and 50,000 feet by turbojets, to Mach 2+ and 70,000 feet with assistance by a rocket engine. Two FJ-4s were even modified as test planes for the concept. But the high-altitude cruise and wero-wind take-off specifications forced a redesign with a large wing, then a larger aircraft to accomodate larger fuel tanks, and finally the addition of a second crew member to assst in targeting and navigation. I don't know if the original NAGPAW had a double fin. Could be, but the overall configuration was probably very different from the A3J NA-233.

 

[elmayerle]

According to a friend and former co-worker who was at NAA-Columbus at the time, the original NAGPAW concept was considerably closer to something like the Intruder than what it evolved (if that's the correct term) into.

That twin-tailed mockup is final mockup for the formal design review. Personally, I wish they'd kept the twin verticals. I'm definitely tempted to model a RA-5C or a NAR-349 with twin verticals; IMHO, the verticals from the old Revell 1/87 A-5A would do quite nicely.

 

[Pioneer]

Help needed!

Gents I am after information, specifications, drawings and picture of mockups of the North American Aviation’s 1953 privately-funded design project – NAGPAW (North American General Purpose Attack Weapon).
The NAGPAW was a carrier-based aircraft that would be a more capable platform for the delivery of a nuclear weapon than the Douglas A3D Skywarrior.
The aircraft was to be capable of delivering a nuclear weapon at speeds of up to Mach 2. In 1954, the NAGPAW was offered to the US Navy in an unsolicited proposal.
Although the US Navy was impressed, they went on too add some conditions. The original NAGPAW proposal called for a low-altitude penetrator which dictated an aircraft with a small wing area with a high loading to give an acceptable low-altitude ride at high speeds. However, the Navy wanted the aircraft to have the ability to launch from a carrier even in zero wind conditions, which requires a larger wing area.
Consequently, in January of 1955, the Navy changed the requirements, making a high-altitude Mach 2 dash capability primary and a low-altitude penetration capability only secondary.
The wing that was finally adopted was mounted high on the fuselage and had a sweep of 37.5 degrees and an area of of 769 square feet.
The original design had twin vertical stabilizers, and this was actually how the mockup was configured when it was reviewed in March of 1956. However this was changed to a single vertical stabilizer shortly thereafter.

This aircraft would become the very advanced, capable and beautiful North American A-5A Vigilante!

Thanks in advance

Pioneer

 

[Skybolt]

Mmmmm, I think we are still at the point we were two years ago...
http://www.secretprojects.co.uk/forum/index.php/topic,659.msg5040.html#msg5040

Only possibility is that some of the company models collectors who helped Tony in his American Secret Projects book ha something up his/her sleeve...

 

[overscan (PaulMM)]

Message from Tony

Unfortunately, none of the collectors I have been in touch with, and there are several, have a model of this design. I would expect a couple of wood models to have been made, but whether they still survive is currently unknown. I understand that the former NAA archive is enormous, and is housed in a large warehouse. Some models may be there but currently it is in the hands of Boeing and nobody has access to it. The only possible source for NAA project documents is the US National archives, or the USAF or USN archives which I do not have access to.

I hope to start writing ASP Bombers in the autumn - handover around late summer 2009.

Best Wishes to All.
Tony B.

 

[lark]

Until Tony's book is published we only can do it with the information
about NAGPAW in the Aerofax Minigraph 9

'North American Rockwell A3J/A-5 Vigillante' bij Michael Grove and Jay Miller.
On the pages 2 to 5 there's a fairly good description about the single seat proposal
and some illustrations of the NAGPAW patent drawing.

 

[Pioneer]

Thanks gents
It was worth a try! ;D
I thought something new may have come to light.
Looking forward to Tony’s efforts

Regards
Pioneer

 

[Skybolt]

Not really necessary to wait... following the Paul's (Lark) hint, I made some research, and: here's the original patent drawings. You'll notice a third sheet not included in Minigraph 9, with a gorgeous (so to speak) perspective view of the NAGPAW, and that in the "proposed method of delivery" sheet, the side view of the aircaft is enough clear for some willing drawrs to try and sketch a preliminary reconstruction... naturally, I'd expect that Tony would acknowledge this to Secret Projects Team in his next book
Uh, applause, please...

 

[Antonio]

Dear gentlemen, a long applause for you and many thanks for the info!

 

[overscan (PaulMM)]

Images extracted for easier viewing, plus pdf with all 9 pages of patent.

 

[Pioneer]

Skybolt and Overscan
I thank you ;D

Regards
Pioneer

 

[Jemiba]

With the drawings of the patent,I’ve made a GA drawing of the
NAGPAW, design number NA-233, as it is designated in Sqad/Signal
Mini N°3.
As it was the starting point for the A3-J/A-5 Vigilante, I added some
details not shown in the patent from this aircraft, e.g. wheel base,
flaps and rudders, that means : DANGER ! WHAT- IF !!
When Tonys book is available, it will be interesting to see, where I got
it wrong

BTW, looking at the patent drawing showing the fuel tanks, which
would have been placed in the linear bomb bay, I cannot help the feeling,
that it was intended as a fast transport for dustbins, too ! ;D

 

[Skybolt]

Jens... GREAT (as usual...) ! But... couldn't it be that the seat arrangement was side-by-side and not tandem ? Also, I've the impression that the wing was stubbier. And the intakes larger.

 

[Jemiba]

Well, the intakes were directly taken from the partial profile, showing how
the bomb and the tanks would be loaded into the bomb-bay.
With the wing you could be right, the drawing above "figure 5" really seem to
show stubbier wings (but here the intakes are much smaller !), I used more or
less the planform of the Vigilante. But the cockpit seemed single seat to me ... ???

 

[lark]

The initial thinking behind NAGPAW was for a single seat aircraft with moderate swept wings
and a low tail.

Ref: Aerofax Minigaph 9 -page 2.

 

[Abraham Gubler]

Full patent is available at:

http://www.google.com/patents?id=2pVeAAAAEBAJ&dq=2977853

 

[Skybolt]

Jens, you're right, it is single seat. :-[

 

[Skybolt]

Forgot: Minigraph says the the NAGPAW concept was intended as a non-competitive venture, but Vought got air of it (or so it was explained...) and proposed a competitor to the same specification. I think it was designated V-406: anyone with Vought connections with infos out there?

 

[Pioneer]

Sorry gents after all these years I failed to acknowledge and thank you for your response!!!!!!!!!
Pometablava - I love the picture of the mock-up
A head-on view of this mock-up could make my wife redundant!

After 3-years does anyone have any more info or pics????????????

Regards and belated gratitude
Pioneer

 

[Stargazer]

There has been some confusion here between NA-233 and NA-247 (not to mention -249 which is NOT Vigilante but Buckeye!). Please allow me to get designations straightened up a bit:

NA-233 = Design engineering / mock-up phase of subsonic twin-jet bomber (A3J)
(this is where the full-scale mock-up seen above fits in)

NA-247 = XA3J-1 (1 ex.), YA3J-1 (1 ex.) and A3J-1 (9 ex., became A-5A)
NA-258 = A3J-1 engineering, transferred to NA-247
NA-263 = A3J-1 (14 ex., became A-5A)
NA-269 = A3J-1 (10 ex., became A-5A), A3J-2 (24 + 12 ex.,became A-5B), YA3J-3 (6 ex., became YA-5C)
NA-272 = A3J-1 long-lead-time material, canceled
NA-279 = A3J-3P (20 ex., became RA-5C)
NA-283 = RA-5C (23 ex.)
NA-296 = RA-5C [27 conversions from former NA-279, some sources give NA-247/-263/-269 instead]
NA-298 = RA-5C [16 conversions from former NA-263, -279]
NA-316 = RA-5C Vigilante (36 ordered, last 10 canceled)
NA-349 = ABC Improved Manned Interceptor (tri-jet Vigilante project)

Hope this helps!

 

[Lampshade111]

The A-5 did have a rather short career. Perhaps it could have been developed into a capable long range conventional strike aircraft. But supposedly it took up a ton of space on a carrier, and had some problems with it's setup of disposable fuel tanks in the weapons bay. In the long-run, the F-4 was probably the better choice for strike missions where you needed more speed than an A-6 or A-7 gave you.

The A-5 had the look of something that should never be landing or taking off from a carrier. But it did anyway.

 

[Tailspin Turtle]

There has been some confusion here between NA-233 and NA-247 (not to mention -249 which is NOT Vigilante but Buckeye!). Please allow me to get designations straightened up a bit:

NA-233 = Design engineering / mock-up phase of subsonic twin-jet bomber (A3J)
(this is where the full-scale mock-up seen above fits in)

NA-247 = XA3J-1 (1 ex.), YA3J-1 (1 ex.) and A3J-1 (9 ex., became A-5A)
NA-258 = A3J-1 engineering, transferred to NA-247
NA-263 = A3J-1 (14 ex., became A-5A)
NA-269 = A3J-1 (10 ex., became A-5A), A3J-2 (24 + 12 ex.,became A-5B), YA3J-3 (6 ex., became YA-5C)
NA-272 = A3J-1 long-lead-time material, canceled
NA-279 = A3J-3P (20 ex., became RA-5C)
NA-283 = RA-5C (23 ex.)
NA-296 = RA-5C [27 conversions from former NA-279, some sources give NA-247/-263/-269 instead]
NA-298 = RA-5C [16 conversions from former NA-263, -279]
NA-316 = RA-5C Vigilante (36 ordered, last 10 canceled)
NA-349 = ABC Improved Manned Interceptor (tri-jet Vigilante project)

Hope this helps!

It's a big help, thank you very much. It's apparent that North American assigned different model numbers to relatively minor configuration changes to the basic type whereas other companies, in most cases, kept the same model number for the same basic airplane.

There should probably also be a number for a J58-powered A3J. A three-view would be nice, too...

 

[Abraham Gubler]

It's a big help, thank you very much. It's apparent that North American assigned different model numbers to relatively minor configuration changes to the basic type whereas other companies, in most cases, kept the same model number for the same basic airplane.

The same practice was picked up by CAC in Australia who based much of their early operation on NAA. Each 'model number' actually corresponds to a contract or work order and is actually an accounting number. So if you recieve a second batch order for a No.1 type of aircraft it is called the No.2 even though the only difference may be minor due to small improvements and changes in sub-contractors, etc. For some aircraft that have a lot of different batch orders, like the CAC Wirraway this can result in large numbers of 'model numbers': CA-1, CA-3, CA-5, CA-7, CA-9, CA-10 and CA-20 (the later just rebuilds for the Navy but they need a new accounting number).

This also means for a design that is not funded by a customer and is in house only it doesn't receive a model number. Which makes it hard to keep track of. A la the NAGPAW. We use these accounting numbers as model numbers when really they aren't.

 

[Tailspin Turtle]

I did a search to see if this had been posted here and was surprised not to find it. It's from the patent application. Taken at face value, NAGPAW was a twin-engine, single-seat, subsonic attack aircraft. In addition to the unique weapon release, it incorporated an inertial navigation system with an en route position update by radar.

 

[Pioneer]

Some great information here thanks gents!
The last couple of years of this forum in limbo has payed off!!!!!!!

Stargazer2006 - thanks for the clarification!

Tailspin Turtle - do you have the corresponding information to the numbers indicated in the drawing you have posted?

Lets hope we can find some more drawings and pictures of this mock-up
The twin tail fin arrangement would have made much greater practicality and sense below deck!
If used in the later A-5 Vigilante design, I think it could have been the first modern type twin tail fin arrangemet on a high speed combat aircraft.
I read somewhere that the MiG-25 'Foxbat' was based on the configuration of the Vigilante (has anyone else read this assumption before?)
I wonder if this was the case, did MiG Bureau know about the NAGPAW twin tail fin arrangement and elect to incorporate it in their interceptor design????????????

Regards
Pioneer

 

[overscan (PaulMM)]

Its been suggested by Yefim Gordon that one account of the MiG-25 had Mikoyan after an airshow, mentioning to someone to draw an interceptor with the Vigilante layout without high lift devices.

The patent is here:
http://www.google.com/patents?id=2pVeAAAAEBAJ

I'm sure we posted it before but I can't find it.

 

[Tailspin Turtle]

Overscan posted the patent reference which I couldn't find again, thanks very much. That provides the drawing numbers and lots of other information.

With respect to the single versus twin tails, you would have to have been there or have a copy of the trade-off analysis. Several things are taken into consideration with hangar height being an additional constraint for the larger carrier-based aircraft. It's interesting to note that the F-14 went from a single tail to a twin tail - however, this may have been decided by the need for lots of rudder control power in a single engine condition due to the widely separated engines. The early General Dynamics studies of the Light Weight Fighter included twin-tail variants but they settled on a single tail for the F-16, whereas Northrop went with a twin tail on the F-17 and reportedly got better high angle of attack capability, at least during the flyoff.

In the case of the A3J, the most significant design constraint was hangar height, probably traded off against supersonic directional stability with weight being used to compare the alternatives. In almost all of these studies, particularly before the introduction of R&M as a design requirement, lowest weight would win.

 

[Skybolt]

Paul, maybe we'd merge the topics...

 

[overscan (PaulMM)]

Topics merged.

 

[Pioneer]

have altered the drawing to less taper and smaller intakes, as shown
in the perspective view.

Sorry my friend but what drawing is this?
Am interested to see!!!!!!!

Regards
Pioneer

 

[Orionblamblam]

What nuke is this?

 

[Orionblamblam]

"... but what drawing is this? "

I've just replaced the drawing in this post #13 with the
modified one.

Just a suggestion... you really should put your name, email, something on those drawings you create.

Done ! Thank you for that advise.

 

[Michel Van]

What nuke is this?

that a old design back from 1950s

must be a Mark 6 nuke
http://skaneateles.org/navy/mkvi.html

List of US Nukes
http://www.globalsecurity.org/wmd/systems/nuke-list.htm
http://www.strategic-air-command.com/weapons/nuclear_bomb_chart.htm

 

[Grey Havoc]

The A-5 did have a rather short career. Perhaps it could have been developed into a capable long range conventional strike aircraft. But supposedly it took up a ton of space on a carrier, and had some problems with it's setup of disposable fuel tanks in the weapons bay. In the long-run, the F-4 was probably the better choice for strike missions where you needed more speed than an A-6 or A-7 gave you.

The A-5 had the look of something that should never be landing or taking off from a carrier. But it did anyway.

Few things could match it as a recon platform though, a fact that the USN learned to its cost in the 1980's after it had being prematurely retired. The USN (or should I say certain members of its top brass) thought that spysats and modified F-14s could take up the slack. Big mistake.

 

[Skybolt]

In my not so humble opinion, the worst handicap of the A3J was indeed its apparent best feature, the tubular bomb bay. Apart the problems it gave in testing and in operations, it severely restricted the plane's armament choices in a clean configuration. The irony is that an aterte solution was at hand and already tested, the rotary bomb bay, patented by Martin and later used in the magnificient Buccaneer. Even if not intended for sea-level operations, you can imagine the Vigilante doing the attack run at low level with conventional armament in the internal bomb bay and laser pointers (impossible to use with a bomb ejected from the tail, at least at the level was laser guiding technology in the late-60s).

 

[Tailspin Turtle]

In my not so humble opinion, the worst handicap of the A3J was indeed its apparent best feature, the tubular bomb bay. Apart the problems it gave in testing and in operations, it severely restricted the plane's armament choices in a clean configuration. The irony is that an alternate solution was at hand and already tested, the rotary bomb bay, patented by Martin and later used in the magnificient Buccaneer. Even if not intended for sea-level operations, you can imagine the Vigilante doing the attack run at low level with conventional armament in the internal bomb bay and laser pointers (impossible to use with a bomb ejected from the tail, at least at the level was laser guiding technology in the late-60s).

Although there are anecdotal comments about problems with the A3J's unusual rearward bomb-release concept, the Navy's formal evaluation at Albuquerque doesn't identify any significant deficiencies with it, as opposed to serious ones with the Bomb Director System. It is true that the internal deliveries during the formal evaluation were less accurate than external deliveries except for the level supersonic high-altitude drops. Reading between the lines, my impression is that the testers thought that internal delivery accuracy could be improved to a satisfactory level by further development of the bomb director system and refinement of the ballistic corrections.

With respect to the rearward ejection of the internal store, the differential between airplane speed and store speed immediately after release was only about 30 knots, not equal to the A3J's forward speed as some have reported. One demonstrated and qualified delivery was the standard over-the-shoulder release, which required that the bomb go up for a while after release to allow the bomber to put some distance between it and the target area before the bomb's detonation. Deliveries using laser designation would not have been a problem.

The A3J-1 was really undone by the success of the Polaris missile program. That said, its longitudinal bomb bay was not so compelling a concept that it was ever imitated even though, according to its inventors, it was lighter than a conventional one.

 

[Triton]

North American Aviation A3J-1 Retaliator model found on eBay.

URL:
http://www.ebay.com/itm/MILTARY-AVIATION-DESK-MODEL-A3J-1-RETALIATOR-NAVY-NORTH-AMERICAN-AVIATION-/221103222597?pt=LH_DefaultDomain_0&hash=item337ac76f45

 

[TsrJoe]

looks like the display stands between this and the USAF marked example have been swapped, oops