Back on Sunday, August 13, 2006, I flew the initial test flight of an ESM Hawker Hurricane for a fellow club member. This was the smaller 72" version and had an RCV 90 SP engine, turning an 18 inch prop ( 12" pitch ? ). So, in theory, it should have had the torque of a 1.80 and the thrust of a 1.00. Here are some notes I made of the flight.
It took off smoothly and
didn't jump into the air, even while holding a lot of up elevator. Climb power
was adequate and scale like with the angle as shallow as possible, just to
clear the trees, retracting the gear ASAP to get rid of some drag.
Once it was trimmed ( right rudder and right aileron ), a few photo passes were made and then a climb to a safe altitude for stall tests.
So, flaps up, it stalled at about 1/2 elevator
input with a slight left wing drop. With full flaps, the nose wanted to pitch
down significantly. Without re-trimming, it stalled at about 3/4 up elevator
input with a violent left wing drop that had the plane right upside down! A
little more right rudder trim...
Relaxing back pressure a little and rolling the
wings level, the plane recovered from the dive and the flaps were retracted
again. So, as long as I didn't exceed 3/4 up elevator on the approach, the
speed could be controlled with no danger of a stalI. The engine was
slowly losing power throughout the flight, so instead of attempting any more low
photo passes or barrel rolls and the like, I elected to land it. With the gear
and flaps down, full throttle was needed on the downwind to maintain height
(engine was really bogging now). A curved final approach turn was made, gradually
pulling the throttle off to idle as it passed over the edge of the field. All the elevator was used in the flare. There was no tendency to stall, due to being in ground effect with the power off. The engine had stopped at this point. It landed
softly with the nose slightly high. I would have liked a full 3 pointer, but so
be it!
I had recommended reducing the throw to about 2/3 of what it was and adjusting the elevator up a little bit, so that it would need a lot of down trim to fly level. In this way, it would be more difficult to stall and yet would still have enough up elevator to flare, once it was re-trimmed with the flaps down. We never got around to making another flight as the owner moved away from the area.
I found it interesting that the model had the same stall characteristics as the real airplane. To quote Dan Griffith from the 1999 issue of Flight Journal, "Unlike the Spitfire-but in common with the P-51-the aircraft has only one real vice: a viscious stall in the landing configuration without any noticeable stall warning. One moment you are straight and level; the next, you have stalled and are almost on your back."
Bruce Lockwood said the following in Warbirds ( Volume 22 Number 5 ). " Once on station, I did a clearing turn then slowed to do some stalls - clean and in idle they come at around 63 kt with a nice buffet and easy right wing roll. Very nice. Next was a stall in the landing configuration. At idle power, the break came at around 50 kt with buffet and a sharper left wing drop. Now, with the power on I did the same thing. This time the nose attitude was very high as the airspeed hovered around 45 kt before stalling and sharply dropping the right wing over 90 deg. "
I found it interesting that the model had the same stall characteristics as the real airplane. To quote Dan Griffith from the 1999 issue of Flight Journal, "Unlike the Spitfire-but in common with the P-51-the aircraft has only one real vice: a viscious stall in the landing configuration without any noticeable stall warning. One moment you are straight and level; the next, you have stalled and are almost on your back."
Bruce Lockwood said the following in Warbirds ( Volume 22 Number 5 ). " Once on station, I did a clearing turn then slowed to do some stalls - clean and in idle they come at around 63 kt with a nice buffet and easy right wing roll. Very nice. Next was a stall in the landing configuration. At idle power, the break came at around 50 kt with buffet and a sharper left wing drop. Now, with the power on I did the same thing. This time the nose attitude was very high as the airspeed hovered around 45 kt before stalling and sharply dropping the right wing over 90 deg. "
