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{{redirects|HVAR||Hvar (disambiguation)}}
{{Use American English|date=November 2024}}
{{Use dmy dates|date=November 2024}}
{{Infobox weapon
| name = High Velocity Aircraft Rocket
| image = HVAR under a wing of TBF Avenger.jpg
| image_size =
| caption =
| origin = United States
| type = [[Air-to-surface missile|Air-to-surface rocket]]

| is_missile = yes

| service =
| used_by = [[United States military]]

| designer =
| design_date =
| production_date = 1944-1955
| manufacturer =
| number =

| spec_label =
| weight = {{convert|134|lb}}
| length = {{convert|68|in|cm|0}}<ref>National Air & Space Museum HVAR exhibit and specifications display, Smithsonian Institution, Washington, D.C.</ref>
| part_length =
| width =
| height =
| diameter = {{convert|5|in|mm|0}}
| crew =
| passengers =

| filling = {{convert|7.5|lb}} of [[TNT]] or [[Composition B]]
| filling_weight = {{convert|45.5|lb}}
| detonation =
| yield =

| engine = {{convert|52|in|cm|0}} long x {{convert|5|in|cm|1}} diameter solid propellant rocket motor
| engine_power =
| pw_ratio =
| payload_capacity =
| fuel_capacity = {{convert|23.9|lb}}
| vehicle_range =
| speed = {{convert|1375|ft/s}} plus speed of launching aircraft
| guidance = None
| steering =

| wingspan = {{convert|15.625|in|cm|1}}
| propellant = [[Ballistite]], extruded
| ceiling =
| altitude =
| depth =
| boost =
| accuracy =
| launch_platform = Ground attack or multirole aircraft
| transport =
}}

The '''High Velocity Aircraft Rocket''', or '''HVAR''', also known by the nickname '''Holy Moses''',<ref name="DS">{{harvnb|Parsch|2006}}</ref> was an American [[unguided rocket]] developed during [[World War II]] to attack targets on the ground from aircraft. It saw extensive use during both [[World War II]] and the [[Korean War]].

==Design and development==
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 {{convert|5|inch|mm|adj=on|0}} diameter warhead but an underpowered {{convert|3.25|inch|mm|adj=on|0}} 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-inch diameter for both warhead and rocket motor, increasing propellant from {{convert|8.5|to|23.9|lb|kg}} of [[Ballistite]]. U.S. Ballistite propellant had a sea level [[specific impulse]] of over {{convert|200|isp}}, compared with about {{convert|180|isp}} 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-inch and 5-inch 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 {{convert|216|m/s|abbr=on}} for the 5-inch AR to {{convert|420|m/s|abbr=on}} for HVAR, giving the coveted flatter trajectory.<ref>{{cite conference|author1=E.W. Price |author2=C.L. Horine |author3=C.W. Snyder |title=EATON CANYON, A History of Rocket Motor Research and Development in the Caltech-NDRC-Navy Rocket Program, 1941-1946 |conference=34th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, Cleveland, Ohio |date=July 1998 |url=http://maji.utsi.edu/courses/09_propulsion_1/Papers/AIAA983977_Price.pdf |publisher=AIAA |url-status=dead|archive-url=https://web.archive.org/web/20100611022817/http://maji.utsi.edu/courses/09_propulsion_1/Papers/AIAA983977_Price.pdf |archive-date=2010-06-11 }}</ref>

==Operational service==
[[File:F-84E launchs rockets.jpg|thumb|left|An [[F-84]]E launching rockets]]
Two different versions of the HVAR were built during [[World War II]]. The warheads were Mk 4 general purpose warheads holding {{convert|7.6|lb|kg}} of [[TNT]] with base and optionally nose fuses; or Mk. 2 AP warheads with {{convert|2.2|lb|kg}} of [[Explosive D]].

HVAR testing was complete by [[D-Day]], 6 June 1944, and air-lifted Navy HVAR rockets were soon being loaded on [[USAFCENT|Ninth Air Force]] [[Republic P-47 Thunderbolt|Republic P-47D Thunderbolt]]s to support the break-out at Normandy. Other single-engine delivery aircraft included the [[Vought F4U Corsair]], [[Grumman F6F Hellcat]], [[Grumman TBF Avenger|Grumman TBF/TBM Avenger]], and [[Curtiss SB2C Helldiver]]. Twin-engine aircraft sometimes armed with HVARs included the [[Lockheed P-38 Lightning]], [[North American PBJ Mitchell]] bomber and the [[Lockheed PV-2 Harpoon]] bomber.

HVAR could penetrate {{convert|4|ft|m|abbr=on}} 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 Ocean theater of World War II|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 [[Ram (rocket)|6.5-inch (170 mm) RAM]] rocket was an oversized shaped-charge head on a standard HVAR motor as well.

HVAR was an effective weapon in the hands of skilled, experienced pilots. It was less effective in the hands of average or inexperienced pilots who were accustomed to taking less careful aim and then "walking in" their gunfire to finally engage a target. HVARs could be fired in pairs or a single rapid-fire salvo but required accurate initial alignment and careful attention to range, or at least a good instinctive sense for the range to the target. HVARs were widely used in the [[Korean War]]. [[Douglas A-1 Skyraider|Douglas AD-1 Skyraider]]s often carried a dozen HVARs, and sometimes an additional pair of much larger but less accurate [[Tiny Tim (rocket)|Tiny Tim]] {{convert|11.75|in|cm|adj=on}} rockets. Targets included ships, bunkers, pillboxes, coastal defense guns, ammunition dumps, and occasionally even destroyers and major bridges. Numerous [[North American P-51 Mustang|North American F-51D Mustang]] "Six-Shooters" (six [[M2 Browning|.50 cal (12.7 mm) machine guns]] plus six HVARs and 2 bombs or ten HVARs) and carrier-based [[Grumman F9F Panther]] jets flew close air support in Korea. Panthers carried 6 HVARs and four [[Hispano-Suiza HS.404|20mm cannons]], while both planes could carry an additional pair of {{convert|500|lb|kg|abbr=on}} bombs, napalm, or fuel tanks. [[Neil Armstrong]] and [[John Glenn]] were among the Panther pilots. It was in Korea that HVARs and Tiny Tims bridged the gap between prop planes and jets: [[Lockheed F-80 Shooting Star|Lockheed F-80C Shooting Star]], [[Republic F-84 Thunderjet|Republic F-84E Thunderjet]], [[Grumman F9F Panther]], and [[North American F-86 Sabre]]. Jets gave the fighter pilots improved forward visibility. F-84E Thunderjets proved to be the most capable load-lifting fighter/bombers in Korea, demonstrating an ability to loft up to 24 HVARs and 2 Tiny Tims with a combined rocket weight of {{convert|5800|lb|kg}}.
{{Clear}}

In April 1945, HVAR rockets were used in [[Operation Bumblebee]] in the Navy's facility on [[Island Beach, New Jersey]]. The HVAR rockets launched {{convert|6|in|mm|adj=on}} [[ramjet]] engines from wooden frames, accelerating the carbon disulfide fuel ramjets to flight speed. On 13 June, the ramjets achieved supersonic speed.<ref>"Flying Stovepipe Developed by APL in 1945", The News, Johns Hopkins University, Applied Physics Laboratory.</ref>

HVAR rockets were used in the 1970s, the Mk.32 HEAT round being used by Air Force A-1E Skyraiders in Vietnam.<ref name="auto">{{Cite web|url=https://bulletpicker.com/_library.html|title=Library|website=bulletpicker.com}}</ref>

==Warheads==
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.<ref>https://archive.org/details/OP2210AircraftRocketspartial {{Dead link|date=February 2022}}</ref><ref name="auto"/> 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.

{| class="wikitable"
! Type
! Model
! Weight
! Filler
! Filler weight, lb
|-
| HE
| Mk 6 Mod 1
| 45.87
| [[trinitrotoluene|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
|-
| [[Armour-piercing ammunition|AP]]/[[Anti-submarine warfare|ASW]]
| Mk 29
| 48.56
| Explosive D
| 3.03
|-
|}

==Ammunition==
A head assembled with a motor is known by a separate designation listed below.
[[File:VT fuze m403.jpg|thumb|right|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."]]

{| class="wikitable"
!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
|-
|}

==Performance==
{| class="wikitable"
!Ammunition Type
!Armor Penetration 0°,<ref name="auto"/><ref>{{Cite web |url=http://www.dtic.mil/dtic/tr/fulltext/u2/035574.pdf |title=Archived copy |access-date=2018-05-07 |archive-date=2017-02-17 |archive-url=https://web.archive.org/web/20170217040845/http://www.dtic.mil/dtic/tr/fulltext/u2/035574.pdf |url-status=dead }}</ref><ref name="auto1">https://archive.org/details/OP12395InchHVAR {{Dead link|date=February 2022}}</ref>
!70°
|-
|GP Mk 6 Mod 0
|25mm
|
|-
| AP Mk 2
| 51-76mm<ref group=note>Penetration is only given as an estimate of 2-3 inches</ref>
|
|-
| HEAT Mk 25
| 263mm<ref group=note>Estimated, as 90mm of armor at 70 degrees is 263mm effective per the [https://panzerworld.com/relative-armor-calculator?armor_thickness=90&angle_type=cosine&angle_1=70&angle_2=0 Relative Armor Calculator]</ref>
| 90mm
|-
|}

{| class="wikitable"
!Ammunition Type
!Concrete Penetration,<ref group=note>NAVORD OP 2210 gives these figures as inches rather than feet, this is believed erroneous as multiple other sources contradict this</ref> 0° <ref name="auto"/><ref name="auto1"/>
!30°
|-
|GP Mk 6 Mod 0
| 1,143mm
| 838mm
|-
|}

==Target Rocket==
[[File:TDU-11B target rocket.jpg|thumb|right|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<ref>{{Cite web|url=https://archive.org/details/OP23092ndSidewinderGuidedMissleMark2|title = OP 2309 ( 2nd Revision) Sidewinder Guided Missile Mark 2}}</ref> 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,<ref>{{Cite web|url=https://archive.org/details/OP23093rdAIM9B|title=OP 2309 ( 3rd) AIM 9 B}}</ref> while the [[USAF]] and [[RAAF]] used the device into the 1980s<ref>{{Cite web|url=https://archive.org/details/LTVA7KWeaponDeliveryManualNonNuclear|title=LTV A-7K Weapon Delivery Manual( Non Nuclear)|via=Internet Archive}}</ref><ref>{{Cite web|url=https://archive.org/details/RAAFWeaponsDeliveryManualMirageIIIOIIID|title=RAAF Weapons Delivery Manual Mirage IIIO & IIID|via=Internet Archive}}</ref>

==See also==
*[[3.5-Inch Forward Firing Aircraft Rocket]]
*[[BOAR (rocket)]]
*[[ASM-N-6 Omar|XASM-N-6]]

==Notes==
{{reflist|group=note}}

==References==
{{reflist}}

==Bibliography==
*{{cite web |url=http://www.designation-systems.net/dusrm/app4/5in-rockets.html |title=Air-Launched 5-Inch Rockets |first=Andreas |last=Parsch |year=2006 |work=Directory of U.S. Military Rockets and Missiles |publisher=designation-systems.net |access-date=2011-01-08 }}

==External links==
{{Commons category|HVAR rocket}}
*{{cite web|url=http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=1943 |title=5-inch HVAR |publisher=National Museum of the US Air Force |date=11 February 2011 |url-status=dead|archive-url=https://web.archive.org/web/20100403005731/http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=1943 |archive-date=3 April 2010 }}

{{U.S. WW2 rockets}}

[[Category:Air-to-ground rockets of the United States]]
[[Category:World War II weapons of the United States]]
[[Category:Weapons and ammunition introduced in 1944]]

High Velocity Aircraft Rocket - Revision history

imported>Gamapamani: - extra tag