Role: Ground-attack aircraft
National origin: United States
Manufacturer: Douglas Aircraft Company; McDonnell Douglas
Designed by: Ed Heinemann
First flight: 22 June 1954
Introduced: October 1956
Retired: 2003, USN; 1998, USMC
Status: Active with non-U.S. users
Primary users: United States Navy; United States Marine Corps
Number built: 2,960
Unit cost: US$860,000 each for the first 500 units
Variants: A-4AR Fightinghawk; A-4SU Super Skyhawk
Pembuatan purwarupa Skyhawk XA-4A (awalnya XA4D-1) dimulai pada bulan September 1953 dan penerbangan pertama pesawat ini, didukung dengan mesin Wright J65-W-2 (32 kN), berlangsung pada 22 Juni 1954. Total 2.960 A-4 Skyhawks telah dibuat. Yang terakhir dibuat pada 1979.
Desain dan Pengembangan
Skyhawk dirancang oleh Ed Heinemann dari Douglas sebagai tanggapan atas kebutuhan AL AS pesawat serang jet pengganti A-1 Skyraider. Heinemann memilih desain yang meminimalisir ukuran, berat, dan kompleksitas. Hasilnya adalah sebuah pesawat yang beratnya hanya setengah dari berat spesifikasi AL. Pesawat memiliki sayap kompak sehingga tidak perlu dilipat untuk penyimpanan di Kapal Induk. Skyhawk yang berukuran kecil ini kemudian segera menerima julukan "Scooter", "Kiddiecar", "Bantam Bomber", "Tinker Toy Bomber", dan karena kinerja yang cepat, dijuluki "Heinemann’s Hot-Rod".
Pesawat ini memiliki desain konvensional pasca Perang Dunia II, dengan sayap delta terpasang rendah di badan pesawat, undercarriage tiga roda, dan sebuah mesin turbojet di bagian belakang badan pesawat, dengan dua intakes udara di sisi badan pesawat. Ekornya memiliki desain cruciform, dengan stabilisator horisontal terpasang di atas badan pesawat. Persenjataannya terdiri dari dua kanon Colt Mk 12 20 mm, satu di setiap akar sayap, dengan 200 amunisi per kanon, plus berbagai jenis bom besar, roket, dan misil yang dibawa pada hardpoint di bagian tengah badan pesawat dan hardpoint di bawah setiap sayap (awalnya satu setiap sayap, kemudian dua).
Desain A-4 adalah contoh yang baik untuk menunjukkan kesederhanaan. Pilihan sayap delta, misalnya, dikombinasikan dengan kecepatan dan manuverabilitas dengan kapasitas bahan bakar besar dan ukuran kecil secara keseluruhan, sehingga tidak memerlukan sayap lipat, walau mengorbankan efisiensi jelajah. Slats ujung depan dirancang untuk “jatuh” secara otomatis pada kecepatan yang tepat dengan adanya gravitasi dan tekanan udara, sehingga berat dan ruang dapat dikurangi. Demikian pula untuk undercarriage dipasang tidak menembus bagian sayap, dirancang agar ketika undercarriage dimasukkan hanya roda sendiri yang masuk ke dalam sayap, sementara penopangnya berada di bawah sayap. Struktur sayapnya dapat diperingan tanpa mengurangi kekuatannya, dan dengan tidak adanya mekanisme pelipatan sayap, berat menjadi jauh lebih ringan. Desain pesawat secara umum, ketika suatu bagian pesawat bertambah beratnya, maka memaksa bagian lain untuk diperkuat sehingga juga menambah berat, yang pada akhirnya mesin yang diperlukan juga harus lebih kuat. Jadi ini adalah suatu lingkaran setan.
A-4 memelopori konsep pengisian bahan bakar udara-ke-udara "buddy". Hal ini memungkinkan pesawat untuk mengisikan bahan bakar pesawat lain yang setipe, sehingga tidak diperlukan pesawat tanker bahan bakar khusus. Dengan sistem ini, pesawat dapat diluncurkan dengan persenjataan penuh sengan bahan bakar secukupnya agar dapat lepas landas tanpa kuatir melebihi berat maksimum lepas landas (MTOW). Setelah mengudara, pesawat dapat melakukan re-fueling di udara sesuai kebutuhan dan jarak target penyerangan.
A-4 juga dirancang untuk dapat melakukan pendaratan darurat, walaupun terjadi kegagalan hidrolik, dengan menggunakan dua tangki yang selalu dibawa oleh pesawat ini. Pendaratan darurat semacam ini hanya mengakibatkan kerusakan kecil pada hidung pesawat yang dapat diperbaiki dalam waktu kurang dari satu jam. Ed Heinemann ini dikreditkan dengan yang besar "KISS" menaruh tanda pada dinding yang menggambar kantor ketika pesawat terbang yang telah dirancang. Apakah hal ini benar, A-4 pasti bersinar adalah contoh penerapan prinsip bahwa untuk desain pesawat terbang.
AL mengeluarkan kontrak untuk pesawat ini pada 12 Juni 1952, dan purwarupa pertama terpang pertama kali dari Edwards Air Force Base, California pada tanggal 22 Juni 1954. pengiriman ke Skuadron AL dan Korps Marinir AS (ke VA -72 dan VMA-224 secara berturut-turut) dimulai pada akhir 1956.
Skyhawk yang masih produksi sampai tahun 1979, dengan total produksi 2.960 pesawat, termasuk buah 555 pesawat latih dua-kursi.
A-4 Skyhawk dan TNI-AU
TNI-AU pernah mengoperasikan sebanyak 37 Skyhawk II tipe A-4E dan TA-4E (ex Angkatan Udara Israel) hingga tahun 2003. Di tahun itu TNI-AU menggantinya dengan dua unit Su-27SK dan dua unit Su-30MK dari Rusia. Belakangan tersebar berita bahwa TNI-AU berkeinginan untuk mengaktifkan kembali armada A-4 Skyhawk-nya melalui pembelian suku cadang baru setelah AS mengakhiri embargo penjualan amunisi dan suku cadang militer kepada Indonesia.
Variants
•XA4D-1: Prototype
•YA4D-1 (YA-4A, later A-4A): Flight test prototypes and pre-production aircraft.
•A4D-1 (A-4A): Initial production version, 166 built
•A4D-2 (A-4B): Strengthened aircraft and added air-to-air refueling capabilities, improved navigation and flight control systems, provision for AGM-12 Bullpup missile, 542 built.
•A-4P: Remanufactured A-4Bs sold to Argentine Air Force known as A-4B by the Argentines.
•A-4Q: Remanufactured A-4Bs sold to Argentine Navy.
•A-4S: 50 A-4Bs remanufactured for Republic of Singapore Air Force.
•TA-4S: seven trainer versions of the above. Different from most TA-4 trainers with a common cockpit for the student and instructor pilot, these were essentially rebuilt with a 28-inch (710 mm) fuselage plug inserted into the front fuselage and a separate bulged cockpit (giving better all round visibility) for the instructor seated behind the student pilot.
•TA-4S-1: eight trainer versions of the above. These were designated as TA-4S-1 to set it apart from the earlier batch of seven airframes.
•A4D-3: Proposed advanced avionics version, none built.
•A4D-2N (A-4C): Night/adverse weather version of A4D-2, with AN/APG-53A radar, autopilot, LABS low-altitude bombing system. Wright J65-W-20 engine with 8,200 lbf (36.5 kN) takeoff thrust, 638 built.
•A-4L: 100 A-4Cs remanufactured for Marine Corps Reserves and Navy Reserve squadrons. Fitted with A-4F avionics (including the fuselage "hump") but retaining J-65 engine and three-pylon wing.
•A-4S-1: 50 A-4Cs remanufactured for Republic of Singapore Air Force.
•A-4SU: This is an extensively modified and updated version of the A-4S, exclusively for the Republic of Singapore Air Force (RSAF), fitted with a General Electric F404 non-afterburning turbofan engine, and modernized electronics.
•TA-4SU: This is an extensively modified and updated version of the TA-4S & TA-4S-1 to TA-4SU standard.
•A-4PTM: 40 A-4Cs and A-4Ls refurbished for Royal Malaysian Air Force, incorporating many A-4M features (PTM stands for Peculiar to Malaysia).
•TA-4PTM: Small number of trainer versions of above (PTM stands for Peculiar to Malaysia).
•A4D-4: Long-range version with new wings cancelled; A-4D designation skipped to prevent confusion with A4D
•A4D-5 (A-4E): Major upgrade, including new Pratt & Whitney J52-P-6A engine with 8,400 lbf (37 kN) thrust, strengthened airframe with two more weapon pylons (for a total of five), improved avionics, with TACAN, Doppler navigation radar, radar altimeter, toss-bombing computer, and AJB-3A low-altitude bombing system. Many later upgraded with J52-P-8 engine with 9,300 lbf (41 kN) thrust; 499 built.
•TA-4E: two A-4Es modified as prototypes of a trainer version.
•A4D-6: Proposed version, none built.
•A-4F: Refinement of A-4E with extra avionics housed in a hump on the fuselage spine (this feature later retrofitted to A-4Es and some A-4Cs) and more powerful J52-P-8A engine with 9,300 lbf (41 kN) thrust, later upgraded in service to J52-P-408 with 11,200 lbf (50 kN), 147 built. Some served with Blue Angels acrobatic team from 1973 to 1986.
•TA-4F: Conversion trainer - standard A-4F with extra seat for an instructor, 241 built.
•OA-4M: 23 TA-4Fs modified for Forward Air Control duties for the USMC.
•EA-4F: four TA-4Fs converted for ECM training.
•TA-4J: Dedicated trainer version based on A-4F, but lacking weapons systems, and with down-rated engine, 277 built new, and most TA-4Fs were later converted to this configuration.
•A-4G: eight aircraft built new for the Royal Australian Navy with minor variations from the A-4F; in particular, they were not fitted with the avionics "hump". Subsequently, eight more A-4Fs were modified to this standard for the RAN. Significantly the A-4G were modified to carry four underwing Sidewinder AIM-9B missiles increasing their Fleet Defense capability.
•TA-4G: two trainer versions of the A-4G built new, and two more modified from TA-4Fs.
•A-4H: 90 aircraft for the Israeli Air Force based on the A-4F. Used 30 mm DEFA cannon with 150 rounds per gun in place of US 20 mm guns. Later, some A-4Es later locally modified to this standard. Subsequently modified with extended jetpipes as protection against heat-seeking missiles.
•TA-4H: 25 trainer versions of the above. These remain in service, and are being refurbished with new avionics and systems for service till at least 2010.
•A-4K: ten aircraft for Royal New Zealand Air Force. In the 1990s these were upgraded under Project KAHU with new radar and avionics, provision for AGM-65 Maverick, AIM-9 Sidewinder, and GBU-16 Paveway II laser-guided bomb. The RNZAF also rebuilt an A-4C and ten A-4Gs to A4K standard.
•TA-4K: four trainer versions of the above. A fifth was later assembled in NZ from spare parts.
•A-4M: Dedicated Marine version with improved avionics and more powerful J52-P-408a engine with 11,200 lbf (50 kN) thrust, enlarged cockpit, IFF system. Later fitted with Hughes AN/ASB-19 Angle Rate Bombing System (ARBS) with TV and laser spot tracker, 158 built.
•A-4N: 117 modified A-4Ms for the Israeli Air Force.
•A-4KU: 30 modified A-4Ms for the Kuwaiti Air Force. Brazil purchased 20 of these second-hand and redesignated them AF-1. Now used in Brazilian Navy on carrier duty.
•TA-4KU: three trainer versions of the above. Brazil purchased some of these second-hand and redesignated them AF-1A.
•A-4AR: 36 A-4Ms refurbished for Argentina. Known as Fightinghawk.
•TA-4R: Refurbished two-seat training version for Argentina.
•A-4Y: Provisional designation for A-4Ms modified with the ARBS. Designation never adopted by the US Navy or Marine Corps.
Specifications (A-4F Skyhawk)
General characteristics
•Crew: 1 (2 in TA-4J, TA-4F, OA-4F)
•Length: 40 ft 3 in (12.22 m)
•Wingspan: 26 ft 6 in (8.38 m)
•Height: 15 ft (4.57 m)
•Wing area: 259 ft² (24.15 m²)
•Airfoil: NACA 0008-1.1-25 root, NACA 0005-0.825-50 tip
•Empty weight: 10,450 lb (4,750 kg)
•Loaded weight: 18,300 lb (8,318 kg)
•Max takeoff weight: 24,500 lb (11,136 kg)
•Powerplant: 1× Pratt & Whitney J52-P8A turbojet, 9,300 lbf (10,000+ USMC A-4M and OA-4M) (41 kN)
Performance
•Maximum speed: 585 knots (673 mph, 1,077 km/h)
•Range: 1,700 nm (2,000 mi, 3,220 km)
•Service ceiling: 42,250 ft (12,880 m)
•Rate of climb: 8,440 ft/min (43 m/s)
•Wing loading: 70.7 lb/ft² (344.4 kg/m²)
•Thrust/weight: 0.51
•g-limit: -3/+8 g
Armament
•Guns: 2× 20 mm (0.787 in) Colt Mk 12 cannon, 100 rounds/gun
•Missiles: 4× AIM-9 Sidewinder, AGM-45 Shrike ARM (anti-radiation missile), MBDA Exocet, AGM-65 Maverick ASM (air-to-surface missiles), AGM-62 Walleye glide bomb, AGM-12 Bullpup ASM (air-to-surface missiles)
•Bombs: 9,900 lb (4,490 kg) on five external hardpoints, Rockeye Mk.20 Cluster Bomb Unit, Rockeye Mk.7/APAM-59 Cluster Bomb Unit, Mk.81 (250 lb) and Mk.82 (500 lb) general-purpose bombs, various tactical nuclear missiles and bombs, Mk.76 practice bombs
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