Prior to the eighties Chile possessed a decrepit fleet of military trainers obtained under the Mutual Defense Assistance Act. However, these trainers had become exceedingly difficult to repair following passage of a US arms embargo in 1976.[3] The PA-28R-300 Pillán was developed by Piper Aircraft in the United States as a two-seat military trainer for assembly in Chile, based on a PA-32R fuselage with a new center-section and wing stressed for aerobatics.[4] The first prototype designated XBT first flew at Lakeland on 6 March 1981 and was followed by a second prototype, designated YBT.[4] The second prototype first flew on 31 August 1981 and was then delivered to Chile.[4] The prototype XBT was delivered to Chile in January 1982 but was written off on 10 March 1982.[4] Production of kits at Vero Beach Municipal Airport commenced with three pre-production kits which were delivered for assembly in Chile in 1982, Vero Beach then produced 120 kits for assembly in Chile for the Chilean and Spanish Air Force.[4] The first production aircraft was delivered by ENAER to the Chilean Air Force Air Academy in August 1985.[4] The Spanish aircraft were assembled in Spain by CASA.[1]
Apart from a few turbine powered aircraft, all Pilláns were powered by a 300hp (224kW) Textron Lycoming AEIO-540-K1K5 six cylinder horizontally opposed piston engine.
In 1985 a turboprop variant was developed by ENAER as the T-35A Aucan.[4] In early 1986 one of the piston-engined pre-production aircraft was sent to Soloy Aviation Solutions in the United States for modification to install a 420 shp Allison 250B-17D engine.[4]
John R. Bawden,"Cutting Off the Dictator: the United States Arms Embargo of the Pinochet Regime, 1974–1988", Journal of Latin American Studies, 45:3 (August 2013): 513–43.