Beechcraft Super King Air 350

The Beechcraft Super King Air 350 is the stretched, most-capable member of the King Air family and the best-selling cabin-class turboprop in history. Introduced in 1990 as a development of the Model 300, it added a 34-inch fuselage stretch, winglets, and upgraded PT6A-60A engines flat-rated to 1,050 SHP each. It remains in production today (as the King Air 360, a 2020 avionics/interior refresh) after more than 35 years, making it the longest-running cabin-class turboprop program in the market.

Operators span corporate flight departments, fractional programs, air ambulance (Life Flight, REVA), special-missions providers (ISR, maritime patrol, photo/survey), and the U.S. and foreign militaries (MC-12W Liberty, RC-12, UC-12W). Over 800 Model 350s have been delivered. Its reputation is for rugged reliability, short-field capability rare in its class, and a true stand-up cabin that can seat 9-11 passengers in a double-club or executive layout. It is the benchmark against which all other turboprops are measured — slower than a PC-12 or TBM but with twin-engine redundancy, larger cabin volume, and unmatched mission flexibility.

Related wiki pages: beechcraft-king-air-90-200, pilatus-pc12, daher-tbm.

The 350ER is mechanically identical in engines but has strengthened Beechcraft 1900-derived landing gear, larger-capacity fuel system in the engine nacelles, and is certified for 16,500 lb MTOW — the configuration favored for ISR, medevac, and long-leg missions.

Book max cruise of 312 KTAS is achievable at FL250-270 on a standard day at mid-weights; typical real-world planning is 290-300 KTAS at FL270-290 burning ~95-105 GPH total. Against a PC-12 NGX (285 KTAS, ~75 GPH) the 350 is faster but burns 25-30% more fuel for the speed. Against a TBM 960 (330+ KTAS, ~60 GPH) the 350 loses on speed and efficiency but wins on cabin size, payload, and engine redundancy.

Field performance is a defining feature: the 350 will clear a 50-ft obstacle in ~3,300 ft at max gross and lands in under 2,700 ft. It routinely operates from 3,500-ft strips that would be marginal for most light jets. Hot-and-high performance is strong thanks to the flat-rated PT6A-60As — the engines don't lose rated power until well above sea level on a standard day. Service ceiling is 35,000 ft but most operators cruise FL270-310 for best range and ride.

The 350ER with full 775 gal nacelle fuel can stay aloft 8+ hours and plan 2,100+ nm legs — a capability no single-engine turboprop matches. Payload-range tradeoff at 16,500 lb ER MTOW still leaves ~3,000 lb useful payload with full fuel.

At the standard 15,000-lb MTOW with ~9,050-lb empty weight, useful load is ~5,950 lb. Full fuel (539 gal × 6.7 lb/gal ≈ 3,610 lb) leaves ~2,340 lb for pilot, passengers, and bags — roughly 11 occupants at 200 lb each. In practice most corporate ops fly 6-8 passengers with plenty of fuel for 1,500+ nm legs.

With 8 passengers and bags (~1,800 lb), fuel load is capped around 4,100-4,200 lb (~615 gal... but the tanks only hold 539 gal), so full tanks plus 8 pax is the operational norm — the 350 is rarely fuel-limited at 15,000 lb.

The 350ER at 16,500 lb MTOW with 775-gallon nacelle-augmented fuel (~5,200 lb fuel) and ~9,400-lb empty weight leaves ~1,900 lb useful payload with full fuel — enough for 8-9 occupants while flying 2,100+ nm. This is the configuration used for medevac missions where sensor pods, medical equipment, and crew eat 800-1,200 lb of the useful load before any patients board.

Trade fuel for payload: reducing fuel by 1,000 lb (~150 gal, ~300 nm of range) adds 1,000 lb of cargo — useful for short-hop freight runs or maxed-out executive configurations. The 350 is one of the very few turboprops that can legitimately fly full seats and useful fuel without compromise, which is the foundation of its market dominance.

Sources:

• GlobalAir King Air 350 specifications
• GlobalAir King Air 350ER specifications
• Beechcraft Super King Air - Wikipedia
• AOPA Beechcraft King Air 360
• Guardian Jet King Air 350 brochure
• King Air 350 Buyer's Guide 2025 - 5x5 Trading
• Simple Flying King Air Cost 2025
• AvBuyer PT6A Engine Values
• King Air Magazine - Hot Section Inspections
• BWI King Air Insurance Cost
• RTC King Air 350 Type Rating Guide
• Elliott Aviation King Air Maintenance
• King Air 350i Specification PDF - Africair
• Flying Magazine King Air 350ER

• Business travel (10/10) — This is the King Air 350's dominant mission. Stand-up cabin with 57.4 in height, 9-11 seats, enclosed lav, pressurized to 6.6 psi (maintaining ~5,000 ft cabin at FL280), and true all-weather dispatch reliability. Twin PT6s give single-engine climb performance no PC-12 or TBM can match for risk-averse corporate/government ops.
• Cross-country (9/10) — 1,800+ nm standard, 2,100+ nm ER. Can do nonstop CONUS legs like NYC-Denver or LA-Miami routinely. Only dinged vs a 10 because fuel burn is roughly 2× a PC-12 for similar missions.
• Cargo hauling (9/10) — 5,400+ lb useful load, large cargo door optional (49 in × 52 in), reinforced floor options. Widely used by freight operators (Martinaire, Ameriflight variants, Alpine Air). Belly pod option on ER adds another ~600 lb capacity.
• Surveying (9/10) — Special-missions king. Belly pods, sensor provisions, long endurance, ability to loiter at low altitude or high altitude. Used extensively for aerial mapping, geophysical survey, ISR, and environmental monitoring. Only PC-12 and Twin Otter compete.
• Backcountry (3/10) — Field length is remarkable for a 15,000-lb airplane but pavement or hard-packed gravel is required; not a true bush aircraft.
• Flight training (2/10) — Used for type-rating training at FlightSafety, SimCom, and CAE, but never an ab-initio platform. Hourly operating cost ($1,500-2,500+) makes it uneconomic for primary training.
• Aerobatics (1/10) — N/A. Transport-category airframe, not certified for aerobatic maneuvers.
• Local fun (1/10) — Possible but absurd; $1,500+/hour to go grab a $100 hamburger.

• 1990-2004 (Model 350, early production) — Collins Pro Line II (EFIS-84/85 CRT displays), Collins APS-65 autopilot, early FMS. Most of these have been upgraded; original panels are now the floor of the market.
• 2004-2008 (late 350) — Collins Pro Line 21 optional then standard: three 10×8 LCDs, integrated FMS-3000, Collins radios, Honeywell KGP-560 EGPWS.
• 2009-2020 (350i) — Pro Line 21 standard with Integrated Flight Information System (IFIS), XM weather, TCAS II, enhanced maps, Rockwell Collins Venue CMS cabin management, dual FMS, CPDLC option.
• 2020-present (360) — Rockwell Collins Pro Line Fusion with three 14-inch touchscreen displays, synthetic vision, graphical flight planning, autothrottle (optional), runway overrun awareness, IS&S ThrustSense option on earlier models.

Aftermarket upgrades: Garmin G1000 NXi retrofit (via Textron STC on some variants) for older 350s runs $500k-900k installed. ADS-B Out is universal. FANS-1/A CPDLC and SATCOM are common on aircraft used internationally. See avionics-pricing.

• Blackhawk XP67A upgrade — Replaces PT6A-60A with PT6A-67A engines (1,200 SHP), restoring takeoff thrust and boosting cruise to ~335 KTAS. Install cost approximately $1.2M-$1.4M. The fastest King Air 350 in service.
• Raisbeck Engineering mods — Ram air recovery system, EPIC platinum package (dual aft-body strakes, high-flotation gear doors, nacelle wing lockers, 4-blade swept props). Packages run $250k-500k; add 5-12 kt cruise and improve climb and short-field performance.
• BLR Aerospace winglets — Although the 350 came with factory winglets, BLR offers upgraded composite winglets and vortex generators improving climb and second-segment performance.
• Executive interior refurbishment — $300k-$800k depending on scope (leather, veneers, cabinetry, LED lighting, IFE, WiFi via Gogo AVANCE L3 or Starlink Aviation).
• Medevac conversion (Aerocare, LifePort) — Stretcher, O2, suction, inverters, 110V outlets. $150k-400k depending on configuration.
• Garmin GFC 600 autopilot retrofit — Available on some older 350s when original Collins APS-65 becomes unsupportable. ~$250k installed.

The King Air 350 benefits from the largest turboprop support network in the world. Textron Aviation service centers, authorized independents (Elliott Aviation, Duncan Aviation, Stevens Aerospace, West Star, Cutter Aviation, Stan Air), and hundreds of experienced King Air shops cover every region. Parts availability is excellent through Textron and an active aftermarket. Pratt & Whitney P&WC engine support is global.

Typical annual operating costs for a 350-400 hour/year owner-operated 350 run $550k-$800k all-in:

• Fuel (400 hr × 100 GPH × $6.50/gal Jet-A): $260k
• Engines (ESP Gold or reserves at ~$350/hour per engine): $280k
• Airframe maintenance and phase inspections: $60k-$120k
• Hangar, insurance, training, nav data, misc: $80k-$150k

Expensive items: hot section inspections ($40k per engine), engine overhauls (~$500k per engine at 3,600-hour TBO), prop overhauls (~$25k each), 6-year gear inspection ($60k-$120k), landing gear actuator overhauls, bleed-air system components, cabin pressurization outflow valves, and avionics DU exchanges. Phase 1-4 inspection cycle averages $15k-$40k per phase. See maintenance-ecosystem.

Market range spans roughly $2M-$8M depending on year, time on engines, avionics, and pedigree.

• 1990-1995 350 — $1.9M-$2.8M. Older Pro Line II panels, may need avionics investment.
• 1996-2004 350 — $2.5M-$3.8M. Mid-life airframes, often with Pro Line 21 retrofits.
• 2005-2008 late 350 — $3.2M-$4.5M. Factory Pro Line 21, newer interiors.
• 2009-2014 350i — $3.8M-$5.5M. Redesigned cabin, quieter, better market demand.
• 2015-2020 350i / 350iER — $5.0M-$7.5M. Late-production, often low-time.
• 2020+ King Air 360 — $7.5M-$9.5M new; early used examples $6.5M-$8.5M.

Value drivers: engines on a P&WC ESP Gold program (full coverage) add $250k-$500k. Fresh hot sections reduce near-term risk. Pro Line Fusion or G1000 NXi retrofits add $400k-$700k. Paint and interior condition materially affect resale — a 2005 350 with new paint, interior, and fresh HSI can exceed a 2008 airplane with tired cosmetics. 350ER variants command a $400k-$700k premium over standard-gross 350s. See valuation-methodology.

• PT6A HSI compliance — Hot section inspection required at mid-TBO (1,800 hours); scrutinize logbooks for compliance and findings.
• Landing gear 6-year / 8,000-hour inspection — Mandatory comprehensive gear overhaul; shop cost $60k-$120k. Critical pre-buy checkpoint.
• Wing bolt inspections — Recurring inspection of the main wing attach fittings; compliance status must be documented.
• Cabin door seal and latch mechanism — Known wear point; AD compliance and recent seal replacement are pre-buy items.
• Collins Pro Line 21 DU failures — Display units on early 350is can fail; exchange units are ~$25k-40k each.
• Bleed-air and pressurization components — Outflow valves, flow packs, and bleed-air valves are expensive overhaul items.
• Prop governor and beta valve leaks — PT6A-60A-specific; routine but not cheap.
• Corrosion in wet wing area and belly — Aircraft based in coastal or de-ice environments need careful airframe inspection; Phase 1-4 inspection cycles catch most of it.
• Engine trend monitoring — ECTM data review is a mandatory pre-buy step; deteriorating ITT margins signal upcoming hot section or overhaul work.

A Beechcraft Service Information Letter program (similar to but not called SIDs) specifies Phase 1-4 inspections on a rotating cycle — pre-buy should verify where the aircraft is in the phase cycle, as a fresh Phase 4 is worth $40k-80k.

The King Air 350 sits in the cabin-class turboprop insurance category — the most expensive GA segment outside jets. A type rating is required (turbine over 12,500 lb MTOW); most insurers further require a PIC type plus FlightSafety or CAE initial and annual recurrent training, and many mandate a qualified second-in-command for corporate/charter ops.

For a well-qualified owner-pilot (ATP, 4,000 TT, 2,000 ME, 500 ME turbine, 250 in type) insuring a $3.5M hull with $5M smooth liability, annual premiums run roughly $22k-$40k. Lower-time pilots transitioning from lighter King Airs or jets may see $40k-$80k premiums plus mandatory mentor-pilot or SIC requirements for the first 25-50 hours. Part 135 charter operators pay $60k-$150k+ per aircraft depending on exposure.

Type rating training: $15k-$25k initial at FlightSafety/CAE; recurrent $8k-$12k annually. Sim-based initial runs 10-14 days. See insurance-underwriting.