The Beechcraft King Air B350i is a medium-range turboprop that can access short and unpaved rural airports. This is a comprehensive guide to the B350i.
The B350i has an 1800 nautical mile range, flying up to FL350 at 407 KIAS. The latest model costs $8 million while a used model averages between $4 and $7.1 million. Its twin PT6A-60As produce 1050 shaft horsepower each.
As a corporate pilot with literally thousands of hours under my belt, I am very familiar with the Beechcraft King Air and Super King Air series, including the B350i.
The Beechcraft King Air 350i is the largest of the King Air series of turboprop aircraft manufactured by the Wichita-based company. It was first announced in October 2008 and began deliveries in December 2009. In the first decade of production, Beechcraft delivered more than four hundred aircraft.
It is a significant update from the B300 in terms of its performance and cabin comfort. Designers at Beechcraft intended the 350i to be a direct competitor of and in competition with the light jets in terms of the number of airports served and in-flight comfort.
Cabin comfort was increased by adding vibration dampers and reducing the sound levels in the cabin by four decibels, while adding a luxurious interior that features, as standard, club seats and electronic shutters. Up front, there is a flat screen, and cabin-wide there is adjustable cabin temperature. The 350i also comes with an aft lav - something some light jets don't have.
There are currently three versions of the Beechcraft 350i - 350iER, the 350iC, and the 350iCER. The ER comes with increased fuel capacity but with an identical payload. It adds an additional 700 nautical miles to the range (hence the “ER” or “Extended Range” designation).
The C version has a larger cargo door to facilitate the entry and egress of bulky items and is for the 350i to be used as a cargo version of itself. And, finally, the CER is an extended-range cargo version of the standard Beechcraft 350i.
The FAA certified the 350i as per 14 CFR 23 in the commuter category. It is also certified for flight into known icy conditions, and for single pilot operation. It is also Reduced Vertical Separation Minimum (RVSM) compliant.
The 350i, as with all the other models in the Super King Air family, have a distinct box-like fuselage cross-section, unlike most jets that use a tubular structure. The Beechcraft philosophy was for better utilization of geometry to provide shoulder and headroom for passengers. The center aisle drops down for better walking posture.
The windshield is Part 23 certified for bird strikes and is electrically heated for icing and fog.
The wing is a semi-monocoque structure with dual spars running from tip to tip. It is a straight wig with zero sweep and a mild dihedral that aids in lateral stability. The wings provide 310 square feet of area, translating to 48 pounds per square foot of wing loading.
The 350i also has winglets, adding a foot of span to each wing and increasing its fuel efficiency while adding to its rate of climb.
The vertical tail has a span of 18 feet 5 inches with an area of 68 square feet. It has a sweep of 17 degrees at 25% chord. The tail is a T-Tail configuration like most of the other King Air models and works well in ground effect giving the pilot good nose-up control in the flare. Unlike low tail configurations, the landing flare does not feel mushy in the yoke.
The vertical tail is 14 feet 4 in height with an area of 52.3 square feet. It is also swept at the 25% chord line by 37.1 degrees.
Due to its design, the 350i has certain speed limitations listed in KIAS, Knots Indicated AirSpeed.
The King Air, as part of its Part 23 certification has multiple redundancies. Even the main gear has two tires, instead of one. Control surfaces, from the ailerons to the rudders and elevators have dual push rods, while each engine houses a 300-amp electrical generator, capable of supporting the operation of all electrical systems. If one goes down, the other seamlessly takes over.
As for cabin pressurization, bleed air comes from both engines. Failure from either will not disrupt full pressurization up to the ceiling. And in case of loss of cabin pressure, there is an oxygen system with an oxygen canister in the rear cargo bay that supplies every passenger.
The wings have deicing boots, as do the horizontal tail. I personally prefer heated leading edges but these work fine. Being able to fly at FL350 for most of the route keeps us away from ice on most parts of the leg. But what is really helpful is that heated bleed air is directed toward the brakes. Landing in less-than-dry conditions during the winter puts this feature to good use.
The Hartzel props also have electric heaters on the blades and prove more than adequate in preventing ice build-up.
The King Air B350i has something a lot of other jets don’t, and that is the ability to carry cargo in its wings, behind the engine. The compartments are long, stretched over the entire chord of the wing, allowing for the storage of things like golf clubs and skis. The eng compartments allow for 300 pounds on each wing compartment.
This keeps the baggage compartment in the fuselage free from odd-shaped objects and allows the bags to be easily arranged.
The King Air has a maximum payload capacity of 2,545 pounds and 9 seats, excluding the co-pilot's seat; if you wish to fill that up as well, you can. At an average of 180 pounds per passenger, that’s 1,620 lbs of payload, leaving you with 925 pounds which you can use to carry baggage.
The King Air B350i uses the PT6A-60A turboprop engine. First developed in 1958, the PT6 entered service in 1964, and by 2016 it had logged more than 400 million hours with an inflight shutdown rate of once in every 650,000 hours.
The PT6 has two sections, and while it shares the same thermodynamics with its sibling, the turbojet or the turbofan, the mechanics of extracting energy from Jet A fuel is a little different in the King Air’s PT6 than it is in, let’s say, a CJ’s FJ44.
While a typical turbojet creates thrust from the expansion of gasses in the combustion chamber, and a turbofan creates thrust from the gas expansion and thrust from the fan, the turboprop creates thrust solely by the props.
Turboprop engines, unlike jet turbines, are seemingly mounted backward from the point that the air scoop below the engine feeds the intake in the rear, while the exhaust exits from the front and then vents outboard.
That’s why you’ve become accustomed to seeing the two characteristic exhaust manifolds sticking out of the King Air engine pods like bicycle handles coming out their sides.
The King Air 350i is designed to fly in rain and known icing. With that in mind, the lip of the intake scoop beneath the engine pod is heated using bleed air from the engines. Heavy moisture entering the inlet is separated before the air is sent into the compression chamber.
A three-stage compressor sends heated and compressed air much like a turbo unit sends compressed air into the cylinder of a piston engine. Fuel is mixed here and ignited forcing the explosive gas out toward the exhaust while turning the high-pressure turbines that are connected to the three-stage compressor in the rear.
As it prepares to exit the exhaust it goes through another turbine. This turbine is not connected by a shaft to the others in the rear. Instead, it is connected to a gearbox in front. That gearbox drops the revolutions down to something that is manageable for the prop shaft and the prop.
Remember from your old ground school, a prop can’t spin too fast otherwise the tip might reach transonic speeds and induce flow separation and killing thrust. For this reason, turboprops have a gearbox to drop the number of revolutions generated.
The engines are capable of producing a lot more power than the flat rate 1050 horsepower. But they are kept at that for two reasons. First, giving it full power on the ground will rip the airframe - that;’s how powerful the PT6s are. Second, a flat rating allows you to keep a constant power as you climb, since the air is getting thinner, the more upside it has to get to cruise altitude faster.
The PT6 is highly automated. In the event of an engine failure, it will attempt reignition
I am used to flying the King Air the way I fly a jet. I just forget that there is a pair of four-bladed Hartzell spinning just outside the side cockpit window while I keep my cockpit flow the same, with just a few minor modifications.
It’s easy to think that they are jets because of the way they perform and the flow in cockpit management. For those who haven’t moved up to a jet yet, this is a great platform to begin your journey.
The 350i has a much lower in-cabin vibration than the other King Air models, which is part of the reason it's easy to forget that you are in a turboprop. However, the King Air is not a jet and it is subject to the thermodynamic limitations that
But in all honesty, it is an easy aircraft to fly, even for a single pilot, except for the fuse panel that sits to the right of the copilot's seat.
Even launching at MTOW, the PT6s are able to generate enough power to allow for quick acceleration without sacrificing any of the cabin comforts that need bleed air. At MTOW the King Air needs 3,300 feet to take off. Remember the PT6 engine is flat-rated in the 350i and so there is always extra power as you ascend and the air gets thinner.
The King Air performs as admirable under perfectly dry runway conditions as well as wet or slushy conditions. The only caution I would suggest is to watch your crosswind during wet runway conditions. That large vertical surface back there is very effective. As long as you remain strict with crosswind limitations you will be fine.
For those who fly the King Air for the first time, it is deceptively easy to fly. There is no doubt about that. It feels as stable as a high performance piston engine twin, yet has the speed and ability of a jet.
If you are getting into the King Air as your first non-piston engine aircraft there are a few habits you need to break and a few you have to adopt.
The King Air has a few more gauges than a priston engine that you now need to monitor as part of your cockpit flow. You also have Fowler flaps below the engine and unlike the lower powered piston engines that allow you to keep them open for most speed ranges, the King Air needs them to be closed before getting to 202 knots. This is typically in your Segment 2 climb and can be easy to forget.
The engineers at Beechcraft thought of everything, I must say. I’ve flown a plane with asymmetric Fowler flap deployment and it soon became a problem. Beechcraft doesn’t have that problem as it has asymmetric Fowler flap deployment detection and prevents it from happening.
You should also remember that extending the Fowler flaps will put out enough drag to drop your airspeed by five knots. It's a good way to start slowing your airplane down as you descend to the terminal area before you hit the Final Approach Fix.
The King Air 350i is an economical workhorse giving you the versatility of range and economy. Being able to fly at its FL350 ceiling and setting the power for long-range cruise, it is not difficult to squeeze the plane to produce 300 knots and still get a 1800 nautical mile range. Fuel flow at FL350 is typically 96 gallons per hour. If I pull it back a little more for cruising at 260 knots, I can bring the fuel flow down to 78 gph.
In loitering mode, the ER that has larger tanks and the 350i with its smaller tanks can be flown at a lower fuel flow. Designed for search and rescue, both the 350i and the 350ER can be trimmed to burn 65 gallons per hour.
While this is more for the ER models, using it when flying the 350i when stuck in a hold can leave you with a lot of options when planning the next alternate or giving you more time aloft.
The King Air 350i was first produced in 2010 as an upgrade to the 350. When Beechcraft first offered them up for sale, it was priced just below $8 million in the typical passenger configuration.
The preowned C version is not easy to come by. If and when they do come up for sale, they are quickly transacted, spending no more than 30 days on the open market. A three year old 350iER averages $7 million.
A preowned CER version is even more rare and are usually pried at a premium. Asking price for a had different price points and is not published. A brand new 2022 King Air 350i CER was recently delivered for $11.8 million.
A current year model for the 350i is priced just over $8 million and can reach $9 million depending on the added specs a prospective buyer wishes to include. A full flushing lav, for instance, can be installed in the 350i as an option. Considering that extended range models can loiter for twelve hours, depending on the mission, adding a lav may not be such a bad idea.
The King Air 350i, as with its predecessors have proven to be robust aircraft with cost effective operations. With depreciation averaging $210,000 annually, and a flight crew average $160,000 a year, it is fairly straightforward to forecast the cost of operating a King Air 350i.
To maintain a crew on standby and provide the necessary training to keep them sharp, the cost is independent of the hours flown. The same can be said for hangaring the aircraft, insurance, and capital costs.
As for depreciation, it is a financial determinant, and you should check with your tax attorney on how you can treat the depreciation of an aircraft depending on your situation and where you register the aircraft.
The capital cost above is taken from a ten-year 5.5% fixed-rate loan. This ends up being $682,809 per year for fixed costs. Just note that this means this is what you would have to pay even if you hangar your aircraft all year.
Direct Operating Cost
We also have to contend with variable costs. These are costs that you fork out for every hour you fly. It includes fuel as well as a portion of the maintenance that is based on the number of hours you fly.
The King Air 350i burns an average of 96 gallons per hour. Jet A at my airport is currently $7.60 per gallon. On average that means it costs me $7.6 x 96 gph. That’s $729.60 per hour just for gas. But the big ticket item that you would have to consider is the maintenance costs that roll around annually like the annual inspections, maintenance like oil changes, and service bulletins.
In total, flying the plane 400 hours a year will cost $566,640. You then have to add the annual fixed costs from earlier, which were $692,809. In total, for a year of flying 400 hours, the cost would be approximately $1,259,449, or $3,148 per hour.
About THE AUTHOR
After spending years watching every video I could find about flying, I finally scratched the itch and got my pilots license. Now I fly every chance I get, and share the information I learn, here.Read More About Joe Haygood