North American NA-40

History of the North American NA-40

Even before the classic WWII North American twin-engine B-25 "Mitchell" medium bomber could be achieved, North American Airlines Group had to pass a series of twin-engine aircraft All are designed to meet the existing requirements of the United States Army Air Corps (USAAC) for twin-engine attack aircraft. The "attack" aircraft was born out of the need to provide ground forces with on-the-spot firepower that fighter jets simply couldn't do, and conventional bombers were overkill.

When all land and naval warfare eventually evolves to require this specialized type, global military powers around the world are looking for capable hyper-battlefield designs. American interest in twin-engine attack/bomber types (represented by the B-25, Douglas A-26 Intruder, and Martin B-26 Marauder) during WWII and design work increased when the war began .

The new requirements were born in 1937 in the years leading up to WWII, and by 1938 some of the leading North American airlines had developed to support their new prototype "NA-40" (after they completed the only, discontinued XB) - 21 1936 "Dragon" prototype). The aircraft is characterized by a deep fuselage, well-glazed nose section, a stepped flight deck and a short/??top tapered tail.

The tail has two external rudder fins, attached to the horizontal plane of the fuselage. The general form of construction of the main wing aircraft components is straight, each housing a nacelle that drives a three-blade traction propeller unit.

Wheeled retractable landing gear is used for ground handling - although the legs are a bit short, combined with the shortened tail section which makes the plane look rather fat on the ground.

The initial prototype of the NA-40 was powered by two Pratt & Whitney R-1830-56C3G air-cooled radial piston engines, each rated at 1,100 hp. Dimensions include a length of 48.2 feet and a wingspan of 66 feet. Internally, the aircraft was operated by a crew of five and had a wartime payload of up to 2,100 pounds. Defensive weapon positions are planned for nose and back/abdominal positions.

This version, which first flew on January 29, 1939, failed to impress (with a test top speed of only 265 mph), so it was repainted as the NA-40B (aka "NA-40-2" )become.

The NA-40B instead uses a pair of Wright R-2600-A71-3 "Twin Cyclone" "Twin Cyclone" 14-cylinder air-cooled radial engines rated at 1,275 hp (each), also including minor modifications to Fix instability and performance/lack of performance on first try. Top speed has been increased to 309 mph, while all other features of the aircraft remain largely unchanged from the original.

However, the only prototype of the program was lost in an accident on April 11, 1939, before the project gained enough momentum. It was not recovered and NA-40 was subsequently terminated.

Nonetheless, North American commitment to the NA-40 prototype led to its excellent WWII-era B-25 "Mitchell" (detailed elsewhere on this page).

Specification

Basics

Year of Service

1939

Origins

United States

Status

Cancel

Development ended.

Crew

5

Production

1

Manufacturer

North American Airlines - United States

Carrier

United States (removed)

Roles

Ground attack (bombing, strafing)

The ability to conduct air strikes against ground targets using (but not limited to) artillery, bombs, rockets, rockets, etc.

Disable support (CAS)

Designed to operate near active ground elements with a wide range of air-to-surface weapon and ammunition options.

X-Plane (development, prototype, tech demo)

Aircraft designed for prototyping, technology demonstration, or research/data collection.

Dimensions and Weight

Length

48. 2 feet

(14.70m)

Width/span

66.0 ft

(20.12m)

MTOW

20,999 lbs

(9,525 kg)

Performance

Installed:

2 x Wright R-2600-A71-3 "Twin Cyclone" 14-cylinder 1,275 hp radial piston air-cooled engines driving a three-blade propeller unit.

Maximum speed

311 km/h

(500 km/h | 270 knots)

Maximum

25,000 feet

(7,620 m | 5 km)

Area

1,199 km

(1,930 km | 3,574 nautical miles)

Range (MPH) Subsonic: <614mph | Transonic: 614-921 | Supersonic: 921-3836 | Hypersonic: 3836-7673 | Hypersonic: 7673-19180 | Reentry: > 19030

Weapon

Proposed: 1 x .30 caliber machine gun, trainable nose position mount. 1 x .30 caliber machine gun, trainable to mount upside down. 1 x .30 caliber machine gun, trainable for abdominal/waist position. Conventional bomb/throwing weapons up to 2,100 lbs.