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High Velocity Aircraft Rocket


High Velocity Aircraft Rocket
"Holy Moses" HVARs mounted on a Grumman TBF Avenger
TypeAir-to-surface rocket
Place of originUnited States
Service history
Used byUnited States military
Production history
Mass134 pounds (61 kg)
Length68 inches (173 cm)[1]
Diameter5 inches (127 mm)
Warhead7.5 pounds (3.4 kg) of TNT or Composition B
Warhead weight45.5 pounds (20.6 kg)

Wingspan15.625 inches (39.7 cm)
Propellantballistite, extruded
Speed1,375 feet per second (419 m/s) plus speed of launching aircraft
single or twin engine aircraft

Design and developmentEdit

The HVAR was designed by engineers at Caltech during World War II as an improvement on the 5-Inch Forward Firing Aircraft Rocket (FFAR), which had a 5 inches (130 mm) diameter warhead but an underpowered 3.25 inches (83 mm) diameter rocket motor. The desire for improved accuracy from the flatter trajectory of a faster rocket spurred the rapid development. HVAR had a constant 5 in (130 mm) diameter for both warhead and rocket motor, increasing propellant from 8.5 to 23.9 pounds (3.9 to 10.8 kg) of Ballistite. U.S. Ballistite propellant had a sea level specific impulse of over 200 seconds (2.0 km/s), compared with about 180 seconds (1.8 km/s) for the British Cordite, German WASAG and Soviet PTP propellants. Hercules Powder Company was the principal U.S. supplier of high performance extruded Ballistite propellants: 51.5% nitrocellulose, 43% nitroglycerine, 3.25% diethyl phthalate, 1.25% potassium sulfate, 1% ethyl centralite, and 0.2% carbon black. The propellant in U.S. 3.25 in (83 mm) and 5 in (130 mm) rocket motors consisted of a single large X-shaped cross-section, "cruciform" Ballistite grain cavity. This went against the common practice of filling rocket motors with different numbers of smaller same-sized tubular charges with a round cavity, the number depending on motor diameter. The central hole in a tubular charge makes it more difficult to extrude, requiring a softer propellant blend that also yields somewhat lower performance. Rocket ∆V increased from 216 m/s (710 ft/s) for the 5 in (130 mm) AR to 420 m/s (1,400 ft/s) for HVAR, giving the coveted flatter trajectory.[3]

Operational serviceEdit

An F-84E launching rockets

Two different versions of the HVAR were built during World War II. The warheads were Mk 4 general purpose warheads holding 7.6 pounds (3.4 kg) of TNT with base and optionally nose fuses; or Mk. 2 AP warheads with 2.2 pounds (1.00 kg) of Explosive D.


HVAR could penetrate 4 ft of reinforced concrete and was used to sink transports, knock out pillboxes and AA gun emplacements, blow up ammo and oil-storage dumps, and destroy tanks, locomotives, and bunkers. Navy F4U Corsairs and TBF/TBM Avengers made the most extensive use of the rockets in the Pacific theater after the victory in Europe. Over a million HVARs were made during World War II, and production continued until 1955. HVARs remained in the Navy's inventory until the mid-1960s. After World War II, newer versions included a new general purpose type with a proximity fuse, White Phosphorus smoke rounds, an anti-submarine head, and a new shaped-charge warhead for use against tanks. The 6.5 inch RAM rocket was an oversized shaped-charge head on a standard HVAR motor as well.



HVAR rockets were used in the 1970s, the Mk.32 HEAT round being used by Air Force A-1E Skyraiders in Vietnam[5]


Initial WW2 HVAR warheads were modified 5"/38 caliber gun shells, with the Mk.6 head being a modification of AA Common shells and the Mk.2 being derived from Special Common rounds. Later heads were purpose-built.[6][7][8] The Mark 6 HE head came in two variations, Mod 0 and Mod 1. Mod 1 had a deep nose cavity to fit the M403 VT fuze and thus carried 0.5lb less explosive fill.

Type Model Weight Filler Filler weight, lb
HE Mk 6 Mod 1 45.87 TNT 7.6
HE Mk 6 Mod 4 45.04 TNT 7.1
AP Mk 2 48.3 Explosive D 2.2
Smoke-PWP Mk 4 48.09 PWP (plasticised White Phosphorus) 19.36
HEAT Mk 25 47.85 Comp B 15.33
AP/ASW Mk 29 48.56 Explosive D 3.03


A head assembled with a motor is known by a separate designation listed below.

A cutaway drawing of the M403 VT fuze used on the Mk 6 Mod 4 head. For security reasons, the actual radar components are not shown, with the space being left empty and vaguely captioned "Volume occupied by electrical gear."
Head Complete Round Type Weight
Mk 6 Mod 1 Mk 28 Mod 4 GP 138.49lb
Mk 6 Mod 4 Mk 28 Mod 5 VT 138.49lb
Mk 25 Mk 32 HEAT 140.47
Mk 29 Mk 34 AP/ASW 138.43lb
Mk 2 Mk 35 AP 138.47lb
Mk 4 Mk 36 Smoke-PWP 140.71lb


Ammunition Type Armor Penetration 0°,[9][10][11][12] 70°
GP Mk 6 Mod 0 25mm
AP Mk 2 51-76mm[note 1]
HEAT Mk 25 263mm[note 2] 90mm
Ammunition Type Concrete Penetration,[note 3] [13][14][15] 30°
GP Mk 6 Mod 0 1,143mm 838mm

Target RocketEdit

TDU-11/B target rocket

Some surviving HVAR rockets were converted to training targets for pilots to practice firing AIM-9 Sidewinder infrared-guided missiles. Known as the TDU-11/B to the US Air Force and Target Rocket Mark 26 Mod 0[16] to the US Navy, it was heavier than the base rocket at about 215lb. The target rocket used a Mk.6 head with inert lead ballast and was fitted with four Mark 21 (aluminum construction) or 33 (steel) tracking flares, 10 inches long by 1 inch wide and carrying 100 grams of pyrotechnic mixture, to provide a strong IR signature for the Sidewinder to lock onto. Carried paired with AIM-9s on AERO-3B launchers, a pilot would fire the rocket, then switch to his Sidewinder, wait for it to acquire the tracking flares, and fire. Target rockets were phased out by the USN in the mid-1960s in favor of towed or drone targets,[17] while the USAF and RAAF used the device into the 1980s[18][19]

See alsoEdit


  1. ^ Penetration is only given as an estimate of 2-3 inches
  2. ^ Estimated, as 90mm of armor at 70 degrees is 263mm effective per the Relative Armor Calculator
  3. ^ NAVORD OP 2210 gives these figures as inches rather than feet, this is believed erroneous as multiple other sources contradict this


  2. ^ Parsch 2006
  5. ^
  6. ^
  7. ^,%20US%20Explosive%20Ordnance.pdf
  8. ^
  9. ^,%20US%20Explosive%20Ordnance.pdf
  10. ^
  11. ^
  12. ^
  13. ^,%20Volume%201.pdf
  14. ^
  15. ^
  16. ^
  17. ^
  18. ^
  19. ^



External linksEdit