Configuration and design. The aircraft features the regular aerodynamic configuration and is an all-metal high-wing monoplane with a trapezoid
wing, twin tails, all-moving empennage, retractable tricycle landing gear and two engines mounted in the rear of the
airframe. The primary materials used in designing the airframe are VNS-2, VNS-4 and VNS-5 steel alloys making up 80% of the
airframe, titanium alloys (8%) and D-19T heat-resistant aluminium alloy.
The semi-monocoque fuselage has no maintenance breaks with its main load-carrying compartment is the integral fuel tank. The airframe is divided into the following bays: front bay (up to frame 1), cockpit (between frames 1 and 2), aft-cockpit bay (between frames 2 and 3), side-mounted air intakes (between frames 2-6), fuel tanks' bay (between 3 and 12), tail bay (between frames 12 and 14) and tail cone (behind frame 14)/ The fuselage nose section mounts the radar antenna cone casing covering radar and IR seeker units. The pressurised cockpit is fitted with the canopy whose hinged part is opened rightwards. The cockpit transparency is made of heat-resistant glass 20 mm (windscreen) and 12 mm (hinged part) thick.
The lower part of the slanted frame mounts ejection seat and nosewheel strut fixtures. The KM-1M ejection seat is effective at any altitude at a minimal speed of 130 km/h. The pressurised and heat-proof upper part of the aft-cockpit bay houses various avionics systems while the lower part houses the nosewheel well.
The fuel tanks' bay is the main airframe structural element carrying the loading of the wing, empennage and landing gear. It is made of VNS-2, VNS-4, VNS-5 and SN-3 steels through the argon welding. Inside the bay, there are six fuel tanks: tanks 1and 2 between frames 3 and 6, tank 3 between frames 6 and 7, tanks 4 and 5 between frames 7 and 11, tank 6 between frames 11 and 12. The area between frames 6 and 9 houses main landing gear wells with the gear strut fixtures being mounted on frame 8/ The airframe rear section houses the bays holding the engines, gearboxes and stabiliser actuators. To mount and maintain engines, there have been hatches between frames 9 and 13 provided for. The engine nacelles' lower surfaces mount ventral fins and two spoilers. The fuselage spine fairing near the nozzles turns smoothly into the drag chute container.
The aircraft features side-mounted horizontal-ramp scoop-type rectangular variable air intakes. The lower part of the air intakes is made as a door which can take three positions. Three boundary layer suction channels are situated on the airframe surface above the air intakes. There are boundary layer drain slots between the air intake sides and airframe sides to drain the air into the engine compartment.
The tapered wing has a leading edge sweep angle of 42.5 degrees in the root and 41 degrees in the tip with the trailing edge sweep angle of 9.5 degrees, dihedral of -5 degrees and setting angle of 2 degrees. The wing airfoil is 3.7% thick in the root and 4.76% thick in the tip. The main elements of the wing are three longerons and two auxiliary beams. There are integral fuel tanks inside the wing with two cells housed by each wing panel. Each wing panel is attached to the airframe by five fixtures. The trailing edge mounts ailerons and flaps. The leading edge slats are detachable for the ease of access to the hydraulic and fuel systems' pipelines. The wingtips carry antiflutter loads. The air-to-air missile launch pylons are mounted under the wing, two at each wing panel. There are fences mounted on the upper surface of each wing panel right above the pylons.
The empennage is all-moving and differentially-deflectable to control the banking. The stabiliser's leading edge has a sweep angle of 50.3 degrees. The stabiliser's deflection angle is 32/-13 degrees during take-off and landing and 12.5/-5 degrees in flight at s max speed.
The aircraft is fitted with two rudder-equipped tails and underbelly fins. The fins' leading edge sweep angle is 54 degrees while the tails are outwardly canted at 8 degrees. The tails are of three-spar design. Their rudders deflect at +/-25 degrees.
The landing gear is retractable, and tricycle-type. The nosewheel strut is fitted with two KT-112 700-by-200 mm breaking wheels and a mudguard and retracts forward. The main struts fitted with KT-111 1,300-by-360 mm breaking wheels are fixed to the airframe and retract in it. The aircraft is equipped with a drag chute of two 50 sq.m canopies. The left ventral fin houses a extendable probe that extends during the landing and touches the runway, thus activating the automatic drag chute deployment.
Powerplant. It comprises two R-15BD-300 engines with a thrust of 11,200-kgf in afterburner. 17,470 litres of the T-6 avgas are carried in six fuselage and four wing tanks. A 5,280-litre drop tank could be mounted under the fuselage. The aircraft systems include the main and auxiliary hydraulic systems, pneumatic system, power supply system, air conditioning system, fire suppressant system, etc.
Avionics. The MiG-25PD sighting system comprises the Sapphire-25 radar, AVM-25 computer and TP-23 IR seeker. The aircraft also carries the Lazur-M radio command system.
The Polyot-1I navigation suite incorporates the RSBN-6s short-range radio navigation system, SKV-2N attitude and heading reference system and SVS-PN-5 air data computer system, ARK-10 radio compass, RV-4 and RV-18 radio altimeters, MPR-56P marker receiver, SO-63B transponder and SAU-155P autopilot and flight director automatic control system.
Communication between the crew and ground control as well as between the crew and other aircraft is performed via the R-832M VHF radio and R-864 short-wave radio.
Weapons suite. It comprises missiles only, which are attached to four underwing hardpoints and include the R-40RD or R-40TD medium-range air-to-air missiles as well as R-60M short-range air-to-air missiles. The missiles can be carried in the following configurations: 2 R-40RDs and two R-40TDs; 4 R-40RDs; 2 R-40RD and 4 R-60Ms.
|NATO code name||FoxBat-E|
|Into the inventory||1979|
|Dimensions & Weight|
|Length (without Pitot tube), m||19,75|
|Overall height, m||5,139|
|Wing Span, m||14,015|
|Wing Area, m2||61,40|
|Wheel base, m||3,85|
|Take-off weight, kg||with 4хR-40||36720|
|Internal fuel, kg||18940|
|Drop tank volume, l (kg)||5300 (4370)|
|Engines||2 Turbojet R-15BD-300|
|Thrust, kgf (kN)||max||8800 (86,3)|
|in afterburner||11200 (109,8)|
|Range, km||supersonic (Mach=2,35)||1250|
|Range with drop tank 5300 l, km||supersonic||-|
|Time in flight||2 h 5 min|
|Max. speed, km/h (M=)||at altitude||3000 (2,83)|
|at ground level||1200|
|Practical ceiling, m||20700|
|Time to climb 19000 m, min||6,6|
|Max g-load||5 (3,8)|
|Take-off run, m||1250|
|Landing run (with brake parachute), m||800|
|Landing speed, km/h||290|
|Missiles AA|| 2 х R-40R & 2 х R-40T or
4 х R-40R or
2 х R-40R & 2 х R-60M
References and Credits: