Design and development
The growing American military involvement in Vietnam in the early 1960s led to strong interest in counter-insurgency (COIN) aircraft. In late 1962, the U.S. Air Force's Special Air Warfare Center at Eglin Air Force Base's Hurlburt Field in Florida evaluated two T-37Cs for the role.
The Air Force found the T-37 promising, but wanted an improved version of the aircraft that could carry a much larger payload, and had much greater endurance, as well as better short-field performance. This meant a heavier aircraft with more powerful engines. In 1963, the Air Force awarded a contract to Cessna for two prototype YAT-37D aircraft: T-37s with modifications that included:
- Stronger wings.
- Three stores pylons on each wing.
- Larger wingtip fuel tanks of 360 litre (95 US gallons) capacity.
- A General Electric GAU-2B/A 7.62 mm "Minigun" Gatling-style machine gun, with a rate of fire of 3,000 rounds/minute and 1,500 rounds of ammunition. The weapon was fitted in the right side of the aircraft's nose behind a large, convenient access panel. A gunsight and gun camera were also fitted.
- Better avionics for battlefield communications, navigation, and targeting.
- Tougher landing gear for rough-field operation.
These changes meant a drastic increase in aircraft weight and the aircraft now had to carry a significant warload as well. Cessna, therefore, doubled the engine power by replacing the two Continental J-69 engines with General Electric J85-J2/5 turbojet engines with 10.7 kN (2,400 lbf) thrust each.
The first YAT-37D flew in October 1964, followed a year later by the second prototype. The second prototype had four stores pylons under each wing, rather than three, and the first prototype was upgraded to this configuration as well.
Test results were good, but USAF interest in counter-insurgency (COIN) aircraft had faded for the moment. The program went into limbo for a time, with the second prototype "put out to pasture" at the National Museum of the United States Air Force at Wright-Patterson Air Force Base in Ohio.
The war in Southeast Asia, however, continued to escalate. Losses of Douglas A-1 Skyraider close-support aircraft in US and South Vietnamese service proved greater than anticipated and USAF interest in COIN aircraft was revived. The YAT-37D seemed like a promising candidate for the job, but the Air Force felt that the only way to be sure was to evaluate the aircraft in combat.
As a result, the USAF issued a contract to Cessna for a preproduction batch of 39 YAT-37Ds, with a few minor changes relative to the prototypes, to be rebuilt from existing T-37Bs. These aircraft were initially designated AT-37D, but the designation was quickly changed to A-37A. The second prototype YAT-37D was pulled out of the Air Force Museum and upgraded to A-37A standards as part of the test program.
The A-37A had a gross takeoff weight of 5,440 kg (12,000 lb), of which 1230 kg (2,700 lb) was warload. The A-37A retained the dual controls of its T-37B ancestor, allowing it to be used as an operational trainer.
In combat "forward air control (FAC)" operations, the second seat was occupied by an observer. Only one crewman normally flew in the aircraft for close support missions, permitting a slight increase in warload.
Operational history
In August 1967, 25 of the A-37As were sent to Vietnam under the "Combat Dragon" evaluation program, and flew from Bien Hoa Air Base on USAF "air commando" missions, including close air support, helicopter escort, FAC, and night interdiction. Combat loads included high-explosive bombs, cluster munition dispensers, unguided rocket packs, napalm tanks, and the SUU-11/A Minigun pod. For most missions, the aircraft also carried two additional external tanks on the inner stores pylons.
During this period the A-37As flew thousands of sorties. None were lost to enemy fire, though two were wrecked in landing accidents. The A-37A was formally named the "Dragonfly", but most pilots called it the "Super Tweet." The Combat Dragon program was successful, but unsurprisingly the combat evaluation revealed some of the deficiencies of the A-37A. The most noticeable problem was that the aircraft lacked range and endurance. Other concerns were heavy control response during attack runs (the flight controls were not power-boosted) and the vulnerability of the aircraft's non-redundant flight control system.
The USAF signed a contract with Cessna in early 1967 for an improved Super Tweet, designated the "A-37B". The initial order was for 57 aircraft, but this was quickly increased to 127. The A-37Bs were primarily intended to be supplied to the South Vietnamese Air Force VNAF as replacements for their Skyraiders. The A-37B prototype was rolled out in September 1967, with deliveries to the South Vietnamese beginning in 1968.
The A-37Bs were all newly built airframes. These were stronger than those of the A-37A, capable of pulling 6 g instead of 5, and were built to have a longer fatigue life of 4,000 hours. Field experience would demonstrate that 7,000 hours between overhauls could be tolerated.
The A-37B weighed almost twice as much as the T-37C. A remarkable fraction of the loaded weight, 2.67 tonnes (5,880 lb), could be external stores. In practice, the A-37B usually operated with at least two and sometimes four underwing fuel tanks to improve combat endurance.
To get this increased weight off the ground, the A-37B was fitted with General Electric J85-GE-17A engines, providing 12.7 kN (2,850 lbf) thrust each. These engines were canted slightly outward and downward to improve single-engine handling. Air commando pilots in Vietnam operating the A-37A had found single-engine cruise an effective means of improving their flight endurance.
Modifications were made to control surfaces to improve handling. To improve aircraft and crew survivability, the A-37B was fitted with redundant elevator control runs that were placed as far apart as possible. The ejection seats were armored, the cockpit was lined with nylon flak curtains, and foam-filled self-sealing fuel tanks were installed.
The A-37B added a refueling probe to the nose, leading to pipes wrapped around the lower lip of the canopy, for probe-and-drogue aerial refueling. This was an unusual fit for USAF aircraft, which traditionally are configured for boom refueling. Other improvements included updated avionics, a redesigned instrument panel to make the aircraft easier to fly from either seat, an automatic engine inlet de-icing system, and revised landing gear. Like its predecessors, the A-37B was not pressurized.
The 20mm GPU-2/A and AMD 30mm cannon pods were tested with favorable results on the A-37B, [1] but reports indicate that such pods were rarely or never used in operation.
A total of 577 A-37Bs were built, with 254 delivered to the South Vietnamese Air Force. At war's end the A-37 had flown over 160,000 combat sorties with only 22 USAF losses, approximately 187 A-37Bs were in South Vietnamese service when the country fell. Ninety-two were recovered by the US, while the other 95 were later used by the Communist Vietnamese in missions over Cambodia and during the China conflict in 1979. These "renegade" aircraft were phased out of service in the late 1970s or early 1980s, in all probability due to lack of spares. Some of the aircraft were shipped to Vietnam's allies like Czechoslovakia, Poland, the Soviet Union, and East Germany. Others were sold to private foreign owners. Six examples of the A-37B became property of American Warbird fans, while four A-37Bs are now privately-owned in Australia and New Zealand.
After the war, the USAF passed their A-37Bs from the USAF Tactical Air Command (TAC) to TAC-gained units in the Air National Guard and Air Force Reserve. In the early 1980s these aircraft were assigned to the FAC (Forward Air Control) role and given the designation OA-37B. The OA-37Bs were eventually phased out and replaced in the FAC mission by the much more formidable Fairchild OA-10A Warthog in Regular Air Force, Air National Guard and Air Force Reserve service.
The A-37B was also exported to Latin America, mostly during the 1970s. It was well suited to their needs because of its simplicity, low cost, and effectiveness for insurgent warfare. Most of the A-37Bs exported south had the refueling probe shortened to act as a single-point ground refueling probe, or deleted completely.
The aircraft, along with the Embraer EMB 312 Tucano, has been widely used for drug - busting operations.[2]
During the brief 1995 Cenepa War, both Ecuadorians and Peruvians used the A-37 for ground support. On February 10, 1995 a Peruvian Air Force A-37B was shot down by a Shafrir 2 AAM fired from an Ecuadorian Air Force Kfir.
Concept aircraft
Cessna also proposed enhanced strike variants of the T-37. The AT-37E/STOL (short takeoff & landing) concept incorporated more powerful engines, thrust reversers, and big flaps. Side-by-side and tandem seating versions were offered.
The A-37D also had more powerful engines, a centerline gun pod, and a single-seat configuration based on the TNT fuselage. As with the improved trainer concepts, the improved strike versions never flew.
Variants
- YAT-37D
- Two former T-37C trainer prototypes converted for counter-insurgency operations with two J-85-GE engines and six underwing pylons as prototypes for the A-37 series, redesignated YA-37A.
- YA-37A
- Two YAT-37D prototypes redesignated.
- A-37A
- (Cessna Model 318D) T-37B rebuilt with two J-85-GE-5 engines, a 7.62mm minigun in nose and eight underwing stores pylons, 39 conversions.
- A-37B
- (Cessna Model 318E) Production version with two J-85-GE-17A engines, provision for inflight refuelling, increased fuel capacity and strengthened airframe, 577 built.
- OA-37B
- The OA-37B Dragonfly was an armed observation aircraft developed during the Vietnam War. The OA-37B Dragonfly replaced the aging O-2A Skymaster in the early 1980s. It continued in use with Air National Guard and Air Force Reserve units as an observation platform until the late 1980s.
Operators
- Chilean Air Force received 44 aircraft - 14 are currently operational.
- Colombian Air Force received 32 aircraft - 13 are currently in service (to be withdrawn by 2008)
- Dominican Air Force received 8 aircraft - all units had been written off or destroyed in accidents by March 2001.
- Ecuadorian Air Force received 28 aircraft - 20 are still operational.
- El Salvador Air Force received 15 aircraft - 9 are currently in service.
- Guatemalan Air Force received 13 aircraft - 2 remain in service.[3]
- Honduran Air Force received 17 aircraft - 10 remain operational.
- Peruvian Air Force received 53 aircraft - only 10 remain operational and Peru has recently bought 24 South Korean Air Force A37B that were replaced by the T-50 Golden Eagle.[4]
- South Korean Air Force - all replaced by T-50 Golden Eagle. Also served with the ROKAF's aerial acrobatic team, the "Black Eagle", up until Seoul Air Show in 2007, the last show which the Black Eagle team used the A-37B. First introduction Time : October, 1976.
- Vietnam Air Force received 254 aircraft.
- Royal Thai Air Force received 20 aircraft.
- Uruguayan Air Force received 14 aircraft - 10 currently in service.
Specifications (A-37B Dragonfly)
General characteristics
- Crew: 2
- Length: 32 ft 1 in (9.79 m)
- Wingspan: 38 ft 5 in (11.71 m)
- Height: 9 ft 3 in (2.82 m)
- Wing area: 184 ft² (17.1 m²)
- Empty weight: 6,210 lb (2,815 kg)
- Max takeoff weight: 15,000 lb (6,800 kg)
- Powerplant: 2× General Electric J85-GE-17A turbojet, 2,850 lbf (12.7 kN) each
Performance
- Maximum speed: 480 mph (420 knots, 770 km/h)
- Cruise speed: 300 mph (260 knots, 480 km/h)
- Range: 800 nm (920 mi, 1,480 km)
- Service ceiling: 41,800 ft (12,700 m)
- Rate of climb: 7,000 ft/min (35.5 m/s)
Armament
- Guns: 1× 7.62 mm GAU-2B/A minigun (mounted in nose)
- Hardpoints: 8 under-wing with a capacity of 1,230 kg
- Gun pods: SUU-11/A (1× 7.62 mm M134 minigun), GPU-2/A (1× 20 mm M197 cannon), 30 mm DEFA-553 cannon,
- Rockets: 70 mm Mk 4/Mk 40 FFAR (LAU-32/A rocket pod, 7 rounds)
- Missiles: AIM-9 Sidewinder
- Bombs: 500 lb (241 kg) Mk.82 (×4 on multiple ejector racks), SUU-14 bomblet dispenser
- Other: Napalm tanks
Fonte: http://en.wikipedia.org/wiki/A-37_Dragonfly
O KIT:
Este kit na escala 1/72, comprimento aproximado de 12,5cm, da Academy com o código 1672 . Com excelente qualidade e detalhamento, linhas de painéis em baixo relevo, tanques auxiliares de combustível e armamentos. Instruções de montagem e decais para 2 versões: A-37, USAF OA-37 Coréia 1980 e Black Eagles 1966. Acompanha cola. Para maiores de 10 anos.
Escolhi montar a versão Black Eagles, portanto vou postar um breve resumo da história deste esquadrão acrobático.
ESQUADRÃO BLACK EAGLES
Formado em 1953, a composição inicial do grupo era de quatro North American P-51 Mustang, que voaram pelo Black Eagles até 1958, quando as suas operações foram temporariamente suspensas. Em 1962, o esquadrão voltou a operar, dessa vez com os modernos jatos de combate North American F-86 Sabre e com um novo nome, Blue Sabres, permanecendo em operação até 1966, quando novamente foi reorganizado sob o nome de Black Eagles e, naquele momento, com os jatos supersônicos Northrop F-5A Freedom Fighter. Em 1978, o esquadrão foi novamente extinto, voltando as operações em 1994, desta vez, com o Cessa A-37 Dragonfly.
Com a chegada dos T-50, que pode atingir velocidades de aproximadamente 1.700km/h, os Black Eagles serão uma das poucas esquadrilhas de demonstração aérea no mundo a voar com um jato supersônico de fabricação própria.
Com custo de aproximadamente US$ 25 milhões, a Coréia do Sul adquiriu 82 exemplares do T-50, sendo 22 desses com capacidade de realizar missões de ataque leve e apoio aproximado.
Ao todo, serão oito aeronaves que vão compor os Black Eagles e, em sua estréia este ano, o esquadrão vai se apresentar junto com os Thunderbirds, o time de demonstração aérea da Usaf (força aérea norte-americana), durante o Seoul International Aerospace and Defense Exhibition.
Aqui tem um video dos caras em ação:
Este é mais um kit que estava montando na praia, portanto não tenho as imagens da montagem. Aqui vai umas fotos dele montado, com primer Spray na cor platina e duas demão de tinta spray branco.
