Sunday 28 June 2009

Dull day and a new jet

Strange weather today, 90% cloud and very warm and humid, winds light and from the South East. Positively tropical. The pits were full and crews were overspilling the pits area at both ends, and despite the wind direction we were deployed on the South side pits.

I arrived shortly after 09:00hrs and started the days flying with the Ember as there was no wind. Whilst in electric mode the Picojet was next. Two new digital, metal gear servos were fitted this week and their reaction to stick movement is very fast. I still need to add lead to the nose as its very twitchy on the elevator. I hate doing this but I can't lighten the tail any more. I'm also a bit worried about over heating the lipo battery so I use full power frugally. The heat in the air was creating thermals and a short five second burst of power would take the Picojet vertically to near out of sight. Stopping the motor and gliding seemed to last for ages before much height was lost.

Late in the afternoon I decided to give the Yak an airing, but as I prepared to fuel it up it started to rain; just a few big spots, so I took that as a warning and packed up all my gear. Turned out it wasn't enough to damp the dust - typical.








The Bobcat

A New Jet on the Blog

Jetcat P60

The connection at the top of the engine is a PTC heater where fuel is ignited as it enters the combustion chamber on start up. This eliminates the need for gas and the associated equipment.

Saturday 13 June 2009

Ballistic

First flight today was with the Picojet, and its fast, really fast at 22,000 RPM it positively honks along. From gliding into wind I can point the nose upwards, open the throttle, and it accelerates vertically and within seconds its almost out of sight. I had a serious problem on a later flight, the elevator was responding abnormally. Up elevator would force a left turn, so would left aileron. Right aileron would force a right turn but it would also lose height rapidly. Eventually it crash landed in the grass and without damage, luckily. The cause? Starboard servo failed in the centered position. Reason undetermined.

Quite a good turnout for a Saturday:-

I was last to leave!



Also flew both Sunbeams, I took the Yak54 but I didn't fly it because the wind was directly across the runway from the South and it was up to maximum strength where flying is concerned.

Sunday 7 June 2009

Its been a funny old day

Arrived at the airfield at around 08:40hrs. and set up on the South side of the runway. The weather was cloudy, but brightening up, and a light air moving from the North East. Time to fly the Ember but not long after it got airborne the wind became a bit stronger, so it was time to land and put it away. The direction settled South Easterly which meant changing the pits to the North side of the runway. That done, Picojet next, and I had a new motor arrive for it yesterday, an in runner this time, and its a bit longer and heavier than the out runner fitted previously, so I thought there may be an issue with the centre of gravity. A balance test showed it should be OK but only a flight test would prove it. I tested the speed of the out runner motor before I removed it and the result was 18,000 RPM on a 5.25" x 4.75" APC propeller. This new motor tested out at 22,000 RPM on the same prop. Imagine what it does when it "unwinds" in the air. Right, lets get it airborne, and what a difference. Its now positively ballistic, but tail heavy making it twitchy on the elevator. I glued some lead into the nose (something I hate doing) to improve centre of gravity position, and a flight test proved it was better, but more weight was required in the nose. But what I'm going to do is move the motor forward as far as it will go so hopefully, no more lead needed. Will keep you posted.

Later a Club Committee member arrived (who shall remain anonymous) and insisted, despite the wind direction, that I change to the South side as it is the Club rules (its not, I double checked),and he refused to fly from the North side. So this means taking off and landing down/cross wind. Anything for a quiet life, so I moved all my gear back to the South side. Paul M and Jim E arrived later and they both asked "Shouldn't we be over the other side?". I had one flight from this side but landing was a bit awkward as the pits were in danger of being in the way, so I didn't fly again until he'd gone and then we all moved to the North side. One for the AGM in December me thinks.




Jims OS Gemini 240 powered Firecracker

I haven't seen this aircraft fly for years, in fact I can't remember the last time I saw it fly, and I still haven't seen it fly. Jim put it together, fuelled it up pumped up the retracts, and prepared to fly and it started to rain. We had enough to seriously wet the aircraft, but barely enough to dampen the dust on the runway. So Jim defuelled and dismantled and packed it up into his car. then the Sun came out and it turned out nice again. Sh!t happens.

Also in the picture is Pauls Ducted Fan F15 Eagle and Fournier powered glider.

Monday 1 June 2009

31st May 2009

I should have done this on the day, that's why I've dated the heading.


A really superb day weather wise although the wind was a bit strong at 8 - 10mph. I took the Yak 54, Sunbeam 1, and the Ember (tempting fate) and flew them all, but the Ember was a very short flight, just up and down again during a quiet spell. That was enough, it was still too windy. I wanted to take the Picojet, unfortunately one of the magnets had displaced itself and It was difficult to get it back in place. Also the bearing had come out of the rear cover so I had to glue it back in again. I think that's poor design. I don't think I'll buy another out runner motor.

A minor accident occurred today, a Club member had landed an electric biplane safely and parked it in the pits. No problem so far, and then picked up his electric glider, and after changing models on the transmitter proceeded to launch the glider having not done the full pre-flight checks. Once the glider was launched, he then switched on the motor, which also switched on the motor on the biplane he'd been flying earlier! It moved forward and hit him in the legs, and whilst looking down to see what had happened, the glider nosedived onto the tarmac. Fortunately there was no injury caused but the glider didn't get away with it so lightly. What he didn't do was disconnect the battery in the biplane before launching the glider, both aircraft being on the same frequency. We live and learn... or do we?

I took some photos of Malcolms Magnatilla to record the how he fitted his four stroke engine. This will be useful information for when I build my Legionaire. The aircraft has a very short nose and its a bit of a tight squeeze getting it in there.

Malcolm says the OS 70fs is way overpowered

Firewall cut away to accommodate carburettor


All pictures shown with rather nice aluminium cowl removed.

That's all for now folks.