Tuesday, March 1, 2005
Adam A700: First Of The Microjets?
The race to bring the first of the very light jets to certification is turning final, And the upstart from Denver is looking like it may be the new leader to the finish line
Jets drink fuel at a higher rate than piston engines, and Adam knew the A500’s 230-gallon tanks wouldn’t be adequate for the A700. The prototype I flew was fitted with standard tanks, but Adam plans to boost capacity with a 100-gallon belly tank. The production fuel system will be simple—the wings will feed into the center tank, and both engines will drain from that tank.
The chief pilot, Glenn Maben, says flight tests so far have suggested cruise projections of 340 knots (Mach .60) at 38,000 feet should be right on target, but the fuel burn will be dramatically lower than on the previous jets. Adam Aircraft’s president Joe Walker ex-plained that the A700 actually will be relatively fuel-efficient. Walker, a 20-year veteran of Cessna before moving to Adam, is intimately familiar with the Cessna Citations, so it’s not surprising that he analogizes his A700 to the Cessna jets.
“Back in 1972, the first Citation 500 was an 11,000-pound airplane with 2,200-pound thrust engines, and it would cruise at about 340 knots on 1,000 pounds an hour,” explains Joe Walker. “Twenty years later, the CitationJet delivered a few more knots with slightly less weight and only 1,900 pounds of thrust, all on only 700 pounds an hour. The A700 should cruise at 340 knots at a 7,000-pound gross weight with 1,200-pound thrust engines while burning only 500 pounds an hour.”
Climb into the A700’s left front seat and you’re facing a representative glass panel, a mixture of Garmin and Avidyne avionics. The panel on the test article included two screens, a large Avidyne PFD on the left and a similar MFD in the right. Two Garmin 530s were installed at left center, and that’s what we used for the flight, as the Avidynes weren’t hooked up.
As on the A500, Adam installed side sticks for roll and pitch control, but they’re not the usual short-throw sticks. Fore, aft and side travel are fairly long to provide more mechanical advantage and ease control pressures. The lack of a yoke not only frees up space in front of the two pilots, but it also adds an impression of spaciousness in all other directions. The cockpit already is extremely accommodating, and it’s comfortable to settle into the seat without a yoke directly in front of you.
Passengers should be pleased as well. At 54 inches wide, 52 inches tall and 16 feet long, the cabin is roughly the size of a Cessna CJ1’s. No matter what performance advantages the other microjets may enjoy, they’ll be hard-pressed to match the A700’s room and creature comforts. I tried every seat, including the aft lav installed in the seven-place prototype, and they were all reasonably comfortable.
The nose gear is non-steerable, so directional control during taxi is with differential brakes, unusual for a business jet, but still effective. Push the thrust levers full forward to leave town, and the twin rudders come alive immediately. Acceleration is exhilarating. The airplane unsticks at about 80 knots and starts uphill without pausing for breath.
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