Beechcraft King Air C90GT Aircraft in Illinois

The Beechcraft King Air C90 series is the entry point into the most successful turboprop family in aviation history. The C90 is a twin-engine, pressurized, six-to-eight seat turboprop powered by two Pratt and Whitney PT6A-21 engines (550 SHP each) that cruises at 215 KTAS with a range of 1,260 nm at FL270. Since the original King Air 90 was introduced in 1964, the C90 family has been the go-to aircraft for small corporate flight departments, charter operators, and owner-pilots stepping up from piston twins to turbine reliability. Over 2,000 King Air 90-series aircraft have been delivered.

Key variants. The C90 (1971-1982) established the platform. The C90A (1982-1992) improved the engine and systems. The C90B (1992-1994) added four-blade propellers and improved noise levels. The C90GT (2005-2008) upgraded to PT6A-135A engines (550 SHP) and Rockwell Collins Pro Line 21 avionics. The C90GTi (2008-2016) further refined the avionics. The C90GTx (2017-present) is the current production model with Innovative Solutions and Support (IS&S) glass cockpit displays and autothrottle.

Why the King Air C90. PT6A engine reliability is legendary — these engines routinely reach 8,000+ hours between overhauls on condition, with 99.95%+ dispatch reliability. Twin-engine safety, cabin pressurization to 4.0 psi differential (cabin altitude of 10,000 feet at FL220), and all-weather capability make the C90 a genuine step up from any piston aircraft. The King Air can operate from short and unimproved strips that jets cannot access. The global King Air support network is the largest for any turboprop.

Buying advice. PT6A engine condition is the primary value driver — verify hot section inspection (HSI) status, compressor turbine (CT) blade condition, and prop governor function. The C90 uses the smaller PT6A-21/135A (versus the -42/-52 in larger King Airs) — parts and overhaul costs are proportionally lower but still significant ($200,000-$350,000 per engine overhaul). Propeller overhaul (Hartzell or McCauley four-blade) runs $25,000-$40,000 per side. Check for spar strap compliance, wing deice boot condition, and pressurization system integrity.

Market. C90A: $400,000-$800,000. C90B: $600,000-$1.2M. C90GT: $1.2M-$2M. C90GTi/GTx: $2M-$3.5M. Beechcraft King Air C90 operating costs run $800-$1,200/hr all-in. A King Air C90 for sale is the most affordable way into turboprop twin ownership.