Glasic International Aircraft Eagle
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| GIA Eagle | |
|---|---|
| Role | Air superiority and strike fighter |
| National origin | Tír Glas |
| Manufacturer | Glasic International Aircraft |
| Designer | Feagh O’Connor Lonan Casey |
| First flight | 1976 |
| Introduction | 1980 |
| Status | In production and service |
| Primary users | Tír Glas Menghe Dayashina Rajamaa |
| Number built | >1,000 |
| Unit cost |
~$80 million (2018 - Black Eagle)
|
The Glasic International Aerospace Eagle (Glasic: Iolar, lit. 'Eagle') is a twin-engine, twin-tail multi-role combat aircraft. Designed as a direct replacement for the Phantom (Glasic: Fantaise lit. Phantom). The Eagle unlike the Phantom was originally designed to be operated by a single person, rather than the pilot and systems operator arrangement formerly employed. Conflicting opinions during the design phase lead to the aircraft being easily convertible between single or twin occupancy, initially with only a change in canopy but more recently simply by adding or removing a fuel tank or cockpit as required. The type's main employment is now that of a strike fighter in the air interdiction and close air support roles; the Eagle however still retains all of its counter-air prowess, being widely regarded as the premier air-combat aircraft amongst aviation analysts.
Design and development
Origins
Initial development
Initial requirements for what would result in the Iolar can be traced back as far as the mid 1960s with requirements for an aircraft or aircraft to complement and eventually supplant the Fantaise in the air defence role and the Píoráid in the aerial interdiction role. Eventually the two competing requirements were combined into a single requirement in the hope to lower procurement costs by sharing development work. An official request for information was put out in March 1970 to Glasic industry and select foreign companies. Ten companies responded, soon being whittled down to four. These were Kelleher, Devaughn, Clarke White and the newly formed Government Aircraft Factories. Between these four companies some three hundred concepts were worked through, many with variable-geometry wings, most were too large. The Air Force redrafted requirements to better define the required aircraft which resulted in a further set of refined proposals more in line with the Fantaise / Píoráid replacement.
The initial versions of the Iolar were the single-seat Iolar A and twin-seat Iolar B, the A being fielded as a dedicated air defence aircraft whilst the B began to supplant both other fighter bombers and the Píoráid.
Description and role
The Eagle as it is known outside of Tír Glas has in its original form an all-metal semi-monocoque fuselage with large cantilevered, shoulder-mounted wings. The wing's planform broadly equates to that of a cropped delta but featuring a cranked trailing edge. The wing's feature a relatively moderate sweep-back angle of 45 degrees with simple ailerons and trailing-edge flaps, leading-edge flaps were not incorporated into the final design, primarily due to low wing-loading combined with a fixed leading edge of varying camber. The airfoil of the wing varies between 6% at the root to 3% at the tip.
In its original form the empennage was of combined metal and composite honeycomb construction resulting in extremely thin and strong tailplanes and rudders. The horizontal all-moving tails feature much the same construction providing roll control in certain flight regimes. A dorsal air-brake is fitted aft of the cockpit, again of composite construction.
The Eagle's manoeuvrability is due in equal parts to low wing-loading and a high thrust-to-weight ratio, further enhanced since 1995 by the introduction of 2D thrust vectoring. As-built the Eagle could obtain an altitude of 9,100m in just over a minute, in certain situations the aircraft is able to accelerate vertically due to a surplus of required thrust, this is often seen during air-show displays where the aircraft from rotation pulls up into a 90 degree climb.
Although the A model flew as a single seater and had systems designed around use by a single person later Eagles have returned to the pilot and systems operator pairing, offloading tasks from the pilot, allowing them to concentrate on flying and manoeuvring the aircraft.
Further developments
The A and B models were replaced in production in 1990 by the C and D which featured a number of changes and improvements over the older aircraft including an extra 905kg of internal fuel, conformal fuel tanks as standard, and an increase in maximum takeoff weight via new landing gear to 31,000kg, this increase allows for a full weapons load, conformal and external tanks to be simultaneously utilised. The C and D aircraft or CDs as they colloquially became known were the first to be fitted with the improved AI.90 Dhampir radar, developed from the AI.75 the AI.90 introduced a variety of changes geared toward improving reliability and easing maintenance.
Throughout the mid to late 1990s and early 2000s a Technology Insertion and Capability Upgrade Programme known as TICUP (pronounced teacup) was undertaken, providing the Eagle with an upgraded central computer derived from that introduced with the Goshawk allowing for easier integration of newer sensor and weapon systems. Also incorporated in the TICUP programme were improvements to the electronic warfare system resulting in minor external changes, enhancements to the AI.90 and upgraded engines fitted with digital engine controls, providing quicker throttle responses, reduced wear, and lower fuel consumption as well as combined thrust-reversing and thrust vectoring nozzles.
Operational history
Variants
GIA production designations
- Eagle A
- Initial single-seat aircraft, provisions for conformal fuel tanks or sensors
- Eagle B
- Twin-seat version of Eagle A, otherwise identical.
- Eagle C
- Improved single-seat aircraft, modifications to and reinforcement of airframe, cockpit canopy changed to utilise the twin-seat canopy regardless of rear seat occupancy.
- Eagle D
- Twin-seat version of Eagle C, otherwise identical.
- Eagle E
- Further improved single-seat aircraft, co-cured composite wing and tail structures, also introduced a fly-by-light system pioneered on the Goshawk allowing outer-wing hardpoints to be reintroduced. The Eagle E also introduced the option for canted tail surfaces on new-build aircraft, reducing weight and radar cross-section.
- Eagle F
- Twin-seat version of Eagle E, otherwise identical.
Glasic Air Force variants
- Iolar C.1
- Initial production model, single-seat air superiority fighter. Built from 1976 until 1990
- Iolar CA.2
- Initial production model, twin-seat strike fighter Built from 1976 until 2000
- Iolar CAT.2A
- Interim twin-seat aircraft, built and re-manufactured between 2000 until 2008
- Iolar CAT.3 (Iolar Fíréan - Golden Eagle)
- Improved version, both single and twin-seat, built and re-manufactured between 2008 and 2015
- Iolar LC.3
- Electronic warfare conversion, converted from a mix of C.1s and CA.2s between 2008 and 2010
- Iolar CAT.4 (Iolar Dubh - Black Eagle)
- Reduced radar cross-section version, built from 2015 onwards
Menghean Army Aviation variants
- GIA designation - White-tailed Eagle
Republic of Dayashina Air Force variants
- GIA designation - Imperial Eagle
Rajaan Air Force
- GIA designation - Eagle Owl
Ostenlandische Luftwaffe
- GIA designation - Little Eagle
Operators
Tír Glas
- Royal Glasic Air Force operates 490 aircraft, all to Eagle E/F standard
Menghe
- Menghean Army Aviation operates...
- Dayashina
- Republic of Dayashina Air Force operates...
- Rajamaa
- Rajan Air Force operates...
- Ostland
- Ostlandic Air Force operates...