As in all airplane development programs, the A500 has gained weight. The airplane I flew, serial number seven and the first with complete systems, had an empty operating weight of 5,460 pounds with a maximum certified ramp weight of 7,050 pounds. Four years ago empty weight was expected to be 4,200 pounds with a maximum takeoff weight of 6,300 pounds. Some of the weight gain came from the unanticipated little things that add up to a lot when the airplane is complete. But some of the empty weight can be blamed on too much unusable fuel which is now at 30 gallons, the weight of a full-size passenger. Adam expects to trim that down to five gallons per side with more testing to show that the fuel is in fact usable even in uncoordinated flight.
With about 175 gallons of the available 230 gallons in the tanks, and two onboard, we were close to the 7,000 pound maximum takeoff weight, though after taxi we would be down to somewhere around 6,950 pounds for the actual takeoff weight.
It makes sense to start the aft engine first so that you can hear it respond even though you can't see the propeller. The starting techniques are typical for any big turbocharged Continental, and the engines fired immediately.
The A500 has a castering nonsteerable nosewheel, which is odd in this size airplane. I found it natural and easy to taxi using differential brakes-though I did keep trying to lead a turn with an engine as in a normal twin, to no effect, a habit experienced twin pilots will need time to break in the A500-but on a long taxi with a crosswind a lot of brake pressure, and thus brake heat, would be needed. The company will probably add nosewheel steering in the future.
It was a hot day at Adam's home base on Centennial Airport near Denver, but the initial acceleration and takeoff roll were surprisingly quick given the airport elevation and our maximum weight. I needed about two seconds to be comfortable with the sidestick control after rotation. The forces are on the heavy side so you need to keep the airplane in pitch and roll trim. As with all sidesticks, the left roll input is where I notice the effort most. Pushing the hand, wrist and forearm away from the body is not a natural motion, particularly for a right hander operating the side stick with his left hand.
Initial climb rate was around 1,000 feet a minute, even though we were starting from a density altitude of nearly 10,000 feet. And the A500 held the rate well as I climbed toward its certified ceiling at FL 250. There are only three recommended power reductions on the way up, and in 29 minutes we were level at 25,000 feet. I was most impressed by the smooth and cool engine operation. Both engines remained within a couple degrees head and oil temperature of each other, and always comfortably in the green. Pilots with memories of hot rear engines in Skymasters can put them to rest with the A500. To get two engines mounted on wings to operate that uniformly would be a challenge, but to accomplish it with fore- and aft-mounted engines is truly remarkable.
At FL 250 the air temperature was 21° C above standard and, with 20 gallons per hour going through each engine, the A500 showed a true airspeed of 208 to 210 knots. I could have shaved two to four gallons per engine and slowed down to 190 to 195 and been able to stretch out the range. We descended to FL 220 where the A500 hits its top airspeed and saw 220 knots true on 44 gph total fuel flow. In the early days of the program Adam had hoped for a top speed of 250 knots, but that was with an airplane weighing considerably less and a program full of youthful optimism. The reality of 200 to 220 knots for an airplane of this size is pretty good.
The A500, as many airplanes do, had a problem with rolling off at the stall, particularly in the so-called "accelerated" stall test where speed is decreased at five knots per second. The solution, which is also a popular one, was to add drooping leading edge cuffs ahead of the ailerons along with vortex generators. The drooped leading edge operates at a lower angle of attack and thus continues to fly while the wing inboard of it stalls, so the ailerons remain active and effective through the stall, allowing the pilot to counteract any roll off. The vortex generators create a high energy wake that helps keep air streaming aft at high angles of attack instead of tumbling off in a span-wise flow that can reduce aileron effectiveness.
I stalled the A500 with no aileron or rudder input and it sort of mushed straight ahead. Even with the stick held full aft the airplane showed no tendency to roll at all, so the wing design is clearly a success.
Landings will be one of the greatest delights of an A500 pilot. The airplane has very long stroke trailing-link main landing gear and very powerful pitch stability, so it is extremely easy to put the airplane in the landing attitude and let it roll on. The greaser will be the typical A500 landing, which is great for the ego.
Adam hopes to begin testing to earn flight into icing condition approval this winter. The company had initially planned to install a weeping wing TKS ice protection system, but will probably go with inflatable deice boots, as it plans to on the A700 light jet. The windshield, propellers and pitot tubes are heated electrically.
The A500 is what I would call a specialty airplane for the pilot who wants the redundancy and performance of a twin, but is uncomfortable with or lacks the experience to be insured in a conventional twin. And it's also for the pilot who simply wants a pressurized piston twin that is less than 22 years old. The last of the pressurized twins from Cessna, Beech and Piper rolled out in the mid-1980s and since then the only choice for piston and pressure was the Piper Malibu/Mirage single. At $1.25 million the A500 is not cheap, but the Mirage comes in at nearly $1 million with one less engine, and the Meridian at nearly $2 million is the lowest priced turboprop single.
For Adam the A500 is important because it is the company's first airplane, and to pave the way for the A700 jet. Adam says about 65 percent of the airframe components are common to both airplanes, and even a higher percentage of the suppliers are the same. The lessons learned in developing the A500 will help push the A700 program along immeasurably.
Adam is under totally new management since founder Rick Adam retired earlier this year, and the new team is focusing its energy on developing production methods that can take much of the man hours and cost out of building both airplanes, while at the same time attacking issues of cosmetic quality. It has taken 15 months to build the first few A500s, but the goal is to shrink that process to 14 weeks. Adam is building subassemblies in Pueblo, Colorado, and will soon begin final assembly of A500s, and then A700s, in a new facility just completed in Ogden, Utah. Adam has raised more than $200 million dollars in the capital markets in the past year and has the funds to see its way into volume production.