Wednesday, 28 December 2011

David Boddington - 1/4 Scale Bleriot XI B - Photos Part 2 Maiden Flight

After rigging the model in the parking area at the flying field and taking some pictures I wheeled  the Bleriot over to  the pits area and got things ready for the Maiden Flight. I was using a 'Fail Safe System' that would set the engine to idle, the elevator to level and a small amount of rudder. This would cause a slow spiral descent if I were to get any radio interference. I did a 'range check' and 'fail safe check' both with and without the engine running. All was OK so the tank was filled and the engine fired up. The engine speed was checked and I couldn't get the recommended  rpm form  the engine, it fell short by approximately 250 rpm. The pull from the engine at full throttle was considered to be sufficient. This however in practice proved not to be the case!

Final checks were made and having run out of excuses to postpone the flight the tank was topped up, engine started and it was off to the 'patch' for takeoff!

I must have aged about 10 years as the wheels left the ground. The engine was running slightly rich and it was down on the maximum rpm, but it was chocks away and off the Bleriot went!

The Bleriot  took off nicely but it was apparent that the RCV was slightly underpowered, being down on the maximum rpm and the Bleriot was gradually loosing height! As it flew further away it was getting alarmingly low in the sky. A decision had to be made, land it in the direction it was going and hope for the best (bad idea) or turn it back towards the takeoff area. The decision was made to turn the model back towards the take area and 'down wind'. Normally this results in the model losing height but on this occasion it lifted a wing and gained height, thankfully. The wind had considerably picked up by now which created yet another problem, landing. Several approaches were made and aborted with the final approach being made at a steep angle to increase the speed and then flared out for the final touch down and safely back on terra firma.

There is lots of drag from all those rigging wires and  the model, like the real Bleriot flies slightly faster than the stalling speed. The angle of flight was very good with no tendency for the tail to drop as I was assured it would. The only adjustment needed was 2 clicks of down trim on the elevator. This trim was later removed by adjusting the movable stabilizer by 2mm.

Subsequent flights were made but this time using a 20 x 12 APC propeller, expensive at about £25 each but what a difference it made to the thrust. The RCV engine is quite powerful and needed that extra weight that the APC propeller has. For the first flight I used a 20 x 12 lighter wooden propeller and it was not as efficient as the heaver APC propeller. Also the wooden propeller was in fact slipping on the 'prop driver' and on occasion stalling the engine when the throttle was opened fully. When the wooden propeller was removed from the engine the 'prop driver' had cut into  the back of the propeller by 3mm or so!

 Chocks Away...

The point of no return...

After gaining height and settling down the
Bleriot really did look the part in the air.

A nice 'flypast'
The Bleriot is really looking at home in that blue sky.

And finally the inevitable landing!

The days flying went well, the weather was superb, all in all a successful day. The RCV engine ran well and didn't let me or the Bleriot down. The engine eventually ran to is maximum rpm with the APC propeller fitted and was well worth the additional expense. Further takeoffs were achieved without using full throttle as the APC propeller was far more efficient than the wooden propeller used during the maiden flight.
Don't forget I will be uploading more photographs of the Bleriot over the next few days so please remember to drop by again for the updates. 

To be continued...

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