Editing CRV7 (section)

==Development==
The CRV7 was an offshoot of late 1950s research at [[CARDE]] (now DRDC Valcartier) into high-performance solid fuel rockets, research 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 rocket|Black Brant]] [[sounding rocket]], which first flew in 1960 and has had a long and successful career since then.<ref>[http://www.astronautix.com/b/blackbrant.html "Black Brant"],  astronautix.com</ref> Engineer Jose Tharayil from Bristol Aerospace is considered the driving force behind the CRV7'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]].<ref>{{citation |url=http://www.drdc-rddc.gc.ca/news-nouvelles/archives/spotlight-pleinfeux/0307-eng.asp |title=Then and Now: The CRV7 |archive-url=https://web.archive.org/web/20090427165003/http://www.drdc-rddc.gc.ca/news-nouvelles/archives/spotlight-pleinfeux/0307-eng.asp |archive-date=2009-04-27 |publisher= Defence Research and Development Canada}}</ref> 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&nbsp;lbf·s (10.3&nbsp;kN·s) and a burn time of 2.2&nbsp;seconds. The empty weight of the rocket is 6.6&nbsp;kg, and it is normally equipped with a 10&nbsp;lb (4.5&nbsp;kg) high-explosive warhead taken from U.S. rockets.

[[File:Apache Helicopter Firing Rockets MOD 45154922.jpg|thumb|left|alt=Photograph of an Apache helicopter firing three rockets at a target out of frame.|A British Army [[AgustaWestland Apache|AugustaWestland Apache AH.1]] attack helicopter of the Army Air Corps in Afghanistan fires rockets at insurgents during a patrol in 2008.]]
Compared to the U.S. [[Mk 4/Mk 40 Folding-Fin Aerial Rocket|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&nbsp;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.<ref name=fixed>''Fixed''</ref>

Unguided rockets are normally spin stabilized like rifle bullets. 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.<ref name=fixed/>

The weapon was originally quoted to have a dispersion of 4 [[milliradian]]s, but testing with the [[McDonnell Douglas CF-18 Hornet]] demonstrated it was even lower, at 3 milliradians.<ref name=roles>{{citation |url=http://www.flightglobal.com/pdfarchive/view/1984/1984%20-%200245.html |title=New roles for Canadian rocket |work=Flight International |date=11 February 1984|page=381 |via=FlightGlobal Archive}}</ref> This is considerably better than the [[autocannon]] that arm most aircraft; the widely used 20mm [[M61 Vulcan]] is rated at 8 milliradians, while the much larger and considerably heavier 30mm [[GAU-8 Avenger]] is rated at 5 milliradians.<ref>[http://www.globalsecurity.org/military/systems/aircraft/systems/gau-8.htm "GAU-8 Avenger"], GlobalSecurity.com</ref>

The CRV7 had just been introduced into [[Royal 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 until it became a deflagration that destroyed the tower. The pilot was disqualified because the judges refused to believe it was unarmed.<ref name=":0">{{Cite web |last=Martel |first=Frank |date=2008-03-27 |title=CRV-7 2.75" (70mm) Rocket Motors |url=http://www.gunplumbers.ca/Weapons/crv7.html |access-date=2024-12-28 |website=Gunplumbers.ca}}</ref>