 On 10 June 1976, further controversy sparked when it was revealed the Royal Air Force (RAF) was reluctant to use the weapon in test launches because of its high cost, limiting training to only two launches per year.By 1979, only half the units slated to receive Blowpipe actually had them.After requests from the Israeli and Brazilian navies for a submarine-launched weapon, Blowpipe was developed in a cluster of six missiles on a mast that could be raised from the submarine's conning tower.