Aircam Flight Performance
With only me in the plane (about 150 lbs, close to tail-heavy limit) stall indicates about 25 mph. But at speeds that
low the speedometer shakes around a lot and probably isn't accurate. I loaded up the plane with a couple of bags of barbells
to around 1700 lbs. The stall speed was 40 or 41 mph both with and without power. With not much load it stalls slower
at full power. That's a wide range on that much weight difference, but it's consistently that way.
Stalling the plane, you have to watch outside the plane and steer it with the rudder into the stall or it will drop a
wing. Watching the ball on the turn coordinator won't do it. You can stall the plane, recover, stall, recover, etc. at
idle without touching the throttle.
The climb angle is so steep that Vx depends a lot on the weight of the plane. Vy is 52-53 mph. This was measured at 4000-6000'
altitude with a lightly loaded plane, 5000 rpm.
I flew up to 17,500 (with oxygen) and could still climb at 500' per minute (6 degrees F). With only me in it at 14,000'
the plane would climb about 100 fpm on one engine and maintain altitude on the other. The engines had the props pitched
slightly differently at the time, both around 13.5 degrees. Since then I repitched the props to about 14 degrees and it
doesn't climb quite as good, but I haven't tested it again yet.
I borrowed a parachute and tried some spins. I did a few in both directions, but I always chickened out after about 1/2
turn when the plane was pointed almost vertically down, slightly inverted. There seems to be plenty of rudder authority
You can check the airspeed indicator by flying in a smooth circle at constant indicated airspeed. Watch the groundspeed
on the GPS. The average of the maximum and minimum speeds through the circle is the true airspeed. Ours was right on it,
after I moved the static port to the bottom of the plane.
I ran each tank dry in the air, and refilled them. They both took within 1/10 of 14 gallons. I'm not sure how much fuel
yawing would cost you. I was circling, but with reasonably coordinated turns.
I ran the plane at 116 mph for 2-3 minutes with no ill effects.