It’s got to be the Sycamore, especially the HAR14 version. This was the basic training helicopter for the RAF until 1965 when they changed to the Sioux because they were crashing so many. It didn’t have a squash plate. The rotor was controlled (????) by a rod that went stuck out of the top of the rotor shaft and bent metal guided the blades. Skeeter and Scout similar, I believe.
It had wooden blades, not interchangeable, they came as a set. A replica of a 20mm cannon shell was the mass balance which stuck out of the tip. You couldn’t hover for very long. 23 inches MAP was the 30 min rating for the Leonides engine, 30 inches for 5 and you were at 27-28 all the time.
Control authority was chronic, No hydraulics, dual controls but only one collective so if you were in the left hand seat it was left hand for cyclic and right hand for collective. You had aeroplane type trim wheels to put Q force onto the stick and you had to anticipate it before a maneuver so that you did not have to re-trim it with you hands full. The collective/throttle cam for the engine was way out of sequence so when you lifted of you had to open the throttle and as you got airborne you had to roll it off. The hand throttle was horizontal like a motorbike but it went the wrong way. You rolled the top forward to increase and vice versa. Right hand seat you had you hand on top if the throttle, left hand seat you had your hand underneath it.
There was 62 pints of water meth in two tanks. One underneath the cabin and a smaller one in the pylon. When you started running out of fore or aft cyclic you pumped water from one end of the aircraft to the other.
Despite this it would cruise at 110 knots, trimmed out, hands off, in perfect comfort.
Practice engine offs were something else. You rolled back the engine, dumped the lever, pulled it up 2 notches, (a collective pitch indicator) set the engine to 1500rpm and went for you landing site, always an airfield. When you were certain you were going to reach it you pulled the throttle back and pulled the slow running cut out. (The 1500 rpm was to stabilize the cylinder head temps before shutdown) At about 100 ft you would fully flare and when it stopped you added another 2 notches and descended vertically. When the ground was just about to swallow you you wacked in all your collective and a bit of forward cyclic to get a couple of knots of groundspeed. You had to do this because at zero speed the undercarriage would splay and roll the tyres off the rims.
You then had to restart the engine. Droop stops on the Sycamore were horrendously unreliable and the blades would punch holes in the boom so you had to get the engine cranked up before the rotor RPM went critical. I never did an engine off during my training, the instructor had his hands on the controls all the time leading me.
Shutting down after a flight you had a mirror so you could check the soldiers (droop stops) on shutdown. Should one not go in than you rev the rotor up and down to persuade it. If that didn’t work you called out the fire crew.
One of them would kneel down with a big hose aiming it just over the top of the boom near the pylon. As you shut the engine down the blades would bounce off this jet of water and wouldn’t hit the boom. The blades had then had it. Being wooden and full of water they would warp and have to be replaced.
It was probably the best helicopter trainer ever used. If you could fly it you could fly anything.
Before any Knowall jumps on me saying they have seen a Sycamore with twin collectives etc there were versions produced with this but the HAR 14 was the standard RAF Sycamore.
Last edited by Fareastdriver; 2nd December 2007 at 14:11.