As jet-powered fighter-types grew evermore impressive during the Cold War decades, it became imperative for manufacturers to develop dedicated advanced jet trainers. And to this requirement was typically added a secondary light strike role which allowed a prospective customer to fulfill two roles with one airframe. While there proved several big name concerns developing well-known systems (the BAe Hawk comes to mind), CASA ("Construcciones Aeronauticas SA") of Spain put together a viable, budget-minded development all their own as the "C-101".
The advanced jet trainer component allowed air powers to provide the necessary hands-on training for airmen that went beyond what piston-powered aircraft could deliver. These aircraft provided high-speed flight with fly-by-wire controlling and modern cockpit systems to simulate the qualities of full-sized, military-grade fighter jets. The addition of an inherent light strike capability further broadened the tactical value of such aircraft, offering (limited) ordnance-carrying capabilities giving an air power a fast-attack platform useful in engaging ground targets across uncontested airspace.
It was during the mid-1970s that the Spanish Air Force moved on acquiring a new advanced jet trainer to replace an aging stock of turbojet-powered, straight-winged designs then in service. Lacking the know-how in producing an advanced aircraft, CASA enlisted the support of Northrop Grumman in America as well as MBB of West Germany. This certainly expedited the learning curve which led to the delivery of four prototypes. The first flew on June 27th, 1977 and the requisite flight testing phase then followed until the design was finalized and formally introduced with the Spanish Air Force as the E.25 "Miro" ("Blackbird") on March 17th, 1980. CASA recognized its product under the designation of "C-101EB".
As designed, the C-101 was a clean and well-streamlined aircraft. The fuselage sported a sharp nose which aided viewing out-of-the-cockpit for the crew of two. The crew sat in a tandem seating arrangement with the rear cockpit set just slightly higher to view out over the front position. Both operators sat under a three-panel, right-side-hinged canopy. In the training role, this meant the student in front with the instructor in the rear. For combat, the primary pilot occupied the forward cockpit and the systems specialist in the rear. The fuselage spine was raised, which restricted views to the rear, but added greater internal volume for avionics, fuel, and the engine. There was a weapons bay in the forward fuselage for carrying a ventral gunpack, reconnaissance pod, laser designator, or Electronic CounterMeasures (ECM) equipment. The wing mainplanes were mounted low on the fuselage sides with half-moon intake ducts featured at the wingroots. Northrop provided the design for the inlet sections as well as the straight edges of the wing assemblies. The twin inlets aspirated the single turbofan engine installation found at the middle-rear of the fuselage. The engine exhausted through a circular jetpipe under the tail with the vertical tail unit extended aft over the exhaust ring along with its applicable, low-set horizontal planes. The undercarriage was retractable and of the tricycle arrangement, featuring a single-wheeled nose leg mounted well-forward of the cockpit floor and a pair of single-wheeled main legs found under the wingroots.
To keep costs in check, a single powerplant arrangement was agreed upon. This was made up of a Garrett (now Honeywell) TFE731-2-2J high-bypass, turbofan engine developing 3,550lbs of thrust - a powerplant more typical to business jets of the period. Performance numbers included a maximum speed of 480 miles per hour with a range out to 2,500 miles, and a service ceiling of 41,000 feet. Rate-of-climb neared 4,900 feet per minute. Not built as a speedy interceptor or dog-fighting mount, the C-101 held the power needed for its training and light attack roles.
When armed, the C-101 could be outfitted with a collection cannons, guns, rockets, and drop bombs (a later variant added support for air-to-surface missiles). In its ventral bay could be fitted a twin 12.7mm heavy machine gun arrangement or a single 30mm DEFA autocannon useful for ground-strafing actions. Three hardpoints were featured to each wing and these supported gunpods, cannon pods, rocket pods, and conventional drop ordnance.
The Spanish Air Force put in a requirement for eighty-eight dedicated trainer types to which it received its first during March of 1980 and these were all of the type added to the Spanish inventory for the life of the aircraft. The dual-purpose trainer/light strike model (C-101BB) was taken on by both Chile (as the "T-36") and Honduras in examples numbering 35 and 4 respectively and brought about use of a more powerful turbofan and ranging radar equipment. A third variant, the C-101CC - a dedicated light strike platform - was then sold to Chile (as the A-36 "Halcon" ("Hawk")) in 23 examples with a further 16 delivered to Jordan. Again the engine output was addressed, now outputting at 4,700lbs thrust.
In May of 1985, CASA unveiled a new take on the C-101 with its improved C-101DD product. The mark featured all-modern systems such as HUD (Head-Up Display), HOTAS (Hands-On Throttle and Stick) controlling, and improved weapons delivery/capability. Despite the added features, the product did not find any takers and was withdrawn.
Total production of all C-101 aircraft reached 166 examples. It has also served with the Spanish Air Force's Patrulla Aguila ("Eagle Patrol") aerobatics team. These debuted on June 4th, 1985 with the team based form San Javier Air Base.