English Electric / BAC Lightning Interceptor
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.