Curtiss XA-43 (Model 29)

[Zipper730]

Since this aircraft, even if it wasn't cancelled, would probably not have made its first flight until 1946, I'm putting it under post-war aircraft.

From what I gathered on the aircraft, it seemed to have started out in late 1944 as a jet-powered attack plane for ground-support with a radius of action of 1000 nm at altitude, 600 nm at either 10,000-15,000 feet or lower. It looked like a scaled down B-45 Tornado, with a bubble canopy with tandem seating, various gun arrangements with provision for rocket-tubes in the nose, and a turret in the rear. It was around 67'6" in length, 73'0" in span, and 20'3" in height gears down.

It never entered service for the minimum reason that it could not meet the 600 nm requirement down low.

Many people thought that the XF-87 was basically a modified XA-43 that was turned into a night-fighter: That's not actually true, it was funded by the money allocated for the XA-43, but it was a different design. It bore similarities in terms of the fuselage shape, but the aircraft was smaller, the fuselage was skinnier, it had side-by-side seating instead of tandem, no tail-gun, and 4 x J34 instead of 4 x J35.

What I'm curious about is if anybody as additional information on the XA-43, particularly regarding the following

• Bomb-load: I have no idea what the maximum bomb-load was
• Forward armament: There were several proposed armament layouts for the nose and am unsure which were the most desired candidates
• Engines: While I know it used 4 x J35s, I remember hearing from one source that it started out as a two-engined aircraft, and others said it started as a four-engined aircraft from the get-go. It was said to outgrown its engine choices, which means it might have been underpowered
• Tail-gun: Was it remote controlled or manned?

 

[vikingBerserker]

Are you sure about the Model number? I show the Curtiss Model 29 being the "SX4-1" Water Glider

EDIT: Ok, it looks like they recycled their numbers.

I only see a brief blurb about it in Curtiss Aircraft 1907-1947 by Bowers.

 

[Zipper730]

Are you sure about the Model number? I show the Curtiss Model 29 being the "SX4-1" Water Glider

They might have recycled the numbers. CW-29 seems to also include the XA-43.

I only see a brief blurb about it in Curtiss Aircraft 1907-1947 by Bowers.

What was mentioned in the blurb and did it mention payload?

 

[vikingBerserker]

Sadly no, from page 508:

"This two-seater (XP-87) evolved from the unbuilt Model 29, a similarly-configured attack type designed for the Army in 1945 as the XA-43. This was cancelled and the funds and the Army serial numbers were transferred to the later XP-87 Blackhawk."

This is from American Attack Aircraft Since 1926 by E R Johnson, page 420:

"Curtiss A-43 (F-87) (1944–1948)
In 1944, after soliciting proposals for a jet-propelled tactical bomber, the USAAF assigned project designations to Curtiss (XA-43), Convair (XA-44), and Martin (XA-45). The smallest of the three designs, the XA-43 was envisaged to have ten fixed .50-caliber machine guns for strafing, two remotely-controlled .50-caliber guns in a tail barbette, plus two internal bomb bays in the belly of the fuselage. But in March 1945, before any construction of a prototype had taken place, the design was re-worked as the XP-87 night fighter to be considered along with Northrop's proposed XP-89. The re-designated XF-87, which made its first flight in March 1948, became the last aircraft completed by the Curtiss-Wright Airplane Division before it shut its doors."


"

 

[Zipper730]

In 1944, after soliciting proposals for a jet-propelled tactical bomber, the USAAF assigned project designations to Curtiss (XA-43), Convair (XA-44), and Martin (XA-45). The smallest of the three designs, the XA-43 was envisaged to have ten fixed .50-caliber machine guns for strafing, two remotely-controlled .50-caliber guns in a tail barbette, plus two internal bomb bays in the belly of the fuselage.

Okay, so we've learned something: The design was the smallest of the other two designs, the gun was remotely controlled, and there were two bomb-bays instead of one.

 

[Graeme]

Bomb-load: I have no idea what the maximum bomb-load was

According to Tony Butler - 12,000 lbs.

 

[Zipper730]

According to Tony Butler - 12,000 lbs.

Now that's impressive -- did it specify if all that was internal?

 

[vikingBerserker]

Hopefully Alan Griffith (aka Niceoldguy58) will see this and comment, I know he has done a lot of research on attack aircraft.

 

[Zipper730]

I'm curious if you have anything on the XA-43, N Niceoldguy58

 

[Graeme]

Now that's impressive -- did it specify if all that was internal?

I believe so Zip.

 

[Niceoldguy58]

I had left a rather lengthy response here earlier tonight on what I THOUGHT were the characteristics of the XA-43.

However, two thing bothered me: The date of the Curtiss brochure I have in my collection (December 12, 1949) and some of the details of the aircraft.

I have determined that what I have may well be a previously-unknown attempt by Curtiss to sell the XF-87 - following its rejection as a night fighter - as a fighter bomber version powered either by J-34's or T-40 turboprops!

I will investigate the XA-43 - assuming the National Archives ever open again.

Regretfully,

Alan Griffith

 

[Zipper730]

Sorry I missed this discussion last year, but I do have some information that I can share on the XA-43.

Thanks!

My copy of the brochure for the XA-43 differs from the information in Johnson's book, but that probably just means I'm missing information on the early design phases on this aircraft. The proposal brochure is dated 12 December 1949, so there was a lot of time in there for multiple redesigns.

Especially when it was initially proposed in 1944... up to this point, I was under the impression that the design was cancelled and the XF-87 (which was a new design) would be built on the funds of the XA-43 and (the XF-87) it flew in 1948.

Engines and performance: The XA-43 is shown to be powered by either four Westinghouse 24-C (J-34) jet engines or two Allison T-40 turboprop engines with 10' 10" Aero Products Supersonic propellers. The drawings show the props to have a square tip. It is clear from the rest of the brochure that the T-40 was the preferred engine.

Up to this point, I never knew there was any proposal for a propeller design (I actually thought it was J35 powered). That said, propellers usually do offer greater range and/or endurance, particularly if there were issues with range at altitudes below 10,000-15,000 feet.

Take-off distance ground roll was estimated to be 3350 feet with the J-34's compared to the T-40's 1600. All of this was with a take-off weight with 4x20mm cannons and 16x5" HVAR's of 41,600lbs with the J-34's and 43,700lbs with the T-40's.

Weight's pretty good

Radar in the nose was to be the APS-21 with both air-to-air and air-to-ground capabilities.

That's one of the three radars used on the F3D Skyknight...

Empty weight with the T-40's was listed as 30,756lbs with nothing given for that with the J-34's. Useful load was stated as 12,951lbs. It is this useful load where things get interesting/confusing.

The Basic Armament loading - all internal - was 4x20mm fixed guns in an extended belly trough with 16 5" HVAR's carried internally behind the guns. Alternate internal loads were:
4x20mm fixed guns and 8 missiles (no indication WHAT missiles, but the drawings show them to be rather large).
4x20mm fixed guns and one (1) 2000lb bomb
4x20mm fixed guns and two (2) 1000lb bombs
4x20mm fixed guns and four (4) 500lb bombs
4x20mm fixed guns and eight (8) 250lb bombs

Just to be clear, did the XA-43 have 4 x 20mm in the nose also, or were they all mounted in the belly trough? I'm surprised we had any kind of cruise missile in that timeframe. If you ever draw out the design, it'd be something interesting to see.

There appear to be a number of additional alternate loadouts possible with the proposed aircraft.

108 2 3/4" rockets in two extendable trays of 54 rockets each. In this case the 20mm guns do not appear to be mounted.
4x20mm turret on the underside of the aircraft with no internal weapons load.

External loads carried under the wings in addition to internal armament loads:
Sixty (60) 5" HVAR rockets
Sixteen (16) 500lb bombs
Eight (8) 1000lb bombs
Four (4) 2000lb bombs
Two (2) 4000lb bombs (interesting, carried at the wingtip stations for the tiptanks)

I have actually wondered why nobody thought of carrying bombs on the wingtip stations (it would have given the F-104 a greatly improved payload).

There was also an option for a Photo Reconnaissance version with cameras in the nose and T-9 radio fuse flash bombs in the internal bomb bay.

Makes sense, there was often a desire to develop variants of bombers like that.

I hope you find this interesting.

Submitted for your consideration,

It's quite interesting, and totally different from what I expected.

 

[Vahe Demirjian]

Here's a spree of images of the XA-43 project.

As you'll see, the XA-43 and XF-87 may look alike, except that the XF-87 differed from the XA-43 in size.

 

[Zipper730]

If I read those numbers right, I get...

Length: 69'6"
Span: 73'
Height: 20'3"

 

[Zipper730]

N Niceoldguy58

While this is quite a long time after the fact, during some research on the XA-44/XB-53 and XA-45/XB-51 I found something interesting: I'm curious if you somehow mixed up the XA-43 and XA-45

Here's some data which seems to conform to your description: B-51

 

[Zipper730]

I believe so Zip.

Which Tony Butler source was this that stated the XA-43 had a 12000 lb. bombload?

 

[Zipper730]

I think I found out why some sources gave 8000 lb. as a payload and others 12000 lb. Some of the light-bombers such as the XA-43, Bell Venus, probably the XA-44/XB-53 were designed to take a Tallboy (yes, you read that right – the 12000 lb. bomb that sank the Tirpitz).

 

[ThomasP]

eek!

 

[Zipper730]

It's interesting that the XA-43 had the designation CW-29 and Model 100.

Responding to preliminary requirements provided in September 1944, a Curtiss-Wright Corporation conceptual attack design was submitted on 14 October. This Model 100 received favourable reviews and a letter contract was inked on 24 November 1944 for the XA-43 (MX-582). Curtiss was initially permitted to proceed into Phase I with a completion date of 15 March 1945 with $2,900,000 programmed. This included preliminary design, wind tunnel testing efforts, and mockup construction in Columbus, Ohio.

Mockup inspection occurred on 19 February 1945. Responding to the comments required significant design changes to prevent weight growth, although shortfalls in TG-180 performance were a contributing factor. At USAAF urging, Curtiss investigated alternative powerplants, to include Westinghouse 24-C (later J34), but the J35 was ultimately retained.

As it shaped up, the design was to have a cigar-shaped fuselage with cruciform tail and a bubble canopy for two crewman seated in tandem. The mockup showed what appears to be a radar in the nose. The straight, mid wing would have two embedded dual-engine pods with two J35s each. The nacelle design was based on NACA research that kept drag to about that of a single, centrifugal-flow engine installation. The main landing gear was housed between the engines. Dive bombing was apparently still anticipated as dive recovery flaps were to be featured under the inboard wing segments.

Typical of this period, the design eschwed manned turrets. A remotely controlled tail turret and AN/APG-3 radar would addresss intercept from the rear quarter. However, during the weight reduction programme, the turret and radar were deleted in favor of a remote turret on each nacelle with a single .50 gun. A gunner was the considered a possible third crewman, operating the turrets with a periscope placed amidships. A remakrable 10 fixed nose guns were to support ground atack. All told, the ship was to carry 4,700 rounds of half-inch ammunition. Eight 20 mm cannon or .60 cal machine guns were also considered. A single 75 mm or 105 mm cannon centred in the nose was also reviewed, but such installations were by then much maligned and would have displaced the radar. Bombs would be within bays accommodating various weapons, potentially including pallets of additional guns or rockets.

Although the AAF was beginning to doubt the XA-43 would suitably meet requirements, the decision was made to continue the programme on at least an
experimantel basis. This, it was hoped, would permit Curtiss to gain experience with jet technology and respond more successfully in the future. onsequently, a supplement to the letter contract was promulgated on 22 May 1945 to cover Phase II. This would fund construction of additional wind tunnel models, a static test article, and three prototypes, in addition to bailment of a single TG-180 engine for testing. However, the Air Forces soon reconsidered and amended the contact on 27 June with reduction of two prototypes (serials 45-59600/1), one stripped-down test bird. The effort was then valued at $5,400,000.

A wingspan of 77.6 ft (23.7m) with 750 ft^2 (70m^2) area, length of 74.8 ft (22.8m), and a height of 22.2 ft (6.8m) was planned for the most mature XA-43 design. Empty weight was projected at 39,080 lb (17,726 kg) and gross 62,000 lb (28,123 kg). A maximum 8,000 lb (3,629 kg) of bombs were to be carried. Projected performance included 585 mph (942 km/h) top speed at sea level, 1000 mi (1,609 km) range with 4,000 lb (1,814 kg) payload, and 40,000 ft (12,192 m) ceiling.

The Army further revised its requirements for the attacker on 23 July 1945 with the Curtiss machine then appearing even less suitable, with range particularly deficient. The predicted 5,500 ft (1,676 m) takeoff distance would have been found objectionable. It was no surprise that the programme was cancelled soon after the war, 29 September, after expending about $863,959. The XA-43 work found use in the XP-87 all-weather/night fighter, one of which was built.

I'll post more tomorrow, which has stuff from another book.