North American YF-93A Sabre - An Afterburning Sabre for the USAF

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North American YF-93A

   Hello everybody. I’d like to suggest the North American YF-93A for US aviation in War Thunder. The YF-93A was another prototype fighter built in response to the United States Air Force requirement in 1945 and a design study in 1947. It used to be known as the F-86C, a variant derived from the F-86A Sabre to become a true penetration fighter and escort fighter. The YF-93A was designed and intended to compete with the XF-88A Voodoo and Lockheed XF-90A to fulfill the USAF’s Penetration Fighter requirement but ultimately lost to the McDonnell XF-88A.


Key Characteristics

  • Long-range jet fighter
  • Derived variant from the F-86A to become a penetration/escort fighter
  • A Pratt & Whitney J48 turbojet engine with an afterburning capability
  • SCR-720 searching radar in the enclosed nose
  • An armament of 6 x 20-mm cannons

History

Introduction and Background

On August 28, 1945, the United States Army Air Forces (later separated as the United States Air Forces) announced a new requirement for a twin-engine penetration fighter with swept wings capable of escorting jet-power bombers over enemy territory and back. It was required to have a combat radius of at least 900 miles.

By this time, World War II was over in Europe and the Pacific. The air doctrine was reshaped and advocated that the large formations of bombers, escorted by long-range fighters, would cause mass destruction on enemy targets below. The fighter escort was essential for the survival of bombers in enemy airspace. With the Soviet Union being the chief Cold War contender, it was undoubtedly attempting to outpace the West with its numerous jet-powered fighters and bombers.

The requirement sought a new fighter that fulfills the long-range penetration fighter and bomber escort roles. Although both terms had similar concepts, they differed in tactical movements. The penetration fighter’s role would not operate in close formation with bombers. Instead, it would penetrate deeper enemy airspace and neutralize any threats ahead of the bombers. These fighters could return to the bombers and continue the escort duty after the incursion. The North American P-51 Mustangs had demonstrated this part of the air doctrine during the turning points of the air war in World War II. In the post-war period, the development of jet-powered strategic bombers made propeller-driven fighters and earlier non-afterburning jet fighters difficult to keep up. Hence, this requirement was created in the first place to bring more modern aircraft designs powered by the after-burning jet engines.

Competitors for the contract included McDonnell’s XF-88, North America’s YF-93, and Lockheed’s XF-90. North American received a contract to construct two prototype YF-93s on December 17, 1947.

YF-93A Development

The YF-93A retained the swept-wing and tail assembly of the F-86A, and everything else was different. Unlike the F-86 and its nose-mounted intake, the YF-93A incorporated a nose cone housing the radar system, and the flush intakes were fitted to the sides of the larger fuselage for a more design approach. It was planned to incorporate the six 20-mm cannons. These guns would reside along the sides of the nose, similar to the case with the F-86A’s machine guns.

The YF-93A was powered by a new Pratt & Whitney J48-P-1 centrifugal-flow turbojet engine. The J48 was an American-licensed version of the Rolls Royce Tay. The J48 was larger than the J47 of the F-86A, so the YF-93A’s fuselage had to be increased both in width and in length. Additional tankage was installed to bring the total fuel capacity to 1,581 gallons per the range requirement. The pair of slab-type brakes were mounted on the fuselage belly for the YF-93A rather than air brakes on the sides of the F-86A fuselage.

All changes had increased the YF-93A’s total weight, as it was much larger and heavier than the F-86A Sabre. Therefore, it had stronger landing gear with twin wheels used to compensate for the accounted weight.

Two unarmed prototypes were built with NACA inlet ducts; the first (48-317) and the second (48-318) were later retro-fitted with more conventional intakes. Six months later, in June 1948, the USAF placed a production order for 118 F-93As. The USAF was comfortable and familiar with other North American Sabre variants. It seemed a sign that the F-93 would be assured operational service with the USAF.

However, in February 1949, the USAF suddenly canceled the production order, as it dropped the requirement for a penetration fighter. It was because of the changes in USAF priorities and a large cut in the military budget. In addition, the USAF was planning to introduce the new Boeing B-47 Stratojet into service, with the performance so impressive that it didn’t require a fighter escort. Furthermore, it anticipated the introduction of the “state-of-the-art” B-52 in service in an eventual time. Nevertheless, the production order for any penetration fighters would have to be held until a competitive fly-off between the XF-88A, XF-90A, and YF-93A could be carried out.

Flight Testing

The YF-93A did not roll out of the factory until late 1949 and was transported to Muroc Dry Lake for flight testing. Finally, on January 24, 1950, the test pilot took the YF-93A (48-317) on its maiden flight. The YF-93A managed to achieve 708 mph and managed to reach Mach 1.05 only in a dive. It was later found to have an issue with the use of the NACA inlet ducts. Although the NACA inlet ducts were intended to improve performance, the more conventional intakes were superior for air combat in high angles of attack.

With too little time, the USAF had to conduct a fly-off amongst the three competing designs to see which was best by the summer of 1950. The fly-off between the Lockheed XF-90A, the McDonnell XF-88A, and the North American YF-93A occurred between June 30, 1950, and July 8, 1950, for the final evaluation by the USAF officials. On August 15, 1950, the Evaluation Board declared the McDonnell XF-88A the winner. McDonnell secured the production contract in September 1950. Yet, the penetration fighter project was canceled and ultimately shelved due to the situation with the war in Korea and changes in USAF priorities.

The two YF-93As were subjected to additional testing by NACA’s Ames Laboratory at Moffett Field, California, for comparison tests of the flush air intakes. At one point, both aircraft had their rear fuselages modified to accept a production F-86D tailpipe and stabilizer, and they were used by NACA as flight test and chase aircraft around in the middle of the 1950s. They were phased out from service to NACA in 1956 and subsequently scrapped.

Had the F-93A been accepted into production, the aircraft would probably have been seen escorting the B-29 Superfortresses and intercepting the MiGs over Korea in 1951-1953.


Specifications

North American YF-93A

General Characteristics

  • Crew: 1 (Pilot)
  • Length: 44 ft 1 in (13.44 m)
  • Height: 15 ft 8 in (4.78 m)
  • Span: 38 ft 9 in (11.81 m)
  • Wing area: 306.1 sq ft (28.4 sq m)
  • Powerplant: Pratt & Whitney J48-P-1 centrifugal-flow turbojet engine*****
    → 8,000 lb (35.58 kN) thrust A/B @ 11,000 rpm
    → 6,000 lb (26.69 kN) thrust dry @ 11,000 rpm
  • Internal Fuel: 1,581 US gal. (5,985 L)
  • Oil Tankage: 1.25 US gal. (4.7 L)
  • Empty Weight: 14,035 lb (6,366 kg)
  • Gross Weight: 21,610 lb (9,802 kg)
  • Max. Takeoff Weight: 26,516 lb (12,027 kg)

“*****” I have seen other sources mentioned the aircraft used the latest J48-P-6 with more pound-force thrust; however, I found no further information about this variant of the turbojet.

Performance

  • Thrust-Weight Ratio: 0.37
  • Sea Level Speed: 708 mph (1,139 km/h)
  • Critical Altitude Speed: 622 mph @ 35,000 ft (1,001 km/h @ 11,000 m)
  • Stall Speed: 150 mph (241 km/h)
  • Wing Loading: 86.7 lb/sq ft (423 kg/sq m)
  • Rate of Climb: 11,960 fpm (60.8 m/s)
  • Time of Climb:
    • 1.8 minutes to 15,000 ft (4,572 m)
    • 4.9 minutes to 30,000 ft (9,144 m)
  • Service Ceiling: 46,800 ft (14,300 m)
  • Combat Radius: 738 miles (1,188 km)
  • Combat Range: 1,836 miles (2,955 km)

Armament

  • Guns:

    • 6 x 20-mm M24 cannons (225 rpg; 1,350 rounds)
  • Bombs:

    • 2 x 1,000-lb bombs
    • 2 x 500-lb bombs
    • 2 x 250-lb bombs
    • 2 x 100-lb bombs
  • Rockets:

    • 16 x 5-inch (127-mm) HVARs
        or
    • 8 x 5-inch (127-mm) HVARs
  • Electronics:

    • SCR-720 Searching Radar
    • AN/APG-5C Rangefinding Radar
    • A-1B Gun-Bomb-Rocket Sight
  • Others:

    • 6 x Assist Takeoff Units
      • 1,000 lbf (4.45 kN) each at duration of 14 seconds

Supplemental Data


Diagrams


Images


Conclusion | Why it should be in the game

   The YF-93A was among the early USAF jets with an afterburner. It was built as a larger fighter for range rather than the superior performance of the F-86A. I feel it should be added as the early jet fighter with an afterburning capability for US aviation in War Thunder. It would serve as a transitional aircraft between the F-86F-2 Sabre and the F-100 Super Sabre. It was faster and had a longer range than the other F-86 variants. It would be a stronger energy fighter and support fighter with slightly weaker acceleration in the game.


See Also

I made a suggestion of the Lockheed F-90A, the YF-93A’s competitor. If you’re interested in this suggestion, check this out!


Sources


Thank you for taking the time to read my suggestion! 😃

7 Likes

That is a MASSIVELY cool-looking plane. Seriously captures the space-age look of the late 40s-early 50s. +1

4 Likes

Yes, please, take my absolute +1!

I would say god this thing is ugly, but different strokes i guess.

This could be a nice event vehicle

It should be noted that both aircraft were very distinct from each other. The first ship (YF-93 #1, S/N 48-317) was to be the flight testbed, while ship two (YF-93 #2, S/N 48-318) would be the armament testbed. The first prototype would be the one to have all the changes made to its aerodynamics, most notably the modified intakes. The second prototype would remain relatively unchanged, until it would be transferred to NACA testing (where its armament would be removed).

Very few photos of the second prototype exist before it was transfered over to NACA. Fortunately I have a book that has 4 photos of it during that timeframe, 3 of which showcase its armament:

YF-93 S/N 48-418


Along with that, here are some extras. I should note that during NACA testing, the fuselage and tail assemblies of both aircraft were marked to distinguish each aircraft (“1” for the first prototype and “2” for the second prototype). In some photos during NACA testing, you can see “mixed” YF-93s.

Extra Stuff





3 Likes

sexy +1

as a event vehicle

Thank you for sharing this! Is this book the North American YF-93A Penetration Fighter by William Simone? I haven’t acquired it. This is very valuable information you have gotten!

Do you have more juicy information regarding its SCR-720 searching radar or J48-P-6 turbojet being mounted in one of these YF-93As?

Edit: Fixed typos and updated YF-93A Sabre suggestion.

2 Likes

Yes, it is that book. I also have one from the same series about the XF-90, which I saw you made a suggestion for as well.

Unfortunately the book is pretty short and the information you’re looking for isn’t there. The only mention of a search radar is the AN/APG-33, for use in a proposed all-weather interceptor variant of the YF-93. This same proposal would use the J48-P-3 engine, which was to provide a considerably higher amount of thrust over the J48-P-1.

I haven’t found anything about the J48-P-6. There is a mention of the first prototype using the J48-P-2 during Phase II Air Force flight tests, however this engine used water injection rather than afterburner.

The book also states that a good portion of the aircraft’s flight data has been lost to time, with the results of many tests being unknown to this day.

1 Like

Ah, bummer. Thanks for the extra info, nonetheless.

Curiously, I have found statements regarding the J48-P-6 in Steve Pace’s XF-88 Voodoo book (Air Force Legends 205):

Spoiler


However this book is from 1999 vs. the YF-93A book from 2023.

2 Likes

Hmm. That’s interesting. Sounds like they planned to incorporate the beefier J48-PW-6 into one of the prototypes, but it never materialized apparently.