English Electric / BAC Lightning Single-Seat Jet-Powered Interceptor Aircraft
The English Electric Lightning remains the only Mach 2-capable jet-powered fighter to emerge solely from Britain.
Authored By Staff Writer; Content ©www.MilitaryFactory.com
The English Electric Lightning was an impressive engineering feat for the British people. She was the first (and only) Mach 2-capable platform ever developed for the island nation and itself the fastest British fighter of all time, the last aircraft to be designed solely by a British aviation firm, the first aircraft to be designed with direct pilot input, the first aircraft to utilize "supercruise" (reaching supersonic flight without the use of afterburner) and the first Royal Air Force platform to feature an integrated weapons system for automated missile delivery. At the time of her inception, the Lightning formed a potent deterrent to Soviet bomber incursions in the region and gave the RAF a potent intercepting arm. One of the most high-performance fighters of the Cold War, the English Electric Lightning went on to find a special place in the hearts of those who flew her and in the admirers of the type all over the world.
In post-war Europe, the victors were quite surprised to find the advanced levels of German turbojet and wind tunnel technology and were quick to recover such data whenever possible. The British were already on the cutting edge of jet technology and began fielding the Gloster Meteor by war's end. This straight-winged, twin-engine platform undoubtedly would have faced off against the German Messerschmitt swept-wing, twin-engine system should the war had progressed beyond 1945. As it was, the air-to-air match would never occur but forays into jet development would continue nonetheless. The Americans and the Soviets each took to evaluating, re-engineering and attempting similar designs following the German research trail. The British, on the other hand, already held sound concepts into high-speed flight but only had one successful design to show for their efforts. German research was advanced enough to be looking into more powerful engines mated to swept-wing designs.
While the Gloster Meteor itself was a relatively successful design, it met with inherent limitations. Other firms tried and succeeded modestly in their attempts with the de Havilland company providing the twin-boom Vampire and the Venom, Supermarine unveiling their Swift jet fighter with swept wings and Hawker jumping into the fray with their fabulous swept-wing Hunter. Of these, the Hawker Hunter was a true success and proved a winning design in many ways. Unfortunately for the changing times, the Hunter was not a speedster as even the hefty ceiling of Mach 1 eluded the airframe except when diving even when utilizing full afterburn. While this collection of British jet fighters essentially represented her protection from Soviet bombers, the arrival of the English Electric Canberra soon wrote all preceding British fighter forms out of applicable contention.
The English Electric Canberra was a "do-everything" straight-wing, twin-engine, jet-powered light bomber sporting a smooth fuselage and conventional empennage. What was most impressive about the type was its high operational ceiling - maxing out at approximately 50,000 feet. This sort of performance within Britain's own ranks left an unsettled feeling about her very own defense against such systems being created in the Soviet Union. While the Canberra went on to serve in a plethora of national inventories and see service for over 55 years, it presented Britain with an internal dilemma and showcased a deficiency that needed to be dealt with in the most serious of ways.
English Electric Chief Designer W.E.W. Petter was already on to something. Knowing the capabilities inherent in his company's own product, he began penciling ideas for a twin-engine, swept-wing interceptor as early as 1946. Petters vision saw an aircraft with 60-degree wing sweep and two engines, one mounted atop the other to reduce frontal drag. With a forward-thinking approach, Petter included provision for cannons and weapon systems should the type ever be accepted into production. A study contract for a transonic research aircraft was awarded by the Ministry of Supply under the designation of ER.103 to English Electric in 1947. This study intended to delve into the world of transonic flight and low supersonic speeds and handling. As the English Electric design proved a first of its kind for Britain, a transonic wind tunnel had to be constructed to take on the evaluation process. This wind tunnel became the first o fits kind to be constructed outside of the United States. By 1950, the contract agreement produced two whole prototypes as well as a static test airframe.
In 1948, Wing Commander R.P. Beamont was sent to the United States and got a chance to fly an early-form North American F-86 Sabre. His experiences in the American product - a single-engine, swept-wing fighter capable of Mach 1 - unveiled a world of possibilities for the future of jet-powered warfare. Upon his return, Beamont met with English Electric engineers to review his experiences in the American fighter and the foundation of the Lightning was now taking shape.
Short Brothers was enlisted through another contract to test out various sweep wing and tailplane configurations and the validity of the Petter design as many personnel in official levels were skeptical of the radical approach. This test aircraft was appropriately designated as the SB.5 and was purposely designed to carry out various speed tests utilizing differing wing sweeps and tail positions. The airframe featured a nose-mounted intake with sloping nose assembly, swept-back wings and a "T-style tail arrangement - this tail arrangement being of particular popularity in early Cold War designs and a preferred element of the Royal Aircraft Establishment (RAE). Under sponsorship of the RAE, the small-scale SB.5 took to the air in December of 1952. Tests were mixed as the airframe proved difficult to fly. As such, the tail arrangement was modified to the English Electric suggestion featuring a low-mounted tail plane. The SB.5 in this revised form flew extremely well and now proved Wetter's design an excellent concept.
Unfortunately for English Electric, Wetter departed the company to pursue other interests at another aviation firm. Frederick Page took his place in the Lightning's development process and soon began work on a full-scale product. The powerplant of choice became two Armstrong Siddeley Sapphire ASSa5s engines of 8,100lbs thrust output without afterburner. The design was of a utilitarian look, with a curved fuselage, rounded-triangular air intake in the nose, mid-mounted monoplane wings with sweep, a smallish vertical tail fin and low-mounted tail planes. On July 24th, 1954, the now-designated P.1 prototype took to the skies in limited flight to successfully test out the controls and applicable trim response. Another test flight two days later yielded similarly successful results. The first "true" flight of the P.1 was conducted by Beaumont on August 4th, 1954, reaching a top speed of Mach 0.85. The flight allowed the airframe to effectively "stretch her legs" and work out any inherent design kinks. A follow-up flight on August 11th, 1954, saw the girl hit speeds of Mach 0.98, even reaching past Mach 1.0 for a short time (this without the benefits of an afterburning powerplant). On another flight, again two days later, the P.1 officially broke the sound barrier and maintained level flight above Mach 1.0 (Mach 1.08 was the official reporting speed, becoming the first British-built aircraft to accomplish this feat). A basic afterburning system was integrated into the design with much anticipation and Mach 1.5 was later reached - though at this speed the aircraft began to suffer from some stability issues - enough to proposed a new design.
The new design became the P.1B prototype - now officially designated as the "Lightning" - and appeared in three prototype forms in 1954. While the P.1 and P.1A were designed as "research" aircraft, the P.1B was more in line with a production-type end-product. Powerplant selection changed to the Rolls-Royce Avons RA24R Mk210 series engines of 11,250lb thrust dry output and capable of 14,350lbs of thrust with afterburner. A shock cone was inserted into the intake opening to house a simplified version of a radar system. The shock cone was positioned as such that air was still allowed into the nose-mounted intake while the cockpit was raised some to allowed for the new addition and better pilot visibility.
Once again in the wind tunnel, prototypes of the P.1B showcased excellent stability and performance with evaluations placing the top speed past the Mach 2.0 mark. Test pilot Beaumont took to the skies once more, this time in a P.1B and netted a top speed of Mach 1.2 on April 4th, 1957. In 1958, he hit Mach 2.0, becoming the first British aircraft to do so. So impressive were the refinements in design that fifty examples of the aircraft were put on order constituting 20 pre-production systems and a further 30 as full-fledged production F.Mk 1 fighters.
In an interesting turn of events in 1957, the Minister of Defense - one Duncan Sandys - proposed the policy of an all-missile defense approach to meet the threats of future warfare through his White Defense Paper. As such, several key aircraft products were placed on the chopping block and axed into history. Chief among these was an Avro supersonic bomber and the Fairey Delta 2 supersonic fighter. While the Lightning program could have been added to the list, it was deemed that the program had excelled beyond the point of return and was spared. Should Sandys vision had come to fruition, the Lightning would have become the last manned fighter aircraft to be produced by the United Kingdom. As reason would have it, this did not turn out to be the case.
The twenty pre-production models were finished by September of 1959 and were differentiated by their P.1B prototype brethren by use of a revised vertical tail fin to compensate in the aerodynamic changes brought about by the inclusion of the Firestreak missiles allocated to the lower forward fuselage. Production F.Mk 1Lightnings went airborne for the first time on October 29th, 1959. Deliveries began in December of 1959 and the system finally reached her first air group on June 29th, 1960, delivered to No.74 Squadron of the Royal Air Force based at Coltishall. No.74 Squadron became the sole operator of the F.Mk 1 production model.
Production Lightnings showcased a fuselage that maintained a clean and oblong form throughout, covered almost exclusively in a bare silver finish. Wings were highly-swept, mid-mounted monoplane assemblies originating just behind the cockpit and pas the mid-way point of the fuselage. The cockpit was maintained well-forward in the design and seated fairly high, offering up good vision for the pilot from all angles. The instrument panel of the original P.1 model was relatively cluster-free but this changed to a high degree by the time of the F.Mk 6 model. The pilot sat in a glazed cockpit consisting of a main piece and the three-paneled front windscreen. The nose was fitted with a cone protruding from the intake opening, giving the Lightning yet another defining characteristic.
The empennage featured a noticeably sharp and relatively small-area vertical fin while the tail plane - also sporting high-sweep - was fitted low on the rear fuselage. Airbrakes were assigned placement above and forward of the tail panes and forward/under the vertical tail fin. One of the most distinguishing design elements of the Lightning became its signature stacked engines which was more pronounced when viewing the aircraft from the rear. Another key feature became the bulging ventral fuel tank added in evolving Lightning forms. The undercarriage was a conventional arrangement featuring two main single-wheeled landing gears and a single-wheeled nose gear. While the nose gear retracted forward into the nose, the main gears retracted outboard into each respective wing. The later addition of an in-flight refueling probe saw the system fitted to the underwing portside. The nose-mounted shock cone fitted within the intake opening housed the radar system. The flight control system was purely hydraulically powered and assisted through cross-coupling in the event of failure. Systems controlled the tailplane, rudder, flaps and the ailerons which were essentially mounted on what would be the aircraft's wingtips. In all, the Lightning showcased a Cold War (albeit decidedly British) beauty about it that was lacking in many of the other world attempts at the time.
Power for the last production Lightning - the F.Mk 6 model - was derived from a pair of Rolls-Royce Avon 301R series afterburning engines able to produce 13,220lbf on dry thrust and up to 16,360lbf on full afterburner. Maximum speed was recorded at an impressive Mach 2.27 (roughly 1,500 miles per hour). While range was always a deficiency in the fuel-hungry Lightning series, the aircraft still managed a distance of 800 miles with a ferry range of up to 1,560 miles. Rate-of-climb was an astounding 50,000 feet per minute - a feat well ahead of her contemporaries and a value seldom achieved by even the most modern of fighter developments.
Armament was, in many ways, a limitation for the entire Lightning series. Considering the type was designed from the outset as an interceptor, this was a somewhat acceptable drawback. 2 x 30mm ADEN cannons were standard fare for most of the Lightning's productive years. Six hardpoints were afforded the system but two of these were most often times used for "overwing" fuel tanks. An additional two were fitted to the forward portion of the fuselage and restricted to air-to-air missile placement. Two underwing hardpoints could fit air-to-air armament as well but could also make use of unguided rockets in their place. Other Lightning forms could sport a limited array of conventional drop bombs as well as additional underwing fuel tanks. Reconnaissance Lightnings made use of a ventral camera pack fitting 5 x Vinteen 360 70mm cameras. Air-to-air missile armament began initially with the de Havilland Blue Jay infra-red homing missiles with these becoming the Firestreak, but this later graduated up to the Hawker Siddeley Red Top missiles.
The Lightning appeared in a handful of varied forms that constituted a single-seat fighter and two-seat trainer model. The P.1A represented the initial prototypes of which two were produced along with a static test airframe. The P.1B became three operational prototypes that led to at least 20 pre-production Lightnings. Fighters were all identified by the use of "F" in their designations.
The F.Mk 1 was the first single-seat production Lightning fighter. Deliveries began in 1960 and became 19 production examples in all. A single example was again delivered as a static test airframe for further evaluation. Power was derived from twin Rolls-Royce Avon 200R-series engines. VHF radio was included as were 2 x standard 30mm ADEN cannons in the nose for close-in work. Additional armament became a pair of Firestreak air-to-air missiles while radar control was provided for by a Ferranti-brand AI-23 AIRPASS radar system. As Fighter Command realized the value of the system it had just purchased, the types classification was now updated from "short-range day fighter" to "night/all-weather fighter".
The F.Mk 1A came next and the aircraft line was now produced under the British Aircraft Corporation (BAC) label. While again being produced as a single-seat fighter, this Lightning featured a pair of Avon 210R-series engines as well as an in-flight refueling probe to compensate for the types inherent short range (45 minutes of flight time in the F.Mk 1 model). UHF radio now replaced the original VHF unit and internal electrical systems were addressed. Production saw 24 (some sources state 28) F.Mk 1A's examples delivered first to No.56 Squadron in December 1960 and in No.111 Squadron in 1961. Ultimately, this longer-ranged Lightning model was fielded in Germany, Cyprus and Malta.
The F.Mk 2 appeared as an improved F.Mk 1 production model. These new models sported improved electronics, steerable nose wheel, liquid-oxygen breathing system, improved avionics with autopilot and a variable afterburning system as opposed to the original's four stage approach. This single-seat fighter first flew on July 11th, 1961 and saw 44 production examples delivered beginning in November of 1962. No.19 Squadron was the first to receive the type followed by No.92 in April of 1963.
The F.Mk 2A followed shortly thereafter and fitted two Avon 211R engines. The 30mm ADEN cannon armament could be supplemented with another two cannons via a ventral gun pack. The ventral fuel tank was also increased in size as was the vertical fin surface area with square cut edges. The main wings were designed with a cambered leading edge. Thirty-one F.Mk 2 models were converted up to the F.Mk 2A standard. Many Lightning pilots have referred to this mark as the best of the Lightning series.
The F.Mk 3 model - another single-seater development - featured an improved AI-23B radar system, liquid-oxygen breathing system, advanced AIRPASS system and "overwing" fuel tanks. Power was derived from 2 x Avon 301R series engines with 13,500lb thrust dry and 16,360lb thrust afterburning output. All 30mm ADEN cannon systems were removed while the Firestreak missile was dropped in the favor of the more advanced Red Top missile. Red Top missiles offered all-aspect engagement with limited head-on qualities over the tail-chasing Firestreaks. The inclusion of the larger Red Tops also forced a revision of the vertical tailfin aerodynamics by the addition of greater surface area and squared-off top edge. At least 62 (some sources state 70) F.Mk 3 models were produced and formed the mounts of Nos.23, 29, 56, 74 and 111 Squadrons.
The F.Mk 3A was of a similar design but with improved range thanks to an enlarged ventral tank and cambered wings. The F.Mk 3A was essentially tied to the development of the upcoming F.Mk 6 - the definitive Lightning. Sixteen F.Mk 3A models appeared at the end of the F.Mk 3 model production.
Minister of Defense Duncan Sandys initiative of 1957 to cancel or curtail the development of manned fighters was finally overturned. As such, funding became available to develop and further new and existing systems to their fullest potential. Once such system was the Lightning in which its engineers now took to bettering the platform for increased performance, range and lethality. The new revised design took to add new wings with cambered leading edges, an increased fuel capacity and the re-integration of the twin 30mm ADEN cannons into a ventral gun station as part of the enlarged ventral fuel tank. The F.Mk 6 became the final production Lightning and was essentially based on the F.Mk 3 - and for a time was referred to as the F.Mk 3A - model featuring better range (now up to an impressive 2 hours of unrefueled flight time) the new wing design including those changes and additions as made between the F.Mk 2 and F.Mk 2A production models. Surprisingly enough, these changes led to little-or-no penalty in overall performance. A total of 39 F.Mk 6 production models appeared. Nine conversions were brought about from existing F.Mk 3 models (known as F.Mk 6(interim) and having no provisions for the overwing fuel tanks or the new AI-23S radar system) and a further 15 conversions appeared from existing F.Mk 3A models. First flight of the F.Mk 6 was achieved on June 16th, 1965. No.5 Squadron became the first happy recipient of the revised F.Mk 6 later that year while full production F.Mk 6 models reached No.74 Squadron in August of 1966. The F.Mk 6 went on to serve with Nos. 11, 23 and 56 Squadrons as well.
Lightning trainer aircraft were also supplied. Trainers were identified by their side-by-side cockpit seating for student and trainer alike complete with dual controls. Trainer versions were built by English Electric out of necessity for original training of Lightning pilots was accomplished by using Hawker Hunter two-seat aircraft with an experienced Lightning pilot as the instructor. Outwardly, these systems maintained their Lightning qualities and - despite the revision of the cockpit - trainer Lightnings retained their awesome performance specifications. Trainer versions could also be modified back to their single-seat combat-ready forms if need be. Trainers were identified by the use of "T" in their designations.
The T.Mk 4 was based on the F.Mk 1A production fighter but fitting a second instructors cockpit in a side-by-side arrangement with dual controls. Two prototypes appeared initially followed by 18 (some sources state 20) production examples. The first prototype crashed into the Irish Sea during a test flight due to a collapsed vertical fin. The second prototype fared better and completed the test program.
Two T.Mk 4 trainers eventually served as conversion prototypes for the development of the improved T.Mk 5 trainer. The T.Mk 5 first flew on July 17th, 1964 and was based on the F.Mk 3 production fighter. T.Mk 5's were delivered to the 226 OCU to which 22 total examples were ultimately constructed.
A dedicated high-altitude version known as the P.8 was considered to fulfill Specification F.155T. This model featured a revised canopy and wingtip mounts for air-to-air missiles but this specialized Lightning form was eventually dropped. Additionally, the Lightning was considered in a dedicated Royal Navy role complete with arrestor hook, revised undercarriage, folding wings and a folding vertical tail fin.
Operationally, the Lightning was given a powerful ability via its radar to scan the forward horizon above and below. The aircraft could automatically take itself within missile range of its intended target and let loose its missile armament with little action required on the part of the pilot. This evolved RAF fighter aircraft from being "cannon-only" platforms to fully-integrated weapons delivery platforms from here on out. The major crutch of the series was always its limited capacity of fuel limiting its effective operational range during the series entire reign. As such, subsequent designs found newer ways to increase the types endurance through more onboard fuel and in-flight refueling but the drawback was never fully conquered. Additionally, armament was severely limited by the few hardpoints the Lightning maintained. Despite this, the Lightning showcased performance specs that few aircraft of the time would ever top - making up for its deficiencies through sheer power, speed and ability.
The RAF interceptor force was eventually replaced by ex-Royal Navy McDonnell Douglas F-4 Phantoms while German-based RAF Lightnings were superseded by the SEPECAT Jaguar. Likewise, mainland Lightning interceptor groups were re-stocked with the new Panavia Tornado F.Mk 3. All of these aircraft brought with them better range specifications as well as better armament loads over that of the Lightning. The Jaguar and the Tornado in particular allowed for strike fighters qualities with air-to-air capabilities making them true multirole performers when compared to the Lightning. The last Lightning squadrons were disbanded in 1988 with many being turned over for scrap.
In its time aloft, the Lightning was credited with only a single air-to-air kill - this being a "runaway" Harrier. The Harrier pilot had successfully ejected but his aircraft continued on course. A Lightning was sent to intercept and destroy the aircraft to which it did.
Foreign orders were in short supply for the Lightning production line. Main export customers were Kuwait and Saudi Arabia. The F.Mk 52 were ex-Royal Air Force Lightnings converted for use by Saudi Arabia. The F.Mk 53 was utilized by both Kuwait (as the F.Mk 53K) and Saudi Arabia. These featured provisions for drop bombs and unguided rockets launched from rocket pods. This model was based on the production F.Mk 6.
Essentially, export Lightning weapon options covered three arrangements. The first being two 30mm ADEN cannons in a center underfuselage position, two drop bombs held underwing and two rocket packs in forward fuselage mounts. The second replaced the underwing bombs with rocket pods while retaining the twin 30mm ADEN cannons and rocket packs. The third option was an interceptor utilized the twin 30mm ADEN cannons, forward rocket packs and made room for two Red Top missiles along the fuselage sides.
The Kuwait Air Force operated up to 12 of the F53K fighter models as well as a pair of T55K trainer forms from 1968 through 1977. A potential deal with Nicaragua fell through when it was deemed that the country lacked the internal logistics to accept (capable unloading docks) and operate the type (airfields were small).
The T.Mk 54 and T.Mk 55 were export trainers of the T.Mk 4 and T.Mk 5 trainers respectively. The T.Mk 54 was utilized exclusively by Saudi Arabia while the T.Mk 55 was used by Kuwait (as the T.Mk 55K) and Saudi Arabia. Saudi Arabia became the second largest Lightning operator behind the United Kingdom with her Royal Saudi Air Force use of the F52, F53 and T55 Lightnings. Saudi Lightnings made up three operational frontline squadrons between 1967 and 1986 and were used against Yenemi border insurgents. While Saudi Arabia held a good opinion of their Lightnings, Kuwait found the aircraft to be too expensive to maintain in the long run.
The United Kingdom fielded the Lightning from 1959 through 1988. At least 12 operational frontline squadrons were delivered the type while two more conversion squadrons were also formed. The Lightning also served with the Tiger and Firebird aerial display teams of the Royal Air Force. Civilian operators have since popped up in the United States and South Africa - allowing passengers to experience the ride of their life for a price. At the end of their production run, total Lightnings amounted to 337 examples made up of all prototypes, 277 fighters and 52 trainers.