acrobatic team flying the 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-200s and Ha.220s. Akin to the majority of contemporary European jet trainers, it was also to have a limited attack capability. During 1972,
Hispano had been absorbed by Spanish aircraft company
Construcciones Aeronáuticas SA (CASA), who took an interest in the trainer requirement. To develop the aircraft, CASA sought technical assistance from abroad. Both the
German manufacturing conglomerate
Messerschmitt-Bölkow-Blohm (MBB) and
American defense company
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. 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. 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 points 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. The design was produced in a
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. The powerplant selected for the aircraft was the
Honeywell TFE731-5-1J turbofan engine. 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. According to Fredriksen, it provided relatively favourable performance and a high level of fuel economy amongst its peers. Overall, the aircraft provided mainly favourable characteristics while remaining an affordable trainer in comparison to international competition. ==Operational history==