Modern-Aviation

The Sukhol Su-27 is a twin-engine fighter plane built by the former U.S.S.R., in an attempt to outdo similarly advanced American aircraft. The plane made its first flight in May 1977, and officially entered service with the Soviet Air Force in 1985. The aircraft can reach a maximum supersonic speed of Mach 2.35 (1,550 mph, or 2,500 km/h), which is 2.35 times the speed of sound.

The Su-27 earned a reputation of being one of the most capable fighters of its time, and some remain in military use in Russia, Belarus and the Ukraine.

Its top speed of 2.35 mach brings it to the very edge of USSR craftmanship with a twin engine and the first fly-by-wire control system on a Russian jet ever. It was built for air superiority to counter the new American 3.5 gen fighters such as the F-15 Eagle. It is armed with a 30 mm gun and 10 external pylons that can hold both Air-to-Air, heat-seeking, short and medium range missiles. Due to all its accomplishments and popularity it has very many different variants. Some of which are top-modern even today, 35 years after the first flight of the Flanker (1977). The Su-27 was designed by Sukhoi OKB as a heavy fighter for the Soviet Air Force (Voenno-Vozdushmiy Sily - VVS) and National (Homeland) Air Defense Forces (Protivo-Vozdushnoi Oborony - PVO) to regain air superiority over the F-15 Eagle operated by the US Air Force. In fact, the requirements were based on the performance of the F-15 adding ten percent. The Sukhoi design fulfilled the requirements and beyond. The Su-27 is often proclaimed the best and most successful Russian fighter of the Cold War era.

After the end of the Cold War and USSR, the Sukhoi OKB (often in cooperation with the KnAAPO plant) developed various advanced variants aimed at prospective foreign customers. The aircraft were marketed at international air shows, putting up superb aerobatic displays. The aircraft performance both on paper as in aerobatic displays has stunned many enthusiasts and experts alike all over the world. Also, the Flanker has proven its air superiority in combat during several African wars. The Su-27 and its derivatives are today some of the most popular fighters to be discussed by both aviation enthusiasts and experts.

Design
The main feature for the success of the Su-27 design is its aerodynamic configuration, known as 'integrated aerodynamic concept' by its designers. This configuration is one with extremely blended wing and fuselage. The low-aspect ratio trapezoidal midwing is fitted with large leading-edge root extensions (LERX) and blending into the fuselage creating a single lifting body.

The aircraft has a near-zero static stability and thus require a fly-by-wire system. The SDU-10 pitch-only fly-by-wire system controls the pitch of the aircraft to ensure stability and controllability for the pilot, increase aerodynamic performance, limit overload and angle of attack when needed and decrease the airframe aerodynamic load.

Two AL-31F afterburning turbofans are placed in seperate, widely spaced engine nacelles that are mounted under the lifting body. The air intakes are fitted with variable ramps.

The Su-27 has twin vertical fins fitted on the outer sides of the fuselage and twin central fins underneath. The airbrake is placed in the center of the mid-section of the aircraft behind the cockpit. The tricycle landing gear of Su-27 and Su-27UB has a single wheel on each strut. The nose wheel is fitted with a mudguard to protect against foreign object damage (FOD).

Systems & Avionics
The basic Su-27 is fitted with the SUV-27 fire control system, which incorporates the RLPK-27 radar sighting system, OEPS-27 electro-optical sighting system, SEI-31 integrated indication system, IFF interrogator and built-in test system. The fire control system in integrated with the PNK-10 flight navigation system, radio command link, IFF system, data transmission equipment and EW self-defence system.

The RLPK-27 system and is controlled by the Ts-100 digital computer and includes the N001 pulse-Doppler lookdown-capable radar with a range of 80-100 km in the front hemisphere and 30-40 km in the rear hemispehere for a fighter-sized target. It can simultaneously track up to ten aerial targets in track-while-scan mode and provide interception of the top priority target.

The OEPS-27 electro-optical sighting system consist of the OLS-27 infrared/laser search-and-track system (IRST) and the Shchel-3UM helmet-mounted target designator and is controlled by the Ts-100 digital computer. The OLS-27 sensor is placed forward of the cockpit canopy in the centre. The system acquires and tracks aerial targets by their thermal signatures. The helmet-mounted sight and the laser range finder of the IRST can also be used to visually acquire and determine coordinates of air and surface targets.

The SEI-31 integrated indication system provides flight, navigation and sighting data on the ILS-31 head-up display (HUD) and CRT. The EW self-defence systems provides warning to the crew when illuminated by enemy radar and employs both passive and active countermeasures. The aircraft is equipped with the SPO-15 Beryoza RWR and APP-50 IR decoy dispenser. Chaff dispensers are placed in the tail section between the engine nozels. In addition, the aircraft can carry the Sorbtsiya active ECM pods on its wingtips.

Cockpit
The cockpit is fitted with the K-36DM Series 2 ejection seat. The seat-back is being inclined at an angle of 17 degrees. In the two-seat Su-27UB version, the seats are placed in tandem with the rear-seat being elevated to ensure good forward vision. The basic Su-27 cockpit layout consist of analogue instruments, HUD and CRT display to display data from radar and electro-optical sight (IRST). On both sides of the HUD control panel, there are sensors for the helmet-mounted target designator system. On the right side below the CRT display the RWR indicator is placed.

Weapons
The Su-27 is fitted with one GSh-301 automatic single-barrel 30mm cannon fitted inside the starboard wing LERX. It can be armed with up to 150 high explosive incendiary or armour piercing tracer rounds.

The basic Su-27's primary armament consists up to six R-27R/ER semi-active radar homer or R-27T/ET heatseeking homer medium range air-to-air missiles, as well as four R-73 IR agile all-aspect short range air-to-air missile. The basic Su-27 has only a limited air-to-surface capability consisting of only unguided bombs and rockets.

General Characteristics
Crew: 1
Length: 21.9 m (72 ft)
Wingspan: 14.7 m (48 ft 3 in)
Height: 5.92 m (19 ft 6 in)
Wing area: 62 m² (667 ft²)
Empty weight: 16,380 kg (36,100 lb)
Loaded weight: 23,430 kg (51,650 lb) with 56% internal fuel
Max. takeoff weight: 30,450 kg (67,100 lb)
Fuel capacity: 9,400 kg (20,724 lb) internal
Powerplant: 2 × Saturn AL-31F turbofans
Dry thrust: 75.22 kN (16,910 lbf) each
Thrust with afterburner: 122.6 kN (27,560 lbf) each

Role: Multirole fighter, air superiority fighter
National origin: Soviet Union / Russia
Manufacturer: Sukhoi
First flight: 20 May 1977
Introduction: 22 June 1985
Status: In service
Primary users: Russian Air Force
                          People's Liberation Army Air Force
                          Ukrainian Air Force
                          others
Produced: 1982-present
Number built: 809
Unit cost: US$30 million
Variants: Sukhoi Su-30
                 Sukhoi Su-33
                 Sukhoi Su-34
                 Sukhoi Su-35
                 Sukhoi Su-37
                 Shenyang J-11

Performance
Maximum speed: At altitude: Mach 2.35 (2,500 km/h, 1,550 mph)
At sea level: Mach 1.13 (1,400 km/h, 870 mph)
Range: At altitude: 3,530 km (2,193 mi; 1,906 nmi)
At sea level: 1,340 km (800 mi; 720 nmi)
Service ceiling: 19,000 m (62,523 ft)
Rate of climb: 300 m/s (59,000 ft/min)
Wing loading: With 56% fuel: 377.9 kg/m² (77.3 lb/ft²)
With full fuel: 444.61 kg/m² (10,550.75 lb/ft²)
Thrust/weight: 1.07 with 56% internal fuel; 0.91 with full fuel
Maximum g-load: +9 g

Armaments
Guns: 1 × 30 mm Gryazev-Shipunov GSh-301 autocannon with 150 rounds
Hardpoints: 10 external pylons with a capacity of up to 4,430 kg (9,770 lb) and provisions to carry combinations of:
Rockets:
S-8KOM/BM/OM
S-13T/OF
S-25OFM-PU
Missiles:
6 × R-27R/ER/T/ET/P/EP air-to-air missiles
2 × R-73E AAMs
Bombs:
RBK-250 cluster bomb
RBK-500 cluster bomb
Avionics
Phazotron Zhuk-MSE radar
Phazotron Zhuk-MSFE radar
OEPS-27 electro-optical targeting system