By Barrett Tillman
Imagine you’re a fighter-bomber pilot entering combat in 1944. Your combat training has emphasized gunnery with some dive-bombing, but suddenly your Thunderbolt or Corsair or Avenger or Typhoon possesses the punch of a Navy destroyer’s broadside: half a dozen five-inch projectiles streaking toward an Axis target. Buck Rogers fantasy in the 1940s.
The high-velocity aerial rocket (HVAR) concept evolved during WW II, the result of collaboration among the military, academia, and industry. Originally inspired by British experiments, in 1943, the U.S. Navy teamed with California Institute of Technology to produce a 3.25-inch diameter rocket motor driving the weapon at nearly 1,200 fps. The tempered steel warhead was designed to penetrate the hulls of enemy submarines. Deployment was achieved late that year with the first U-boat kill attributed to rockets in January 1944.
The 3.5-inch weapon was effective but not as lethal as many fleet operators desired. Therefore, a 5-inch version was developed for use against tougher targets: warships and concrete bunkers. The heavier 5-inch weapon was necessarily slower than its predecessor, achieving some 700 fps, so it had to be fired relatively close to the target. A Navy ordnance report in early 1944 noted that some TBF Avenger squadrons were reluctant to use the rockets on heavily defended targets because the “closer is better” parameters resulted in heavier losses to flak.
Science to the rescue. Again CalTech’s backroom scientists and engineers produced a refined version, the 5-inch high velocity aerial rocket (HVAR). Testing began in late 1943, and HVARs were issued to Navy and Army units the following summer.
Dubbed Holy Moses (reputedly due to the exclamations the rocket drew when demonstrated), the HVAR streaked off its rails at 1,400 fps despite being 60 pounds heavier than the 80-pound FFAR. The 45-pound warhead, was effective against a variety of targets.
The Royal Air Force made heavy use of home-grown, three-inch rockets, armed with 25 or 60-pound warheads. “RP3s” gained a hefty if somewhat exaggerated reputation during the Normandy campaign as Hawker Typhoons fired thousands at German tanks, vehicles, and emplacements. RAF Coastal Command and Royal Navy aircraft took RPs to sea, especially as antisubmarine weapons.
U.S. unguided rocket development continued well after the war, with navy “ordies” at China Lake, California, producing the Mk 16 Zuni folding-fin rocket. The new weapon was adapted to a variety of warheads for greater mission flexibility. The ultimate Mk 71 entered production in 1957 and was widely used by tactical aircraft and helicopter gunships during the Vietnam War. The Zuni’s most unusual employment occurred during a 1967 mission over North Vietnam when Lt. Cdr. T.R. Schwartz used his A-4C Skyhawk’s rocket pod to shoot down a MiG-17.