The Sukhoi Su-15 (NATO reporting name: Flagon) is a twinjet supersonic interceptor aircraft developed by the Soviet Union.

A variety of development aircraft evolved, including the Sukhoi T-49, which shared the fuselage of the Su-9 (including its single engine), but used cheek-mounted intakes to leave the nose clear for a large radome for the RP-22 Oryol-D ("Eagle") radar (NATO "Skip Spin"), and the T-5, essentially a heavily modified Su-11 with a widened rear fuselage containing two Tumansky R-11 engines.

These led to the T-58, which combined the twin engines with a modified version of the T-49's nose, but with side inlets further back, behind the cockpit.

Aerodynamic demands forced a redesign of the radome with an ogival shape, earning a new NATO reporting name, "Flagon-F", although again the Soviet designation did not change.

Although many components of the Su-15 were similar or identical to the previous Su-9 and Su-11, including Sukhoi's characteristic rear-fuselage air brake, the Su-15 abandoned the shock-inlet cone nose intake for side-mounted intake ramps with splitter plates feeding two powerful turbojet engines, initially the Tumansky R-11F2S-300.

The change allowed room in the nose for a powerful search radar, initially the RP-22 Oryol-D (NATO 'Skip Spin').

If all else failed, IR homing versions of the K-8 would provide a last opportunity to shoot down the intruder, along with any gun pods the Su-15 might be carrying.

This eventually led to the MiG-23P, which did have look-down/shoot-down capability, becoming the preferred asset of the V-PVO, especially once NATO switched to low-level penetration tactics.

Although it was produced in large numbers (1,290 of all types), the Su-15, like other highly sensitive Soviet aircraft, was never exported to the Warsaw Pact or any other country due to its sophisticated systems.

Proposed advanced version with Tumansky R-67-300 three spool turbofan engines, each producing 78.44 KN of afterburning thrust.

Sukhoi Su-19 would have ogival wing, improved avionics suite with new Look down - shoot down radar and additional pylons for missiles.

[4] Data from Wilson[6] airwar.ru,[7] Gordon[8]General characteristics Performance Armament Avionics Related development Aircraft of comparable role, configuration, and era