The CRV7, short for "Canadian Rocket Vehicle 7", is a 2.75 inch (70 mm) folding-fin ground attack rocket
Rocket (weapon)
A rocket is a self propelled, unguided weapon system powered by a rocket motor.- Categorisation :In military parlance, powered munitions are broadly categorised as follows:* A powered, unguided munition is known as a rocket....

 produced by Bristol Aerospace
Bristol Aerospace
Bristol Aerospace is a Canadian aerospace firm located in Winnipeg, Manitoba and is an operating division of Magellan Aerospace.-History:Bristol Aerospace began in 1930 as the MacDonald Brothers Aircraft Company. Brothers Jim and Grant MacDonald moved to Winnipeg from Nova Scotia in 1904 to start a...

 in Winnipeg, Manitoba. It was introduced in the early 1970s as an upgraded version of the standard US 2.75 inch air-to-ground rockets. It was the most powerful weapon of its class, the first with enough energy to penetrate standard Warsaw Pact
Warsaw Pact
The Warsaw Treaty Organization of Friendship, Cooperation, and Mutual Assistance , or more commonly referred to as the Warsaw Pact, was a mutual defense treaty subscribed to by eight communist states in Eastern Europe...

 aircraft hangars. The CRV7 remains the most powerful rocket to this day, and has slowly become the de-facto
De facto
De facto is a Latin expression that means "concerning fact." In law, it often means "in practice but not necessarily ordained by law" or "in practice or actuality, but not officially established." It is commonly used in contrast to de jure when referring to matters of law, governance, or...

 standard for Western-aligned forces, at least outside the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...



The CRV7 was an offshoot of late 1950s research at CARDE
Cardè is a comune in the Province of Cuneo in the Italian region Piedmont, located about 40 km southwest of Turin and about 40 km north of Cuneo. As of 31 December 2004, it had a population of 1,077 and an area of 19.3 km²....

 into high-performance solid fuel rockets, performed as a part of a general program studying anti-ballistic missile
Anti-ballistic missile
An anti-ballistic missile is a missile designed to counter ballistic missiles .A ballistic missile is used to deliver nuclear, chemical, biological or conventional warheads in a ballistic flight trajectory. The term "anti-ballistic missile" describes any antimissile system designed to counter...

s. With Aerojet
Aerojet is an American rocket and missile propulsion manufacturer based primarily in Rancho Cordova, California with divisions in Redmond, Washington, Orange, Gainesville and Camden, Arkansas. Aerojet is owned by GenCorp. They are the only US propulsion company that provides both solid rocket...

's assistance, CARDE and Bristol developed the "Propulsion Test Vehicle" to test new fuel and engine designs. This program led to the development of the Black Brant sounding rocket
Sounding rocket
A sounding rocket, sometimes called a research rocket, is an instrument-carrying rocket designed to take measurements and perform scientific experiments during its sub-orbital flight. The origin of the term comes from nautical vocabulary, where to sound is to throw a weighted line from a ship into...

, which first flew in 1965 and has had a long and successful career since then.

In the early 1970s, CARDE and Bristol decided to use the same propellant and engine design for a new 2.75 inch rocket to equip the CF-104 Starfighter. The resulting RLU-5001/B (C-14) engine was first delivered by Bristol in production form in 1973. It had a total impulse of 2,320 lbf·s (10.3 kN·s) and a burn time of 2.2 seconds. The empty weight of the rocket is 6.6 kg and it is normally equipped with a 10 lb (4.5 kg) high-explosive warhead taken from U.S. rockets.

Compared to the U.S. Mk 40 Mighty Mouse
Mk 4/Mk 40 Folding-Fin Aerial Rocket
The Mk 4 Folding-Fin Aerial Rocket , sometimes called the Mighty Mouse, was a 2.75 in diameter unguided rocket weapon commonly used by U.S. military aircraft. It was intended as an air-to-air weapon to allow interceptor aircraft to shoot down enemy bombers with greater range and effectiveness than...

 rockets the CRV7 replaced, the higher energy fuel and newer fuselage design led to a longer and much flatter trajectory, with twice the energy on impact. Its maximum effective range is over 4,000 m, allowing launch from beyond the envelope of most short-range anti-aircraft weapons. In comparison, the Mighty Mouse or Hydra 70
Hydra 70
The Hydra 70 rocket is a weapon derived from the 70 mm Mk 4/Mk 40 Folding-Fin Aerial Rocket developed by the United States Navy for use as a free-flight aerial rocket in the late 1940s.-Overview:...

 requires launches from much shorter ranges, potentially placing the launch aircraft within the range of ground-based weapons arranged around the target.

Unguided rockets are normally spin stabilized, like a rifle bullet. The spin is imparted by small fins at the rear of the rocket body that flip out into the airstream once the rocket leaves its launch tube. The fins take a short time to open, and more time to start the rocket spinning. During this period the rockets can drift significantly from their original aim point. The CRV7 solved this problem by adding small vanes projecting into the rocket exhaust to start the rocket spinning even before it left the launch tube, greatly increasing accuracy. A salvo of CRV7's will impact the target area in one-third the footprint of older designs.

The weapon was originally quoted to have a dispersion of 4 milliradians, but testing with the CF-18 Hornet
CF-18 Hornet
The McDonnell Douglas CF-18 Hornet is a Royal Canadian Air Force fighter aircraft, based on the American McDonnell Douglas F/A-18 Hornet fighter. In 1980, the F/A-18 was selected as the winner of the New Fighter Aircraft competition, and a production order was awarded...

 demonstrated it was even lower, at 3 milliradians. This is considerably better than the autocannon
An autocannon or automatic cannon is a rapid-fire projectile weapon firing a shell as opposed to the bullet fired by a machine gun. Autocannons often have a larger caliber than a machine gun . Usually, autocannons are smaller than a field gun or other artillery, and are mechanically loaded for a...

 that arm most aircraft; the widely-used M61 Vulcan
M61 Vulcan
The M61 Vulcan is a hydraulically or pneumatically driven, six-barreled, air-cooled, electrically fired Gatling-style rotary cannon which fires 20 mm rounds at an extremely high rate. The M61 and its derivatives have been the principal cannon armament of United States military fixed-wing aircraft...

 is rated at 8 milliradians, while the much larger and considerably heavier GAU-8 is rated at 5 milliradians.

The CRV7 had just been introduced into Canadian Air Force service when it was entered as a part of a general competition in France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

. One part of the competition required the contestants to hit a tower with unarmed rockets. The Canadian pilot hit it on his first try, but aimed as if firing the much lower-powered Mk 40 and was therefore close enough that the rocket motor was still firing. The motor shattered and destroyed the tower, and the pilot was disqualified because the judges refused to believe it was unarmed.

Engine development

The aluminium
Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....

-based fuel in the C-14 engine generated considerable amounts of smoke. While suitable for high-speed aircraft that quickly clear the plume, it is not suitable for slower aircraft and helicopters which would be flying in the smoke for some period of time. This problem led to the development of the RLU-5002/B (C-15) engine, which did not include aluminium and produced considerably less smoke, with a slightly smaller impulse of 2,185 lbf·s (9.7 kN·s). The original C-15 used a tail-mounted igniter that was ejected by the rocket when it was fired. In some cases the igniter would hit the aircraft, causing minor damage. To address this, the RLU-5002A/B (HEPI) was introduced, with a "Head-End Permanent Igniter" that is not ejected on launch.

The latest C-17 and C-18 engines for helicopter use offer somewhat lower impulse at 1,905 lbf·s (8.5 kN·s), but with almost no smoke at all.


The primary warhead for the original CRV7 was the U.S. M151 High Explosive Point Detonating (HEPD) round, a simple impact-fired 10 lb (4.5 kg) high explosive shell. Like the U.S. 2.75 inch weapons, the CRV7 could also be equipped with the M156 Smoke or M257/278 Illumination (flare
Flare (countermeasure)
A flare is an aerial infrared countermeasure to counter an infrared homing surface-to-air missile or air-to-air missile. Flares are commonly composed of a pyrotechnic composition based on magnesium or another hot-burning metal, with burning temperature equal to or hotter than engine exhaust...

) rounds. Bristol also introduced their own WTU-5001/B Practice round consisting of an 8 lb flat-ended soft steel rod encased in a nylon fairing, and later introduced a similar version with a hardened steel rod, the WTU-5001A/B. These rounds matched the ballistics of the M151 for training purposes, and were widely used during the development and introduction of the weapon to the Canadian Forces.

Bristol followed this with the 16 lb WDU-50001/B "Anti-Bunkerette" round, a semi-armor piercing high explosive incendiary
High Explosive Incendiary/Armor Piercing Ammunition
High Explosive Incendiary/Armor Piercing Ammunition is a form of shell which combines both an armor-piercing capability and a high-explosive effect. In this respect it is a modern version of armor piercing shell...

 (SAPHEI/HEISAP) warhead designed specifically for use against reinforced concrete buildings, specifically hardened aircraft shelters. Its heavy steel shell allows the round to penetrate the hangar wall before the 75 g incendiary warhead is ignited. The round can penetrate 13 ft of earth, 3 ft of concrete and 1 inch of steel, in series.

The CRV7's kinetic energy was so high that testers were surprised to find that practice rounds (fitted with an 8-inch solid steel rod penetrator) were penetrating out-dated Centurion tanks used for target practice. This resulted in the development of a dedicated antitank warhead that replaced the steel rod in the practice warhead with a tungsten rod. This new antitank warhead could penetrate a Russian T-72
The T-72 is a Soviet-designed main battle tank that entered production in 1970. It is developed directly from Obyekt-172, and shares parallel features with the T-64A...

 main battle tank armour from any attack angle. Further study into this effect led to the WDU-5002/B FAT warhead, Flechette Anti-Tank, containing five tungsten
Tungsten , also known as wolfram , is a chemical element with the chemical symbol W and atomic number 74.A hard, rare metal under standard conditions when uncombined, tungsten is found naturally on Earth only in chemical compounds. It was identified as a new element in 1781, and first isolated as...

-reinforced steel flechette
A flechette is a pointed steel projectile, with a vaned tail for stable flight. The name comes from French , "little arrow" or "dart", and sometimes retains the acute accent in English: fléchette.-Bulk and artillery use:...

s that could penetrate a T-72's side and top armour at a distance of 10000 feet (3,048 m). It was also found to be a useful warhead for use against medium and light armoured vehicles. Further development led to the WDU-500X/B "General Purpose Flechette" for use against personnel, some light armour, thin skin vehicles and helicopters which releasing 80 tungsten flechettes that can penetrate 1.5 inches of roll-hardened armor.

Bristol also re-sells the RA-79 from Raufoss Ammunisjonsfabrikker, a semi-armor piercing round designed to attack shipping.

Guided version

In 2006 Bristol started testing a new version of the CRV7, the CRV7-PG. The weapon was introduced at Eurosatory 2006. Bristol's current owners, Magellan Aerospace
Magellan Aerospace
Magellan Aerospace Corporation is a Canadian manufacturer of aerospace systems and components. Magellan also repairs and overhauls, tests, and provides aftermarket support services for engines, and engine structural components. The company's business units are divided into the product areas of...

, offered it for sale starting in 2007.

The PG version, for "precision guided", adds a seeker developed by Kongsberg Defence & Aerospace
Kongsberg Defence & Aerospace
Kongsberg Defence & Aerospace , one of two operating companies of Kongsberg Gruppen of Norway, is a supplier of defence and space related systems and products, mainly anti-ship missiles, military communications, and command and weapons control systems for naval vessels and air-defence applications...

 to the front of any version of an otherwise unmodified CRV7. The seeker uses a simple inertial guidance system though the midcourse, and homes during the terminal approach using a laser designator
Laser designator
A laser designator is a laser light source which is used to designate a target. Laser designators provide targeting for laser guided bombs, missiles, or precision artillery munitions, such as the Paveway series of bombs, Lockheed-Martin's Hellfire, or the Copperhead round, respectively.When a...

. Other versions offer anti-radiation seeking, or GPS guidance. Combining the laser seeker with the FAT warhead produces a capable long-range anti-tank missile that is faster and much less expensive than traditional platforms like the AGM-114 Hellfire
AGM-114 Hellfire
The AGM-114 Hellfire is an air-to-surface missile developed primarily for anti-armor use. It has multi-mission, multi-target precision-strike capability, and can be launched from multiple air, sea, and ground platforms. The Hellfire missile is the primary 100 lb-class air-to-ground precision...


A version of the CRV7-PG was also developed for special forces
Special forces
Special forces, or special operations forces are terms used to describe elite military tactical teams trained to perform high-risk dangerous missions that conventional units cannot perform...

 use, fired from a single tube mounted on a 6 x 6. In use, the weapon would be driven into the field and fired from behind cover, aiming at a designated location from a forward team.

See also

  • Mk 4/Mk 40 Folding-Fin Aerial Rocket
    Mk 4/Mk 40 Folding-Fin Aerial Rocket
    The Mk 4 Folding-Fin Aerial Rocket , sometimes called the Mighty Mouse, was a 2.75 in diameter unguided rocket weapon commonly used by U.S. military aircraft. It was intended as an air-to-air weapon to allow interceptor aircraft to shoot down enemy bombers with greater range and effectiveness than...

     (Mighty Mouse)
  • Hydra 70
    Hydra 70
    The Hydra 70 rocket is a weapon derived from the 70 mm Mk 4/Mk 40 Folding-Fin Aerial Rocket developed by the United States Navy for use as a free-flight aerial rocket in the late 1940s.-Overview:...

  • SNEB rocket (68mm)
    The SNEB rocket is an unguided air-to-ground rocket projectile manufactured by the French company TDA Armements, designed for launch by combat aircraft and helicopters. Two other rockets were developed in the and caliber...

  • Vought HVM
    Vought HVM
    Vought's HVM, short for Hyper-Velocity Missile, was an anti-tank missile developed during the 1980s. The HVM carried no warhead, and killed its targets with kinetic energy alone using a metal penetrator...

External links

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