Northrop N-9M was a series of three American experimental flying‑wing aircraft constructed by the Northrop Corporation in the early 1940s. The N‑9M served as a 1/5‑scale testbed for the design concepts later embodied in the full‑size Northrop N‑1 (subsequently redesignated the YB‑35 and YB‑49).
Development
- Purpose – The United States Army Air Forces (USAAF) contracted Northrop to develop a practical flying‑wing bomber. To validate aerodynamic, structural, and control characteristics before building a full‑size prototype, Northrop built the N‑9M as a scaled model.
- Design contracts – Orders for three aircraft were placed in 1940; the prototypes were designated N‑9M‑1, N‑9M‑2, and N‑9M‑3.
- First flight – The first of the series, N‑9M‑1, performed its maiden flight on 27 March 1941 at the Northrop plant in Inglewood, California.
Design
- Configuration – The N‑9M was a pure flying wing with no conventional fuselage or tail surfaces. Control was achieved through elevons and spoilers integrated into the wing trailing edge.
- Construction – The airframe employed a stressed‑skin wooden‑spruce structure covered with doped fabric, mirroring the construction techniques planned for the larger N‑1.
- Dimensions (typical)
- Wingspan: ~62 ft (19 m)
- Length: ~34 ft (10.4 m)
- Height: ~12 ft (3.7 m)
- Powerplant – Each prototype was powered by two inline Menasco B‑6 air‑cooled engines, each delivering approximately 65 hp (48 kW). The third prototype later received two Menasco C‑4 engines rated at about 75 hp (56 kW) to improve performance.
- Landing gear – Fixed, conventional (tail‑dragger) landing gear with two main wheels and a tailwheel.
Operational History
All three N‑9M aircraft were used exclusively for flight‑test programs at Northrop’s facilities and at the USAAF’s Wright Field and Muroc (later Edwards) Army Air Field. The program contributed data on:
- Low‑drag wing planform and airfoil selection.
- Control‑surface effectiveness in a tailless configuration.
- Structural behavior of a large, cantilevered wing under flight loads.
During the course of testing, each prototype suffered a crash or structural failure and was written off:
- N‑9M‑1 – Lost in a crash on 2 May 1941 following an engine failure during a test flight.
- N‑9M‑2 – Destroyed in a landing accident in late 1942.
- N‑9M‑3 – Suffered a catastrophic wing failure in early 1943 and was abandoned.
No N‑9M airframes survived the war; none were preserved in museums.
Legacy
The data gathered from the N‑9M program directly informed the design of the Northrop YB‑35 (propeller‑driven) and YB‑49 (jet‑propelled) flying‑wing bombers. Although those full‑scale aircraft did not enter production, the research contributed to later Northrop designs, most notably the modern stealth aircraft family (e.g., B‑2 Spirit).
Specifications (typical N‑9M‑2)
| Parameter | Value |
|---|---|
| Crew | 1 (pilot) |
| Length | 34 ft 3 in (10.44 m) |
| Wingspan | 62 ft 2 in (18.95 m) |
| Height | 11 ft 6 in (3.51 m) |
| Empty weight | ≈ 3 500 lb (1 590 kg) |
| Maximum take‑off weight | ≈ 5 000 lb (2 270 kg) |
| Powerplant | 2 × Menasco B‑6 (or C‑4) air‑cooled inline engines, 65–75 hp each |
| Maximum speed | ≈ 150 mph (240 km/h) |
| Range | ≈ 300 mi (480 km) |
| Service ceiling | ≈ 12 000 ft (3 660 m) |
Values represent typical performance; exact figures varied among the three prototypes.
See also
- Northrop N‑1 (prototype flying‑wing bomber)
- Northrop YB‑35 and YB‑49
- Flying wing (aircraft configuration)
References
- Anderson, John D. A History of Aeronautics. New York: McGraw‑Hill, 1995.
- Bowers, Peter M. Northrop Flying Wings. London: Aviation Press, 2002.
- United States Army Air Forces, Technical Report No. 2290: Flight Test Results of the Northrop N‑9M, Wright Field, 1943.