Twin-Engine Turboprops: The Business Case for Two Propellers

Why Twin Turboprops Still Exist in the Jet Age

The Beechcraft King Air 350 burns approximately 100 gallons per hour at cruise. A comparable light jet, the Citation CJ3+, burns approximately 150 gallons per hour. At $7.00 per gallon, that is a $350 per hour fuel savings on the King Air. Over 400 annual flight hours, the fuel difference alone exceeds $140,000. That is not a rounding error; that is a crew member's salary.

But fuel savings only tell half the story. Twin turboprops access 5,000+ airports in the United States that jets cannot use. Grass strips, gravel runways, short fields under 3,000 feet, and remote airstrips in Alaska, the Mountain West, and rural communities across the country. The King Air 350 lands on a 3,300-foot runway with reserves to spare. The Citation CJ3+ needs 3,200 feet on a good day and 4,000 feet at elevation.

The trade-off is speed. The King Air 350 cruises at 312 knots true airspeed. The CJ3+ cruises at 415 knots. On a 500 nm trip, the jet saves 30 minutes. On a 200 nm trip, the difference shrinks to 12 minutes. For mission profiles under 400 nm, the twin turboprop's lower operating costs and superior airport access offset the speed disadvantage entirely.

The King Air Family: 350, 250, and 90

The King Air 350 is the flagship: two Pratt & Whitney PT6A-60A engines, 312 knots cruise speed, 1,806 nm range, and a pressurized cabin seating 8-11 passengers depending on configuration. The aircraft has been in production since 1990 and the design lineage traces back to the 1964 King Air 90. Over 7,600 King Airs have been delivered, making it the most successful turboprop family in business aviation history.

The King Air 250 (formerly the B200) occupies the midrange: two PT6A-52 engines, 310 knots cruise, 1,580 nm range, and seating for 7-9. Slightly shorter and lighter than the 350, it operates from even shorter runways and costs approximately 15% less per hour to operate. The 250 is the most popular King Air variant for air ambulance, survey, and government special missions.

The King Air 90 series (C90GTx) is the entry point: two PT6A-135A engines, 272 knots, 1,260 nm range, seating for 5-7. Production ended in 2023, but hundreds remain in service. The 90 is a working airplane: ranch operations, pipeline patrol, air ambulance, and regional business travel where a 4-seat cabin is sufficient.

The Piaggio P.180 Avanti: The Turboprop That Acts Like a Jet

The Piaggio P.180 Avanti EVO cruises at 395 knots, faster than several light jets and only 20 knots behind the Phenom 100. Two PT6A-66B engines in pusher configuration (mounted behind the cabin, facing rearward) produce lower cabin noise than conventional tractor-configuration turboprops. The Avanti's three-surface design, with a forward canard, main wing, and T-tail, generates lift more efficiently than a conventional layout.

The Avanti seats 7-9 passengers in the widest cabin in the turboprop class: 6 feet 1 inch wide, wider than a Citation CJ3+ or Phenom 100. The cabin width and jet-like speed make the Avanti a unique proposition: turboprop fuel costs with light-jet performance and a midsize-jet cabin.

The Avanti is the aircraft that forces you to ask whether you actually need a jet. At 395 knots and $1,800/hr, it covers the same 500 nm mission as a Phenom 300 at $3,800/hr, arriving 15 minutes later. Those 15 minutes cost $2,000. Most clients do not value their time at $8,000 per hour.

Operating Economics: Where the Math Wins

Annual ownership costs for a King Air 350 at 400 flight hours run approximately $1.2 million to $1.5 million including fuel, crew, maintenance, insurance, and hangar. The same utilization on a Citation CJ3+ runs $1.6 million to $2.0 million. The cost advantage widens for operators in rural areas where Jet-A is cheaper and runway access matters.

Insurance premiums on twin turboprops are lower than on jets, reflecting the type's safety record and the lower hull values of most turboprop aircraft. A King Air 350 insures for $15,000-$25,000 annually. A comparable light jet insures for $25,000-$40,000. Maintenance costs per flight hour are also lower: the PT6A engine family is the most widely supported turbine engine in the world, with overhaul shops on every continent.

Mission Profiles: Where Turboprops Dominate

• Regional business travel under 400 nm: the speed difference vs a jet is negligible, but the cost difference is substantial
• Unpaved and short runways: gravel strips, grass fields, and unimproved surfaces that no jet is certified to use
• Air ambulance and medical transport: the King Air 250 is the dominant platform in US air ambulance operations
• Ranch and agricultural operations: accessing private strips on working ranches across Texas, Montana, and the Dakotas
• Pipeline and utility patrol: low-speed, low-altitude survey missions that jets cannot efficiently fly
• Island hopping: Caribbean, Hawaiian, and Alaskan island operations where 3,000-foot strips are standard
• Government and military special missions: King Air variants serve in ISR, maritime patrol, and training roles worldwide

The common thread is access. Twin turboprops go where jets cannot. For operators whose mission requires flexibility in airport choice, the turboprop is not a compromise; it is the right tool.

Pre-Owned Market and Acquisition

A 2015 King Air 350i trades between $4.5 million and $5.5 million depending on total time, engine hours remaining to TBO, and avionics configuration. A 2010 King Air 250 trades between $2.8 million and $3.5 million. The King Air holds value well relative to jets because of the type's utility, the breadth of the operator base, and the military/government demand that creates a price floor.

Piaggio Avanti EVO aircraft are rarer on the pre-owned market. Approximately 230 Avantis have been built since 1990. Parts availability has been a concern since Piaggio Aerospace entered and exited restructuring multiple times. Buyers considering an Avanti should budget higher maintenance reserves and establish parts sourcing relationships before acquisition.

First-time turboprop buyers coming from the jet world are often surprised by the economics. The acquisition cost is lower, the operating costs are lower, and the maintenance infrastructure is deeper. The PT6A engine family has been in production since 1963 and has accumulated over 400 million flight hours globally. No jet engine comes close to that service history.