De Havilland Venom


The de Havilland DH 112 Venom is a British post-war single-engined jet aircraft developed and manufactured by the de Havilland Aircraft Company. Much of its design was derived from the de Havilland Vampire, the firm's first jet-powered combat aircraft.
The Venom entered service with the Royal Air Force, where it was used as a single-seat fighter-bomber and two-seat night fighter. A dedicated model for aerial reconnaissance was also operated by the Swiss Air Force. The Venom functioned as an interim stage between the first generation of British jet fighters – straight-wing aircraft powered by centrifugal flow engines such as the Gloster Meteor and the Vampire – and later swept wing, axial flow-engined combat aircraft, such as the Hawker Hunter and de Havilland Sea Vixen. Accordingly, the type had a relatively short service life in the RAF, being withdrawn from frontline operations by the service in 1962 as a result of the introduction of more capable designs. However, it was used in combat during the Suez Crisis, the Malayan Emergency, and the Aden Emergency.
The Venom proved to be popular on the export market, being sold in substantial numbers to Iraq, New Zealand, Sweden, Switzerland and Venezuela. The Swiss Air Force was the last active military operator of the Venom, retiring their last examples during 1983. Large numbers of ex-military Venoms have since been acquired by private entities and several have continued to fly, performing aerial displays at various air shows, while many examples have been preserved in static display conditions in museums and as gate guardians. A specialised derivative, the Sea Venom, was produced as a navalised version of the aircraft suitable for carrier operations.

Development

Origins

In 1948, de Havilland proposed a development of the Vampire, furnished with a thinner wing and a more powerful engine, to serve as a high altitude fighter, designated as the Vampire FB 8. The design gradually shifted, becoming the DH 112 Venom, in order to fill an Air Ministry requirement, Specification F.15/49, which sought a fast, manoeuvrable and capable fighter-bomber to replace the Royal Air Force's existing Vampires in that capacity. From the onset, the envisioned role had been intended as an interim fighter-bomber, while the development of aircraft capable of even greater performance had already been anticipated by the service.
Although generally similar in appearance to the preceding Vampire, sharing the distinctive twin-boom tail and composite wood/metal structure, the Venom was a completely new design. As originally designed, it was powered by the de Havilland Ghost 103 turbojet engine, which was capable of generating 4,850lb of thrust, considerably more powerful than the earlier de Havilland Goblin that had been used on the Vampire. The Venom adopted a wing designed with a leading edge sweepback of 17.6 degrees, a minimised thickness/chord ratio reduced from 14 per cent to 10 per cent, while the trailing edge was straight; a pair of optionally-fitted wing tip tanks were also designed to be fitted without any negative impact on the aircraft's overall combat maneuvering capability.
In order to test elements of the new design, a single Vampire F 1 was converted and outfitting with the new Ghost engine. On 2 September 1949, the first Venom prototype, VV612, performed its maiden flight at Hatfield, Hertfordshire, piloted by John Derry. In May 1950, following the end of company trials, the prototype was delivered to RAF Boscombe Down for official trials by the Aeroplane and Armament Experimental Establishment. In the course of these trials, the aircraft proved capable of satisfactory performance, including the besting of some contemporary fighters during mock combat, while some minor faults were also uncovered. On 23 May 1950, the second prototype, VV613, officially joined the development programme; it was delivered to the A&AEE for further trials on 3 April 1951.
The first six production Venom also participated in trials performed by both de Havilland and the A&AEE. On 21 April 1952, the first delivery of a production-standard Venom, a single-seat fighter-bomber, occurred to the Central Fighter Establishment, where it was used for a full service evaluation prior to the type being cleared for active service. During 1952, the initial production model entered operational service with the RAF as the Venom FB 1. A total of 375 of this initial model were constructed.

Further development

On 22 August 1950, an improved Venom, the NF.2 night fighter, performed its first flight, piloted by John Derry. de Havilland had developed it from the single seat ground attack-oriented Venom to serve as a replacement for the Vampire NF 10. For this variant, the fuselage was redesigned to accommodate a two-man crew,, seated in a side-by-side configuration, and an airborne interception radar installed in the extended nose. During late 1953, the Venom NF.2 entered squadron service, after being delayed to resolve minor problems that had been discovered. Specifically, preliminary handling trials had revealed unsatisfactory performance in poor weather conditions.
The Venom NF.2 was modified after being involved in several accidents in which pilots had difficulty making night-time approaches. Changes included the adoption of jettisonable clear canopies and alterations to the flight control surfaces, and the altered aircraft were re-designated NF.2As. The Venom NF.2 was soon followed by the NF 3, which was the ultimate night fighter variant of the Venom. It incorporated further improvements, including power-actuated ailerons and an improved air interception radar. In 1953, the Venom NF 3 performed its first flight; it entered operational service with the RAF during June 1955.
The final Venom for the RAF was the single-seat FB.4 which first flew on 29 December 1953. It entered service in 1955 and 250 were built. It was powered by a single 4,850 lbf thrust de Havilland Ghost 103 turbojet engine. It was the first Venom to be fitted with an ejector seat, as well as being furnished with redesigned tail surfaces and hydraulically-powered ailerons. The new rudder design prevented excessive yaw and eliminated incidents of rudder locking at low speeds. The FB 4 variant was the first to be compatible with the underwing fuel tanks.
The majority of the type's production was conducted by de Havilland themselves. Following the completion of an initial batch of 15 production Venoms, manufacturing was transferred from de Havilland's Hatfield facility to their larger production plant at Hawarden Airport. On 26 July 1952, the first Hawarden-built Venom was delivered to the RAF. In addition, the construction effort was augmented by numbers of Venom FB.1, FB.4 and NF.51 aircraft that were produced by Fairey Aviation at Manchester Airport. At one point, the production of further Venoms at the Bristol Aeroplane Company's Filton facility was considered but was ultimately not pursued. During the early 1950s, the prospects for Italian aircraft manufacturer Fiat Aviazione producing the type under license were explored; these did not materialise however. Due to substantial demand from the Swiss Air Force, a license production arrangement was established with a consortium of Swiss aviation manufacturers in 1953, who did produce large numbers of Venoms.

Design

The de Havilland Venom was a jet-propelled combat aircraft, featuring a distinctive twin-boom tail and composite wood/metal structure. Originally developed as a ground-attack fighter, it served as an interceptor as well. It possessed a favourable rate of climb and other positive characteristics that lent itself well to combat operations, and represented a significant advance over the preceding Vampire. It was a sound ground attack aircraft, possessing good maneuverability, steadiness, endurance, handling, and a range of compatible stores. The Venom's manoeuvrability even gave it an edge against many dogfighters of the era, although its limited top speed proved to be a weakness in this role. Early issues, such as a rear spar weakness and flash fires due to the ingestion of vented fuel by the engine air intakes under some conditions, were quickly identified and overcome.
The Venom FB 1 was armed with four nose-mounted 20 mm Hispano Mk V autocannons and could carry either two 1,000 lb bombs or eight RP-3 60 lb air-to-ground rocket projectiles – the heavier bombs being an improvement over the Vampire FB 5. For additional range, each of the wing tips could accommodate the installation of a 75gal tip tank, freeing up the underwing stores positions for other stores and munitions, these were not jettisonable during flight. When installed, the tip tanks had the effect of improving the aircraft's roll rate, which was lower than many of its contemporaries. Early production Venoms commonly suffered from weaknesses within the wing structure, leading to flight limitations and warning markings being applied to distinguish them from typical aircraft.
The Venom FB 1 was powered by a single 4,850 lbf thrust Ghost 48 Mk.1 turbojet engine; later marks were equipped with increasingly powerful models. The engine was ignited using explosive cartridges, known as Coffman engine starters; at the time, many operators were not previously familiar with such means of start up. Early production models lacked ejection seats, which was subject to official criticism; in response, later production models were furnished with them. The airframe itself had a relatively short life due to having been designed for its role as a short term interim aircraft pending development of what would become the Hawker Hunter; in Swiss service, where the type was subject to a lengthy service life, several strengthening modifications were performed to more than double its viable lifespan. It was known for its simplicity in construction and relative cost-effectiveness, which contributed to its popularity to export customers.

Operational history

In August 1952, No. 11 Squadron become the first overseas squadron to convert to the Venom in exchange for their existing Vampires inventory; No. 11 was responsible for conducting the type's operational service trials for the service. Upon their introduction to service, none of the single-seat fighter-bomber Venoms were deployed to home-based squadrons; priority was given to overseas forces, such as the Second Tactical Air Force stationed in Germany as well as those stationed in hotter climates where the benefits of the more powerful engine were most felt, such as Cyprus, the Middle East, Africa, and Asia.
During September 1952, the Venom participated in its first NATO training operation, Exercise Mainbrace. In mid-1953, a second Venom wing, consisting of Nos. 14, 98 and 118 Squadrons, was formed at RAF Fassberg, Lower Saxony; a third wing, comprising No.s 16, 94, and 145 Squadrons, was also formed at RAF Celle, Lower Saxony, during the following year. In this capacity, the Venom was only operated for a short time, those squadrons stationed at RAF Faßberg transitioned to the Hawker Hunter in 1955, while those at RAF Celle were disbanded in 1957.
Throughout the mid-1950s, Venoms were dispatched to the furthest corners of the British Empire, being typically used to replace the Vampire in the fighter-bomber role. In August 1955, a flight of four Venoms conducted a 10,000 flight from RAF Habbaniya, Iraq to Wingfield Aerodrome, South Africa and back; while on the return leg of this journey, a speed record was set on the Cape Town-Pretoria route, covering the 807-mile distance in 1 hour 23 minutes.
On 6 May 1953, the first of the Venom night fighters was delivered to the RAF. From 1955 onwards, an improved model of the night fighter, the Venom NF.3, was introduced to squadron service. However, the night fighter Venom had only a relatively brief career with the RAF, having been procured to serve as an interim solution while more capable designs were developed. Accordingly, in 1957, the RAF's night fighter Venoms began to be withdrawn in favour of the newly introduced Gloster Javelin twin-engined all-weather fighter. In the night fighter role, the Venom was also adopted by export customers; the Swedish Air Force adopted the type as their principal night fighter in 1955 and operated three squadrons in this capacity.
RAF Venoms saw action during the Malayan Emergency, which took place between 1948 and 1960, although these aircraft did not commence operations until the mid-1950s with Nos. 45 and 60 Squadrons. While there, the Venom supported counterinsurgency operations against Communist guerrillas as part of Operation Firedog, the codename for RAF operations in Malaya. By 15 November 1957, the day on which the Venom was withdrawn from combat in the theatre, the type had conducted more than 300 strikes against guerillas. Several Venoms were lent to the Royal New Zealand Air Force for use during the same conflict, being operated by No. 14 Squadron RNZAF.
display team in formation over Interlaken, Bern, 1983
The Venom also saw combat service during the Suez Crisis during late 1956. The type was operated by Nos. 6, 8 and 249 Squadrons, flying from RAF Akrotiri, Cyprus. The Anglo-French invasion, codenamed Operation Musketeer, took place in response to the nationalisation of the Suez Canal by Egypt's leader, General Nasser. The air war began on 31 October 1956. The Venoms attacked a variety of military installations on the ground; only a single RAF Venom was lost throughout the crisis.
From 1956 onwards, Middle Eastern-based RAF squadrons progressively received the improved Venom FB 4. Starting in 1956, RAF Venoms were deployed during the Aden Emergency, where they were used in support of counterinsurgency operations against terrorists and rebel tribesmen in Aden and Oman. in Oman In 1957, British RAF Venoms participated heavily during Jebel Akhdar War in Oman to expand the territory of the Sultanate, which was a de facto British colony, in order to gain access to oil wells in the interior parts of Oman. The RAF made 1,635 raids, dropping 1,094 tons and firing 900 rockets at the interior of Oman between July and December 1958 targeting insurgents, mountain top villages, water channels and crops in a war that remained under low profile. As the conflict progressed, squadrons equipped with the Venom were reequipped, mainly by the English Electric Canberra; in 1960, the final squadron in the region that used the type was reequipped with the Hawker Hunter. Venoms additionally saw service during the Mau Mau insurgency in Kenya.
Outside of the RAF, the Swiss Air Force were the most prolific user of the Venom. In addition to the domestic production of 136 ground attack-orientated models and its Ghost engine to power them, Switzerland also produced a dedicated aerial reconnaissance variant of the aircraft, which were outfitted with specially modified underwing fuel tanks that had automated cameras installed in the forward section. Swiss Venoms were also subject to multiple improvement and upgrade programmes, including life extension modifications, the addition of ultra high frequency radio sets, and an improved license-built bombsight.
In 1962, all of the remaining Venoms in RAF service were withdrawn from first-line duties, having proven their worth in a variety of locations across the world, in peace and war, and in some of the most difficult climates the RAF has ever faced. The last non-RAF Venoms to leave active service were the aircraft in service with the Swiss Air Force, the last of which being retired from combat duties during the latter part of 1983. About 10–20 Venoms continue to fly as of 2017, performing at various air shows, while a number of examples are preserved in museums in the United Kingdom and abroad, in non-flying, static display condition.

Variants

;DH.112 Prototypes
;FB.1
;NF.2
;NF.2A
;NF.3
;FB.4
;FB.50
;NF.51
;Fiat G.80

Operators

The Venom has been preserved in significant numbers, mainly due to its longevity with the Swiss Air Force. In the UK, a number of Sea Venoms are preserved, along with examples of the NF 3 and Swiss-built FB.50 and 54. In Sweden, two examples of the NF.51 are preserved. There are many survivors in Switzerland, and other Swiss aircraft are scattered throughout Europe. One such aircraft is preserved in the Israeli Air Force Museum in Hatzerim, although in the colours of the Iraqi Air Force. In Australia, a number of Sea Venom FAW.53s have also survived. Venezuela has the only complete surviving British-built single-seat Venom.
Polish Aviation Museum has British-built Sea Venom, which was used for experiments at de Havilland and Aeroplane and Armament Experimental Establishment, and then was transferred to Imperial War Museum, which sold it to PAL in 2013.
Although the Venom was, for a time, a popular and cheap warbird the number of airworthy aircraft is dwindling. Currently there are two in the UK that fly regularly, along with a single example in Switzerland, that flew from 1988 until 2011, when it went to New Zealand. World Heritage Air Museum fleet owns 1 Venom and operated an additional Venom. N747J crashed on 20 July 2018, while preparing for the EAA AirVenture Show, killing the pilot, World Heritage Aviation Museum co-founder, Martin J. Tibbits. All are licence-built Swiss examples.

Specifications (Venom FB 1)

Citations