The RP-3 (from Rocket Projectile 3 inch) was a British rocket projectile used during and after the Second World War. Though primarily an air-to-ground weapon, it saw limited use in other roles. Its 60-pound (27 kg) warhead gave rise to the alternative name of the "60-pound rocket"; the 25-pound (11 kg) solid-shot armour-piercing variant was referred to as the "25-pound rocket". They were generally used by British fighter-bomber aircraft against targets such as tanks, trains, motor transport and buildings, and by Coastal Command and Royal Navy aircraft against U-boats and shipping. The "3 inch" designation referred to the diameter of the rocket motor tube.

RP-3
3 in RP 60 pdr Loading On Typhoon.jpg
Loading 3in 60-pdr SAP/HE rocket projectiles onto a Hawker Typhoon
TypeUnguided air-to-surface rocket
Place of originUnited Kingdom
Service history
In service1943–1968 (UK)
Used byRoyal Air Force, Royal Navy, Royal Australian Air Force and others
WarsWorld War II, Indonesian National Revolution, Malayan Emergency, Suez Crisis, Korean War, Aden Emergency
Production history
Variantssee variants
Specifications
Mass17.9 kg (39 lb) Mk 1 engine
17.2 kg (38 lb) Mk 2, 3, 4 engine
Length55 in (1.4 m)
Diameter82.7 mm (3.26 in) rocket body
Warhead weight25–60 lb (11–27 kg) total warhead weight

Enginesolid fuel rocket
800 kgf (1,800 lbf)
Propellantcordite
Operational
range
1,600 m (1,700 yd)
Maximum speed With 25 lb warhead: 380 m/s (1,200 ft/s)
With 60 lb warhead: 230 m/s (750 ft/s)
Guidance
system
unguided
Launch
platform
Several aircraft
Landing Craft Tank (Rocket)

HistoryEdit

The first use of rockets fired from aircraft was during World War I. The "unrotated projectiles" (UPs) were Le Prieur rockets which were mounted on the interplane struts of Nieuport fighters. These were used to attack observation balloons and were reasonably successful. Sopwith Baby and Pup and Home Defence B.E.2 fighters also carried rockets.[1][page needed] With the war ended the Royal Air Force, intent on retrenching, forgot about firing rockets from aircraft. The British Army, however, did see a use for rockets against low-flying aircraft; from late 1940 parts of Britain were defended by increasing numbers of "Z-Batteries" 2-inch (51 mm) rockets supplementing the conventional anti-aircraft guns.[1][2][page needed]

When German forces under the command of Rommel intervened in the Western Desert from early 1941, it became clear that the Desert Air Force lacked weapons capable of damaging or destroying the large numbers of armoured fighting vehicles, particularly the heavier Panzer III and Panzer IV tanks possessed by the Germans. Consequently, in April 1941 Henry Tizard, the Chief Scientist, called together a panel to study "Methods of Attacking Armoured Vehicles."[1]

The types of weapons investigated included the 40 mm Vickers S gun and related weapons manufactured by the Coventry Ordnance Works, as well as the Bofors 40 mm and the US 37 mm T9 cannon fitted to the Bell P-39 Airacobra: however, it was already recognised that these weapons were only capable of dealing with light tanks and motor transport, and using larger weapons on fighter-bombers was ruled out because of weight and difficulties handling recoil. The chairman of the panel, Mr. Ivor Bowen[3] (Assistant Director of Armament Research) turned to the idea of using rocket projectiles as a means of delivering a large warhead capable of destroying or disabling heavy tanks. Information was sought from the Soviets, who had just started using unguided RS-82 rockets against German ground forces in the opening phases of Operation Barbarossa.[1][note 1]

By September 1941 it was decided that two models of UP would be developed:

  • A 23 lb plastic explosive on a standard 2-inch UP.
  • A 20 lb solid armour-piercing head on a 3-inch UP.

When it was realised that the 2-inch version would be less effective than the Vickers S cannon, it was decided to concentrate on development of the 3-inch version, which could be developed from the 2-inch rocket used in the Z-Batteries.[1]

DesignEdit

 
Attaching 60-pdr SAP warheads onto 3 in rocket projectile bodies

The rocket body was a steel tube 3 inches (76 mm) in diameter filled with 11 lb (5.0 kg) of cordite propellant, fired electrically. The warhead was screwed into the forward end, and was initially a solid 25-pound (11 kg), 3.44-inch (87 mm) diameter armour-piercing warhead which was quickly supplemented by a 6-inch-diameter (150 mm), 60-pound (27 kg) high explosive head. Another type of head was a 25-pound (11 kg) mild steel (later concrete) practice head. Once the rocket had been mounted on the rails, an electrical lead (or "pigtail") connected the rocket to the firing controls.

Four large tailfins induced enough spin to stabilize the rocket, but as it was unguided, aiming was a matter of judgment and experience. Approach to the target needed to be precise, with no sideslip or yaw, which could throw the RP off line. Aircraft speed had to be precise at the moment of launch, and the angle of attack required precision. Trajectory drop was also a problem, especially at longer ranges.[note 2][4]

On the plus side the rocket was less complicated and more reliable than a gun firing a shell, and there was no recoil on firing. It was found to be a demoralising form of attack against ground troops, and the 60-pound warhead could be devastating. The rocket installations were light enough to be carried by single-seat fighters, giving them the punch of a cruiser.[note 3] Against slow-moving large targets like shipping and U-boats, the rocket was a formidable weapon.

The weight and drag of the all-steel rails initially fitted to British aircraft blunted performance. Some aircraft such as the Fairey Swordfish biplane used against submarines had steel "anti-blast" panels fitted under the rails to protect the wing, which further increased weight and drag. Aluminium Mark III rails, introduced from late 1944, reduced the effect. American experience with their own rockets (the USAAF's 3.5-Inch Forward Firing Aircraft Rocket (FFAR) and the USN's 5-inch FFAR and HVAR[5]) showed that the long rails and anti-blast panels were unnecessary; zero-length launchers were introduced in May 1945. British aircraft started being fitted with "zero-point" mounting pylons in the post-war years.

The 3-inch rocket motors (less warhead) were used in the bunker buster "Disney bomb" (official name: 4500 lb Concrete Piercing/Rocket Assisted bomb), 19 of them propelling the 4,500-pound (2.0 t) bomb to 990 mph (440 m/s) at impact with the target.[6]

Service historyEdit

Air-to-ground useEdit

 
A gun camera picture of a rocket salvo, launched by a Hawker Typhoon towards railway wagons in a siding at Nordhorn, Germany (1945)

Before the new weapon was released for service extensive tests were carried out by the Instrument, Armament and Defence Flight (IADF) at Royal Aircraft Establishment, Farnborough. Hawker Hurricanes were fitted with rockets and rails and flown during June and July 1942. Further tests were undertaken from 28 September to 30 November to develop rocket firing tactics. Other aircraft used were a Lockheed Hudson, a Fairey Swordfish biplane torpedo bomber, a Douglas Boston II medium bomber and a Sea Hurricane.[4] At the same time the Aeroplane and Armament Experimental Establishment (A&AEE) had to develop tactics for all the individual aircraft types which were to be armed with the RPs. Aiming was through a standard GM.II reflector gunsight. A later modification enabled the reflector to be tilted with the aid of a graduated scale, depressing the line of sight, the GM.IIL.[7] For rockets only the Mk IIIA was the most successful – it was used on the Lockheed Ventura and Hudson.

The first operational use of the RP was in the Western Desert as a "tank-busting" weapon on Hawker Hurricane Mk. IIEs and IVs. The 25-pound armour-piercing heads were found to be ineffective against the Tiger I tanks coming into German service. With the example of the success of Royal Artillery gunners using high-explosive shells from the 25 pdr gun-howitzer, it was decided to design a new 60-pound semi-armour-piercing (SAP) head. These were capable of knocking turrets off tanks.

A typical RP-3 installation was four projectiles on launching rails under each wing. A selector switch was fitted to allow the pilot to fire them singly (later omitted), in pairs, or as a full salvo. Towards the end of the war some RAF Second Tactical Air Force Hawker Typhoons had their installation adapted to carry an additional four rockets doubled up under the eight already fitted.[8]

Possibly the best known action involving RP-3s was that of the Falaise pocket of mid-August 1944. During the battle German forces, retreating to avoid being trapped in a pincer movement by Allied ground forces, came under air attack. Amongst the waves of light, medium and fighter bombers attacking the German columns the Typhoons of 2 TAF attacked with their rockets, claiming hundreds of tanks and "mechanised enemy transport".[note 4] After the battle Army and 2nd TAF Operational Research Sections studying the battleground came to the conclusion that far fewer vehicles (17 in total) had been destroyed by rocket strike alone. What was clear was that in the heat of battle it was far harder for pilots to launch the weapons while meeting the conditions needed for accuracy. Smoke, dust and debris in the target areas made accurate assessment of the damage caused almost impossible.[8]

But it was also clear rocket attacks devastated the morale of enemy troops – many vehicles were found abandoned intact, or with only superficial damage. Interrogation of captured prisoners showed that even the prospect of rocket attack was extremely unnerving for them.[8]

Anti-submarineEdit

 
A rocket-armed Swordfish lands aboard the escort carrier HMS Tracker.

Soon after some encouraging results from the initial deployment, trials of the weapon were conducted against targets representing U-boats. It was discovered that if the rockets were fired at a shallow angle, near misses resulted in the rockets curving upwards in seawater and piercing the targets below the waterline. Soon Coastal Command and the Royal Navy's Fleet Air Arm aircraft were using the rockets extensively.

The first U-boat destroyed with the assistance of a rocket attack was U-752 (commanded by Kapitän-Leutnant Schroeter), on 23 May 1943, by a Swordfish of 819 Naval Air Squadron (819 NAS). The rockets used on this occasion had solid, cast-iron heads and were known as "rocket spears".[9] One of these punched right through the submarine's pressure hull and rendered it incapable of diving; the U–boat was scuttled by its crew. On 28 May 1943, an RAF Hudson of 608 Squadron destroyed a U-boat in the Mediterranean, the first destroyed solely by rocket.[4] These rockets were, among other factors, credited with making it too dangerous for the Germans to continue operating their Flak U-Boats, which were initially designed with heavy anti-aircraft weaponry to hold off air attacks.

From then until the end of the Second World War in Europe, Coastal Command and the Fleet Air Arm used the rockets as one of their primary weapons (alongside torpedoes, which, to a certain extent they replaced) against shipping and surfaced U-boats.

Ground-to-ground useEdit

 
Rocket-armed Sherman tanks of the Coldstream Guards, 28 April 1945

In 1945, some British M4 Sherman tanks were fitted with two or four rails – one or two either side of the turret – to carry 60-pound headed rockets. These were used at the Rhine Crossing by tanks of the 1st Coldstream Guards. The tanks were called "Sherman Tulips". The tanks fitted included both conventional Shermans and the more heavily armed Sherman Fireflies.[10]

The modifications were first tried out by two officers of the 1st Armoured Battalion, Coldstream Guards, 5th Guards Armoured Brigade, who obtained rockets and launching rails from an RAF base and carried out the first test firings on 17 March 1945. They were inspired after hearing the idea had been earlier tried, but abandoned, by a Canadian unit, the 18th Armoured Car Regiment (12th Manitoba Dragoons), who had fitted RP-3 rails to a Staghound Armoured Car.[10] There are photos of four such rockets on a Cromwell cruiser tank, however little is known about it for certain.

Within a week all the tanks of Number 2 Squadron had been fitted with launch rails, some tanks had two launching rails, others had four. The rails were at fixed elevations and the rockets had fixed ranges either 400 or 800 yards (370 or 730 m).[10]

The rockets were highly inaccurate when fired from a tank as they were being fired from a stationary point and had little slipstream over the fins. Despite this, the RP-3 was valued by tank crews for the destructive effect of its 60-pound warhead.[11][page needed] In combat, they were also used for short-range, saturation bombardment of an area and were effective as an immediate counter to German ambushes.[10]

Swedish serviceEdit

The 25 lb AP No. 1 Mk. I and 60 lb SAP and saw use with the Swedish Air Force from 1946[12] to 1953.[13] In Swedish service the 60lb was originally designated 8 cm sprängspets m/46 ("8 cm explosive-tip m/46"), but this changed to 15 cm spränghuvud m/46 (15 cm explosive-head m/46), or 15 cm shu m/46 for short, in 1950.[12] When combined with an RP-3 rocket engine the complete rocket was designated as 8 cm sprängraket m/46 (8 cm explosive-rocket m/46), later 15 cm sprängraket m/46, or 15 cm srak m/46 for short.[12] The 25 lb was originally designated 8 cm pansarspets m/46A (8 cm armour-tip m/46A), but this changed to 8 cm pansarhuvud m/46A (8 cm armour-head m/46A), or 8 cm phu m/46A for short, in 1950.[12] When combined with an RP-3 rocket engine the complete rocket was designated as 8 cm pansarraket m/46A (8 cm armour-rocket m/46A), or 8 cm prak m/46A for short.[12]

The 25 lb AP No. 2, Mk. I warhead was used from 1946[12] to 1957.[14] In Swedish service it was originally designated 8 cm pansarspets m/46B (8 cm armour-tip m/46B), but this changed to 8 cm pansarhuvud m/46B (8 cm armour-head m/46B), or 8 cm phu m/46B for short, in 1950.[12] When combined with an RP-3 rocket engine the complete rocket was designated as 8 cm pansarraket m/46B (8 cm armour-rocket m/46B), or 8 cm prak m/46B for short.[12] Due to problems with fins detaching during the projectile trajectory the complete rocket type was modified in 1953 with swept fins to resolve the issue. Around 30% of each fin's surface was removed. This type was called 8 cm pansarraket m/46C.[12]

VariantsEdit

 
25 lb armour-piercing, No. 1 loaded onto Coastal Command Beaufighter
25 lb armour-piercing No. 2
 
Hawker Typhoon wing loaded with six 60 lb semi-armour piercing rockets
 
Practice

WarheadsEdit

Shell, 18 lb, HE
8 kg (17.6 lb) "high-explosive" warhead.[citation needed]
Shot, 25 lb, AP, No. 1, Mk. I
Armour-piercing (anti-submarine) warhead made out of hardened steel.[15]
Shot, 25 lb, AP, No. 2, Mk. I
Improved design over the Shot, 25 lb, AP, No. 2, Mk. I warhead made longer and pointier to increase penetration.[15]
Shot, 25 lb, SAP, Mk. I
Semi-armour-piercing" warhead; same design as the "Shot, 25 lb, AP, No. 2, Mk. I" but made out of mild steel and having the spigot fuzed together with the body.[15] By 1946 the design was obsolete and only used for advanced training.[15]
Shot, 25 lb, Practice, Concrete, Mk. I
Practice warhead ​11 12 inches by 5 inches diameter made out of concrete,[16] meant to simulate shooting the 25 lb AP and SAP warheads.[15]
Shell, HE, 60 lb, "F"., No. 1, Mk. I
Fragmentation warhead for use against unarmoured vehicles and personnel. Converted from a 4.5 in (114 mm) howitzer shell with No. 899 fuze fitted to the nose, the whole warhead was 22 in (560 mm) long and weighed 50.5 lb (22.9 kg). The 4 lb (1.8 kg) TNT or RDX/TNT filling produced "heavy fragments" which caused damage at "considerable distance".[note 5][16][18]
Shell, HE, 60 lb, SAP, No. 1, Mk. I
Semi-armour-piercing high-explosive warhead with base Fuze No. 865 Mk I (with delay) to allow it to penetrate into a target before detonating.[16][15]
Shell, HE, 60 lb, SAP, No. 2, Mk. I
Same design the Shell, HE, 60 lb, SAP, No. 1, Mk. I but with a non-delayed base Fuze No. 878 Mk I for use where the No. 865 fuze gave too long of a delay[16][15]
Shell, HE, 60 lb, SAP, No. 1, Mk. II
Same as the Shell, HE, 60 lb, SAP, No. 1, Mk. I but with the warhead nose and body forged as one piece.[15]
Shell, HE, 60 lb, SAP, No. 2, Mk. II
Same as the Shell, HE, 60 lb, SAP, No. 2, Mk. I variant but with the warhead nose and body forged as one piece.[15]
Shell, Practice, Concrete, 60 lb Mk. I
Practice warhead 20 in long by 6 in diameter formed of concrete over steel reinforcing rods.[16] Used to simulate shooting the 60 lb SAP/HE warheads. This warhead could also be fitted with the "Smoke container, No. 1, Mk. I", which pressed on over front of the warhead and gave off a smoke signal on impact. The filling was 16 oz (450 g) of titanium tetrachloride.[15]
Shell, HE, 60 lb, G.P.
High-explosive general-purpose (Hollow charge) warhead, trials ongoing as of September 1946.[12]
Comparison of rocket projectiles[note 6]
Warhead Shot, 25 lb, AP, No. 1 Shot, 25 lb, AP, No. 2 Shell, HE, 60 lb, SAP Shell, P., Concrete, 60 lb
Warhead diameter 88 mm (3.5 in) 152 mm (6.0 in)
Engine diameter 82.7 mm (3.26 in)
Width with fins 336 mm (13.2 in)
Warhead length
(including spigot)
314 mm (12.4 in) 378 mm (14.9 in) 553 mm (21.8 in) 608 mm (23.9 in)
Engine length 1,400 mm (55 in)
Overall length 1,639 mm (64.5 in) 1,703 mm (67.0 in) 1,880 mm (74 in) 1,933 mm (76.1 in)
Weight of complete rocket
with 17.2 kg (38 lb) engine
28.5 kg (63 lb) 44.6 kg (98 lb) 44.4 kg (98 lb)
Warhead weight 11.3 kg (25 lb) 27.4 kg (60 lb) 27.2 kg (60 lb)
Explosive charge none 6 kg (13 lb) TNT or Amatol 60/40[21] none
Propellant charge 5.2 kg (11 lb) cordite
Performance
Propellant burn time
at 15 °C (59 °F)
1.6 s
Thrust at 15 °C (59 °F) 800 kgf (1,800 lbf)
Maximum velocity 380 m/s (1,200 ft/s) 230 m/s (750 ft/s)

A 25lb AP Shot could penetrate 88 mm (3.5 in) at 700 yd (640 m); a flight time of 1.29 seconds from aircraft travelling at 350 ft/s (240 mph). The hollow charge "60lb HE/GP" 198 mm (7.8 in) at any range.[20]

Rocket enginesEdit

The RP-3 rocket engine was updated a number of times during its lifespan, which gave rise to a number of variants. For example, it was necessary to modify the rocket engine's propellant charge in order to be able to use several types of warheads. Initially the rocket engine was only designed to use warheads up to 25 lb (11 kg), but when warheads up to 60 lb (27 kg) were introduced the propellant charge had to be modified in order to use them. Variants capable of carrying warheads up to 60 lb were then given the supplementary designation TH.[15]

Aircraft rocket motor, 3 in., No. 1, Mk. 1
The Mk. 1 engine had a 12.5 lb (5.7 kg) tubular-shaped cordite propellant charge.[22] The ignition cables are routed through the tubular propellant charge. This variant was suitable for use with 25 lb solid warheads.[22] It was not suitable for tropical climates (above 80 °F (27 °C))[23]
Aircraft rocket motor, 3 in., No. 1, Mk. 1/TH
TH variant of the Mk. 1 engine that could mount solid or shell warheads up to 25 lb. It could likewise not be used in hot climates.[23]
Aircraft rocket motor, 3 in., No. 1, Mk. 2
The Mk. 2 engine replaced the tubular propellant charge with a 11 lb (5.0 kg) cruciform (cross-shaped) propellant charge[22] through a different metal grid. The ignition cables where routed in one of the inner corners of the cruciform propellant-charge. This variant was only capable of mounting 25 lb warheads.[15]
Aircraft rocket motor, 3 in., No. 1, Mk. 2/TH
TH variant of the Mk. 2 engine that could mount warheads up to 60 lb.[15]
Aircraft rocket motor, 3 in., No. 1, Mk. 3/TH
The Mk. 3 engine replaced the two-pin ignition plug with a single-pin one[15]
Aircraft rocket motor, 3 in., No. 1, Mk. 4/TH
The Mk. 4 engines extended the ignition cables to allow for double hanging, were one RP-3 was mounted below another RP-3. During storage the extra length of the ignition cables was held in place by loose metal clips in the nozzle.[15]


Aircraft using the RP-3 in the Second World WarEdit

These are aircraft that used the RP-3 operationally, a number of aircraft types were fitted with RP-3s on an experimental basis.

RAF and Commonwealth Air ForcesEdit

Royal Navy Fleet Air ArmEdit

Post Second World WarEdit

The 3-inch RP continued to be used on RAF and RN aircraft in the ground attack role until replaced by the SNEB podded rocket (RAF) and the 2-inch podded RP (RN).[citation needed]


See alsoEdit

  • M8 American air-ground barrage rocket, 4.5-inch (110 mm) calibre
  • Land Mattress
  • Tiny Tim, an American 11.75-inch (298 mm) calibre, 1,255-pound (569 kg) mass unguided rocket projectile

ReferencesEdit

Notes

  1. ^ The possibility of the Soviets sending a team of engineers to help set up production of these weapons was a possibility in August 1941. However, the Soviet offer was withdrawn, in spite of British efforts at supplying a Wing of Hawker Hurricanes and training Soviet aircrew in their use.[citation needed]
  2. ^ In tests carried out by the A&AEE, dispersion (when aimed at a 20-foot (6.1 m) square target) was 13 ft 6 in (4.11 m) at 1,000-foot (300 m) range – equal to 3° to 4° aiming error.
  3. ^ A typical cruiser gun of the era, the 6-inch gun used on Royal Navy ships for instance, fired perhaps four or six 112-pound (51 kg) projectiles, while a fighter could fire eight 60-pound PR-3 in a single salvo.
  4. ^ also known as "motorized enemy transport", as opposed to "horse-drawn transport" (HDT)
  5. ^ The safety instructions advised against firing at less than 600 yd (550 m) range due to the risk to the aircraft.[17]
  6. ^ Unless specified, data is from the Swedish Air Force 1950 manual "Bestämmelser för rakettjänst".[19] This manual uses original data collected in metric by the Royal Swedish Air Force Materiel Administration.[12] Compare with Imperial units data:[20][15]

Citations

  1. ^ a b c d e Aeroplane Monthly June 1995
  2. ^ The Blitz Then and Now: Volume 3
  3. ^ "King's Collections : Archive Catalogues : BOWEN, Ivor (1902-1984)". kingscollections.org.
  4. ^ a b c Aeroplane Monthly July 1995
  5. ^ 3.5 in FFAR 5 in FFAR and HVAR Retrieved 6 March 2008
  6. ^ Burakowski, Tadeusz; Sala, Aleksander (1960). Rakiety i pociski kierowane [Rockets and guided missiles] (in Polish). Część 1 – Zastosowania (Volume 1 – applications). Warsaw: Wydawnictwo Ministerstwa Obrony Narodowej (Ministry Of National Defense Publishing House). pp. 556–557.
  7. ^ GM.IIL 429sqn.ca
  8. ^ a b c Shores and Thomas 2005, pages 245-250
  9. ^ Gerald Pawle, The Wheezers & Dodgers, Seaforth Publishing 2009 ISBN 978-1-84832-026-0[page needed]
  10. ^ a b c d Moore, Craig (April 28, 2016). "Sherman Tulip Rocket Firing Tanks". www.tanks-encyclopedia.com.
  11. ^ Fletcher, David (2008). Sherman Firefly. New Vanguard 141. Osprey Publishing. ISBN 978-1-84603-277-6.
  12. ^ a b c d e f g h i j k Sjögren, Sven. Raketbeväpning i svenska flygvapnet, FV raketbeväpning 1944-1954 [Rocket-armament in the Swedish air force, AF rocket-armament 1944-1954] (in Swedish). Stockholm, Sweden: Kungliga Flygförvaltningen (Royal Swedish Air Force Materiel Administration). p. 12.
  13. ^ Flygvapnets raketmateriel, 1953 års upplaga [The Air Force's rocket-ordnance, 1953 edition] (in Swedish). Stockholm, Sweden: Kungliga Flygförvaltningen (Royal Swedish Air Force Materiel Administration). 1953.
  14. ^ Flygvapnets raketmateriel, 1957 års upplaga [The Air Force's rocket-ordnance, 1957 edition] (in Swedish). Stockholm, Sweden: Kungliga Flygförvaltningen (Royal Swedish Air Force Materiel Administration). 1957.
  15. ^ a b c d e f g h i j k l m n o p AP 2802A volume 1: Aircraft rocket installations, sighting and ammunition, 1946-12-12 edition. Royal Air Force. 1946.
  16. ^ a b c d e OP 1665
  17. ^ AP2802 Chapter 6 para 80
  18. ^ AP2802 Chapter 6 para 3-9
  19. ^ Bestämmelser för rakettjänst [Provisions for rocket-use] (in Swedish). Stockholm, Sweden: Kungliga Flygförvaltningen (Royal Swedish Air Force Materiel Administration). 1950. p. 2.
  20. ^ a b Boyd, 2009
  21. ^ OP 1665
  22. ^ a b c AP2802 Section 3 Chapter 2, paragraph 19
  23. ^ a b AP2802 Section 3 Chapter 2, 22
  24. ^ "Ground Attack". www.seavixen.org.

BibliographyEdit

External linksEdit