Tuesday, December 15, 2009
The Single-Engine Jet From Diamond
Why do I want one? Four reasons: It’s fast, efficient, easy to fly, and has great ramp presence. It’s the perfect first jet to get an aspiring jet owner/pilot up and cruising in the flight levels at speeds above 350 mph.
On the day of my test flight, I was to fly serial number 003, the most recently built of Diamond’s three test planes. S/N 003 conforms aerodynamically to the production version, and thus, has almost identical performance to the future production aircraft. It’s your typical experimental flight-test airplane, with the interior replaced by flight-test equipment and instrumentation. Additionally, due to the test nature of the D-Jet, Transport Canada (the Canadian equivalent of the FAA) requires that all flight crew wear a parachute and the full suite of survival gear.
I’ve had my eye on the D-Jet since Diamond announced the program three years ago, and I wasn’t going to pass up an opportunity to fly it. So when Diamond President Peter Maurer asked, “Do you mind wearing a flight suit, helmet, oxygen mask and parachute?” I responded, “Sign me up!” without hesitation.
I suited up for the flight and then met with Diamond’s experimental test pilot, Mark Elwess, who briefed me on the test area and general operating procedures for the test plane. After our preflight briefing, we walked out to the plane, did our preflight inspection and strapped into the D-Jet. Though it’s not outfitted with a production interior, the cockpit was quite comfortable, with more than adequate forward and side visibility while sitting on the ground. After we completed our before-engine-start checklist, Elwess instructed me to turn the engine switch from “Off” to “Start”—pretty simple. At ground idle, the Williams International FJ33-5A engine was burning 84 pounds per hour, or about 12 gph at 24.7% N1. After we got the engine started, we taxied out to runway 15 at London, Ontario’s airport. The weather for our flight was perfect: light winds out of the south, scattered cumulus clouds and a ground temp of 20 degrees C.
Cyrus Sigari (left) and Diamond’s Mark Elwess (right) prepare to fly Diamond D-Jet S/N 003. Because the aircraft is still in the testing stage, Transport Canada requires all flight crew to wear a parachute and full suite of survival gear.
After I got my takeoff clearance, we lined up, and I smoothly advanced the single thrust lever to takeoff thrust, then quickly began accelerating down the runway. I began my rotation at 83 knots and broke ground about 2,500 feet down the runway. Shortly after liftoff, I trimmed out for an initial climb of 165 KIAS, climbing at 1,700 fpm and burning 850 pounds of fuel per hour.
The D-Jet’s climb performance was impressive. Climbing through 16,000 feet, we were at 175 KIAS (235 KTAS) with a 1,300 fpm climb rate, and we were burning 588 pounds per hour at ISA+10 degrees C.
Due to airspace restrictions, we were limited to 20,000 feet, which is short of the D-Jet’s 25,000-foot service ceiling. At 20,000 feet, I allowed the D-Jet to accelerate to a max forward speed of 307 KTAS, burning 523 pounds of fuel per hour, or 78 gph. With a day that was 10 degrees warmer than standard temperature, and 5,000 feet below the D-Jet’s “sweet spot,” the aircraft was already outperforming initial performance targets.
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