[1] The whole JAS-project was complicated already without considering the parliamentary aspects, where a not insignificant minority spread over the party-lines either was principally against the military industry or opposed the growing costs of developing a domestic aircraft.

chief of the airforce and Försvarets Materielverk (FMV), along with other major actors with different competences and areas of responsibility, while the Ministry of Defence interfered at random to prove that they were keeping things in control.

Continuous studies done by FMV and Volvo Flygmotor AB (VFA) throughout the 1970s meant the candidates for what the new engine should be based on were quickly reduced to Pratt & Whitney F100 that would have resulted in an aircraft larger than the targeted 50%, or the smaller Turbo-Union RB199 and General Electric F404-400 that did not offer enough performance.

include a better tolerance to birdstrikes with minimal thrust loss (6% was achieved during a test, after ingesting a half-kilogram (1.1 lb) pigeon-size bird at take-off conditions), adjustable stators behind the inlet vanes before the fans and the compressor stages to optimise airflow regardless of speed and AoA, redesigned and doubled circuit ignition systems, the 1996 development of 50W a full authority digital engine control (FADEC) system with a mechanical calculator as seamless backup, and a completely redesigned, internally cooled flame holder for the afterburner.

[5][3][4] Several subsystems and components were also redesigned to reduce maintenance demands, including a modular design that split the engine into 7 distinct parts that can be replaced independently.