MILAVIA - MILITARY AVIATION

Sukhoi Su-33 (Su-27K) Naval Flanker

Role: ship-borne air superiority fighter
Builder: Sukhoi, KnAAPO
Variants: Su-33 (Su-27K), Su-33UB (Su-27KUB), Su-33M (Su-27MK), Su-33MK
Operators: Russia, (China)

In 1985 the first conceptual design for a navalized version of the Su-27 fighter was approved to provide the navy's new carriers with an air superiority fighter for air defense. The carrier-borne aircraft was designated Su-27K (K = Korabelny, Ship-Borne) , factory designation T-10K and was later given the Su-33 designation by Sukhoi. NATO reporting name for the new type of Su-27 was 'Flanker-D'.

Changes from the basic Su-27

Changes from the shore-based Su-27 were the addition of canards, re-profiled leading-edge root extensions, redesigned folding outer wing panels, seperately controlled aileron and flaps. These changes were supported by an upgraded fly-by-wire control system and hydraulic system.

The Su-27K airframe and landing gear was strengthened to cope with the additional stress from carrier landings. The nose gear was changed to a twin-wheeled one with a telescopic strut and features an additional landing light and three-colour indicator lights for the carrier's flight controller's reference regarding glide-patch and landing speed.

The aircraft was equipped with a retractable hook system. The AL-31F engines were uprated to enable the pilot to recover from a failed hook up.The drag chute was removed from the tail boom. The boom itself was shortened and flattened. The wings, the horizontal stabilisers as well as the nosecone were made to fold up to reduce the aircraft's dimensions. Other visible changes included the addition of two hardpoints and a retractable in-flight refuelling probe on the port side forward of the cockpit. The IRST sensor was shifted to the starboard side.

The fighter's navigation, landing and fire control systems were all upgraded for the new environment. The SUV-27K fire control system enables the fighter to intercept aerial targets with the support of the aircraft carrier's command and control.

The 24 series produced Su-27Ks were deployed with the Northern Fleet and were assigned to the Admiral Kuznetsov aircraft carrier, which deployed on her first long-term ocean cruise in 1995 with 13 Su-27K naval fighters onboard.

Upgrade

The Su-27KM (Su-33M) is a proposed upgrade of the Su-27K similar to the Su-27M upgrade. The upgraded fire control system enables the fighter to deploy the latest RVV-AE (R-77) air-to-air missile and guided air-to-surface weapons, including laser and TV guided missiles and the Moskit heavy anti-ship missile. Other features include updated navigation, communication, ECM and cockpit with LCD screens and modern HUD. There were also plans for an export version of the Su-27MK (Su-33M) designated Su-33MK.

Trainer

To train Su-27K pilots the Su-27KUB was developed. The Su-27KUB is a combat capable trainer which features a side-by-side cockpit similar to the Su-27IB (Su-32/34) bomber. This layout was needed because the Su-27UB tandem cockpit gave not sufficient visibility for the instructor to make a safe carrier landing.

The Su-27KUB has a larger wing area, canards, ventral fins, rudders and horizontal stabilisers. These changes enable lower approach speeds and a smoother and thus safer landing. The nose section has considerably been modified to fit the side-by-side cockpit, but retains the circular nose (unlike the Su-27IB). The pilots enter the cockpit via the nosewheel bay. The IRST is, unlike on the Su-27K, centered in front of the cockpit and the IFR probe is placed on the port side just below the canopy. The gear, air intakes, fins, hook, etcetera remained the same as on the Su-27K. The maiden flight, first carrier landing and take off all took place in 1999. In the following years, the Su-33UB has succesfully completed testing and certification, which enables the type to enter series production.

Future

Until recently the Su-33 future seemed to be limited to the Russian Navy's fleet of 24 Su-33s operating from its sole aircraft carrier Kuznetsov. Although it plans to have two new aircraft carriers by 2017, at the same time it was revealed a new multi-purpose fighter would be developed to equip them.
However in late 2006 it was revealed by Russian newspaper Kommersant that Russian State arms export agency Rosoboronexport is in negotiation with China for the sale for up to 50 Su-33 naval fighters. A $100 million deal is said to be finalized in December 2006 for the sale of two Su-33s for evaluation, including options for a further 12 aircraft. China plans to operate the aircraft from the former Soviet carrier Varyag, which it acquired from the Ukraine in 1999 and is currently being refitted at the Dalian shipyard to enter service in 2010. The 12 aircraft option could be eventually increased to 48 aircraft. Although China plans to develop its own naval fighter to equip its future fleet of three indigenously developed carriers in 2016, it will take some time to develop it.

Sources:
- Fomin, A., Su-27 Flanker Story
- ACIG.org Forums
- Air Forces Monthly 2002-2005
- Air Forces Monthly 2006: December
- Websites (see related links)