Bell YFM-1 Airacuda

https://en.wikipedia.org/wiki/Bell_YFM-1_Airacuda

The Bell YFM-1 Airacuda was an American heavy fighter aircraft, developed by the
Bell Aircraft Corporation during the mid-1930s. It was the first military
aircraft produced by Bell. Originally designated the Bell Model 1, the Airacuda
first flew on 1 September 1937. The Airacuda was marked by bold design advances
and considerable flaws that eventually grounded the aircraft.

The Airacuda was Bell Aircraft's answer for a "bomber destroyer" aircraft.
Although it did see limited production, and one fully operational squadron was
eventually formed, only one prototype and 12 production models were ultimately
built, in three slightly different versions.

In an effort to break into the aviation business, Bell Aircraft created a unique
fighter concept touted to be "a mobile anti-aircraft platform" as well as a
"convoy fighter." Created to intercept enemy bombers at distances beyond the
range of single-seat fighter interceptors, the YFM-1 (Y, service test; F,
fighter; M, multiplace) was an innovative design incorporating many features
never before seen in a military aircraft, as well as several never seen again.
Using a streamlined, "futuristic" design, the Bell Airacuda appeared to be
"unlike any other fighters up to that time."

According to Major Alexander De Seversky's 1942 book, Victory Through Air Power,
the Bell Airacuda "represents a great engineering achievement. But its
designation as 'convoy fighter' is erroneous, since that requires different
disposition of armament. With its maximum firepower directed forward, it really
offers a preview of an effective long-range interceptor fighter."

A forward-firing 37 mm (1.46 in) M4 cannon with an accompanying gunner was
mounted in a forward compartment of each of the two engine nacelles. Although
capable of aiming the cannons, the gunners' primary purpose was simply to load
them with the 110 rounds of ammunition stored in each nacelle.

The crew of five included the pilot and gunners; a copilot/navigator who doubled
as a fire-control officer, using a Sperry Instruments "Thermionic" fire control
system (originally developed for anti-aircraft cannon) combined with a
gyro-stabilised and an optical sight to aim the weapons; and a radio
operator/gunner armed with a pair of machine guns stationed at mid-fuselage
waist blisters for defense against attack from the rear.

An unusual feature of the Airacuda was the main door for entry. The door was
opened and pulled down and hinges folded in on three steps for the crew to climb
into the aircraft.

The Airacuda was plagued with problems from the start. The lofty performance
estimates were unobtainable as, despite its sleek looks, the Airacuda was heavy
and was slower than most bombers. In the event of interception by enemy
fighters, the Airacuda was not maneuverable enough to dogfight, while the meager
600 lb (270 kg) bombload was of little use in the intended fighter-bomber role.
Even the 37 mm cannons were of less value than predicted. The cannons had a
tendency to fill the gun nacelles with smoke whenever fired and, additionally,
fears persisted as to how the gunners would escape in an emergency, with the
propellers directly behind them. An emergency bailout would have required both
propellers to be feathered, though additional provision was made with the use of
explosive bolts on the propellers to jettison them in the event of a bailout. As
with other types armed with the 37mm M4, the low muzzle velocity of the weapon
made it difficult to use as an aerial weapon, limiting the useful range
significantly (although this was never a problem for the YFM-1 since it never
actually entered combat).

Initial flight testing by Lt. Ben Kelsey proved the Airacuda virtually
impossible to control with only one engine, as the aircraft would go into an
immediate spin. Problems with stability in pitch were also encountered, and had
to be corrected by reducing power. Test pilot Erik Shilling described his
experiences in a later book, Destiny: A Flying Tiger's Rendezvous With Fate as:


Flying the Bell Airacuda was a new experience for me, since it was the first
pusher aircraft I'd ever flown. Its handling characteristics were foreign to
anything I had ever had my hands on. Under power it was unstable in pitch, but
stable with power off. While flying straight and level, if a correction in pitch
was required, a forward push on the control resulted in the airplane wanting to
pitch over even more. Pitch control became a matter of continually jockeying the
controls, however slightly, even when the aircraft was in proper trim. The same
applied if pulling back on the control. It would tend to continue pitching up,
requiring an immediate corrective response. The same happened in a turn with
power off, the Bell became stable in pitch. This was fortunate because during
approach and landing, it was very stable, and a nice flying airplane."

The Airacuda was also saddled with a complex and temperamental electrical system
and was the only aircraft ever built to rely on an independent auxiliary power
unit (APU) to power both engine fuel pumps, as well as all aircraft electrical
systems. Systems usually powered by an aircraft's engines were instead powered
by the single generator. The generator, with its own supercharger, was located
in the belly of the aircraft. In the event of a failure (and they occurred
frequently), the crew was instructed to begin immediate emergency restart
procedures as the aircraft basically shut down. When the APU failed, the pilot
had "NO fuel pressure, NO vacuum, NO hydraulic pressure, NO gear, NO flaps and
NO ENGINES".


Role
Interceptor

National origin
United States

Manufacturer
Bell Aircraft

First flight
1 September 1937

Introduction
23 February 1940

Retired
1942

Primary user
United States Army Air Corps

Produced
1937–1939

Number built
13

Program cost
$3.6 million USD

Unit cost

$219,000 USD

Despite problems, one fully operational Airacuda squadron was eventually
assembled, and operated from 1938 until 1940. Funds were appropriated, but never
released, for the purchase of two groups of Airacudas. Continuing problems gave
the aircraft a reputation as "hangar queens". Near the end of the type's
operational life, the aircraft were flown primarily for photo opportunities and
always accompanied by a chase plane for safety. Eventually the decision was made
to disperse the aircraft to various airfields to give pilots an opportunity to
add the unusual aircraft to their log books. Airacudas were sent at various
times to Langley Field, Virginia; Maxwell Field, Alabama; Hamilton Field,
California; and Wright Field, in Dayton, Ohio. YFM-1 38-488 was displayed at the
1940 World's Fair in New York, finished in the markings of the 27th Pursuit
Squadron. During this time, the aircraft saw limited flight time, as few pilots
were interested in flying the unusual aircraft.

Specifications (XFM-1)

General characteristics
Crew: five (pilot, copilot/navigator, radio operator/gunner, two gunners)
Length: 44 ft 10 in (13.67 m)
Wingspan: 69 ft 10 in (21.29 m)
Height: 13 ft 7 in (4.14 m)
Wing area: 684 sq ft (63.5 m2)
Airfoil: NACA 23018/NACA 23009
Empty weight: 13,376 lb (6,067 kg)
Gross weight: 17,333 lb (7,862 kg)
Max takeoff weight: 21,625 lb (9,809 kg)
Fuel capacity: 400 US gal (1,500 l)
Powerplant: 2 × Allison V-1710-9 liquid-cooled turbosupercharged V-12, 1,090 hp
(810 kW) each
Propellers: three-bladed

Performance
Maximum speed: 277 mph (446 km/h, 241 kn)
Cruise speed: 244 mph (393 km/h, 212 kn)
Range: 2,600 mi (4,200 km, 2,300 nmi)
Service ceiling: 30,500 ft (9,300 m)
Rate of climb: 1,480 ft/min (7.5 m/s)

Armament

Guns:
2 × 37 mm (1.46 in) M4 cannons (110 rpg)
2 × .30 in (7.62 mm) M1919 Browning machine guns in front of nacelles
2 × .50 in (12.7 mm) M2 Browning machine guns (600 rpg) in side blisters

Bombs: 20 × 30 lb (14 kg) fragmentation bombs in wing bays



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