United States of America (1953)
Long Range Interceptor Proposals [None Built]
Detailed drawing of the N-144, with cutaway section
Born from the Long Range Interceptor program, the first of Northrop’s contenders were three aircraft that had large delta wings and overall similar shapes and designs. The first, the N-126, started as a modified version of Northrop’s F-89D Scorpion fighter but would become its own unique aircraft by 1954. The second, the N-144, was a large four-engine interceptor design that dwarfed current bombers of the time and could carry an impressive arsenal. The third, the N-149, differed the most from its two siblings. It was much smaller and used General Electric engines over Wright engines. The N-144 was the most successful out of the entire program, but would prove to be too costly and a maintenance nightmare if produced. The N-126 and N-149 would also not meet expectations, as did none of the other competitors in the doomed program.
The LRI Competition
At the start of the Cold War, it was realized that if a Third World War would ever happen, defending the mainland United States from airborne threats would be a top priority. ICBMs and nuclear missiles are the go-to threat everyone imagines when they think of the Cold War, but these wouldn’t be operational until the late 1950’s. In the early years, nuclear weapons would be deployed by strategic bombers and these would be the major threat. Intercepting these long range aircraft would be of the utmost importance if the war went hot in the 1950’s. Developing an aircraft able to reach these bombers and destroy them led to the creation of the modern interceptor. Most countries had begun developing an interceptor of their own. At the forefront was the United States Long Range Interceptor program (LRI). This program originated in early 1952, with Major General L.P. Whitten of the Northeast Air Command noticing that a capable aircraft would be able to takeoff and intercept enemy bombers using the warning time of the Semi-Automatic Ground Environment (SAGE) system, which was an integrated defense network of SAM, radar and fighters across the US and Canada, able to intercept enemy bombers well before they were able to reach the United States. Although the idea was put out, no official requirements for the idea came about until December of 1953, when the Air Council put out extremely demanding needs. The aircraft would need to be airborne in two minutes from getting the scramble alert. Maximum speed would be Mach 1.7 with a range of 1,000 nm (1,850 km). Combat ceiling would be 60,000 ft (18,000 m) with a climb rate of 500 ft/min (150 m/min). The aircraft would be minimally armed with forty-eight 2.75 inch rockets, eight GAR-1A Falcon AAMs or three unguided nuclear rockets. This requirement became known as Weapon System WS-202A. Most companies developed submissions, but McDonnell and Northrop had an early start with a long range interceptor design being conceived very early on, well before an official requirement had been requested. Northrop had three aircraft designs that would fit the requirement for WS-202A; the N-126, N-144 and N-149. All three were visually similar to each other and shared concepts and equipment with one another.
Northrop N-126: The Delta Scorpion
Bottom view of the N-126 Delta Scorpion model [US Secret Fighter Projects]The first of the designs Northrop submitted was the N-126 Delta Scorpion. This aircraft actually began development months before an official requirement was put out. The design was submitted in February of 1953 and was essentially a Northrop F-89D Scorpion modified with a new delta wing design and Wright YJ67 engines. The aircraft received a performance review sometime in 1953 along with McDonnell’s two-seat version of the F-101 Voodoo. Neither design was chosen for production. The N-126 did show promise, as it came close to meeting the very first requirements and it was supported by the Air Defense Command. However, the predicted first flight in twenty-one months was a bit too optimistic and the design was disliked by the United States Air Force Headquarters, as it didn’t exactly meet requirements compared to the F-101 variant. Northrop pushed this early design and adamantly tried to acquire production.
Front quarter view of the N-126 Delta Scorpion model [US Secret Fighter Projects]They were quick to begin working on an improved design that would be longer and yield better results. It took over fifty concept designs before they found a suitable improvement. The aircraft itself no longer resembled the F-89D Scorpion it got its name from, but the name would stick until the end of the project. This new design was submitted in August of 1954. The N-126 was now much sleeker, with a forty-five degree delta wing and two underwing Wright J67-W-1 engines (Allison J71-A-11 engines were a weaker alternative choice). The delta wings all three projects used provided lower weight than generic straight wings and minimized drag. The trailing edge of the wing would have a split speed brake on the outer surface, an aileron located in the middle and a feature on the inboard section only referred to as an “altitude flap”. For the landing gear, a bicycle configuration with two wheels on each gear would be mounted directly under the aircraft, with a smaller landing gear being placed under the wings.
For armament, the aircraft would use the required eight Falcon AAMs and forty-eight rockets being mounted in a 20 ft weapon bay. Four external hardpoints would allow extra ordnance to be carried, such as bombs or extra missiles. Alternative loadouts included any combination of four AIR-2A unguided nuclear rockets, six Sidewinders, or two Sparrow guided missiles. The N-126 would use the Hughes E-9A fire control system, one of the few remnants carried over from the F-89. The E-9A would be linked to a long-range search radar that would have a range of 100 nm (185 km). For fuel, one large internal tank and two smaller tanks in the wings would hold 4,844 gal (22,025 l). Extra drop tanks could be mounted under the wings and offer an additional 1,600 gal (7,275 lit). For its predicted mission, the N-126 would be able to launch and engage enemy bombers twenty-seven minutes after scramble. Northrop expected a prototype would be ready for a first flight by June of 1957.
Northrop N-144: The Monstrous Interceptor
Color photo of the N-144 model [US Secret Fighter Projects]The N-144 was the second design Northrop submitted. It was made to offer the best results in regard to the WS-202A requirements. It resembled the N-126 but was much larger and had four J67 engines. The N-144 dwarfed its siblings, competitors, and even several current bombers of the time. With a wingspan of 78 ft and a length of 103 ft, this was no small aircraft. In comparison, the Convair B-58 supersonic bomber had a wingspan of 56 ft and a length of 96 ft (interesting to note, a plan to convert the B-58 into a long range interceptor was proposed).
Its appearance wasn’t the only thing carried over from the N-126. The E-9A fire control system, its accompanying scanner, and its landing gear design (now with four wheels on the main gear) were all reused in the N-144. The N-144 also had a forty-five degree delta wing like the N-126. The N-126 and N-144 would both have their engines on pylons on the wings. This configuration allowed much more powerful engines to be used and a simpler intake system compared to having the engines be built into the body, not to mention the layout being much safer in the event of a fire.
Top down view of the N-144 model. Note the 45 degree delta wing [US Secret Fighter Projects]The N-144 utilized many features that would directly improve the aerodynamics of the aircraft. The aircraft would have low wing loading which would increase its cruise altitude and improve takeoff and landings. The addition of a horizontal tail, which isn’t often seen in delta wing designs, gave the N-144 improved handling and stability over designs that lacked the horizontal tail (see the Convair F-102 Delta Dagger for example). When the aircraft would be supersonic, the wing would have a chord flap that would retract into the wing to reduce drag. Area ruling was a feature involving tapering the center of the fuselage which would reduce drag while the aircraft was flying at supersonic speeds. Most current delta wing designs utilized area ruling, but none of Northrop’s interceptors surprisingly did. Northrop ruled that the advantages would only affect supersonic flight, and not provide anything useful during subsonic flight. Having no area rule also made the aircraft simpler in design and easier to produce. Northrop’s studies into the delta wing expected to see performance increase as time went on, with more modifications and better engines being used on the N-144 if it went into production. With these expected improvements, Northrop theorized a 14% improvement in top speed and service ceiling.
Frontal view of the massive N-144 model. The size of its engine pods are evident. [US Secret Fighter Projects]For armament, the N-144 would still utilize the standard eight Falcon AAMs and forty-eight rockets, but could also carry twelve Falcon AAMs, six AIR-2A Genie (Ding Dong) rockets, 452 2.75 in FFAR rockets or 782 2 in (5.1 cm) rockets internally in any order. External hardpoints could also be fixed for carrying bombs or more ordnance. For fuel, a large fuel tank would be in the wings and fuselage and could carry 6,910 gal (31,419 l) of fuel. Given the size of the aircraft, Northrop advertised that it could be used in alternative roles.
Northrop N-149: The Opposite End
Model of the N-149. The additional fuel tanks can be seen. [US Secret Fighter Projects]The N-149 was the third and final design submitted by Northrop for WS-202A. Submitted in July of 1954, the N-149 was almost the polar opposite of the N-144. Instead of opting for raw power and utilizing four engines, the N-149 was meant to be the smallest option available while still performing just as well as its competitors. In comparison, the N-126 would be 85 ft (25.9 m)long with a wingspan of 62 ft (19 m), while the N-149 would be 70 ft (21.5 m) long with a wingspan of 50 ft (15.5 m). This size decrease would save cost, space and fuel consumption. The N-149 used the same wing layout as the previous entries and would also retain the E-9A fire control system and accompanying radar. Given the advancements of the N-144’s wings, it is likely the N-149 would also benefit from them as well. The N-149 did not use Wright J67 jet engines like the N-126 and N-144, but would instead use General Electric J79 engines. These engines were longer than the J67 but would benefit the aircraft, given its small size, to achieve the required speed and rate of climb. The bicycle landing gear with outer wing gear was once again used, but now with two wheels on each gear like the N-126. The armament for the N-149 was less than its predecessors, but it would make up for weapons in the amount able to be built. Once again, eight Falcon AAMs and forty-eight 2.75in rockets were standard, but alternative armaments would be a single Sparrow AAM, four Sidewinder AAMs, another 105 2.75 in rockets or 270 2 in rockets. Additional armament could be mounted on four external hardpoints like the N-126 and N-144, however, two of these would be taken up by external fuel tanks. These tanks would be 600 gal (2,730 l). The majority of the fuel would be in a large tank that spanned the fuselage and into the wings and would carry 2,050 gal (9,320 l) of fuel. Northrop expected a first flight of the aircraft by the summer of 1957.
The Program Concludes
Detailed drawing of the N-149 with cutaway
Although Northrop is the center of this article, Boeing, Douglas, Lockheed, Martin, McDonnell, North American, Chance-Vought, Grumman and Convair all submitted designs. When the assessment of all the designs was completed, it was concluded that none of the proposals exactly met up the set requirements. The N-144, however, came the closest to meeting the specification. After assessment, the N-144 had a predicted speed of Mach 1.76, a combat ceiling of 58,500 ft (17,800 m) and a combat range of 1,015 nm (1,880 km).
McDonnell’s design came close, as it could go faster and reach the same altitude, but its range was much less compared to the N-144. Materials Command was not too keen of the N-144 and it is obvious why. The cost, production and maintenance of it would be tremendous. Given its four engines, the aircraft would require much more maintenance compared to its two-engine competitors. Producing such a large aircraft would be extremely costly given its size and engine count. The best option for performance would also be the worst option considering its cost.
Its siblings didn’t meet the specifications as well. No reason was put out as to why the N-126 failed the competition, but given the state of the program, it can easily be assumed it didn’t meet either the range, speed, or altitude requirements. The N-149 did have a specified reason for its rejection, though. After taking off at full power and reaching its maximum height, it would only offer 20 minutes of flight, with 5 minutes at full power for combat. Having your aircraft destroy as many bombers before reaching their target is necessary and only 5 minutes wouldn’t be sufficient to fulfill its duty. Ultimately, WS-202A wouldn’t produce any aircraft. The requirements had gone too high, and the companies wouldn’t be able to produce a cost effective aircraft in time that would meet the expected specifications. The program would go on to become the new LRI-X program in October of 1954, and Northrop would be one of three companies tasked with creating a new interceptor, which their Delta-Wing trio would surely influence in a number of ways.
Variants
Northrop N-126 (February 1953) – The 1953 N-126 Delta Scorpion was an improvement upon the F-89D Scorpion by having a delta wing and YJ67 engines.
Northrop N-126 (1954) – The 1954 version of the N-126 no longer resembled the F-89 but was now longer and more streamlined.
Northrop N-144 – The N-144 would be the second design submitted to the LRI competition. It was much larger than the other two submissions and would utilize four engines.
Northrop N-149 – The N-149 was the smallest of the three designs and was meant to be the best performing for its size. It looked visually similar to the N-126 but would carry slightly less ordnance and utilize Gen Elec XJ79-GE-1 jet engines over the Wright J67-W-1s.
Operators
United States of America – All three designs would have been operated by the United States Air Force had they been constructed.
Northrop N-126 – Artist Impression of the Delta Scorpion in USAF Prototype StageNorthrop N-144 – Artist Impression of the N-144 the in Late Prototype StageNorthrop N-149 – Artist Impression of the N-149 in service with the 171 Fighter Interceptor Squadron, Michigan, circa 1960s
3-Way drawing of the N-126 Delta Scorpion [US Secret Fighter Projects]3-Way drawing of the N-149 [US Secret Fighter Projects]Underside quarter view of the N-126 model [US Secret Fighter Projects]
3 view drawing of the N-126 Delta ScorpionA photo of the N-126 Delta Scorpion in wind tunnel testing
3-Way drawing of the N-149 [US Secret Fighter Projects]Colored photo of the N-149 model. Note the tail has been slightly damaged. [US Secret Fighter Projects]Rear view of the N-149 model. Damage to the tail is evident here. [American Secret Projects: Fighters & Interceptors, 1945-1978]Credits
United States of America (1953)
