Heinemann’s Rocket

Though Douglas had been chosen as the manufacturer to replace the Skyraider in the form of the XA2D-1 Skyshark, this aircraft was experiencing severe engine development problems which eventually were the cause of its cancellation and demise.

In the early fifties, the designers at Douglas had evinced concern at the growing complexities and costs of high-performance jet aircraft. Detailed studies conducted by the company revealed that to reduce costs as well as complexities, a resultant reduction in weight was needed to meet any performance criteria.

The findings of these studies were eventually pooled into the design of a new lightweight, low-cost fighter, this in turn being submitted to the US Navy. They were suitably impressed by this ‘paper aeroplane’ but their interest was in the direction of rather a new attack aeroplane than a new fighter. In turn, Douglas was encouraged to investigate the feasibility of developing their concept into a new shipboard attack aircraft to replace the Skyraider and the missions it fulfilled so admirably, but with the added performance of a jet.

A design team was therefore commissioned with the task of developing the design studies to the navy requirements which envisaged a maximum speed of 500 mph (800 km/h), a radius of action of 460 miles (736 km) and a total gross weight of 30 000 lbs (13 605 kg).

At the head of this design team was the chief engineer of Douglas’ El Segundo Division, Edward H. Heinemann. After only six months of redevelopment and alteration, the design team presented the Navy with a mock-up that bettered the stated requirements in every important factor. It was 90 knots faster, had an increased range of 100 nautical miles and, most importantly, weighed less than half of the specified 30,000 lbs gross weight. By February 1952, the first full-scale mock-up was ready for inspection by the Navy Board. ,

Following additional alterations as a result of the board’s inspection, a contract was signed on 12 June 1952 covering 20 aircraft with the designation A4D-1, these would be used in evaluation tests prior to service entry.

The navy contract specified that the A4D·1 was to be ‘a lightweight, high performance, single-engine, day attack land plane capable of performing dive-bombing, interdiction, and close support missions.’ It was also envisaged to be capable of delivering conventional weapons as well as ‘special’ weapons, i.e. nuclear, on both land and sea targets with or without fighter escort and regardless of the local air threat.

Construction of the first prototype XA4D·1 (Bu Aer No. 137812) began in September 1953 at the El Segundo plant. The first flight of this aircraft occurred on 22 June 1954, with test pilot Robert Rahn at the controls.

The second aircraft to fly, a pre-production YA4D-1 (Bu Aer No. 137813), did so on 14 August 1954. This and subsequent pre-production aircraft of the 19 contracted for carried production standard equipment including two Colt 20 mm Mk. 12 cannons in wing roots, unlike the XA4D-1 which was a ‘clean’ aircraft. These aircraft also differed from the prototype in being powered by the 7800 lb (3537 kg) Wright J65-W-4 engine instead of the former’s J65-W-2 of 7200 lb (3265 kg).

Another difference incorporated in the YA4D-1 was the tail cone, an arrestor hook and vortex generators on the wings.

In September 1955 preliminary carrier qualification trials began off the USS Ticonderoga. This was followed on 15 October 1955 by a record-setting flight by a YA4D-1 (Bu Aer No. 137814) when it set a new 500 km closed-circuit world speed record of 695. 127 mph (1112. 2 km/h) at Edwards AFB with Lieutenant Gordon Grey of the Navy’s test pilot team at the controls.

As a result of standardisation of letter-number designations of aircraft by the US Department of Defence, the A4D-1 became A-4A and to simplify the designation of variants in this article, all aircraft will be termed by their new designations, e. g. A-4B, A-4C etc.

First deliveries of the A-4A began on 9 September 1956 when US Navy squadron VA-72 received their aircraft at Quonset Point NAS, Rhode Island. This unit incidentally, served as the service trials test squadron for the FIP (Fleet Indoctrination Program). In that period, VA-72 used A-4s in a 600 hour flight test program, achieving an availability rating the best of any new design ever tested.

October 26, 1956, saw the Skyhawk officially declared operational by the US Navy with the first Marine air attack squadron, VMA-224, forming in January 1957 at El Toro.

A total of 166 A-4A Skyhawks was eventually built, the aircraft passing through various subsequent updates including the uprating of the Wright J65-W-4 engine, this being substituted in the end for the J65-W-18 of 8500 lb (3855 kg). All-up empty weight totalled 8400 lb (3810 kg) while maximum takeoff weight amounted to 20,000 lb (9070 kg).

Even before the US Navy began taking delivery of the A-4A, an improved version of the Skyhawk had been planned and ordered. This version, the A-4B, was an extensively improved aeroplane that made up for deficiencies its predecessor had possessed.

Features introduced to the A-4B included an improved bonding system and gunsight, the capability to carry and fire the Bullpup air-ground missile, the airframe was ‘beefed-up’ to allow airframe tolerances of up to 7 g, a new ‘inside out’ rudder, i.e. external stiffeners and an internal skin was incorporated called a ‘tadpole rudder’ by Douglas engineers.

Powered flying controls, dual hydraulics, provision for in-flight refuelling via a straight refuelling boom on the starboard side, a dead reckoning· navigation computer system and a specially developed Douglas ‘buddy tank’ fitted to the centreline station, were other new features that distinguished the ‘Pi model from the ‘B’.

Powered initially by the 7700 lb (3492 kg) J65-W-16A, the A-48 eventually benefited by the 8500 ib (3855 kg) -W18A. Total empty weight increased to 9146 b (4148 kg) and maximum takeoff weight to 22 000 lb (10 205 kg).

Flown for the first time on 26March 1956, the A-48 commenced integration into Marine Corps squadrons in September 1957 with VMA-211 being the first recipient and USN squadrons the following February with VA-12. A total of 542 was built, of these, 137 were later refurbished and sold to Argentina (75 A-4P, 16 A-4O) and Singapore (39 A-4S, 7 TA-4S).

With the ever-changing operational experiences and requirements which were dictated by the ‘Cold War’ of the ’50s and the constant updating of the ‘state of the art’ technology, the Skyhawk once again went through an update phase and resultant model change, with significant development beginning in 1957.

Until this time, the Skyhawk had been a pure day attack aircraft that did riot possess sufficient range or capability to operate through foul weather and cloud covered terrain. A proposal was therefore submitted for a new aircraft in the Skyhawk family to be designated A-4C.

The A-4C was to have a limited night/adverse weather capability, made possible by the installation of a small, lightweight radar: the Westinghouse APG-53A. To accommodate this. new radar arid other avionics; the nose was lengthened nine inches (approx. 22 cm). With the APG-53A, the pilot could now fly a terrain clearance path at very low altitudes and high speed.

Also included in the new avionics package for the A-4C were the TPQ-10 ground control, blind bombing system, AJB-3 low altitude, loft bombing system with all attitude reference, airstream direction detector, an improved oxygen system, revised cockpit layout and a new gun sight, as well as the new Escapac low-level ejection seat.

Empty weight totalled 9728 lb (4412 kg), while the engine, the J65-W-16A; was later retrofitted to -16C standard.

The A-4C became the most numerous of the Skyhawk series, 638 were built, with the first flight occurring on 21 August 1958. USMC squadron VMA-225 at Cherry Point, South Carolina became the first unit to operate the A-4C in March 1960. VA-192 began conversion to this type at the end of 1961, being the first USN squadron to do so.

In 1961, two A-4Cs were fitted experimentally with twin-wheel main landing gear and brake parachute in a rear fuselage pod for evaluation and competitive fly-off, by the US Army, against the Northrop N-156 (later F-5A) Freedom Fighter and Fiat G-91R, when that service was considering operating their own high-performance combat aircraft. However, these plans came to naught and the Skyhawks were reconverted to A-4C standard.

Some 23 Navy and nine Marine squadrons eventually were equipped with the A-4C as well as several training units.

Continuing in the alphabetical order of the Skyhawk series, there was to be no A-4D, but the next model in the family was the A-4E. This version first flew on 12 July 1961. Eventually, this was to emerge as a completely re-engined aircraft with a beefed-up airframe, these alterations amounted to an almost 30 per cent redesign. Two additional weapons pylons on a strengthened wing were added, making a total external load of 9155 lb (4152 kg) possible.

Another major change in the A-4E was the substitution of the J65 powerplant for the Pratt & Whitney J52-P-6 with a static thrust of 8500 lb (3855 kg). This engine was lighter and more economical than the ageing J65. As a result, the A-4E’s range was increased by 27 per cent.

Other new equipment added included a TACAN radar altimeter, Doppler navigation radar, and an improved AJB-3A LABS/all attitude and heading reference system. The forward section of the fuselage had to be redesigned also, so as to accommodate the new radar. Range with a ton of ordnance totalled 1400 miles. The total empty weight came to 9853 lb (4468 kg).

First deliveries began in November 1962 with VA-23 attaining full operational status the following year. A total of 500 A-4Es were built, including two YA-4Es.

The final major version in the Skyhawk series for the US Navy was to be the A-4F, of which a total of 146 were manufactured. One major feature which the A-4F introduced was the somewhat unusual ‘hump’ or dorsal fairing atop the fuselage which provided additional avionics capacity (a feature later retrofitted to the A-4C).

Also introduced was the more powerful J52-P-8A engine of 9300 lb (4218 kg), although 100 A-4Fs were later retrofitted with the 11,000 lb J52-P-501 which required slightly enlarged air intakes. Additionally, extra cockpit armour protection, low-pressure tyres, zero/zero ejection seat, nosewheel steering, a brake chute in under tail fairing and wing spoilers were added. This last feature, the wing spoilers, improved landing performance, particularly in crosswinds.

The total empty weight rose to 10 448 lb (4738 kg). The first A-4F to fly did so on 31 August 1966, with service introduction occurring in June 1967.

Though the A-4F was the last of the ‘new-build’ Skyhawks produced for the US Navy, earlier versions of the family, namely the A-4C, were recognised as having a long enough service life to allow them to continue in service with the US Navy and Marine Reserve squadrons with a reasonable amount of updating and retrofitting.

The A-4L was to be the eventual result of a modernisation program applied to the A-4C. Prime changes included the distinctive avionics ‘hump’ and weapons and control systems. Other than these changes, the A-4L retained the standard A-4C features of the J65-W-16C engine and the three external weapons pylons. A total of 100 A-4Cs was converted to the A-4L standard at the Naval Air Rework Facilities (NARF). First flight of the A-4L was made on 21 August 1969 with service deliveries beginning at the end of that year.

As a result of requirements issued in May 1963, the Skyhawk was to have been replaced by the winner of this contest, the Vought A-7 Corsair II. However, it was plain to see that the A-7 was far more expensive and complicated when it came to maintenance than the Skyhawk. Also, it was found that the Marines possibly did not require all of the enhanced mission capabilities the A-7 could offer.

Therefore, the US Navy and Marines decided on their own choice of aircraft for their needs, the Navy for the Corsair 11, the Marines for an even more improved version of the Skyhawk.

The end result of this Marine requirement was to be the A-4M Skyhawk, initially referred to as Skyhawk II; this title was later transferred to the A-4N. The A-4M incorporated yet a further engine update and resultant increase in thrust. The J52-P-408A offering 11 200 lb (5080kg) of thrust was added. This extra power therefore reduced the takeoff run by 20 per cent and increased the climb rate by 50 per cent.

New improvement features of the A-4Mincluded a larger bubble canopy for improved pilot vision, an angled flight refuelling probe to reduce interference with the radar, an increased ammunition capacity for the 20 mm cannon, a braking parachute, an uprated electrical generator, a self-contained gas turbine starter and ram air turbine for emergency starts.

The first of two A-4M prototypes flew on 10 April 1970 and deliveries began a year later to VMA-324 at Beaufort, South Carolina. The A-4Mpresently equips all the Marine Corps front-line attack squadrons other than those equipped with the AV-BA Harrier.

A total, including the two A-4Fs converted to A-4M standard, of 158 A-4Ms were built, the final one being delivered to the Marine Corps on 27 February 1979 in a special acceptance ceremony, this being the 296oth A-4 produced, going to VMA-331 at Cherry Point.

Two Seaters

In 1964, the US Navy issued a requirement for a two-seat operational conversion trainer, this becoming the TA-_4E, the first of which made its maiden flight on 30 June 1965.

In order to accommodate the extra seat, the fuselage had to be lengthened some 28 inches (71 cm), some of the avionics were duplicated, the J52-P-8A powerplant of the A-4F was added, and the fuel tankage V°!’ as reduced by 136 US gallons (5151). Many of the features incorporated in the A-4F discussed previously were also included resulting in a redesignation to that of TA-4F.

Later, to overcome the shortfall in fuel capacity facilitated by the addition of the second cockpit, Douglas designed a saddle fuel tank that could be mounted over the engine.

Of the TA-4F model, 241 were eventually built (including the two TA-4E prototypes, first deliveries beginning in May 1966 to VA-125 at Lemoore NAS. Later, the bulk of these TA-4Fs were converted to TA-4J standards. Another 292 -Js were ‘new build’ aircraft.

The TA-4J took to the air on 21 November 1969 with VT-21 and VT-22 training squadrons accepting their new aircraft in December 1969 at Kingsville NAS, Texas.

Currently the US Navy’s advanced trainer, the TA-4J Skyhawk, also serves with some fleet training squadrons and Marine squadrons. It will be replaced during the late ’80s by the winner of the VTX trainer requirement, the BAe Hawk.

The latest member of the two-seat Skyhawk series is the OA-4M, twenty-three of which were recently converted from TA-4F standard, for the Marine Corps in the forward air control task. All of these aircraft were converted by the Naval Air Rework Facility at Pensacola, the first flight of an OA-4M taking place on 23 May 1978 with the USMC accepting these aircraft at Cherry Point in late 1979.

Export Skyhawks

Argentina, so much in the news in the first half of 1982, with the Falklands conflict, was the first export recipient of the Skyhawk. During this conflict, Argentine Skyhawks took the brunt of much of the air offensive against the British forces, losing 45 in total by the war’s end.

Initially, 25 aircraft, all ex-US Navy A-4Bs, were delivered in 1966 for use by the Argentine Air Force (Fuerza Aerea Argentina), redesignated as A-4Ps. Two further 25 aircraft batches were subsequently received in 1970 and in 1976 respectively.

Serving in the attack role, the Skyhawks serve with I Escuadron de Casa Bombardier of IV Brigada Aerea at El Plumerilla AB, Mendoza, and with the V Brigada at General Pringles AB, Villa Reynolds.

The Comando de Aviacon Naval Argentina in 1971 purchased 16 refurbished A-4Bs designated A-4O. Operated by the 3 Escuadrilla Aeronaval de Caza y Ataque at Comandante Espora NAS, these Skyhawks regularly operate as detachments aboard the carrier 25 de Mayor. Prior to the Falklands conflict, five A-4Qs had been lost in accidents with a further six being lost in the course of the war, though no Skyhawks were launched from the carrier, all operating from land bases.

At present, some 24 ex-Heyl Ha’ Avir (Israeli Air Force) A-4E and A-4H Skyhawks are reportedly in the process of delivery to Argentina. Presumably, these aircraft will have been fully refurbished in Israel and could be destined for either or both the Argentine Air Force and Navy.

Though the Skyhawk was considered a bit dated or long in the tooth by some observers prior to the outbreak of hostilities, they did however assume the lead in the Argentine air offensive against the British task force. A flight of such aircraft was responsible for the Bluff Cove disaster involving the landing ships HMS Sir Galahad and Sir Tristram, when they caught the disembarking forces off-guard with horrific consequences.

Despite some successes, like that above, the Skyhawk was outmoded by its opposition, a number falling to Sea Harriers and others to SAMs (e. g. Sea Wolf, Sea Dart, Sea Cat, Rapier, Blowpipe), and to AAA. Restricted by the distance needed to travel to and from the targets, the Skyhawks had time only for a single pass attack. Thus their overall effectiveness in the Falklands air war was disappointing.

The Royal Australian Navy was the first export customer for ‘newbuild’ Skyhawks when, in July 1967, they received eight A-4Gs and two TA-4Gs. The first flight of the A-4G occurred on 19 July 1967 while the TA-4G flew for the first time on 7 August 1967.

A further eight ex-US Navy refurbished A-4Es and two TA-4Es were added in 1971. These aircraft operated off HMAS Melbourne, and at the RAN Naval Station at Nowra.

During their period of operations, the Skyhawks gave sterling service though in later times, something like half of the Skyhawk force was lost in accidents, a number whilst operating off the since retired Melbourne.

The remaining eight A-4Gs and two TA-4Gs operating from the naval air station at Nowra constituted VF-805 and training squadron VC-724, but the days of the RAN FAA fixed wing force are numbered. The present Hawke Labor government’s scrapping the new carrier search, decommissioning the Melbourne, and planning disbandment of the Skyhawk squadrons by July 1984, has, needless to say, not gone down well with the Fleet Air Arm and particularly with the Skyhawk pilots themselves.

To our immediate north, Indonesia has become another more recent operator of the Skyhawk, receiving 14 ex-Israeli A-4Es and two TA-4Hs in 1980 and a further batch of 16 refurbished ex-US Navy A-4Es in 1982-83 for service with the Indonesian Air Force (TNI-AU).

The Heyl Ha’ Avir has, since late 1967, operated the Skyhawk as its frontline attack plane, it having become a veteran in the process of two major conflicts, the 1969-70 War of Attrition and the 1973 Yom Kippur War. Israel is by far the largest export customer of the Skyhawk and, until the Falklands conflict, the only other country outside the United States to use her Skyhawks in combat.

Initial deliveries consisted of 48 A-4Hs which were built to Israeli specifications including the new modified squared tip fin, a new armament system consisting of two 30 mm DEFA cannons with 150 rounds per gun, and a braking parachute.

Subsequent batches of Skyhawks were ordered which included a further 42 A-4Hs and 10 two seat TA-4Hs, the latter of which first flew on 15 April 1969, and at least another 60 ex-US Navy A-4Es and 17 TA-4Js. These aircraft arrived in batches, some in 1969, others during the Yorn Kippur war of 173 to replace combat attrition.

Not content with the capabilities the Skyhawk could perform for them, the Israelis set about ordering a ‘custom’ made Skyhawk to needed specifications, the resultant aircraft, the A-4N (Skyhawk 11), being one of the best of the family built.

The first flight of an A-4N took place on 8 June 1972, and the first deliveries of the initial 91 aircraft began later that year. Essentially similar to the A-4M, the -N model had an improved nav-attack system including Lear Siegler digital computer, Singer Kearfott inertial platform and Marconi head-up display (HUD). The 30 mm DEFA cannon also was a feature while the distinctive avionics hump was also added.

In total 117 A-4Ns were delivered, including 26 attrition replacements ordered after the J73 conflict.

During the course of their operation, many of the first batches of A-4H Skyhawks have been retrofitted with the avionics hump improving their mission capabilities markedly.

In Heyl Ha’ Avir service, the Skyhawk has not just proved itself an able ground attack aeroplane but also quite adept at air-air combat as well, coming off victorious against Arab MiGs on more than one occasion.

In 1970, a Syrian MiG-19 was downed by a 2. 5-inch air-ground rocket fired from a Skyhawk when the MiG got in his sights, while another Skyhawk shot down a Syrian MiG-17 with its 30 mm DEFA cannon. At the height of the 1973 Yom Kippur War, one Skyhawk was attacked by a flight of MiG-21s. Jettisoning its bombload, the Skyhawk made good use of its agile manoeuvrability and was able to get behind one of his attackers, shooting it down with his 30 mm cannon. A second MiG-21 fell to his guns almost immediately and the third was certain to follow when suddenly two Israelis Mirage Ills arrived on the scene and scored the final MiG.

The Skyhawk was the real workhorse of the Yom Kippur conflict, bearing the brunt of the dangerous anti-SAM missions and the Syrian assault on the Golan Heights in particular and therefore losses of this aircraft were consequently the highest. Of the 102 aircraft lost by Israel, 53 were Skyhawks.

More recently, many Israeli Skyhawks have been modified with an unusually extended tailpipe developed by IAI which reduces the infra-red signature of the aircraft and the effectiveness of the SAM-7 missiles that the PLO possesses.

Early model Skyhawks delivered to Israel have subsequently been refurbished and resold to foreign governments, notably Indonesia and Argentina. At present, there are about 200 A-4E/H/M/N and TA-4E/H Skyhawks in Heyl Ha’ Avir service operated by six front-line and reservist squadrons.

The Israelis’ favourable experience with the Skyhawk possibly led to the Kuwait Air Force ordering 30 A-4KUs and six TA-4KUs in late 1974. All based upon the A-4M, deliveries began in 1977 with the first flight of the A-4KU on 20 July 1976 and TA-4KU on 14 December 1976, they now serving in two attack squadrons.

Another of our northern neighbours, this time Malaysia, has become an operator of the Skyhawk. Though the aircraft intended for operation will have to be refurbished, the first should be in service in 1984.

The order covers 88 aircraft, 25 A-4C and 63 A-4L, all of which are to be removed from their storage at the Davis Monthan ‘boneyard’ in Arizona. It is reportedly intended that only 40 of the 63 A-4L will initially be refurbished by Grumman Aerospace while the A-4Cs will be cannibalised for spares.

Plans are that two squadrons will equip with the Skyhawk in the newly formed strike role, though three squadrons had been originally planned.

New Zealand took delivery in 1970 of the first of 10 A-4Ks and four two-seat TA-4Ks based upon the A-4F and which equip No. 75 Squadron RNZAF at Ohakea.

Similar features as those on the A-4H and A-4M including the squared-off fin tip, a braking ‘chute and modified radios were incorporated in the -K. The surviving nine A-4K and three TA-4K are expected to be soon equipped with a nav-attack system and are expected to be retained in service for a number of years yet.

The Republic of Singapore Air Force purchased 46 ex-US Navy A-4Bs in 1973. These were converted by Lockheed Aircraft Services to A-4S and TA-4S standard, eight of the conversions taking place at Lockheed’s California plant, with the first flight on 14 July 1973, whilst the remainder were completed in Singapore by 1976.

Some of the more than 100 modifications specified by Singapore for her Skyhawks included the J65 -W-20 engine of 8100 lb (3674 kg), the adoption of 30 mm ADEN cannon in place of the Colt 20 mm, a modern nav-attack system including a Ferranti computing sight, wing spoilers and a braking parachute.

The Singaporean two-seaters could be termed the most unusual of all the Skyhawk family. All seven TA-4s, the first of which flew on 21 February 1975, were originally single-seaters and had the rear seat in a separate cockpit and canopy behind the first.

Serving with No. 142 Gryphon and No. 143 Phoenix squadrons at Tengah airfield and with No. 141 OCU alongside Hunters at the same base, the36 remaining A-4s and five TA-4s are expected to be joined by 40 ex-US Navy A-4E Skyhawks which will be brought up to -S standard to ultimately replace the service’s Hunters in the near future.

In summary, the Skyhawk proved that a low-cost lightweight fighter was possible to achieve but with adequate performance and load-carrying capability. In addition, the Skyhawk possesses one of the best roll rates and ease of handling of any aircraft in its class. It is because of this fact that the US Navy’spremier aerobatic team, the Blue Angels, converted from the huge F-4 Phantom II in 1974 to suitably modified A-4Fs, and also why it has become an ideal aircraft to simulate subsonic Soviet fighters in air combat manoeuvres (ACM).

With the current trend for Third World countries to buy secondhand aircraft, something which Indonesia and Malaysia for example have already done, the Skyhawk makes for an attractive proposition for cheap to purchase and operate high-performance aircraft. This is especially so when considering the cost of even the cheapest trainer cum COIN/ground attack aircraft on offer and the number of stored Skyhawks in the Arizona desert.

Though now more than a quarter of a century old, the Skyhawk can be expected to be seen around for quite some time yet. As Flight International in tribute once said, ‘time has filled out that compact body, but with muscle, not fat. ‘ And as Heinemann himself once said, ‘a pretty good aeroplane. ‘