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| A great picture of a pair of Rocs. The Roc was a very large aircraft, note how small the pilot looks in his cockpit. You can see the "light series" bomb rack beneath the wing and the larger rack for a 250 lb (113 kg) bomb inboard of it. The nearest Roc has the serial number L3118. Pictured here when used by 759 Squadron at Eastleigh in 1940, it later went on to serve in the Orkney Islands and mainland Scotland, being written off after an accident in April 1944. |
The Blackburn Roc (company designation B-25) was a naval fighter aircraft designed and produced by the British aviation company Blackburn Aircraft. It took its name from the mythical bird of the tales of the Arabian Nights, the Roc. It was operated by the Fleet Air Arm (FAA) and was active during the Second World War.
The Roc was designed to Air Ministry Specification O.30/35 and was derived from the Blackburn Skua dive-bomber/fighter and developed in parallel to it. Unlike the Skua, the Roc had its armament in a turret. A large proportion of the work was subcontracted to another aircraft manufacturer, Boulton Paul, which had also designed their own turret fighter, the Boulton Paul Defiant. On 23 December 1938, the prototype Roc performed its maiden flight. Testing soon revealed it to have a relatively low maximum speed of only 223 mph (194 kn; 359 km/h). The float plane version of the Roc was even slower, leading to the cancellation of plans to equip float plane squadrons with the type. Cancellation of the project was discussed but this move was dismissed largely due to the wider impact on aircraft production.
During April 1939, the conventional version of the Roc was brought into FAA service. The type was present during the Allied campaign in Norway, as well as Operation Dynamo and Operation Aerial, the evacuations of Allied forces from Dunkirk and other French ports. The Roc quickly came to be viewed as inferior to existing aircraft, such as the Skua and the type had only a limited career in front-line service. The Roc's sole confirmed aerial victory occurred on 28 May 1940, when a patrolling Roc of 806 Naval Air Squadron, flown by pilot Midshipman A. G. Day, shot down a Junkers Ju 88 bomber from below. Towards the end of 1940, the Roc was largely relegated to air sea rescue and target-towing duties. Only sporadic engagements occurred after this point, with no substantial accomplishments occurring. The Roc was withdrawn during 1943.
General Information
Type: Carrier-based fighter
Manufacturer: Boulton Paul
Designer: Blackburn Aircraft
Primary user: Royal Navy
Number built: 136
Introduction date: April 1939
First flight: 23 December 1938
Retired: 1943
Developed from: Blackburn Skua
Design and Development
Background
On 31 December 1935, the Air Ministry issued Specification O.30/35, which sought a carrier-based turret-armed fighter for the Fleet Air Arm (FAA). The Blackburn Aircraft design team was headed by G. E. Petty. It was decided to pursue a derivative of its new Skua dive bomber, of which two prototypes had been ordered for the Fleet Air Arm earlier that year. There were several substantial differences, not least that the Skua did not use a turret; the fuselage was widened around the mid-section to accommodate it.
The rival aircraft manufacturer Boulton Paul proposed the P.85, a redesigned version of its land-based P.82 turret fighter (for Specification F.9/35, which would enter service as the "Defiant"), alternatively powered by a Bristol Hercules radial engine or a Rolls-Royce Merlin inline engine. Although the "Sea Defiant" was expected to be 85 mph (137 km/h) faster, the Air Ministry decided to select Blackburn's proposal instead.
Similar to the Skua, the B-25 Roc was a two-seat low-wing cantilever monoplane of all-metal construction. It was fitted with a retractable tailwheel undercarriage and its wings could be folded for storage aboard aircraft carriers. Attachment points for a float undercarriage were present as standard, unlike on the Skua. The Roc also retained the wing-mounted dive brakes present on the Skua but the mainplane was redesigned with a slight dihedral to obviate the upturned wingtips. It was powered by a Bristol Perseus radial engine that drove a three-bladed propeller. Amongst other things, the rear fuselage housed marine equipment, including a collapsible dinghy.
The Roc's primary armament was the same Boulton Paul Type A power-operated gun turret as used on the Defiant, with four .303 in (7.7 mm) Browning machine guns. The turret could rotate in any direction and the guns elevated as high as 85 degrees above the horizon; this movement was achieved via a control column. The turret was hydraulically powered by an electrically-driven pump, the guns were fired electrically and had integrated automatic interruption to prevent the tail unit or propeller being hit. Additional armaments included two 250 lb (110 kg) bombs and eight practice bombs, carried upon bomb racks under each wing; provisions for a close-fitting 70-gallon external fuel tank were also present on the underside of the central fuselage.
On 28 April 1937, the Air Ministry placed an "off the drawing board" order for 136 Rocs. As Blackburn already had full order books for the Skua and the Botha torpedo bomber, it was decided to sub-contract the detailed design and production of the aircraft to Boulton Paul at Wolverhampton; this arrangement has been attributed for the delayed delivery of the company's own turret aircraft, the Defiant. [The Air Ministry had not expected to order the P.82/Defiant into production and Boulton Paul was able to take on the work. It was not until the Hawker Hotspur program fell behind that the first orders for the Defiant were placed. During January 1938, the Hotspur was cancelled for Hawker to increase Hurricane production in favor of the Defiant.]
Specifications
Crew: 2
Length: 35 ft 7 in (10.85 m)
Wingspan: 46 ft 0 in (14.02 m)
Height: 12 ft 1 in (3.68 m)
Wing area: 310 sq ft (29 m2)
Empty weight: 6,121 lb (2,776 kg)
Gross weight: 7,950 lb (3,606 kg)
Powerplant: 1 × Bristol Perseus XII nine-cylinder air-cooled sleeve-valve radial piston engine, 890 hp (660 kW)
Propellers: 3-bladed variable-pitch propeller
Maximum speed: 194 kn (223 mph, 359 km/h) at 10,000 ft (3,000 m)
Cruise speed: 117 kn (135 mph, 217 km/h)
Range: 700 nmi (810 mi, 1,300 km) with 70 imp gal (320 L; 84 US gal) long-range tank
Service ceiling: 18,000 ft (5,500 m)
Rate of climb: 1,500 ft/min (7.6 m/s)
Armament:
Guns: 4 × 0.303 in (7.7 mm) Browning machine guns in power operated dorsal turret
Bombs: 8 × 30 lb (14 kg) bombs
Into Flight
On 23 December 1938, the prototype Roc performed its maiden flight in the hands of Blackburn test pilot H. J. Wilson. Contractor's trials were conducted at Brough after which, during March 1939, the aircraft was delivered to Aeroplane and Armament Experimental Establishment (A&AEE) at RAF Martlesham Heath for handling and armaments trials. Early modifications, such as alternative de Havilland-supplied propellers, were also evaluated. Early flight testing revealed its handling to be not only acceptable but superior to that of the Skua; while not suitable for aerobatic maneuvers, it demonstrated its steadiness in steep dives. The aircraft also demonstrated poor performance in some areas, particularly that its maximum speed was only 223 mph (194 kn; 359 km/h).
By this point, some officials had already recognised that the Roc's performance would be inadequate; during October 1938, the Fifth Sea Lord (the Chief of Naval Air Services) Alexander Ramsay issued his recommendation that the development of the Roc be abandoned. Production was allowed to continue as the project's cancellation would have caused too much disruption for Boulton Paul; plans were laid to adapt the aircraft to perform target towing and other secondary duties.
As well as its primary role as a carrier-based fighter, the Roc was also required to be capable of operating as a floatplane. A conversion kit was designed that allowed for a set of floats from a Blackburn Shark to be fitted. These floats, which was largely composed of Alclad, were fitted with pneumatically-actuated water rudders that connected directly with the aircraft's conventional braking system; the tail wheel was also replaced by a mooring ring.
During testing, the first conversion demonstrated direction instability and during December 1939, it crashed at Helensburgh Marine Aircraft Experimental Establishment where it had been transferred at the outbreak of the war. Testing continued using the other conversion, with particular effort paid to addressing its instability. While the addition of an enlarged ventral fin largely resolved the problem, the effect of the floats on the aircraft's performance was too great to be ignored, as the maximum speed had fallen to only 193 mph (168 kn; 311 km/h), thus plans to form a fighter squadron equipped with Roc floatplanes were abandoned. During 1942, the Roc floatplane was again evaluated to determine whether the aircraft could be useful as a target tug for the fleet, replacing Blackburn Shark floatplane target tugs. The Roc floatplane was rejected in this role as well, resulting in the fleet's requirements for target tugs being fulfilled by landplanes, such as the Miles Martinet, instead. By August 1940, production of the Roc had ceased and manufacturing resources were diverted to more capable aircraft such as the Fairey Fulmar and the Hawker Sea Hurricane.
Operational History
During April 1939, preparations commenced for the Roc's entry into squadron service; that same month, the fifth production aircraft was delivered to the Central Flying School to assist with personnel familiarization. Later that year, deliveries of the Roc commenced to the Skua-equipped 800 and 803 Naval Air Squadrons, with three or four Rocs supplementing the Skuas. When 803 Squadron relocated to RAF Wick in northern Scotland to provide fighter cover for the Royal Naval base at Scapa Flow in the Orkney Islands, the Rocs proved ineffective; they were described by the squadron's commanding officer as a "constant hindrance", who requested that the type be replaced by additional Skuas.
During the Allied campaign in Norway, a small contingent of Rocs traveled with 800 and 801 Naval Air Squadrons in HMS Ark Royal (By this point, 803 Squadron had abandoned its Rocs to become an all-Skua squadron). In the Norwegian theatre, they were used to carry out combat air patrols over the fleet, but were regarded as being of little use, showing inadequate performance when intercepting German aircraft.
Both Skuas and Rocs operated over the English Channel in the summer of 1940 in Operation Dynamo and Operation Aerial, the evacuations of Allied forces from Dunkirk and other French ports. What is believed to be the Roc's sole confirmed aerial victory occurred on 28 May 1940, when a patrolling Roc of 806 Naval Air Squadron, flown by pilot Midshipman A. G. Day, alongside two Skuas, intercepted five Junkers Ju 88s which were attacking a convoy off Ostend in Belgium. Flying underneath the Junkers while the Skuas attacked from above, Day's Roc destroyed one Ju 88 before returning safely to RAF Detling. On 12 June, Rocs and Skuas of 801 Naval Air Squadron strafed and dive-bombed German E-boats in Boulogne harbor, damaging several E-boats. On 20 June, Skuas and Rocs were used to bomb gun emplacements at Cap Gris Nez.
The Roc was relegated to air sea rescue and target-towing duties at various locations. The majority of aircraft were dispatched from the production line to second-line squadrons. No. 2 Anti-Aircraft Co-operation Unit at Gosport received 16 Rocs to replace its Blackburn Sharks during June 1940. The type was commonly deployed for air-sea rescue patrols, searching for the survivors of sunken ships and downed aircraft in the Channel.
On 26 September 1940, during one such patrol, Pilot Officer D. H. Clarke and his gunner, Sergeant Hunt, engaged a Heinkel He 59 seaplane, also on a rescue mission, which had fired on them first. The two aircraft exchanged fire until they reached the coast of France, where the Heinkel escaped in a damaged condition. Some Rocs were dispatched to distant locations such as Bermuda. However, the last pair of operational aircraft were withdrawn from service during June 1943. The last four Rocs stationed at HMS Daedalus in Gosport survived until late 1944, all unairworthy, with their turrets still being used for anti-aircraft defense.
Operators
United Kingdom
Royal Air Force
No. 2 Anti-Aircraft Co-operation Unit, RAF
No. 24 Squadron RAF
241 Squadron RAF
Royal Navy Fleet Air Arm
725 Naval Air Squadron
758 Naval Air Squadron
759 Naval Air Squadron
760 Naval Air Squadron
765 Naval Air Squadron
769 Naval Air Squadron
770 Naval Air Squadron
771 Naval Air Squadron
772 Naval Air Squadron
773 Naval Air Squadron
774 Naval Air Squadron
775 Naval Air Squadron
776 Naval Air Squadron
777 Naval Air Squadron
778 Naval Air Squadron
782 Naval Air Squadron
787 Naval Air Squadron
789 Naval Air Squadron
791 Naval Air Squadron
792 Naval Air Squadron
793 Naval Air Squadron
794 Naval Air Squadron
800 Naval Air Squadron
801 Naval Air Squadron
803 Naval Air Squadron
805 Naval Air Squadron
806 Naval Air Squadron
Bibliography
Brew, Alec. The Turret Fighters: Defiant and Roc. Ramsbury, Marlborough, Wiltshire, UK: Crowood Press, 2002.
Brown, Eric; William Green and Gordon Swanborough. "Blackburn Skua and Roc." Wings of the Navy, Flying Allied Carrier Aircraft of World War Two. London: Jane's Publishing Company, 1980, pp. 29–40.
Buttler, Tony (2004), British Secret Projects: Fighters & Bombers 1935-1950, Hinckley: Midland Publishing.
Green, William. War Planes of the Second World War: Volume Two Fighters. London: Macdonald, 1961.
Jackson, A.J. Blackburn Aircraft since 1909. London: Putnam, 1968.
Kinsey, Gordon. Boulton & Paul Aircraft : The History of the Companies at Norwich and Wolverhampton. Lavenham: Terence Dalton Ltd, 1992.
Lumsden, Alec and Terry Heffernan. "Probe Probare: Blackburn Skua and Roc Part Two". Aeroplane Monthly, March 1990, Vol. 18, No. 3. pp. 146–150.
Mason, Francis K. The British Fighter since 1912. Annapolis, Maryland, USA: Naval Institute Press, 1992.
Mondey, David. The Hamlyn Concise Guide to British Aircraft of World War II. London: Chancellor Press, 1994.
"Rocs on Floats". Aeromilitaria. Air-Britain, 1982, No. 1. pp. 23–26.
Stenman, Kari (July–August 2001). "From Britain to Finland: Supplies for the Winter War". Air Enthusiast. No. 94. pp. 56–59.
Sturtivant, Ray and Theo Ballance. The Squadrons of the Fleet Air Arm. Tonbridge, Kent, UK: Air Britain (Historians) Ltd, 1994.
Thetford, Owen. British Naval Aircraft since 1912. London: Putnam, Fourth edition, 1978.
Thomas, Andrew. Royal Navy Aces of World War 2. Oxford, UK: Osprey Publishing, 2007.
Willis, Matthew. "Database: The Blackburn Skua & Roc". Aeroplane, December 2007, Vol. 35, No. 12, pp. 52–69.
Willis, Matthew. Blackburn Skua and Roc. Sandomierz, Poland/Redbourn, UK: Mushroom Model Publications, 2007.
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| The prototype Blackburn Roc L3057 in May 1939. |
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| The Blackburn Roc Mark I, seaplane, L3059, parked on trestles outside the hangars at the Marine Aircraft Experimental Establishment, Felixstowe, Suffolk. This is the original L3056 which did not have a ventral fin extension. In many books and articles on the Roc, the use of floats is often presented as almost an afterthought; yet it was essential to the initial doctrine of having a catapult-launched spotter aircraft that could defend itself and also attack enemy spotters, as well as drive off enemy fleet-shadowing aircraft. (Imperial War Museum photo CH 563) |
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| Blackburn Roc Mk.I. |
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| The first Royal Navy Blackburn Roc (s/n L3057), which made its first flight on 23 December 1938. (Imperial War Museum photo MH4521) |
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| The Boulton Paul "Type A" turret fitted to the Roc. Normal entry was via sliding doors in the rear panels of the turret although entry via a hatch in the floor was also possible. |
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| Nice close-up shot of a Roc in flight. You can see the racks under the wings for both a 250 lb bomb and the "light series" rack for up to four small bombs on each wing. The large lugs protruding from the bottom of the aircraft are attachments for the launch trolley used to catapult FAA aircraft from aircraft carriers early in the war. Although it had no forward-firing guns, this Roc has a reflector gunsight for the pilot; this was also used as a sight when dive bombing and allowed fighter training with a gun camera (carried in a small pod on top of the wing on the starboard side). The protrusion at the top of the front windscreen is a signal lamp (the Skua had this positioned on top of the canopy, near the aerial). |
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| Two Rocs in formation. |
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| Blackburn Roc profile from wartime aircraft recognition manual. Note it does not show correctly the "flat bottom" area or the gunner's underside hatch. |
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| Early production Roc L3059. The Roc was a large aircraft; look how small the pilot looks in the cockpit. The two lines behind the landing light on the wing are two small strakes, a permanent feature on both the Roc and Skua; it was to these that the light bomb carriers were attached when needed. This is the first Roc to be fitted with floats. In December 1939, it crashed on test near the Blackburn factory at Brough on the river Humber. The aircraft was recovered and broken up for spare parts. |
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| Roc floatplane L3143 is rolled out of a hangar. The sheer size of the Roc is evident in this picture. Notice the undercarriage recess has been covered over but not painted. The enlarged ventral tail fin can be seen. |
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| This picture shows the large ventral tail fin used on subsequent conversions. |
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| Roc L3089, with a turret adapted for a cine camera and a modified fairing between the front cockpit and the turret. L3089 was one of the longest serving Rocs, not being retired until May 1944, although it had four major accidents during its career. |
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| Late production Roc L3186, photographed in a pristine camouflage finish. Notice the turret, stripped of guns, and the modified area between the turret and front cockpit. It lacks the "triangular" windows of the standard Roc and does not retract. This Roc was used by 771 Squadron in the Orkney Islands. It crashed with the loss of both crew members in December 1941. |
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| Diagram from AP1571A showing the interior of the Roc. Note the single fuel tank (3) and escape/access hatch in the floor (35), also the "Combined transmitter-receiver unit" (4), "Separate Receiver unit" (32) and the Morse code "Tapping key in turret" (13). Perhaps surprisingly it still has space for an Air Ministry "Fog Bell" (28); this handbell was to attract attention if the aircraft landed or crashed in a fogbound field, it has a secondary role to scare off inquisitive cattle! The cocking handles on each of the Browning machine guns were something that was dropped after the first few prototype Boulton Paul "A" type turrets (a single detachable cable loop was used instead). This indicates the diagram may be of an initial layout and not necessarily fully representative of production Rocs. |
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| Above is a photo of the single Roc fitted with the "pregnant" belly bulge to accommodate an extra fuel tank to boost range. |
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| A factory-fresh Roc (L3084) on a test flight. Note the projections under the fuselage, these are the forward pair of four fittings for attaching the catapult launch trolley. This Roc may have been fitted with floats for trials at Lee-on-Solent during 1940. The airframe survived the longest of any of the Rocs, being used as a static test rig for engines at Eastleigh until at least August 1945. |
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| Another view of Roc L3084. |
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| Nice view of Roc L3090 with type "A" roundels on both the wings and fuselage. Notice the line where the tail assembly joins the fuselage. Production of the tail assemblies of both the Skua and Roc were subcontracted to the General Aircraft Company and brought in as complete units. This Roc served with 774 Squadron in the UK. In 1942 it was shipped to Sierra Leone in West Africa for use by 777 Squadron. |
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| Rocs in flight. Note the two styles of fuselage roundels: Type B.1 on the center aircraft and Type A.1 on the other two. |
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| Blackburn Roc L3085 of 2AACU, the aircraft flown by DH "Nobby" Clarke during his encounter with a Heinkel He 59 over the Channel. Notice Clarke's "saint" insignia in a diamond on the fuselage. Standing in front of the Roc is Don Sutherland who helped service the aircraft. The photo is from the Sutherland family collection. The Roc had been delivered to 2AACU on the 16 August 1940. In April 1941, it survived a collision with a barrage balloon cable, but lost its pitot tube in the process, meaning the pilot misjudged his landing and the undercarriage collapsed. It was repaired and went on to serve in the Orkney Islands, being written off after a ditching in February 1943. |
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| Roc target tug in Egypt, probably L3086 of 775 Sqdn at Dekheila (Alexandria). |
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| Roc L3183, another target tug in Egypt. Again, used by 775 Squadron at RNAS Dekheila. |
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| Roc target Tug L3100, operating from Kindley Field on Bermuda. |
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| Blackburn Roc used as a static machine gun post. The engine has been removed and the rear fuselage is protected by sandbags. The setting is clearly Eastleigh; in high resolution, you can see details of the terraced housing with a railway line running in front of it. The distinctive roof styles match up exactly with the houses that run along the A335 Southampton Road / Wide Lane alongside the current Southampton Airport. At the time this photo was taken the Roc would have been in a field just north of Eastleigh Airfield as it was then known. The field was used as a dispersal area for aircraft (clearly shown in Luftwaffe reconnaissance photos of the period). Southampton airport has now been extended north so that the Roc's position would now be in the middle of the runway. In the background can also be seen the factory chimney of the old Pirelli Cable Works. Eastleigh was used by both RAF and Royal Navy units which explains the sailor on top of the Roc. |
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| This interesting picture shows a formation of Rocs. Note the wide difference in the type of fuselage and wing roundels. Also, note that the second aircraft has a reflector gunsight and there is a gun camera mounted in a pod near the wing root. All the aircraft carry bomb racks. It seems to have been common for the front sliding portion of the cockpit to be removed altogether (as in the fourth aircraft). The fairing aft of the turret and the section of cockpit "greenhouse" between the pilot and turret were raised and lowered automatically to allow the turret to be rotated without obstruction, hence the difference in profile between the aircraft. The wireless aerial also "bent" with the retracting greenhouse section. |
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| Another Roc with a Type B.1 roundel on the fuselage. |
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| The picture above is not of a Roc, but of the stub wings on the wheels of a Westland Lysander; however, it does show up close exactly the same type of bomb racks used on the Roc. On the right is the Light Series Carrier, able to take four light bombs, this bomb rack was also used on Skuas. On the left is the 250 lb (113 kg) rack, in this case holding a supply container. In late 1940 a number of Rocs were used alongside Lysanders by the Canadian 110 Squadron in the UK in the army co-operation role. |
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| Head-on view of a Roc without the front spinner on the propeller. This picture clearly shows the two small sections of undercarriage door which flipped out at right angles to the airflow when the undercarriage was extended. It also shows well the "flat bottom" of the Roc, you can just make out the hatch in the bottom of the aircraft for the gunner to exit. The half-black/half-white color scheme was that adopted at the start of the war to try to make friendly fighters more easily identified by the Observer Corps through binoculars at height. |
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| The dust jacket of this wartime boy's adventure story shows a Roc over an aircraft carrier. Many books on World War II aviation that mention the Roc, even Putnam's Blackburn Aircraft since 1909, mistakenly state that the Roc never made any carrier flights at all; they most certainly did, and not just training flights either, this is confirmed in the combat reports of the squadrons involved. A photo of Roc L3062 of 803 Squadron operating from HMS Ark Royal is featured on page 57 of Stuart Lloyd's book Fleet Air Arm Camouflage and Markings. To prove that Roc trainers also operated from carriers another photo on page 72 of the same book shows a Roc target tug on HMS Formidable. The combat reports of the various Fleet Air Arm Squadrons that used Rocs on operations are available via the Public Record Office at Kew. |
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| Blackburn Rocs. |
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| Second float-equipped Blackburn Roc L3057 was the first prototype originally flown on 23 December 1938. |