Sukhoï Su-24

Le biréacteur à géométrie variable Sukhoï Su-24 expliqué sur Wikipedia.en

[Vous devez être inscrit et connecté pour voir ce lien]

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

The Sukhoi Su-24 ([Vous devez être inscrit et connecté pour voir ce lien]: Fencer) is a [Vous devez être inscrit et connecté pour voir ce lien], all-weather [Vous devez être inscrit et connecté pour voir ce lien] developed in the [Vous devez être inscrit et connecté pour voir ce lien].

This [Vous devez être inscrit et connecté pour voir ce lien], [Vous devez être inscrit et connecté pour voir ce lien] two-seater carried the USSR's first integrated digital [Vous devez être inscrit et connecté pour voir ce lien].

It remains in service with former Soviet air forces and various air forces to which it was exported.

Development


Background


One of the conditions for accepting [Vous devez être inscrit et connecté pour voir ce lien] into service in 1961 was the requirement for Sukhoi to develop an
all-weather variant capable of precision air strikes.

Preliminary investigations with S-28 and S-32 aircraft revealed that the basic Su-7 design was too small to contain all the [Vous devez être inscrit et connecté pour voir ce lien] required for the mission.

OKB-794 was tasked with developing an advanced [Vous devez être inscrit et connecté pour voir ce lien], codenamed Puma, which would be at the core of the new aircraft.

In 1962-1963, Sukhoi designed and built a mockup of S-6, a [Vous devez être inscrit et connecté pour voir ce lien] aircraft powered by two [Vous devez être inscrit et connecté pour voir ce lien] engines and with a crew of two in a [Vous devez être inscrit et connecté pour voir ce lien] arrangement.

The mockup was inspected but no further work was ordered due to lack of progress on the Puma hardware.

In 1964, Sukhoi started work on S-58M. The aircraft was supposed to represent a modification of the [Vous devez être inscrit et connecté pour voir ce lien] interceptor (factory designation S-58).

In the meantime, revised [Vous devez être inscrit et connecté pour voir ce lien] requirements called for a low-altitude strike aircraft with [Vous devez être inscrit et connecté pour voir ce lien] capability.

A key feature was the ability to cruise at supersonic speeds at low altitude for extended periods of time in order to traverse enemy air defenses.

To achieve this, the design included two [Vous devez être inscrit et connecté pour voir ce lien] afterburning turbojets for cruise and four [Vous devez être inscrit et connecté pour voir ce lien] turbojets for STOL performance.

Side-by-side seating for the crew was implemented since the large Orion radar antennae required a large frontal cross-section.

To test the six-engine scheme, the first Su-15 prototype was converted into S-58VD flying laboratory which operated in 1966-1969.

Design phase


The aircraft was officially sanctioned on 24 August 1965 under the internal codename T-6.

The first prototype, T-6-1 was completed in May 1967 and flew on 2 July with V.S. Ilyushin at the controls.

The initial flights were performed without the four lift engines, which were installed in October 1967.

At the same time, R-27s were replaced with [Vous devez être inscrit et connecté pour voir ce lien]Fs.

STOL tests confirmed the data from S-58VD that short-field performance was achieved at the cost of significant loss of flight distance as the lift engines occupied space normally reserved for fuel, loss of under-fuselage [Vous devez être inscrit et connecté pour voir ce lien], and instability during transition from STOL to conventional flight. So the six-engine approach was abandoned.

On 7 August 1968, the OKB was officially tasked with investigating a [Vous devez être inscrit et connecté pour voir ce lien] for the T-6.

The resulting T-6-2I first flew on 17 January 1970 with Ilyushin at the controls.

The subsequent government trials lasted until 1974, dictated by the complexity of the on-board systems.

The all-weather capability was achieved - for the first time in Soviet tactical attack aircraft - thanks to the Puma nav/attack system operating in conjunction with Orion-A attack radar, Relyef terrain radar, and Orbita-10-58 computer.

The crew was equipped with zero-zero [Vous devez être inscrit et connecté pour voir ce lien]D [Vous devez être inscrit et connecté pour voir ce lien].

The first production aircraft flew on 31 December 1971 with V. T. Vylomov at the controls, and on 4 February 1975, T-6 was formally accepted into service as the Su-24.

Upgrades


Surviving Su-24M and Su-24MK models are going through a life-extension and updating program, with [Vous devez être inscrit et connecté pour voir ce lien], upgraded cockpit with multi-function displays (MFDs), [Vous devez être inscrit et connecté pour voir ce lien], digital moving-map generator, helmet-mounted sights, and provision for the latest guided weapons, including [Vous devez être inscrit et connecté pour voir ce lien] air-to-air missiles.

It is unclear if the Su-24MR and Su-24MP will receive the cockpit and navigation upgrades.

The upgraded aircraft are designated Su-24M2.

Design


The Su-24 has a shoulder-mounted [Vous devez être inscrit et connecté pour voir ce lien] outboard of a relatively small fixed wing glove, swept at 69°.

The wing has four sweep settings: 16° for take-off and landing, 35° and 45° for cruise at different altitudes, and 69° for minimum [Vous devez être inscrit et connecté pour voir ce lien] and wing area in low-level dashes.

The variable geometry wing provides excellent [Vous devez être inscrit et connecté pour voir ce lien] performance, allowing a landing speed of 230 km/h (143 mph), even lower than the [Vous devez être inscrit et connecté pour voir ce lien] despite substantially greater take-off weight.

Its high wing loading provides a stable low-level ride and minimal gust response.

The Su-24 had two [Vous devez être inscrit et connecté pour voir ce lien]A [Vous devez être inscrit et connecté pour voir ce lien] engines with 109.8 kN (24,700 lbf) thrust each, fed with air from two rectangular side mounted intakes with splitter plates/boundary-layer diverters.

In early Su-24 ("Fencer A" according to [Vous devez être inscrit et connecté pour voir ce lien]) aircraft these intakes had variable ramps, allowing a maximum speed of 2,320 km/h (1,440 mph), [Vous devez être inscrit et connecté pour voir ce lien] 2.18, at altitude and a ceiling of some 17,500 m (57,400 ft).

Because the Su-24 is used almost exclusively for low-level missions, the actuators for the variable intakes were deleted to reduce weight and maintenance.

This has no effect on low-level performance, but absolute maximum speed and altitude are cut to Mach 1.35 and 11,000 m (36,100 ft).

The earliest Su-24 had a box-like rear fuselage, which was shortly changed in production to a rear exhaust shroud more closely shaped around the engines in order to reduce [Vous devez être inscrit et connecté pour voir ce lien].

The revised aircraft also gained three side-by-side antenna fairings in the nose, a repositioned braking chute, and a new ram-air inlet at the base of the tailfin.

The revised aircraft were dubbed "Fencer-B" by NATO, but did not merit a new Soviet designation.

The Su-24's fixed armament is a single fast-firing [Vous devez être inscrit et connecté pour voir ce lien] with 500 rounds of ammunition, mounted in the fuselage underside.

The gun is covered with an eyelid shutter when not in use.

There are eight external hardpoints (two under the inner wing glove, two swiveling pylons under the outer wing, and four on the fuselage) for a maximum warload of 8,000 kg (17,600 lb), including various [Vous devez être inscrit et connecté pour voir ce lien].

Two or four [Vous devez être inscrit et connecté pour voir ce lien] missiles are usually carried for self-defense.

Initial Su-24s had basic [Vous devez être inscrit et connecté pour voir ce lien] (ECM) equipment, with many Su-24s limited to the old Sirena radar-warning receiver with no integral [Vous devez être inscrit et connecté pour voir ce lien] system.

Later-production Su-24s had more comprehensive radar warning, missile-launch warning, and active ECM equipment, with triangular antennas on the sides of the intakes and the tip of the vertical fin.

This earned the NATO designation "Fencer-C", although again it did not have a separate Soviet designation.

Some "Fencer-C" and later Su-24M ("Fencer-D" by NATO) have large wing fence/pylons on the wing glove portion with integral [Vous devez être inscrit et connecté pour voir ce lien]/flare dispensers; others have such launchers scabbed onto either side of the tailfin.