4 Jun 98 - Flight Test
completed. 4 Jun 98 - Flight Test
completed.
The flight test was conducted on 4 Jun 98 at 16:20 GMT at Charmy Down Airfield, near Bath. The weather conditions were good with 0 - 5 mph winds, 3/8 cloud cover and about 10 mile visibility.
Climb Out - Model was pointed into wind the stopwatch started and throttle opened. Take off occurred after a less than 30' ground run and a climb of about 30° was easily sustainable. At about 50' up I reduced power to about 2/3 throttle and a climb of about 15° was possible.
Handling - The climb was continued to about 150' and several circuits were flown. The model responds very positively to all controls but is not in the least bit twitchy. To trim the model 3 clicks of up elevator and 1 click of right aileron were required.
Stalls - Throttle cut and nose held level with progressive up elevator - speed reduces until the nose gently nods with no wing drop. Speed increased and nose lifted about 10° above level - nose drops and right wing dips into incipient spin - recovers as soon as up elevator released.
Touch & Go - A standard left hand circuit was set-up and the model touched down within feet of my expected position. The throttle was opened and the model took off again after about 15'. As the handling was so good and the stall uneventful I decided that some aerobatic tests were required.
Loops - Model climbed back to 150' and held level building speed at full throttle - Up elevator applied and a really smooth loop of about 40' was comfortably completed. Throttle reduced to 3/4, speed allowed to settle in level flight, and exercise repeated - again a comfortable loop resulted. Reduced again to 1/2 throttle - achieved about a vertical pull up and stall with the model flipping over on it back to vertical descent.
Stall Turns - Full power applied and model climbed vertically, power cut, allowed model to slow and applied full left rudder - too slow, almost no yaw occurs, and model flips over on its back. Repeated the manoeuvre and applied rudder a little earlier - similar result after about a 20° yaw. A third attempt was made and rudder applied even earlier - a good stall turn resulted. I think that a little more than the present 30° rudder deflection is required for easy stall turns.
Remainder of flight - The model was then flown for another few minutes. The power very quickly reduces to a point were level flight can't be maintained. Model landed short of strip about 15' from my position in the semi-rough - total flight time was 12 minutes. I will have to conduct a few flights with landings earlier and measure the remaining capacity.
Thoughts & Summary - I was extremely impressed by the climb performance and power of the model in flight. It really did look like a real aircraft and when the trim is completed will look even better. I expect that flights of 20 minutes are likely if flown at a low throttle setting and with energy conservation in mind. I look forward to flying this aircraft in the company of the die hard 'slimers' - will they get a shock as it out performs most of the 4 stroke models in the club and is virtually silent. As the club operates a no noise rule at Charmy Down on Mondays, Tuesdays and Fridays this type of electric model is superb - you can fly any day. I would recommend this set-up to anyone.