Sukhoi Su-7

infobox Aircraft
name =Su-7
type =Fighter-bomber
manufacturer =Sukhoi OKB



caption =Su-7BKL
designer =
first flight =7 September 1955
introduced =1959
retired =1986 (Soviet Union)
status = Limited active service
primary user =Soviet Air Force
more users =
produced =1957-1972
number built =1,847
unit cost =
variants with their own articles ="For the World War II mixed-power ground attack aircraft see Su-7"

The Sukhoi Su-7 (NATO designation Fitter-A) was a swept wing, turbojet-powered fighter-bomber used by the Soviet Union and its allies.

Design and development

On 14 May 1953, the Sukhoi OKB was reopened and initially tasked with copying the American F-86 Sabre fighter.cite web|url=http://sukhoi.org/planes/museum/su7/|title=Sukhoi Su-7|work=Sukhoi Company Museum|accessdate=2007-04-15] By the summer, the OKB began work on a swept-wing tactical fighter for establishing air superiority over the battlefield ("frontovoi istrebitel", фронтовой истребитель, front-line fighter in Soviet terminology). The first prototype, designated S-1, was designed to use the new Lyulka AL-7 turbojet and it was the first Soviet aircraft to utilize the all-moving tailplane and a translating centerbody, a movable cone in the air intake for managing airflow to the engine at supersonic speeds.cite book|last=Green|first=W|coauthors=Swanborough, G|year=2001|title=The great book of fighters|edition=|publisher=MBI Publishing|location=|id=ISBN 0760311943] The aircraft also had a dramatic wing sweep of 60°, irreversible hydraulically boosted controls, and an ejection seat of OKB's own design.

The S-1 first flew on 7 September 1955 with A. G. Kochetkov at the controls. Fitted with an afterburning version of the AL-7 engine after the first 11 flights, the prototype set a Soviet speed record of 2170 km/h (1,170 knots, 1,350 mph, Mach 2.04) in April 1956. The prototype was intended to be armed with three 37 mm Nudelman N-37 cannon and 32 spin-stabilized 57 mm (2.25 in) unguided rockets in a ventral tray. The second prototype, S-2, introduced some aerodynamic refinements. Testing was complicated by the unreliable engine and S-1 was lost in a crash on 23 November 1956, killing its pilot I. N. Sokolov. The aircraft entered service as Su-7 in 1959, although it saw only limited operational use.

On 31 July 1958, Soviet tactical aviation ("Frontovaya aviatsiya", фронтовая авиация) tasked Sukhoi with developing a ground-attack version of the Su-7. The resulting S-22 retained the basic layout of its S-2 predecessor, incorporating primarily structural refinements for high-speed low-altitude operations. It first flew in March 1959, and began entering service in 1961 as the Su-7B.

A total of 1,847 Su-7 and its variants were built, of which 691 were exported.

Operational history

The Su-7 saw combat with Egypt in the Six Day War in 1967 and the War of Attrition. The Indian Air Force used the Su-7 extensively in the 1971 war with Pakistan. The six Indian Su-7 squadrons flew almost 1500 offensive sorties during the war, and undertook the bulk of the daytime attack efforts. The IAF managed to retain a very high operational tempo with its Su-7's, managing a sortie rate of six per pilot per day. Fourteen Sukhois were lost during the war, but the type had acquitted itself well. [ [http://www.bharat-rakshak.com/IAF/History/Aircraft/Su-7.html A whale of a fighter: Su-7 in IAF service ] ]

Operationally, Su-7s were hampered by high takeoff and landing speeds dictated by the thin, highly-swept wing. The landing speed of 450 km/h (245 knots, 280 mph) combined with poor visibility from the cockpit and lack of an instrument landing system made for difficult operations, especially in poor weather. [cite book|author=Nijboer, Donald, and Patterson, Dan|title=Cockpits of the Cold War|year=2003|publisher=The Boston Mills Press|id=ISBN 1-55046-405-1] In 1961-1962, Sukhoi experimented with blown flaps on S-25 but the benefit was too small to warrant implementation. JATO rockets tested on S-22-4 proved more useful and were incorporated into Su-7BKL. Attempts to improve takeoff and landing performance eventually resulted in the Sukhoi Su-17.

Variants

;Su-7:First production version, tactical air superiority fighter, factory designation S-2. Manufactured 1957-1960 with 132 built. Remained in operational service until 1965.;Su-7B:Ground attack version, factory designation S-22. Manufactured 1960-1962.;Su-7BM:Upgraded AL-7F-1 engine, upgraded fuel system with external piping on either side of the fuselage spine, fuel tanks installed in the wings, "wet" underwing hardpoints for carrying external fuel tanks, capable of carrying tactical nuclear bombs. Manufactured 1963-1965.;Su-7BKL:Rough-field capable variant with skids affixed to the sides of the main landing gear, provision for two SPRD-110 JATO rockets of 29.4 kN (13,300 lbf) thrust, and twin brake parachutes. Introduced in 1965, factory designation S-22KL. Manufactured 1965-1972.;Su-7BMK:Export version of Su-7BM. Manufactured 1967-1971.;Su-7U (NATO designation: "Moujik"):Two-seat trainer version with reduced fuel capacity. First flight 25 October 1965. Manufactured 1966-1972 in parallel with the export version, designated Su-7UMK.;Su-7UM:Two-seat training version of the Su-7BM.;Su-7UMK:Two-seat training version of the Su-7BMK.;Su-7IG:Experimental variable geometry wing aircraft which was developed into Sukhoi Su-17.;100LDU Control Configured Vehicle:A Su-7U modified with canards and a longitudinal stability augmentation system. It was designed as a testbed for a fly-by-wire system for the Sukhoi T-4. It was later used in 1973-1974 during the development of the Su-27's fly-by-wire system.

Operators

;AFG
* 46, including 16 Su-7U trainers, were delivered to the Afghan Air Force from 1972. Substantial replacement deliveries during the 1980s may have raised the total number of aircraft to serve to about 120. None remain in service.;DZA
* The Algerian Air Force no longer operates the Su-7.;BGD
* Possible service.;CZS
*The Czech Air Force operated 60 aircraft, last Su-7s were phased out in 1990.;HUN
*No longer in service with the Hungarian Air Force.;EGY
*Egyptian Air Force;IND
*160 aircraft delivered, no longer in service with the Indian Air Force.;IRQ
*No longer in service with the Iraqi Air Force.;PRK
*18 are in service with the North Korean Air Force.;POL
*46 were operated by the Polish Air Force, no longer in service.;USSR
*Soviet Air Force;flag|South Yemen;SYR
*Syrian Air Force;VNM
*Vietnam People's Air Force

pecifications (Su-7BKL)

Aircraft specification

plane or copter?=plane
jet or prop?=jet
ref=Green, Sukhoi
crew=One
length main=16.80 m
length alt=55 ft 1 in
span main=9.31 m
span alt=30 ft 7 in
height main=4.99 m
height alt=16 ft 4 in
area main=34 m²
area alt=366 ft²
empty weight main=8330 kg
empty weight alt=18,365 lb
loaded weight main=13570 kg
loaded weight alt=29,915
max takeoff weight main=15210 kg
max takeoff weight alt=33,530 lb
more general=
*Fuel capacity: 3220 kg (7,100 lb)
engine (jet)=Lyulka AL-7F-1
type of jet=afterburning turbojet
number of jets=1
thrust main=66.6 kN
thrust alt=14,980 lbf
afterburning thrust main=94.1 kN
afterburning thrust alt=22,150 lbf
max speed main=1,150 km/h
max speed alt=620 kn, 715 mph, Mach 0.94
max speed more=at sea level; 2150 km/h (1,160 kn, 1,335 mph) at high altitude
range main=1,650 km
range alt=890 NM, 1,025 mi
ceiling main=17600 m
ceiling alt=57,740 ft
climb rate main=160 m/s
climb rate alt=31,500 ft/min
loading main=434.8 kg/m²
loading alt=89.05 lb/ft²
thrust/weight=0.71
more performance=
*Takeoff roll: 950 m (3,120 ft)
*Landing roll: 700 m (2,300 ft)
armament=
* 2× 30 mm Nudelman-Rikhter NR-30 cannon, 80 rounds each
* Up to 2000 kg (4,410 lb) on six hardpoints, typically including two 600 l (160 US gal) fuel tanks under the fuselage, and a combination of 250 kg (550 lb) or 500 kg (1,100 lb) bombs and 57-mm spin-stabilized unguided rockets in UB-16-57U pods. A 8U69 5-kiloton nuclear bomb could be carried on the left fuselage hardpoint.

References

External links

* [http://www.globalsecurity.org/military/world/russia/su-7.htm Su-7 from Global Security]
* [http://www.globalaircraft.org/planes/su-7_fitter-a.pl Su-7 from Global Aircraft]
* [http://www.militaryfactory.com/aircraft/detail.asp?aircraft_id=69 Su-7 from Military Factory]

ee also

aircontent
related= Su-17/Su-20/Su-22

similar aircraft= Hawker Hunter - Nanchang Q-5 - HAL HF-24 Marut

sequence=

see also=
* List of military aircraft of the Soviet Union and the CIS