Every Su-27 Flanker has a tail that does not quite end. Between the two big engine exhausts, the centre of the fuselage keeps going, a long pointed boom sticking out behind the jet like a sting. Spotters call it the "stinger", and it is one of the easiest ways to recognise a Flanker from any angle.

It is not there for looks. On a fighter where every cubic centimetre counts, the stinger is valuable real estate. Depending on the version, it carries the brake parachute, the chaff and flare dispensers, a rear-facing radar or even an auxiliary power unit.

Why the Flanker has a tail boom

In the Flanker's layout, the two engines sit in separate nacelles with a wide gap between them, rather than side by side in one fuselage like an F-15. The central fuselage, which carries most of the fuel and systems, continues aft between them and ends in the stinger well behind the engine nozzles.

That gave Sukhoi a long, slim compartment at the very back of the aircraft where equipment could be packed without stealing space from fuel or avionics further forward.

A parachute in the tip

The pointed end of the standard Su-27's stinger can house the brake parachute, according to the Aircraft Recognition Guide. After touchdown, the chute deploys from the tip of the boom and helps slow the heavy fighter, saving brakes and runway.

As the photo at the top of this article shows, the Su-27's braking chute streams out directly behind the aircraft from the end of the stinger, on the centreline between the two engines.

Flares and chaff

The stinger also carries the Su-27's self-protection. According to MiGFlug's Aircraft Encyclopedia entry for the type, the APP-50 chaff and flare dispensers are built into the tail boom between the engines. From there, flares can be fired behind and around the aircraft to decoy heat-seeking missiles, and chaff to confuse radars.

Later production Su-27s can be recognised by box-like extensions on the sides of the stinger, while earlier aircraft had only small strakes along the sides of the tail cone.

Radar, power and a carrier version

Because the stinger points backwards, it is also the obvious place for anything that needs to look behind the aircraft. On the Su-27M, the 1990s upgrade that first carried the Su-35 name, the N012 rear-looking radar was located in the central tailboom, according to MILAVIA.

The Su-34 strike fighter has a longer and thicker stinger that contains an auxiliary power unit, while the naval Su-33 has a shorter tail cone that points slightly upwards. The modern Su-35S, meanwhile, has a reshaped stinger without the rectangular boxes of the late Su-27s.

Look closely at any Flanker and the stinger tells you a lot about which one you are seeing. It is a small part of a big aircraft, but it is the bit you see last as it flies away.

Sources: MiGFlug Aircraft Encyclopedia, Aircraft Recognition Guide, MILAVIA, Wikipedia