The Beech King Air 350 is for people who want to make their airplane budget in ink, not pencil. Its rugged design, more than 40 years of heritage and robust systems make the 350 one of the most dependable and predictable turbine airplanes around. The entire King Air fleet has logged an estimated 40 million flight hours since the first one was delivered in 1964, and more than 6,000 have been built.
That’s why Spartan Chemical bought the 500th 350 built. This is the third 350 that Spartan, a maker of environmentally friendly specialty cleaning chemicals, has owned in sequence, and it uses the airplane to visit more than 500 distributors plus current and prospective customers from its headquarters near Toledo, Ohio.
And – I don’t want to jinx the airplane and its crews – the 350 has not been involved in a reported accident in the United States since the first one entered service in 1990. The King Air fleet has posted one of the best safety records of any business airplane, but the 350 stands out as the best. The 350 is the biggest King Air with a cabin nearly three feet longer than the model 200. That provides room for a spacious dual club seating arrangement, plus a large and private lavatory in the rear. With full fuel tanks and a 200-pound pilot, 1,600 pounds of payload remains, so a full-sized person plus baggage can be carried in every seat. And 55.3 cubic feet of baggage can be stored in the aft compartment of the fuselage where it is heated and pressurized and accessible in flight. Long items such as skis or fishing poles fit nicely in the engine nacelle lockers. If you want to haul more people than baggage, two more seats can be put in the aft baggage compartment, and another person can sit on the belted potty seat.
The 350 is a rare airplane that can carry full fuel and full seats, and it can do it under extreme conditions. High air temperature robs all airplanes of takeoff performance, but the 350 has enough margin to safely take off at maximum weight at sea level on a 126º F day. Move up to Denver and it can still take off at maximum weight on a 90º F day. And if for some reason you need to fly a short hop, no problem, because the maximum landing weight is the same as max takeoff, 15,000 pounds. If you guessed the landing gear and airframe structure must be super strong, you’d be right.
The takeoff performance of the 350 is even more impressive when you consider that it is certified in the commuter category of FAR Part 23. That means pilots must have a type rating to fly it and must observe minimum runway requirements that assure a margin of safety if an engine fails during takeoff, just as the rules do in jets.
The required takeoff runway length in the 350 is the distance needed given weight, air temperature, wind and so on to accelerate to decision speed, have an engine fail, and stop on the remaining runway; or the distance needed to lose an engine after reaching decision speed and continue the takeoff to an altitude of 35 feet above the runway; or the distance needed to take off and climb to 35 feet above the runway with both engines running increased by 15 percent. In piston twins or other turboprops that are not certified in the commuter category – which is nearly all – there is no required runway and pilots can legally plan on a “two engine” takeoff with no margin built in.
On a standard day the 350 needs 3,330 feet of runway to take off, or under 5,000 feet at Denver. Even on that 90º F day in Denver the runway requirement is only 8,000 feet, and runways in that part of the country are routinely longer than that. And, remember, those numbers are for full fuel – enough to fly 1,500 nm or more with reserves – and a hefty body in every seat. For a mere 500 nm trip with a cabin full, runway lengths drop well under 3,000 feet on a standard day. It is a very versatile airplane.
The huge 355-cubic foot cabin is the 350’s primary attraction, but until recently there wasn’t enough cooling capacity to make the cabin comfortable on the ground and early in flight on very hot days. Beech solved that problem with a new environmental control system that increases cabin airflow by more than 250 percent. The system was developed by air conditioning experts at Keith Products and has now been incorporated into production airplanes. Included is an automated temperature control system that allows pilots to select the temperature for the cockpit and cabin individually. There are now seven outlets in the glareshield to cool pilots sitting in the hot sun, and the entire system weighs 35 pounds less than the manually controlled, less powerful system it replaces.
One of the best features of any King Air cabin is the big, round windows, and the 350 has seven of them on each side. The structure between the windows is so narrow I have the sensation of the whole cabin side being one big window. You can rotate a polarized inner window pane to reduce sun intensity. Several years ago Beech had problems with the polarization fading over time, but that seems to be resolved and every passenger can select their own level of light coming in the window.
Beech also has restyled the cabin chairs with recessed headrests, retractable armrests, and inboard and outboard tracking. The cabin overhead has indirect lighting that glows softly from a geometric pattern that surrounds cabin air outlets and reading lights. And cabin furniture has been upgraded with a large hot and cold beverage unit forward, plus pyramid-shaped cabinets between the seat backs. The entire cabin and exterior fit and finish, as well as materials, has returned to what most of us know as traditional Beech quality after a period where the company had failed to live up to its reputation.
Collins Pro Line 21 avionics, with dual flat-screen primary flight displays (PFD) and central multifunction display (MFD), are standard, along with the basic file server that allows the system to show weather and charts. The Pro Line 21 system includes a single flight management system (FMS) that can be used for all navigation, including the new GPS approaches with vertical guidance. You can dial com and nav frequencies using the FMS keyboard or the knobs on the single radio management unit in the panel. And I’m pleased to report that the automatic flight control mode selection panel is located on the glareshield instead of down in the pedestal where it resided out of sight for many years.
The 350’s systems, as they must be to meet commuter category rules, have a high level of redundancy. The main electrical bus is fed by both generators and the battery, and this triple-fed bus can support essential equipment from any of the three sources, which are in turn isolated from each other. Nonessential loads are automatically shed if generators are lost. The fuel transfer system from tank to tank and to the engines is automatic with no pilot intervention required. And an all-electronic standby display in the middle of the panel shows attitude, heading, airspeed, altitude and nav guidance independently of the primary air data computers or attitude-heading reference systems.
With its up-to-date flat glass panel, but its traditional toggle switches and big throttles and propeller control levers, the 350 is an interesting mix of the old and new. In most respects, I generally forget that the airplane is a turboprop and not a jet, because the avionics and size of the airplane are so like a jet. And I think passengers don’t think much about the propellers, either – except on the ground.
The 350 has automatic propeller feathering and rudder boost to immediately feather the prop if an engine fails on takeoff and to step on the proper rudder to overcome the asymmetric thrust. An engine failure in the 350 is virtually identical to the loss of an engine in a jet because the autofeather immediately eliminates the drag of the windmilling propeller on the failed engine. As you can imagine, autofeather and rudder boost are required items, and that means they need to be tested once each day. The test requires a ground run-up to high power to check each system, and that’s when passengers are reminded the 350 is not a jet. Pilots who want to give their passengers the best possible experience will do the high power run-up before loading the people on the first flight of the day.
The airplane flown for this report was the 500th King Air 350 delivered by Beech. The standard 350 is very complete with only a few optional avionics and cabin furnishings. Warranty on the airframe and avionics is five years, with five years or 2,500 hours coverage on the engines, and a two year warranty on systems and components. Raytheon’s “Support Plus” maintenance service plan can lock in all hourly maintenance and repair costs. All data here is from the airplane manuals and reflects standard day conditions at sea level unless noted.
The engines are mounted further outboard on the 350 than on other King Airs, and the propellers are further forward, moving their tip noise away from the cabin. The leading edge of the wing root between the nacelles and fuselage is extended forward and drooped to give the 350 more lift and good stall behavior. The huge wing has a span of just under 58 feet, and its structure is certified for infinite life, a demanding standard in the commuter category. The winglets appear to help in all phases of flight, but probably add the most at high-altitude climb and cruise. The 350 is certified to 35,000 feet and will get there at most weights and air temperatures, and that is the level where it delivers the lowest fuel burn and longest range, but cabin altitude is around 10,000 feet, so most pilots fly lower unless a very long trip or a strong tailwind lures them to the certified ceiling.
With nearly full fuel and two of us onboard, we weighed 12,600 pounds for takeoff at Beech Field in Wichita. The V1 decision speed was 97 knots, with rotation at 104 knots, and V2 engine-out climb speed at 111 knots. Those speeds are for a flaps-up takeoff. As in most airplanes, using flaps reduces takeoff speeds a few knots and shortens runway roll in the 350, but also reduces engine-out climb performance, so it’s a trade-off. With plenty of runway and climb reserve, I like the flaps-up takeoff better. I think it makes for a smoother rotation and initial climb, but the choice is up to each pilot.
Initial climb rate topped 2,000 fpm, and in 15 minutes the 350 was level at 27,000 feet, despite air temperatures at least 9º F above standard all the way up. The high 20s are good altitudes for the 350 because it cruises right around 300 knots true airspeed with a fuel flow of about 650 pounds per hour. The mid-to-high 20s are not crowded altitudes, and the tanks’ full range at maximum power is at least 1,000 nm with enough reserves to continue to an alternate 100 nm from the destination.
Except for takeoff, all climb and cruise is conducted with the propellers set at a slow 1500 rpm. At that setting you are aware of the props in the cockpit, but in the aft club chairs the sound could be as easily coming from a jet engine as a turboprop. And the vibration level compares very favorably with a business jet.
For several years Beech had included an active noise attenuating system to quiet the cabin. As in headsets with active noise reduction, a network of microphones detects ambient noise, and then speakers deliver an opposing sound that is 180 degrees out of phase with the unwanted noise. The clash of the two sound waves cancels most of the noise. The active system works well, but proved to be a maintenance issue. There were some failures of the electronic equipment, but more often an adjustment of microphone position or other tweaking was required to make the system work properly. So, Beech has now replaced the active electronic system with a passive noise reduction system that uses 83 “tuning fork” sound absorbers and insulation sealed in plastic bags. The tuning forks are bolted firmly to the airframe structure, and their vibrations, tuned to the propeller frequency, absorb sound energy and help stop it from being transmitted via the metal airframe. There is zero maintenance to the system, and no electrical power is required, but it does add 30 pounds to the empty weight compared to the electronic system. The flying qualities of the 350 are as predictable and dependable as the rest of the airplane. The wind was gusting to 30 knots when I flew the airplane last December, and as you can imagine, it was bumpy down low. The control forces on the 350 are heavy, but the harmony of forces between ailerons, elevator and rudder is excellent. But most importantly, there is lots of power in those control surfaces. It takes muscle to move the controls, but the 350 responds with precision and smoothness, and despite the gusts, my landings were darn good.
Many people wonder how long the King Airs can go on given the host of business jets on the market and in development, but I don’t doubt their future because other airplanes can’t do what the 350 does in terms of payload, speed, range and runway requirements. Given the continual improvements Beech makes to the airplane, and the welcome return of the company’s famous top level of quality, a lot more than 500 King Air 350s will be loading up and taking off in the years to come.