The SDY-Sciathan 22 Fairtheoir Carrier Support Aircraft is a twin-turboprop carrier-borne AWACS, ground attack and generally support aircraft with twin-booms.

The term fairtheoir means watchman.


The SDY-Sciathan 22 Fairtheoir Carrier Support Aircraft is a 14.1 metres long, 5.1 metres high aircraft with a wingspan of 16.1 metres when extended and 8.0 metres when folded up for storage. It's main defining trait are the twin-booms, two longitudinal booms extending from the main wing backwards on either side of the centreline. The cockpit is housed in a central nacelle, where pilot and radar operator sit.

This arrangement allows for easier access to the nacelle, and the systems housed in it, for maintenance and repairs, as well as less surface area of the aircraft, which results in less aerodynamic drag and thus either more speed or less fuel consumption. The engines are generally easy to maintain, although skilled personnel is required for that.

A pilot and a radar operator fly the aircraft in the small cockpit nacelle in a tandem configuration with the radar operator facing backwards onto his screens. The cockpit is fully digital, with LCD screens displaying all relevant information and more. It can be hooked up to a helmet with Heads Up Display. The aircraft is also controlled by fly-by-wire controls with triple-redundant controls and dual redundant digital databusses. An inertial navigation system provides the pilot with data about speed, heading and position. With the aid of additional fuel tanks, the radar operator can also make use of the flying boom installed at the rear of the nacelle, allowing the SDY-Sciathan 22 Fairtheoir Carrier Support Aircraft to act as an aerial gas station.

The SDY-Sciathan 22 Fairtheoir Carrier Support Aircraft can act as a node for the Artio Battlescape Network, a including satellite communication systems. As such, it is also compatible with many of the most common battlescape network systems, but we still recommend reading the manual.


The SDY-Sciathan 22 Fairtheoir Carrier Support Aircraft is equipped with not one, but two radars: One is a small aircraft radar with a range of up to sixty kilometres and operating on the X-Band, placed in the nose and mostly serving normal flight operations.

More important, however, is the actual AWACS Radar, a Nuacht N-45 Mark III Planar Phased Array Radar, which is a sibling to the one used on theSDY-Greadtóir 19 Cuaifeach Mark I Shipborne AWACS Helicopter. The N-45 is a planar array radar, which, in Mark III configuration, is a dual-sided antenna mounted onto the back of the SDY-Sciathan 22 Fairtheoir Carrier Support Aircraft – modular architecture of that mounting allows for easy removal for maintenance.

The N-45 Mark III can detect and track aircraft-sized targets at a maximum range of 250 kilometres, as well as ask for their identity. Ships can be detected, depending on their size, at a range of 300 to 400 kilometres. These ranges can be reached along the 'broadsides' of the radar array, while aircraft-sized targets can be acquired and tracked at a distance of 100 kilometres when in front or the back.

In addition to merely detecting aircraft and asking for their identity, the N-45 Mark III is capable of processing signals it receives, for example from other radars, and identifying them as well – or sending the signatures down for analysis. The N-45 can also track while scan and features frequency-hopping, which allows the radar to counteract jamming. The N-45 has an air-search and a sea search mode.


The SDY-Sciathan 22 Fairtheoir Carrier Support Aircraft is powered by two Luas L-40 Mark XIX Turboprop Engine, which provide 3,250 kW of power each. It is a single-shaft, modular engine with a 14-stage axial flow compressor driven by a 4-stage turbine. These engines drive two seven-bladed scimitar propellers and are equipped with FADEC Units, or Full Authority Digital Engine Control Units, which regulate the engines better to provide maximum fuel efficiency and save weight, as well as on indicators, which the pilot has to monitor, thus making the SDY-Sciathan 22 Fairtheoir Carrier Support Aircraft easier to fly.

The great advantages of turboprops, especially at flying below 725 km/h, is their greater fuel efficiency when compared to a turbojet aircraft flying at a similar speed – however, the great disadvantage in this comparison is, that a turbojet can fly at greater altitudes, which allow for higher speeds.

The L-40 is one of the longest-serving aircraft engines in the history of the Free Lands, the Mark II being introduced in 1960 with the Sciathan Méid, a civilian passenger aircraft. Mark XIX was developed in the mid-2010s, a rugged and reliable engine for the application with turboprop aircraft designed for difficult environments and short airstrips (like a carrier's flight deck, although we still recommend the usage of a catapult).


The SDY-Sciathan 22 Fairtheoir Carrier Support Aircraft is equipped with eight hardpoints with provisions to carry 7.5 tons in additional fuel tanks or ammunition. If the aircraft is to be launched from carriers, we recommend a weapons load of around five tons for safe operations. The hardpoints can be used to carry smart and dumb bombs, rockets, missiles and the aforementioned additional fuel tanks, as well as support equipment such as ECM-pods and cameras or even cargo pods. While the aircraft is not a fighter aircraft, the SDY-Sciathan 22 Fairtheoir Carrier Support Aircraft can be equipped with air-to-air missiles.

The Gabha G-116 Mark III is a 30 millimetre revolver canon, the same as on the SDY-Sciathan 18 Stuama Mark II Light Multirole Fighter, has a selectable rate of fire of either 200, 400, 800, 1,400 or 2,500 rounds per minute. The chamber is electrically operated, which is reliable and safe, as well as fast, nearly twice as fast as the gas-operated predecessor, and housed in the wing-roots.


Sciathan has always been one of the chief suppliers of aircraft to the SDF. The first jet, the Sciathán Fabhcún, had been built by Sciathan and while such orders brought much profit and prestige, the company did not rest on laurels.

In the 1960s, with the Sciathan Méid, the company opened itself to turboprop aircraft, an option, which was rarely used until then – but once the Méid turned out to be a success, Sciathan began multiple projects. One of these was, in the early 70s, the Sciathan Fairtheoir, a twin-engine, turboprop aircraft with normal fuselage and butterfly tailplanes, built as a patrol and attack aircraft. It was an ambitious project, which came to a screeching halt in the Yard Crisis, a huge economic crisis in the Free Lands. Sciathan itself barely survived.

The project was revived for a short while after the Second Vellenge War in 1983, but was shelved again in 1985.

Fast forward, Sciathan became a subsidiary of SDY, built a number of aircraft, while SDY built an aircraft carrier, the Beag-class Aircraft Carrier, which led to the need for carrier-borne aircraft. One of the roles needed was a support aircraft and someone remembered the Sciathan Fairtheoir – of course, the original design was unsuited and development, under the name SDY-Sciathan 22 Fairtheoir Carrier Support Aircraft, began anew and from scratch.

First Flight was in the spring of 2018, the SDF evaluating the design for its own, land-borne usage. Several other countries expressed interest as well. In late 2019, the SDF decided to adopt the Fairtheoir, for the Navy as a supplement to the Guairdeall and for the Army as a heavier alternative to the Veilbhit-II Light Attack Aircraft and general support plane.

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