![Royal Military Museum Brussels 2007 138](https://upload.wikimedia.org/wikipedia/commons/5/5b/Royal_Military_Museum_Brussels_2007_138.JPG)
The CRV7, short for "Canadian Rocket Vehicle 7", is a 2.75-inch (70 mm) folding-fin ground attack
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 ...
produced by
Bristol Aerospace
Bristol Aerospace is a Canadian aerospace firm located in Winnipeg, Manitoba and is an operating division of Magellan Aerospace. Today it is the only remaining and surviving subsidiary of Bristol Aeroplane Company.
History
Bristol Aerospace b ...
in
Winnipeg, Manitoba
Winnipeg () is the capital and largest city of the province of Manitoba in Canada. It is centred on the confluence of the Red and Assiniboine rivers, near the longitudinal centre of North America. , Winnipeg had a city population of 749,6 ...
. It was introduced in the early 1970s as an upgraded version of the standard U.S. 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
The Warsaw Pact (WP) or Treaty of Warsaw, formally the Treaty of Friendship, Cooperation and Mutual Assistance, was a collective defense treaty signed in Warsaw, Poland, between the Soviet Union and seven other Eastern Bloc socialist republic ...
aircraft hangars. The CRV7 remains one of the most powerful air-to-ground attack rockets to this day, and has slowly become the
de facto
''De facto'' ( ; , "in fact") describes practices that exist in reality, whether or not they are officially recognized by laws or other formal norms. It is commonly used to refer to what happens in practice, in contrast with ''de jure'' ("by la ...
standard for Western-aligned forces outside the United States. Beginning in 2021, 83,303 stored Canadian CRV7s are slated for disposal having been removed from service from 2005 to 2007.
Development
The CRV7 was an offshoot of late 1950s research at
CARDE
DRDC Valcartier is a major Canadian military research station at Canadian Forces Base Valcartier, Quebec, one of nine centres making up Defence Research and Development Canada (DRDC).
Originally formed at the end of World War II in 1945 as the Can ...
into high-performance solid fuel rockets, performed as a part of a general program studying
anti-ballistic missile
An anti-ballistic missile (ABM) is a surface-to-air missile designed to counter ballistic missiles (missile defense). Ballistic missiles are used to deliver nuclear weapon, nuclear, Chemical weapon, chemical, Bioagent, biological, or conventiona ...
s. With
Aerojet
Aerojet was an American rocket and missile propulsion manufacturer based primarily in Rancho Cordova, California, with divisions in Redmond, Washington, Orange and Gainesville in Virginia, and Camden, Arkansas. Aerojet was owned by GenCorp. ...
'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
The brant or brent goose (''Branta bernicla'') is a small goose of the genus '' Branta''. There are three subspecies, all of which winter along temperate-zone sea-coasts and breed on the high-Arctic tundra.
The Brent oilfield was named after ...
sounding rocket
A sounding rocket or rocketsonde, sometimes called a research rocket or a suborbital rocket, is an instrument-carrying rocket designed to take measurements and perform scientific experiments during its sub-orbital flight. The rockets are used to ...
, which first flew in 1965 and has had a long and successful career since then. Engineer Jose Tharayil from Bristol Aerospace is considered the driving force behind the CRV-7's development and production.
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
Canadair CF-104 Starfighter
The Canadair CF-104 Starfighter (CF-111, CL-90) is a modified version of the Lockheed F-104 Starfighter supersonic fighter aircraft built in Canada by Canadair under licence. It was primarily used as a ground attack aircraft, despite being ...
. 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.
![Apache Helicopter Firing Rockets MOD 45154922](https://upload.wikimedia.org/wikipedia/commons/a/a4/Apache_Helicopter_Firing_Rockets_MOD_45154922.jpg)
Compared to the U.S.
Mk 40 FFAR ''Mighty Mouse'' 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
The Hydra 70 rocket is a diameter fin-stabilized unguided rocket used primarily in the air-to-ground role. It can be equipped with a variety of warheads, and in more recent versions, guidance systems for point attacks. The Hydra is widely used by ...
requires launches from much shorter ranges, potentially placing the launch aircraft within the range of ground-based weapons arranged around the target.
[''Fixed'']
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 ]milliradian
A milliradian ( SI-symbol mrad, sometimes also abbreviated mil) is an SI derived unit for angular measurement which is defined as a thousandth of a radian (0.001 radian). Milliradians are used in adjustment of firearm sights by adjusting ...
s, but testing with the McDonnell Douglas CF-18 Hornet
The McDonnell Douglas CF-18 Hornet (official military designation CF-188) is a Royal Canadian Air Force (RCAF) variant of the American McDonnell Douglas F/A-18 Hornet fighter aircraft. In 1980, the F/A-18 was selected as the winner of the New ...
demonstrated it was even lower, at 3 milliradians. This is considerably better than the autocannon
An autocannon, automatic cannon or machine cannon is a fully automatic gun that is capable of rapid-firing large-caliber ( or more) armour-piercing, explosive or incendiary shells, as opposed to the smaller-caliber kinetic projectiles (bull ...
that arm most aircraft; the widely used 20mm M61 Vulcan
The M61 Vulcan is a hydraulically, electrically, or pneumatically driven, six-barrel, air-cooled, electrically fired Gatling-style rotary cannon which fires rounds at an extremely high rate (typically 6,000 rounds per minute). The M61 and its ...
is rated at 8 milliradians, while the much larger and considerably heavier 30mm GAU-8 Avenger
The General Electric GAU-8/A Avenger is a 30 mm hydraulically driven seven-barrel Gatling-style autocannon that is primarily mounted in the United States Air Force's Fairchild Republic A-10 Thunderbolt II. Designed to destroy a wide variety of ...
is rated at 5 milliradians.
The CRV7 had just been introduced into Royal Canadian Air Force
The Royal Canadian Air Force (RCAF; french: Aviation royale canadienne, ARC) is the air and space force of Canada. Its role is to "provide the Canadian Forces with relevant, responsive and effective airpower". The RCAF is one of three environm ...
service when it was entered as a part of a general competition in 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 remaining unburned propellant shattered allowing more surface area of the rocket motor to burn, in turn increasing the pressure and rate of combustion to a speed that was no longer considered burning but was now a deflagration and destroyed the tower, and the pilot was disqualified because the judges refused to believe it was unarmed.
Engine development
The aluminium
Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. I ...
-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
A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes ...
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 lower 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.][''Rotary'']
Warheads
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
An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An expl ...
shell. Like the U.S. 2.75-inch (70 mm) weapons, the CRV7 could also be equipped with the M156 Smoke or M257/278 Illumination (flare
A flare, also sometimes called a fusée, fusee, or bengala in some Latin-speaking countries, is a type of pyrotechnic that produces a bright light or intense heat without an explosion. Flares are used for distress signaling, illumination, ...
) rounds. Bristol also introduced their own WTU-5001/B Practice round consisting of an 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 WDU-50001/B "Anti-Bunkerette" round, a ]semi-armor-piercing high-explosive incendiary
High-explosive incendiary/armor-piercing ammunition (HEIAP) is a form of shell which combines armor-piercing capability and a high-explosive effect. In this respect it is a modern version of an armor-piercing shell. The ammunition may also be ca ...
(SAPHEI/HEISAP) warhead designed 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 of earth, of concrete and of steel, in series.[
The CRV7's kinetic energy was so high that testers were surprised to find that practice rounds fitted with an steel rod were penetrating outdated 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 Soviet ]T-72
The T-72 is a family of Soviet/Russian main battle tanks that entered production in 1969. The T-72 was a development of the T-64, which was troubled by high costs and its reliance on immature developmental technology. About 25,000 T-72 tanks ha ...
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, or wolfram, is a chemical element with the symbol W and atomic number 74. Tungsten is a rare metal found naturally on Earth almost exclusively as compounds with other elements. It was identified as a new element in 1781 and first isolat ...
-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. They have been used as ballistic weapons sinc ...
s that could penetrate a T-72's side and top armour at a distance of . 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" which releases 80 tungsten flechettes that can penetrate of roll-hardened armor for use against personnel, some light armour, thin skin vehicles and helicopters.
Bristol also re-sells the RA-79 from Raufoss Ammunisjonsfabrikker, a semi-armor-piercing round designed to attack shipping.
The CRV-7 Multi-Purpose Sub Munition (MPSM) contained nine M73 submunitions in each rocket. It could therefore be classified as a ]cluster bomb
A cluster munition is a form of air-dropped or ground-launched explosive weapon that releases or ejects smaller submunitions. Commonly, this is a cluster bomb that ejects explosive bomblets that are designed to kill personnel and destroy vehicl ...
.[Hansard, 25 Mar 2010, Column 415W]
/ref> Britain destroyed the last of its CRV-7 MPSMs in July 2009 in accordance with its interpretation of the Convention on Cluster Munitions
The Convention on Cluster Munitions (CCM) is an international treaty that prohibits all use, transfer, production, and stockpiling of cluster bombs, a type of explosive weapon which scatters submunitions ("bomblets") over an area. Additionally, ...
.
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 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 busin ...
, offered it for sale starting in 2007.
The PG version, for "precision guided", adds a seeker developed by Kongsberg Defence & Aerospace
Kongsberg Defence & Aerospace is one of three business units of Kongsberg Gruppen (KONGSBERG) of Norway and the supplier of defence and space related systems and products, mainly anti-ship missiles, military communications, and command and weapon ...
to the front of any version of an otherwise unmodified CRV7. The seeker uses a simple inertial guidance
An inertial navigation system (INS) is a navigation device that uses motion sensors (accelerometers), rotation sensors ( gyroscopes) and a computer to continuously calculate by dead reckoning the position, the orientation, and the velocity (dire ...
system through the midcourse, and homes during the terminal approach using a 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, AGM-114 Hellfire, or ...
. Other versions offer anti-radiation seeking, or GPS guidance. The precision guided kit includes the addition of tail fins and an in-flight control system. Combining the laser seeker with the FAT warhead produces a capable long-range anti-tank missile
An anti-tank guided missile (ATGM), anti-tank missile, anti-tank guided weapon (ATGW) or anti-armor guided weapon is a Missile guidance, guided missile primarily designed to hit and destroy Armoured fighting vehicle, heavily armored military v ...
that is faster and much less expensive than traditional platforms like the AGM-114 Hellfire
The AGM-114 Hellfire is an air-to-ground missile (AGM) first developed for anti-armor use, later developed for precision drone strikes against other target types, especially high-value targets. It was originally developed under the name '' Heli ...
.
A version of the CRV7-PG was also developed for special forces
Special forces and special operations forces (SOF) are military units trained to conduct special operations. NATO has defined special operations as "military activities conducted by specially designated, organized, selected, trained and equip ...
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.[Milan Machala & Radek Doskocil ]
"Contemporary Trends in Development and Modernization of Rocket Systems"
See also
*Mk 4/Mk 40 Folding-Fin Aerial Rocket
The Mk 4 Folding-Fin Aerial Rocket (FFAR), also known as "Mighty Mouse", was an unguided rocket used by United States military aircraft. It was 2.75 inches (70 mm) in diameter. Designed as an air-to-air weapon for interceptor aircraft to ...
(Mighty Mouse)
*Hydra 70
The Hydra 70 rocket is a diameter fin-stabilized unguided rocket used primarily in the air-to-ground role. It can be equipped with a variety of warheads, and in more recent versions, guidance systems for point attacks. The Hydra is widely used by ...
* Forges de Zeebrugge
Forges de Zeebrugge (since 1 January 2017: Thales Belgium) is an arms manufacturer in based in Herstal, Belgium.
Forges de Zeebrugge was founded as a munitions factory between Zeebrugge and Zwankendamme, in the 1930s, as a subsidiary of Carcoke ...
* SNEB rocket (68 mm)
*Vought HVM
{{no footnotes, date=November 2015
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 rod penetrator. Devel ...
*S-8 (rocket)
The S-8 is a rocket weapon developed by the Soviet Air Force for use by military aircraft. It remains in service with the Russian Air Force and various export customers.
Developed in the 1970s, the S-8 is an 80 mm (3.1 in) rocket used b ...
References
;Notes
;Bibliography
*
*
External links
{{commonscat, Canadian Rocket Vehicle 7
CRV7 Rocket System - Bristol Aerospace
CRV-7 page on the RAF official site shows the modern version's complete lack of smoke
Air-to-ground rockets
Weapons of Canada
Military equipment introduced in the 1970s