Martin NBS-1

Martin NBS-1. The Martin NBS-1 was a twin-engine biplane night bomber developed for the United States Army Air Service in the early 1920s. Designed and built by the Glenn L. Martin Company, it was the first American-designed bomber produced in large quantity following World War I. The aircraft served as a cornerstone of early Air Corps bombing doctrine and saw extensive service until its replacement by more advanced monoplane designs.

Development and design

The NBS-1 originated from a 1919 requirement by the United States Army Air Service for a dedicated night bomber, leading to the development of the Martin MB-1. Following successful testing, the Air Service ordered an improved version designated NBS-1, with "NBS" standing for "Night Bomber, Short-range". The design was a conventional biplane with a fabric-covered, steel-tube fuselage and wooden wings, powered by two Liberty L-12 V-12 engines. Key design features included a defensive armament of five Lewis guns and a substantial internal bomb load carried in a ventral bay. The aircraft's crew typically consisted of a pilot, a co-pilot/gunner, a nose gunner/bombardier, and a rear gunner, operating from open cockpits. Its robust construction and reliable powerplants made it suitable for the demanding roles of coastal defense and long-range patrol envisioned by planners at the Langley Field research center.

Operational history

Entering service in 1920, the NBS-1 became the standard heavy bomber for the United States Army Air Service throughout the decade. It equipped several frontline squadrons, including those based at Mitchell Field in New York and March Field in California. The bomber participated in numerous military exercises and aerial demonstrations, such as the controversial Project B tests which evaluated the effectiveness of aerial bombardment against naval vessels. In one of its most notable operational deployments, a formation of NBS-1s completed a dramatic long-distance flight from McCook Field in Ohio to Panama to reinforce defenses for the Panama Canal Zone. The type was also flown by the 1st Pursuit Group for bomber escort training and was a frequent participant in the National Air Races. By the late 1920s, the NBS-1 was rendered obsolete by newer aircraft like the Keystone LB-5 and was completely phased out of active service by 1929, though some airframes were used as flying testbeds at Wright Field.

Variants

The primary production model was the standard NBS-1 bomber, with 130 aircraft built. A single example was completed as the Martin NBS-2, which was experimentally fitted with more powerful Packard engines, but this variant did not enter production. Several airframes were modified for specialized duties; these included conversions for photographic survey missions and for use as engine test aircraft. The basic design also directly influenced the development of the Martin T3M and Martin T4M series of torpedo bombers for the United States Navy.

Operators

The sole primary military operator was the United States Army Air Service, which later became the United States Army Air Corps. Bomber squadrons operating the type included the 11th Bombardment Squadron, 96th Bombardment Squadron, and the 20th Bombardment Squadron. No NBS-1s were exported to foreign air forces, and the aircraft did not see service with the United States Marine Corps or any civilian operators.

Specifications (NBS-1)

* Crew: 4 (pilot, co-pilot/gunner, bombardier/nose gunner, rear gunner) * Length: 42 ft 8 in (13.0 m) * Wingspan: 74 ft 2 in (22.6 m) * Height: 14 ft 8 in (4.5 m) * Empty weight: 7,268 lb (3,297 kg) * Gross weight: 12,027 lb (5,455 kg) * Powerplant: 2 × Liberty L-12 V-12 water-cooled piston engines, 420 hp (310 kW) each * Maximum speed: 99 mph (159 km/h, 86 kn) * Range: 390 mi (630 km, 340 nmi) * Service ceiling: 8,500 ft (2,600 m) * Armament: 5 × 0.30 in (7.62 mm) Lewis guns * Bombs: Up to 1,800 lb (820 kg) of bombs

Category:United States bomber aircraft 1920–1929 Category:Martin aircraft Category:Biplane aircraft