09 February 2007

Flightdeck Friday - Fleet Air Arm Edition: Hawker Sea Hawk

Hawker Sea Hawk F.Mk.1-6

It may (but really shouldn’t) surprise some readers that the Royal Navy once boasted an air arm of flattops with airwings similar in composition to those of the US (mix of fighters, attack, ASW and of course, AEW) which saw action in various corners of the world. Alas, that heritage is receding rapidly in the mists of time and if current trends continue, the fate of even the new construction CVs appears to be in jeopardy.

Still, there is a rich tradition in the Fleet Air Arm (FAA) to be celebrated and we will endeavor to give it the recognition it is properly due. Presented today, for example, is one particularly long-lived example, the Hawker Sea Hawk.

The Sea Hawk traces its origins to the P.1040 which was developed as an interceptor for the RAF. The early days of jet aircraft design were heady ones, with many different configurations tested and discarded (ed: for one example in the US, check out the Vought Pirate – a previous Flightdeck Friday subject). The P.1040 was right in line with this philosophy, despite its seeming conventional layout as viewed today.

Beginning with a Hawker Sea Fury, modifications were made to the nose, cockpit and tail. A Rolls-Royce B.41 centrifugal flow get engine was mounted in the fuselage with intakes in the wing roots and a long tailpipe for the exhaust. Re-thinking the design, the Hawker engineers split the exhaust and routed it back to the aft wing roots. The advantage of this was two-fold – the shorter exhaust ducts ensured less loss of thrust than what a single, long tailpipe would provide. In those days, thrust was a precious commodity with the early jet engines – the B.41 produced in the neighborhood of 5,000 lb static thrust. Look closely – if it seems familiar, that’s because Pratt & Whitney license built the B.41 as the J42, powering the F9F Panther. It also made an appearance on the other side of the Iron Curtain as a reverse-engineered model in the MiG-15.

The second advantage of splitting the exhausts came in the form of keeping the aircraft balanced. The engine was located at the aircrafts center of gravity and with intakes/exhausts in the wing roots; internal fuel storage was made available in fuselage, forward and aft of the engine. With a solid nose, there was ample room for four 20 mm cannon and their rounds.

The RAF, however, passed on the design as it was deemed little advanced over the Gloster Meteor and the de Havilland Vampire. Not dissuaded, Hawker proposed a sea-based variant to the Admiralty in January 1946. Three prototypes were ordered with first flight coming on 2 Sept 1947 of a non-navalised prototype and the first navalised version flying a year later on 3 Sep 1948. The layout was similar to the P.1040 but, of course, with concessions to the naval environment, not the least of which was the addition of a tailhook and folding wings. Unlike the first jet to enter FAA service, the Supermarine Attacker, the Sea Hawk utilized tri-cycle gear which would prove very beneficial when flying around the ship. The third and final prototype flew on 17 Oct 1949 and incorporated additional improvements, drop tanks being the chief item.

The first production aircraft, a Sea Hawk F.Mk.1 part of a 151 aircraft buy, flew on 14 Nov 1951. With the other projects Hawker was engaged, production after the first 35 units was shifted to Sir W. G. Armstrong Whitworth Aircraft for the balance of the first batch and all of a second run of F.Mk.2 variants. During production, continued improvements were made to the Sea Hawk, including a stiffened wing and the addition of boosted ailerons. That in turn, led to a third run of what was now a fighter-bomber, the F.B.Mk.3. The Mk.3 was able to carry 2 x 500 lb bombs or 2 x 90 Imp gallon fuel tanks. The Mk.4’s added another hard point on each wing, permitting the carriage of up to 4 x 500 lb bombs, or 2 x 500 lb bombs and twenty 60-lb rockets. The final, definitive version of the Sea Hawk was the F.G.A. Mk. 6 (ground-attack). Incorporating the more powerful Nene 103 (rated at 5400 lb s.t.). Eighty-six of this variant were manufactured for the Royal Navy through 1956, when the production line was finally shut down and dismantled.

Performance of the Mk.6 was about typical for a straight wing jet of the period – 587 kts/Mach .83 @ 20K ft, a climb rate of 5,700 fpm with time to 35,000 ft at about 11 minutes. Service ceiling was 44,500 ft and combat radius (w/2 drops and 2 x 500 lb bombs) of 288 nm. Thrust to weight was on the order of 0.38. To put this in perspective, consider the F9F-5 Panther, the definitive variant of that model which evolved at about the same time and also morphed into an attack role. The -5 was powered by the J48 which produced 7,000 lb st. Max speed for the Panther was 600 kts; service ceiling was 42,800 ft with a climb rate of 6,000 fpm. Range was 1300 nm and armament consisted of 4 x 20mm internal cannon and a variety of bombs and rockets that could be carried on 8 external wing stores.

Foreign Service

The Sea Hawk saw naval service with India, onboard the Vikrant and with the Netherlands aboard the Karel Doorman. Yes, the Netherlands had a carrier. When the Doorman was sold to Argentina (as the Veinticinco de Mayo). The Sea Hawk also saw service ashore with the Federal German Marineflieger der Bundeswehr as an all weather attack aircraft.

Combat action

The Mk.6 saw combat with the FAA and Indian Navy. The most notable actions in each case were the Suez Canal Crisis and the Indo-Pakistani wars of 1965 and 1970. Six Sea Hawk squadrons, embarked in HMS Eagle (2), HMS Albion (2) and HMS Bulwark (2) took part in strikes against Egyptian. Used primarily in the ground attack mode, the Sea Hawk destroyed numerous Egyptian targets, performing exceptionally well by all accounts. Jumping into the next decade, the Sea Hawk again distinguished itself – first in the 1965 war between Pakistan and India operating from shore bases and again in 1970 from the Vikrant.

On the day of the Pakistani attacks against Indian airfields that started the war, India's carrier, the INS Vikrant, had one boiler out of action which reduced her speed and maneuverability. Despite this and an attempted submarine attack she sailed for the major Pakistani port of Chittagong. On 4 Dec 71, Sea Hawks from the Vikrant attacked Cox's Bazaar and Chittagong. Further attacks against other nearby harbors followed the next day, then Chittagong was attacked once more. Suffering no losses, the Sea Hawks left a scene of devastation with the Pakistani port and its nearby airfield in shambles.

An interesting sea story and record is found with the Sea Hawk at center and still with the Indian Navy. Five years after the Indo-Pakistani war, the Sea Hawk was still in service and on 4 Mar 76, Cdr. Peter Debras, IN, suffered a catapult failure while launching from Vikrant. The aircraft ditched in the sea ahead of the carrier and sank. Unable to stop or turn, the carrier passed over the sinking aircraft and Cdr. Debras waited in his seat until the carrier had passed before ejecting. He survived and set a world record for the deepest underwater ejection. The ageing Sea Hawks continued to serve until the early 1980s, when they were finally replaced by Sea Harriers.

The Sea Hawk had a long, noteworthy career, if not one overshadowed by more prominent aircraft. The long service, including frontline service in foreign navies is exceptional, especially compared to the shorter life of its contemporaries and others that followed. It’s clean, elegant design would provide the basis and inspiration for other hawker aircraft to follow, most notably the Hawker Hunter.


Green, William. The World's Fighting Planes (1965)

Indian Navy Gallery

Wikipedia: Sea Hawk, Suez Crisis, RN Carrier entries