T.553 Konge

The T.553 Konge is a twin-engine tactical transport featuring a cargo hold, a rear-access ramp beneath an upswept tail, a high-mounted wing and turboprop engines. The T.553 is designed to perform cargo and troop transport duties, aerial delivery of supplies and equipment and is designed to be compatible with international railway loading gauges to simplify cargo logistics and loading. In flight the cargo area is pressurized and kept at a constant temperature by integrated air conditioning systems.

Additionally, the landing gear can be partially retracted while on the ground. This lowers the T.553, making it easier to move vehicles into the hold as they don't need to climb a ramp.

One aspect of the T.553 that made the type well suited to tactical operations was the type's short airfield performance; including the ability to perform steep descents of up to 20 degrees and perform landings on airstrips as short as 400 meters. In the airlift role, a later production T.553 could carry up to 8.5 tons across a distance of 5,000 kilometres, and take off from airstrips as short as 700 meters. Dependent upon aircraft configuration, a single aircraft could airdrop as many as 88 paratroopers or transport up to 93 equipped troops.

Advantages of the twin-engine configuration over four include reduced unit and production cost, lower weight and fuel consumption, simplified design and reliability. Each engine is equipped with an auxiliary generator system, providing the aircraft with both electricity and hydraulic pressure. An auxiliary power unit is used to power the aircraft while on the ground, and for rare use in mid-air emergencies.

An updated second generation of the T.553 was produced during the late 1980s and early 1990s. Amongst changes made, the new variant was equipped with additional fuel tankage, aerial refueling probes and enhanced avionics. While there were considerable changes to instrumentation, including the navigational and autopilot systems, the second generation T.553 retained the original operating characteristics to simplify crew transfers between types.

The T.553 proved to be a versatile aircraft, leading to a long operational service life. Between its introduction and 1999, approximately 2000 modifications and upgrades were incorporated upon the type, split 60/40 between the structure and equipment respectively. Many changes were made over time in regards to the aircraft's avionics, incorporating new features such as GPS and laser inertial navigation systems, modern autopilot and crew management systems.

First Generation

 * T.553A Konge:: Standard Airlifter variant introduced in 1963
 * ET.553B Hermóðr: Submarine Communications Relay model entering service in 1969
 * ST.553C Ragnarök: Original Gunship model entering service in 1972

Second Generation

 * T.553D Konge:: Updated second production run airlifter variant introduced in 1987
 * ET.553E Loki: Electronic Warfare model entering service in 1990
 * ET.553F Hermóðr: Submarine Communications Relay model entering service in 2002
 * ST.553G Ragnarök: Updated Gunship model entering service in 2006

General characteristics

 * Crew:3 flight crew + loadmasters
 * Capacity: 16,000 kg or 93 troops or 88 Paratroops or 62 Stretchers
 * Length: 32.4 m
 * Wingspan: 40 m
 * Height: 11.65 m
 * Crew: 160 m2
 * Empty Weight: 27782 kg
 * Gross Weight: 46000 kg
 * Max Takeoff Weight: 51000 kg

Performance

 * Maximum Speed: 513 km/h
 * Stall Speed: 177 km/h
 * Never Exceed Speed: 593 km/h
 * Range: 1853 km
 * Service Ceiling: 8230 m

Armament (ST.553G Ragnarök)

 * 1x Kanon 04 derived Short 105mm Howitzer
 * 1x Twin 35×228mm Autocannon derived from LvK.58
 * 1x Lett Automatisk Kanon 73 20×102 mm Autocannon

Operators

 * Ringerike: In service with the Royal Ringerike Air Force
 * Kironia: In service with the Kironian Defence Force
 * Poja: In service with the Pojacki National Air Force