It takes time to work the bugs out of most all-new airplane designs, and the Beechcraft Premier is no exception. The Premier’s design goals of being the fastest light jet with the largest cabin cross section were accomplished when it entered service in 2001, but it is now, with the IA version, that the Premier is hitting its stride as a mature design.
The Premier is a pioneer as the first business jet to use carbon graphite epoxy as primary structure. The Premier fuselage is made from carbon fiber while the wing is constructed of conventional aluminum alloys. The carbon fiber fuselage probably saves some weight, but more importantly, it allows for a larger interior cross-section size for a given external dimension because the composite structure is thinner than a conventional metal fuselage. Boeing is using a similar scheme in its new 787 Dreamliner.
The Premier cabin is 5 feet 5 inches high, which provides a half a foot more headroom than other light jets. The extra diameter of the circular cabin translates into an even greater advantage in cabin width, particularly at the floor level. The cabin cross section of the Premier is actually closer to that of a conventional midsize than to the competitive light jets.
However, the size advantage of the Premier was ill used in the original cabin design. Routing of air ducts, wires, controls and other necessary items was not optimized, so they claimed usable cabin space. The headliner with its lighting panels did not maximize the headroom the fuselage structure offered. And the window reveals that surrounded the very large cabin windows were sort of a retro automotive-inspired design that made the cabin smaller, both visually and in reality.
The newly designed interior in the Premier IA now takes full advantage of the potential offered by the carbon fiber fuselage. What Beech did is copy the best of the interior design in its other airplanes and in the competition. The sidewalls are now smooth, one-piece elements that provide maximum shoulder room when seated.
Unlike some other light jets, you can sit upright without your shoulder, or your head, being squeezed inboard by the curve of the fuselage.
The window openings are maximized for visibility and to enhance the spacious feeling of the cabin.
Overhead Beech created a smooth headliner without the protrusions of the original. The environmental duct work that took up cabin space has been redesigned and offers improved temperature control, and soft light washes down the sidewalls from the new headliner. While the original cabin design was dramatic, perhaps even gaudy, the IA cabin is subtle and elegant, with obviously only top grade leathers, wood veneer and carpet.
It is the wing, the wing to fuselage fairing, and the shaping of the aft fuselage that controls drag and gives the Premier its Mach .80 maximum speed and 451-knot high-speed cruise.
The Premier wing is quite small with only 247 square feet of area and a span of 44.5 feet. That equals a moderately high aspect ratio of 8.6, meaning the chord is fairly narrow compared to the span. In general, a higher aspect ratio wing with small area is lower in drag. Additional drag control at high cruise speed comes from the 20-degree leading edge sweep that helps to control the formation of a Mach shock wave when the airplane is operating at nearly 80 percent of the speed of sound.
There are, as always, tradeoffs, and the small, slender wing does add complexity. Because wing loading-the amount of weight carried by each square foot of wing area-is fundamental to stalling speed, a small wing will stall at a higher speed than a larger one. To overcome that the Premier has large Fowler flaps that occupy most of the trailing edge of the wing. The wing is of the “cranked” design, meaning that the trailing edge is straight at the root and then sweeps back to mimic the sweep of the leading edge. With a cranked wing the flaps must be segmented into inboard and outboard sections. The Premier flaps are made from composites and are electrically actuated.
Because the flaps take up so much of the trailing edge of the wing the aileron is quite small, not large enough to provide all necessary roll control on its own. The solution for the small aileron is to augment the roll authority with spoilers. After 10 degrees of aileron travel, the spoilers on the down-going wing start to rise to provide more roll authority. This system is common in virtually all larger jets, but is rare in a light jet, and is transparent to the pilot when flying.
As with most modern business jet designs, the Premier fuselage sits atop the wing so the spar does not intrude on the cabin. This is great for cabin room, but is a challenge to the aerodynamicist to create a fairing that joins the fuselage to the wing with the lowest drag. Because the Premier fuselage is so big around compared to its length, the wing-to-fuselage fairing needs to occupy most of the available fuselage length. Many have commented that the fuselage fairing gives the Premier a “pregnant guppy look,” but its design is very state of the art. All modern jet designs have a similar fairing, but it doesn’t stand out as much as on the Premier because there is so much fuselage ahead of and behind the fairing. The shape of the Premier fairing never bothered me because I understand its objectives and even appreciate the skill the designers applied, but not all pilots agree. In another improvement to the IA, Beech paint designers have created schemes that minimize the appearance of the fairing and, along with people growing more accustomed to the shape, should help the Premier look more conventional.
The aft fuselage of the Premier is another example of drag control shape that appears extreme because of the short but wide fuselage. Ahead of and inboard of the engine nacelles there are very deep hollows that are called “area ruling.” The area rule was developed early in jet design and, in general, states that total area of a body is more important than the shape when it comes to creating drag. In the case of a jet with engines mounted on the fuselage as in the Premier, the presence of the engines increases the area of the aft fuselage. To minimize the drag created by the extra area of the engines, Beech scooped big hollow areas out of the aft fuselage so the total area remains as constant as possible. Many jets apply the area rule near the engines, but the shape is more dramatic in the Premier because of its wide fuselage.
Beech got all of these design features correct on the very first Premier and the airplane met its performance goals for speed, climb and range. But the systems didn’t exactly match expectations.
|Price…$6,205,130 Engines…Williams-Rolls FJ44-2A, 2,300 lbs each TBO…3,500 hrs Passenger seats…6 Cabin height…5.5 ft Cabin width…5.5 ft Passenger cabin length…13.6 ft Overall height…15.3 ft Overall length…46 ft Wingspan…44.5 ft Wing area…247 sq ft Wing sweep…20 degrees Wing aspect ratio…8.6 Max ramp weight…12,590 lbs Max takeoff weight…12,500 lbs Basic operating weight (includes one pilot)…8,550 lbs Max useful load…4,040 lbs Max zero fuel weight…10,000 lbs Max payload…1,450 lbs Max fuel capacity…3,670 lbs Payload with max fuel…370 lbs Max landing weight…11,600 lbs Wing loading…50.5 lbs/sq ft Power loading…2.7 lbs/lb Ceiling (certified)…41,000 ft Pressurization…8.4 psi 8,000 ft cabin @…41,000 ft Takeoff runway…3,792 ft Climb to 37,000 ft…17 min High speed cruise…451 kts NBAA IFR range at long range cruise…1,460 nm Landing distance…3,170 ft Vmo/Mmo…320 kts/Mach .80|
One issue that turned up early was the lift dump system that deployed to enhance braking. There are three individual spoiler panels on each wing, and when lift dump is selected all panels pop up, planting the Premier firmly on its tires to aid braking while adding drag in the slipstream. The lift dump system worked fine with test pilots at the controls, but in real world flying it didn’t always perform as expected. In the original airplane the squat switches had to close to tell the Premier it was on the ground before the lift dump could deploy. But if the pilot bounced the landing, it took time to get the squat switches to close again after the second, or perhaps third touchdown. This all delayed lift dump deployment and runway was racing by before maximum braking became available.
The fix for that was to make the lift dump system independent of the squat switches and make a new control handle on the center pedestal to activate the system. Now, the pilot arms lift dump for takeoff or landing and then moves the handle to activate the system. The lift dump system is now always under the pilot’s control, so he can get maximum braking after touchdown or during an aborted takeoff no matter what the squat switches say. Lift dump is locked out during other phases of flight to prevent an unintended deployment.
The brakes on the Premier have always been effective, and the airplane can land and stop in 3,170 feet of runway after crossing the threshold at 50 feet at maximum landing weight. But, the brakes were hard to use at lower speeds, particularly during taxi. The reason is the brake pedals were linked to the hydraulic valves by cables and pushrods, and it was impossible to remove every bit of play from the system. When a pilot moved his feet on the brakes there was a slight lag before the brake valve sent high pressure hydraulic fluid to the brake pads, and that caused a lot of jerking around. The Premier IA has its pedals linked directly to the hydraulic valves and that, combined with a new anti-skid system, has totally solved the problem. Now it’s easy to taxi the IA at any speed, and landing rollout is a smooth, straight-ahead affair.
The Premier was the first airplane to use Collins Pro Line 21 avionics with the big 8-by-10-inch flat panel displays, and the system has worked well. But the original system had only a primary flight display (PFD) in the front of the pilot and a multi-function display (MFD) in the center as standard. The IA now has a third display as PFD on the right side, plus Collins digital radios and the file server system that allows you to see Nexrad and other weather information, enhanced maps, Jeppesen approach charts, and other data we have come to expect in a modern cockpit.
It had been a couple of years since I had flown a Premier, and I was very impressed with the redesign of the cabin and the new paint schemes, the most visible changes in the IA. The mission was to fly from Wichita to Nashville to pick up photographer Russ Munson and then on to the Beechcraft Heritage Museum in Tullahoma to photograph the IA with the museum’s serial number 18 Model 35 Bonanza.
The Premier cockpit is, like the cabin, roomy for a light jet with excellent visibility. The cockpit design is clean, modern and free of clutter. The Williams FJ44 engines have electronic fuel control units that behave exactly like full authority digital engine controls (fadec) except they are single channel and are backed up by mechanical units. A true fadec must be multiple channels since there is no mechanical redundancy. The electronic engine controls in the Premier handle all power limit management from start to shutdown automatically, just as a fadec does.
You can really appreciate the new brakes as soon as you roll off the chocks. It takes no skill or practice to make a smooth stop from any speed. You may think it should be easy to make smooth powered brakes, but that task has driven most jet makers crazy at one time or another, and Beech now has it right in the Premier.
The IA that I was flying had an empty weight of 8,338 pounds. With three onboard plus bags, and 2,950 pounds of fuel, our takeoff weight was 11,970 pounds. It was 9? C in Wichita and we needed 3,768 feet to balance the runway for takeoff with V1 takeoff decision speed coming at 104 knots.
The Premier is a precise handling airplane that is not light on the controls, but neither does it require any unusual effort in any axis. I find it easy to keep the airplane on target airspeed and heading, and the airspeeds, particularly in climb, are much higher than I’m accustomed to in light jets. Controllers leveled us three times on the way up, but the Premier IA reached 37,000 feet in just under 20 minutes where, with air temperature 10? C above standard, it settled down to cruise at Mach .75 for a true airspeed of 440 knots. At max cruise power, the speed increased to Mach .77 for a 450-knot true airspeed on 1,000 pounds per hour of fuel flow.
I was treated to a nearly direct crosswind at Nashville, but the Premier was no problem to land smoothly with a Vref final approach speed of 111 knots at our fairly heavy landing weight. I deployed the new lift dump system at touchdown, and it, combined with the new brakes, took the sweat out of the crosswind landing rollout. The crosswind was even more direct and gusting past 20 knots at Tullahoma, but the Premier was up to the task. It has the authority available with its aileron-spoiler system that makes control in the turbulence a positive experience.
It was on the return trip from Tullahoma to Beech Field in Wichita where I was able to put the Premier in its optimum environment. There was a widespread area of thunderstorms along the route and in the Wichita area, so I climbed the Premier to 40,000 feet to get on top of the surrounding clouds. At that level the IA made a true airspeed of 440 knots on just 880 pounds of fuel flow. The clouds climbed higher and Kansas City Center approved FL 410, even though it was wrong for direction and the Premier maintained its speed and lost another 20 pounds of fuel flow. Almost instantly we flew through a front of some kind and the air temperature dropped from 2? C above standard to 8? C below, and the Premier’s indicated Mach jumped from .76 to .79 with a true airspeed of 448 knots. That is what the Premier does best?fly fast. Only the new Hawker 4000 super midsize is faster than the Premier in the company model lineup.
The small wing area of the Premier also translates into higher wing loading, which helped soften the bumps as I maneuvered around heavy rain on the way into Beech Field. Crosswinds had been my lot for two days, and the weather didn’t disappoint with gusts to 25 knots blowing 70 degrees to the right of runway heading. My landing worked out great, but after touchdown is where I really appreciated the new positive control lift dump system. The runway was wet from the heavy rain I landed in, and the gusts were strong, but the six spoiler panels of the lift dump system planted the Premier on the pavement, and the new brakes made a straight-ahead stop easy for a midfield turnoff. An approach and landing in heavy rain with a strong crosswind really builds confidence in a jet, and the Premier IA has earned that trust with its many improvements.
I expect that Beech won’t stand still with the Premier IA and that more good things are to come in the future as this solid design matures. But with the IA version the jet is delivering what the company promised, its fit and finish are top notch, and Beech has expanded the warranty out to five years to match the coverage of its larger jets. Highest speed, biggest cabin cross section and longest warranty are reason enough to consider the Premier IA, but the many changes that have solved its teething problems are equally important. It’s now a grown-up airplane.