CRV7 The CRV7 , short for " Canadian Rocket Vehicle 7 " , is a 2 . 75 inch ( 70 mm ) folding - fin ground attack rocket produced by Bristol Aerospace in Winnipeg , Manitoba . 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 aircraft hangars . The CRV7 remains the most powerful rocket to this day , and has slowly become the de facto standard for Western - aligned forces outside the United States . Development . The CRV7 was an offshoot of late 1950s research at CARDE into high - performance solid fuel rockets , performed as a part of a general program studying anti - ballistic missile s . With Aerojet ' 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 , 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 " 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 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 demonstrated it was even lower , at 3 milliradians . This is considerably better than the autocannon that arm most aircraft ; the widely used M61 Vulcan 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 . 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 - 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 . 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 shell . Like the U . S . 2 . 75 inch weapons , the CRV7 could also be equipped with the M156 Smoke or M257 / 278 Illumination ( flare ) 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 ( 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 Soviet T - 72 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 - reinforced steel flechette 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 " 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 . The CRV - 7 Multi - Purpose Sub Munition ( MPSM ) was classified as a cluster bomb ; each rocket contained nine M73 submunitions . Whether the CRV - 7 MPSM was covered by the Convention on Cluster Munitions was a matter of opinion . Britain destroyed the last of its CRV - 7 MPSMs in July 2009 in accordance with its interpretation of the convention . 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 , offered it for sale starting in 2007 . The PG version , for " precision guided " , adds a seeker developed by Kongsberg Defence & Aerospace to the front of any version of an otherwise unmodified CRV7 . The seeker uses a simple inertial guidance system through the midcourse , and homes during the terminal approach using a laser designator . 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 . A version of the CRV7 - PG was also developed for special forces 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 .