Die Quelle für den kompletten Text ist bei dem Flying Magazine
ZitatAlles anzeigenTo see the 4000 in action we planned a flight from Beech Field in Wichita to Aspen and back. We had two passengers and 7,000 pounds of fuel to bring takeoff weight up to 30,950 pounds, well below the maximum of 39,500 pounds. Available payload with full tanks is 1,600 pounds, so all eight standard seats can be filled. However, the 7,000 pounds of fuel was plenty for a high-speed flight halfway across the country to Los Angeles from Wichita so it was actually a pretty typical fuel load. The fuel planning rule of thumb for the 4000 is to burn about 2,600 pounds in the first hour, 2,000 in the second and about 1,800 pounds an hour after that for an endurance of over seven hours at Mach .82 cruise with full tanks. The temperature in Wichita at 25° C made the required takeoff runway just 3,355 feet.
The Pratt PW308A engines are rated at 6,900 pounds of thrust each, and have the capability to produce all of that thrust up to an air temperature of 37° C at sea level. That means you get full power on the hottest day, and a big chunk of rated power on a hot day at a high elevation airport. The engines are, of course, controlled by full-authority digital engine computers (fadec) so all starting and operating parameters are automatically controlled. However, the 4000 has an autothrottle system as standard -- another midsize first -- so pilot workload is further reduced because the autothrottle maintains the desired airspeed.For takeoff you engage the autothrottle and advance the levers about halfway, and then the system takes over to set the power. With the high bypass fan design of the PW308 engines, acceleration is very brisk and we were quickly at the 111-knot rotation speed. The pitch response of the airplane is totally predictable and it's easy to rotate to the desired target and hold it. The real challenge is to keep from blowing through the 200-knot airport area speed limit, but the autothrottle helps take care of that by bringing the power back in advance of leveling at the assigned altitude.
We had two brief level offs at lower altitude but at 15 minutes after takeoff the 4000 was climbing through 37,000 feet, despite air temperature that averaged 5° to 10° C above standard. With the autothrottles locked onto a Mach .78 climb speed, the 4000 was going up at 1,800 fpm through 40,000 feet, where the temperature had dropped to standard, and at 20 minutes after takeoff we were level at 43,000 feet despite the two intermediate altitude assignments. Acceleration from climb to high-speed cruise of Mach .82 took barely a minute and we settled on a true airspeed of 471 knots with total fuel flow of 1,800 pounds per hour.
After a few minutes we asked the flight management system for max cruise and the 4000 accelerated to Mach .83 for 477 knots true on 1,900 pounds of fuel flow. Even at that speed the airplane was moving through the air .251 nm for every pound of fuel burned for a remarkably good specific range. The wing is so efficient at Mach .82 or .83 that very little range can be gained by slowing down, so I doubt many 4000 pilots will, unless they need to stretch for the last couple hundred miles of a very long trip.
The very smooth contours of the carbon fiber fuselage, and the way the windshields have been blended into the sophisticated canopy shape, makes the cockpit very quiet even at maximum indicated airspeeds. The same is true in the cabin where sound pressure levels measure well below that of many other jets. The cabin sound level is so low, in fact, that people from one company that went on a demonstration flight asked if an acoustic curtain could be installed between the fore and aft seating groups because normal conversation from each area could be heard by all. If there is such a thing as being too quiet, maybe the 4000 is approaching that level, but I'm sure most are going to be more than pleased with the very low sound and vibration levels.
Pressurization controls are fully automated with the system consulting the database for both departure and arrival airport elevations. It was interesting to watch the system in action while approaching Aspen as it gradually raised the cabin altitude from the cruise level of around 5,000 feet to smoothly meet the 7,800-feet elevation at Aspen with no bumps in the pressure, nor intervention required by the crew.For the return trip from Aspen to Beech Field we added fuel to bring the total up to 5,050 pounds so our takeoff weight was 28,845 pounds. It was a beautiful summer day in the Rockies with the temperature at 23° C, which is about 22° C above standard, so the density altitude was very high. Despite the conditions the 4000 needed only 5,060 feet of runway for a balanced field takeoff and we could have easily added enough fuel to fly to any point in the lower 48 states.
This time the controllers kept clearing us higher with no steps and we were at 45,000 feet in 17 minutes after takeoff. Yes, we departed at nearly 8,000 feet, but that is still impressive. With temperatures a little below standard the 4000 quickly accelerated to Mach .82 for a true airspeed of 465 knots on just 1,640 pounds of total fuel flow. At that level we were covering .272 nm for every pound of fuel burned.
Overall the flying qualities of the 4000 are precise and predictable at any altitude or airspeed. The speed brakes are linear, meaning they respond to the amount you move the handle, and can be used at any airspeed or altitude. I tried steep turns and found that with a little practice -- and by watching the flight path indicator -- I could hold altitude to the required stand-ard. Approach to stalls are a nonevent with loads of power to accelerate away from the stick shaker warning.Learning to land the 4000 does, however, take a little practice. Unlike most jets, the deck angle on approach is level, or perhaps even a little nose down. To make a good landing you need to make a sort of round out 100 or so feet in the air, and then let the airplane settle. It's not really a flare, but more a leveling of the attitude. With the confusing visual illusions of the mountains and uphill runway at Aspen for my first landing, I didn't get it right and banged the airplane on. The automatic ground spoilers did their job and kept the airplane firmly on the runway for an easy rollout. Back on the level land at Wichita I got the hang of the sight picture on very short final and turned in a decent landing. With a little practice, and the long stroke trailing link landing gear, 4000 pilots will be rolling the airplane on. There was a 90-degree crosswind gusting to 18 knots for my last landing and it worked out just fine, so the airplane surely has the capability and control authority to handle demanding conditions.
Hawker Beechcraft has a dedicated team of service reps to smooth entry of the 4000 into service and plans to ramp up production gradually to a rate of about 30 per year. More than 130 are on order, and 2010 is the next available gap in the delivery schedule.
It's been a long road for the 4000 but in the end the airplane delivers. It was the first airplane to be announced in the super midsize category, and in terms of performance, cabin comfort and system redundancy the emphasis certainly ended up being on the "super." For everyone who has loved the Hawker and wanted more, the 4000 is the one.
The airplane flown for this report was the first production model delivered. It was equipped with the optional six chairs and three-place divan instead of the double club seating for eight. The basic operating weight (BOW), which includes 400 pounds for the two pilots, and 300 pounds for cabin stores such as water, galley provisions and manuals, was 23,450 pounds, which is 50 pounds less than the expected typical BOW. The data below is from the aircraft manuals and reflects standard day conditions.