The 3.5-inch Forward Firing Aircraft Rocket, or 3.5-Inch FFAR, was an American

rocket A rocket (from it, rocchetto, , bobbin/spool) is a vehicle that uses jet propulsion to accelerate without using the surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely fr ...

developed during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

to allow aircraft to attack enemy

submarines A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely o ...

at range. The rocket proved an operational success, and spawned several improved versions for use against surface and land targets.

Design and development

Following trials by the

Royal Air Force The Royal Air Force (RAF) is the United Kingdom's air and space force. It was formed towards the end of the First World War on 1 April 1918, becoming the first independent air force in the world, by regrouping the Royal Flying Corps (RFC) and ...

of rocket-propelled, air-launched weapons for

anti-submarine warfare Anti-submarine warfare (ASW, or in older form A/S) is a branch of underwater warfare that uses surface warships, aircraft, submarines, or other platforms, to find, track, and deter, damage, or destroy enemy submarines. Such operations are t ...

during 1942, the

United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...

launched a high-priority project during the summer of 1943 for the development of an anti-submarine rocket of its own.Parsch 2004 The resulting rocket was a simple design with four tail fins for stabilization at the rear, powered by a rocket motor that had been under development by

Caltech The California Institute of Technology (branded as Caltech or CIT)The university itself only spells its short form as "Caltech"; the institution considers other spellings such a"Cal Tech" and "CalTech" incorrect. The institute is also occasional ...

since 1943. The warhead contained no explosive. The rocket's nose was a solid steel mass, weighing , that punctured the

pressure hull A submarine hull has two major components, the ''light hull'' and the ''pressure hull''. The light hull (''casing'' in British usage) of a submarine is the outer non-watertight hull which provides a hydrodynamically efficient shape. The pressure ...

of a target submarine through the kinetic energy and momentum from its high velocity and mass.Campbell 1985, p.170. The nose of the 3.5" FFAR was given a relatively blunt conical shape that had been shown experimentally to give a maximum pitch-up as the rocket entered the water. This caused the rocket to shoot forward at a shallow depth deadly to submarines that were surfaced or traveling at snorkel or

periscope depth A periscope is an instrument for observation over, around or through an object, obstacle or condition that prevents direct line-of-sight observation from an observer's current position. In its simplest form, it consists of an outer case with ...

. The rockets were launched in a shallow dive, since entry into the water at too steep an angle would defeat their ability to shoot forward at the required shallow depth. The rocket remained lethal even after passing through up to of water, giving the pilot a target several times the actual size of the submarine. The sweet spot for targeting was considered to be in front of the near side of the submarine. Typical firing range was about .

Operational history

Following expedited development, the weapon, officially designated the "3.5-inch forward firing aircraft rocket", entered operational service with the U.S. Navy late in 1943; production of 10,000 rockets per month had been ordered that August. The FFAR's first "kill" of an enemy submarine took place 11 January 1944. The rocket was originally carried by the

Grumman TBF Avenger The Grumman TBF Avenger (designated TBM for aircraft manufactured by General Motors) is an American World War II-era torpedo bomber developed initially for the United States Navy and Marine Corps, and eventually used by several air and naval av ...

torpedo bomber A torpedo bomber is a military aircraft designed primarily to attack ships with aerial torpedoes. Torpedo bombers came into existence just before the First World War almost as soon as aircraft were built that were capable of carrying the weight ...

s. Excessive drag caused by the original channel-slide launchers was largely eliminated with the introduction of zero-length launchers in May 1945. Zero-length launchers quickly became standard on most fighters and many light bombers for firing a variety of rockets with 3.25" or 5" diameter rocket motors. Although the rocket's accuracy was more than sufficient to allow usage against surface targets, the narrow body diameter restricted the size of any explosive warhead that could be fitted. Therefore, for use against ships and land targets, the rocket was given a warhead consisting of a re-fused 5" (127 mm) Mark 35 artillery shell, producing the 5-inch forward firing aircraft rocket, usually shortened to 5" AR.Parsch 2006

References

;Citations ;Bibliography * * * * *

External links

{{USA WW2 rockets Anti-submarine missiles of the United States World War II weapons of the United States Weapons and ammunition introduced in 1943

Design and development

Operational history

See also

References

External links