Editing CASA C-101 Aviojet (section)

==Design and development==
[[File:CASA C-101 Aviojet Spanish Air Force Patrulla Aguila (19945001451).jpg|thumb|[[Patrulla Águila]] acrobatic team flying the C-101]]
[[File:HAF C-101 Aviojet.JPEG|thumb|A C-101 Aviojet aircraft of the Honduran Air Force]]
[[File:CASA C-101CC Aviojet - Jordanian Air Force.jpg|thumb|A C-101 Aviojet aircraft of the Jordanian Air Force]]
[[File:Construcciones Aeronáuticas SA C-101EB Aviojet.jpg|thumb|CASA C-101 prototype.]]
[[File:CASA C-101EB Aviojet, Spain - Air Force AN1584619.jpg|thumb|Spanish CASA C-101]]

The C-101 was designed in response to a [[Spanish Air Force]] requirement issued in 1975, calling for a new jet trainer to replace its aging fleet of [[Hispano HA-200]]s and Ha.220s. Akin to the majority of contemporary European jet trainers, it was also to have a limited attack capability. During 1972, [[Hispano Aviación|Hispano]] had been absorbed by Spanish aircraft company [[Construcciones Aeronáuticas SA]] (CASA), who took an interest in the trainer requirement.<ref name = "fredriksen 71"/> During October 1975, CASA was awarded a development contract based upon their submission, requiring a pair of static airframes and four flight-capable [[prototype]]s to be built for testing purposes at a cost of 1,297 million pesetas ($22 million).<ref name = "oct1975 flight">[https://www.flightglobal.com/pdfarchive/view/1975/1975%20-%202194.html "Casa C-101 go-ahead."] ''Flight International'', 16 October 1975. p. 560.</ref>

To develop the aircraft, CASA sought technical assistance from abroad. Both the [[West Germany|German]] manufacturing conglomerate [[Messerschmitt-Bölkow-Blohm]] (MBB) and [[United States|American]] defense company [[Northrop Corporation|Northrop]] opted to participate in the venture; specifically, engineers at MBB worked on the design of the rear fuselage and tail section while Northrop's team were responsible for the design of the aircraft's wings and engine inlets.<ref>Frawley 2002, p. 58.</ref><ref name = "fredriksen 71">Fredriksen 2001, p. 71.</ref> Out of these efforts, a relatively conventional design was developed; according to aviation author John C. Fredriksen, the principles of simplicity and economy were highly emphasised by the design, shunning high performance features.<ref name = "fredriksen 71"/>

In terms of its basic configuration, the C-101 is a low-mounted [[monoplane]], with [[Wing configuration#Wing sweep|unswept]] wings. The [[cockpit]], which was relatively spacious amongst its peers, accommodated a crew of two in a [[tandem]] seating; the seats were staggered to provide the instructor in the rear position with greater visibility.<ref name = "fredriksen 71"/> The fuselage provided considerable internal space, permitting the installation of various additional aviation or supplemental systems as to suit future requirements or other secondary roles.<ref name = "fredriksen 71"/> Foreseen secondary roles included ground attack, armed escort, [[aerial reconnaissance|photographic reconnaissance]], and as an [[electronic countermeasures]] (ECM) platform.<ref name = "oct1975 flight"/><ref>[https://www.flightglobal.com/pdfarchive/view/1976/1976%20-%201870.html "Garrett's TFE731 turbofan."] ''Flight International'', 4 September 1976.</ref>

The only unconventional feature of the aircraft was the presence of a large internal weapons bay located beneath the rear cockpit; this allowed for a wider variety of armament to be carried than the underwing [[hard point]]s could accommodate; alternatively, this bay enabled the carriage of other equipment, including [[reconnaissance]] payloads. In addition to the weapons bay, both armaments and stores could be fitted upon six underwing hard points.<ref name = "fredriksen 71"/> The design was produced in a [[Modularity|modular]] fashion, which eases both manufacture and maintenance activities. It was provisioned with a considerable endurance range as a result of the initial requirement having called for a self-deployment capability to the [[Canary Islands]] from the Spanish mainland.{{Citation needed|date=August 2019}}

The powerplant selected for the aircraft was the [[Honeywell TFE731-5-1J]] [[turbofan]] engine.<ref name = "fredriksen 71"/> This unit was actually a commercial engine that had been re-developed for military use. Even from an early stage of development, the TFE731 was viewed as a front runner for the aircraft.<ref name = "oct1975 flight"/> According to Fredriksen, it provided relatively favourable performance and a high level of fuel economy amongst its peers.<ref name = "fredriksen 71"/> Overall, the aircraft provided mainly favourable characteristics while remaining an affordable trainer in comparison to international competition.<ref name = "fredriksen 71"/>