Gladeus Gu-21

Gu-21
Gu-21
Role	Medium bomber
National origin	Tarsas
Manufacturer	Gladeus
First flight	7 October 1960
Introduction	1962
Retired	1984
Primary user	Tarsas
Produced	1960-1965
Number built	210

The Gladeus Gu-21 was the first supersonic bomber to enter production in the Empire of Tarsas. It followed a long history of aircraft innovation from Tarsas, beginning with the Falcus Designs Fe-440, which was one of the world's first operational jet aircraft. Development of the prototype began in 1954 to utilize alongside the Gladeus Gu-18. The aircraft entered service in 1962 in the 192nd Heavy Bomber Regiment, which was stationed on the border with Ulthrannia. The aircraft proved to be a relative disappointment due to a lack of range and speed that had been expected. Only 210 were produced before serial production was halted in 1965 due to technical issues with the AA-16 Turbojets.

Development

The Gu-21 was intended as a direct replacement for the Gladeus Gu-18, which was not capable of supersonic speeds. It was the brainchild of an Air Legion requirement for a bomber capable of high speed, long range supersonic strikes against targets deep within the interior of Bahktar. It was developed by Gladeus Aircraft Workshop, today apart of the Alliance of Aircraft Manufacturers.

Development of the Gu-21 started in 1953 and borrowed design elements and language from earlier aircraft and applied a more modern and powerful airframe design language. The first prototype (X21A) flew in 1958 with the AA-15 Turbojets produced by Anacom Aerospace. The AA-15 proved to be heavy and unreliable at sueprsonic speeds, suffering from a mechanical failure mid flight and forcing an emergency landing. The next prototype (X22B) flew in 1959 with the updated AA-16 Turbojet. These engines were developed with input from Falcus Designs which had produced other highly successful jet aircraft designs.

The first serial production Gu-21 left the factory gates at the Gladeus Large Aircraft Production Plant in 1960 the following year after receiving approval for production. It was presented to the public at the National Legionary Exposition in Marvius. The first five aircraft were delivered just weeks later to the 192nd Heavy Bomber Regiment, which was stationed at Talmae Air Legion Base. Initial problems were widespread as the AA-16 engines tended to heat up to dangerous temperatures during supersonic flight. This caused the compressor section to heat up and distort the fuel lines, sometimes clogging them or reducing output. This problem caused the crash of one aircraft in December of 1963 when it lost a primary engine at high speeds.

An additional problem emerged in the form of a vast landing and takeoff distance that was almost a half mile longer than the Gu-18. This required airstrips to be lengthened significantly at all bases operating Gu-21s and severely limited the aircraft's capability to operate because of the necessity of planning specific landing bases. This was initially thought not to be an issue since the aircraft was going to operate from several specific bases initially. However, after the decision to introduce more aircraft due to their preconceived combat effectiveness, it was noted that this would become a major problem. The mechanical complexity of the design often required an extensive maintenance crew of highly trained technicians to be on station at operating bases to keep squadrons in the air. This quickly became expensive and cumbersome.

Initially, pilots were selected from high performing Gu-18 crews. This quickly became an issue, however, when the significant differences in the crew configuration (one single pilot) and the complexity of flying the aircraft made the transition difficult. Pilot selection was changed over to JF-86 pilots which eased the transition significantly. The single pilot configuration made the Gu-21 easier to become accustomed to. The difficulty of flying it, however, caused the pilots to have to undergo additional training.

By the time the first squadrons entered service, it was determined that operational use would be limited. Despite its greater speed, it proved to be wholly inferior in payload, range, and combat radius. Production was subsequently halted in 1965 after only 210 aircraft had been built. The Air Legion had declared they would take delivery of no more aircraft as of March 1965.

Design

The Gu-21 has a low-middle mounted wing swept at an angle of 55°. The two large turbojet engines are mounted atop the rear fuselage on either side of the large vertical stabilizer, with a low mounted tailplane. Continuing a Gladeus design feature, the main landing gear are mounted in pods at the trailing edge of each wing. The very swept wings gave little drag at transonic speeds, but resulted in very fast landing speeds and a long take-off run.

The cockpit placed the pilot forward, offset slightly to the left, with the weapons officer behind and the navigator below, within the fuselage, sitting on downwards-firing ejector seats. The cockpit design had poor visibility, uncomfortable seats, and poor locations for instruments and switches. This caused numerous complications with initial pilot training and operation of the aircraft.

The defensive armament, operated by the weapons officer, consisted of a tail turret beneath the engine pods, containing a single 20mm gun. The turret was directed by a small ERS-23 gun-laying radar to compensate for the weapons officer's lack of rear visibility. The main weapon load was carried in a fuselage bomb bay between the wings, capable of carrying up to 24 FFO-1000 general-purpose bombs, one FFO-5000 bomb, or various free-fall nuclear weapons. Later variants were reconfigured to carry two Falcus FE-22 supersonic anti shipping cruise missiles. The weapons caused enormous stress on the airframe due to their great weight and further complicated already difficult handling.

The early Gu-21 had an optical bombing system with an ERS-4 attack radar. Later variants had an additional ERS-73 radar to guide the missiles. The Gu-21C could carry a camera array or a VF-22 jammer pack in the bomb bay as an alternative to bombs. Later variants included ELINT equipment, and later with an under-fuselage palette for R-10 side looking airborne radar, as well as cameras and an infrared line-scanner. Tests were committed on a variant equipped to find and destroy enemy sensor emplacements but this never came to fruition before the program's cancellation in 1965.

Variants

• Gu-21A - Initial production variant designed to carry free fall bombs and large tactical nuclear weapons. Only twenty airframes were produced of this variant which were all relegated to test and training aircraft by 1963.
  • Gu-21Tr - Training variant of the Gu-21A converted from existing airframes. Ten placed in service at the Manales Flight School in 1964.
• Gu-21B - Improved A variant with the capability to carry missiles and redesigned Aa-17 Turbofans introduced in early 1961. Suffered from continuous control surface failure due to excessive heat buildup on the airframe.
• Gu-21Cr - Reconnaissance airframe introduced in 1962 equipped with ELINT systems and airframe modifications to relieve heat issues. Comprised the bulk of the production run.
• Gu-21C - Missile carrier variant built as the primary production model from 1963 onward. Put in service with several naval bomber regiments.
• Gu-21Dr - Variant equipped with aerial refueling equipment introduced in 1964. Additional modifications to the engine warranted it receiving a new variant letter.
• Gu-21E - Final variant introduced in early 1965 in an attempt to revitalize the aircraft after the program's cancellation was being considered. Included GTF-1 Turbofans, the first jet engine wholly designed and manufactured by Gladeus. The variant eliminated many of the former problems of the design with the exception of the complexity. Small numbers were produced before the program was cancelled in late 1965 and Gladeus halted production.
• Gu-21Ex - Export variant introduced in 1966 after serial production for the Legion was halted. Exported in small numbers before the Gu-21 program was cancelled entirely by Gladeus in 1968.

Operators

• Tarsas
  • Imperial Air Legion - Retired in 1984 and mothballed
  • Imperial Sea Legion - Retired in 1983 and scrapped.

Specifications

General characteristics

• Crew: three – pilot, navigator, weapons officer
• Length: 44.60 m (146.3 ft)
• Wingspan: 25.17 m (82.58 ft)
• Height: 10.13 m (33 ft 3 in)
• Loaded weight: 85,000 kg (187,000 lb)
• Max. takeoff weight: 92,000 kg (203,000 lb)
• Powerplant: 2 × AA-16 Turbojet turbojets
  • Dry thrust: rated 107.9 kN (24,300 lbf) each
  • Thrust with afterburner: 161.9 kN (36,400 lbf) each

Performance

• Maximum speed: 1,510 km/h (938 mph, Mach 1.42)
• Range: 4,900 km (3,000 mi)
• Service ceiling: 13,300 m (43,600 ft)
• Wing loading: 525 kg/m² (107 lb/ft²)
• Thrust/weight: 0.39

Armament

• Guns: 1 × Vs12 20mm cannon in tail
• Bombs: 9,000 kg (20,000 lb) or
• Missiles: 2 x Falcus FE-22