For much of its existence, the Chilean Air Force has been hugely dependent upon foreign design types to stock its active flying inventory and this included a modest fleet of basic trainers. Pressed by a 1976 U.S. arms embargo, the country called on Piper Aircraft for assistance in design and development of a new trainer aircraft. A first-flight of this machine was had (in prototype form) on March 6th, 1981. From this arrived the ENAER T-35 "Pillan" ("Volcano") in 154 examples, mostly assembled locally in Chile. Production spanned from late-1984 into 1991.
Piper completed two flyable prototypes as "XBT" and "YBT" under the "PA-28R-300" company designation (XBT was later lost in a crash in Chile). The initial production form became the "T-35A" and this entered service with the Chilean Air Force during August of 1985. The design was very conventional, seating the student and instructor in tandem under a large, side-hinged canopy. The engine was fitted to the nose in the usual way and the tail was given a single fin with low-mounted horizontal planes. The wing mainplanes were low-mounted along the fuselage sides and fitted just ahead of midships. The tricycle undercarriage was retractable.
Dimensions included a length of 26 feet, a wingspan of 28.9 feet and a height of 7.7 feet. Empty weight was 1,835lb against an MTOW of 2,900lb. Power from the Avco Lycoming AEIO-540-K1K5 6-cylinder, air-cooled engine reached 300 horsepower. Maximum speed was 195 miles per hour with cruising at 165 mph. Its range was out to 750 miles with a reported service ceiling of 19,000 feet and rate-of-climb of 1,525 feet-per-minute.
While the T-35A designation served to cover the primary flight training models, the "T-35B" arrived as an instrument training platform. The "T-35C" became a primary trainer form that was delivered to Spain (final local assembly by CASA) for use by the Spanish Air Force and known locally as the E.26 "Tamiz". The "T-35D" was a similar model but shipped to both Panama and Paraguay. The "T-35DT" arrived as a turboprop-powered form fitting the Allison 250-B17D series engine of 420 horsepower. It was originally known as the "T-35XT".
The "T-35S" became an aerobatic high-performance model seating just one crew and the T-35T "Aucan" was an improved turboprop model.
The "Pillan 2000" was a modernized form of the original T-35.
The complete list of operators became Chile, the Dominican Republic, Ecuador, El Salvador, Guatemala, Panama, Paraguay and Spain. All of these powers continue to operate the aircraft in varying numbers with Spain the largest (35 examples) as of 2017. The Chilean Air Force relies on some nineteen T-35 trainers today (2017).