Monday, August 19, 2013

The joy of Control Line Flying -- Percy Attfield

Some of you know I was going to fly yesterday; wind or no wind

The past 3 weeks the wind was such that I threatened to go flying a few times and never did.  I bought a few Xoar wooden 2 blade props and wanted to test the difference between the 12x6 and the 12x5 as compared to the APC F2B 12x5 that I have been flying. I was planning these tests for the past 2 weeks but it was always windy and I never did any testing; yesterday I was determined to fly.

I decided to start with the APC prop so that I could get comparative timings.The wind was reasonably steady at 9 meters per second and I decided I would fly (no other C/L people were there) a few RC people were talking at the club (no one flying). The windsock was blowing 1/4 from the top of the pole not quite level with the ground.

Confident that I can fly at least level in the wind I armed the plane went to the handle and as I waited for the motor to start a big piece of plastic blew across the field from the car park and folded around the prop and nose section.  I could only watch the drama as it unfolded.  The motor started and the the plastic spun with the prop but the plane remained standing. A long few seconds, the plastic shredded and some of it blew away, some of it stayed with the prop and some went into the cowl.

The plane accelerated and took off.  It was flying slower than usual and I stayed down in the wind.  Suddenly the wind increased a lot but but with gusts and eddies.  On some laps as the plane came up wind it rolled with its inside wing over the top then a few laps later the outside wing over the top.  Jerking the lines levelled the plane out each time and it was clear I just needed to catch the roll before the wing went all the way over or under the plane.  Now that is a wake up call!

Suddenly the plane turned and I was looking at the spinner and the leading edges of both wings.  I jerked the lines and the plane went back to its flight path.  Now that was scary!!

I realised that with power on I had a reasonable chance but when the motor cut it was going to be real drama.  A few quick looks at the windsock showed it had first moved to level with the ground and now was actually showing upwards towards the sky by about a 1/4.  It reminded me of the immortal words of Roston Dugmore a few years ago in KZN when he eyed the windsock: “Thou shalt not fly”.

If I was not grey already I would have gone grey in these 5 minutes which felt like 20 minutes as I waited for the inevitable end play to arrive.

The motor slowed down and then speeded up and cut as it came into the wind. I touched down  less than a quarter lap later as the plane was wind up traveling fast.  Down elevator kept the trike undercart down, it travelled around the up wind quarter lap and then the wind was from behind, the plane actually gathered speed in the next quarter of the lap with the wind from behind.  Suddenly it was on the down wind side.  Determined not to get it back into the wind I ran with the plane and straitened out the landing run.  Initially I was a short distance ahead of the plane dragging the inboard wing forward but the plane was gaining on me coming back into the circle.  Dragging the wing forward plus the side wind slowed the plane and it stopped just as it got to the edge of the tar circle but still mostly down wind.  More than a 3/4 lap ground run.

I ran out and secured the plane and all ended well.  In the pits I found the the plastic was very light (like Saran wrap) a small piece had wrapped around the prop and a piece around the the motor shaft and can.  No damage that I could see.

You can imagine that was the end of my flying for the day and so I still have not done any Xoar wooden prop testing.

See you at the round and round; sure keeps us young.

No comments:

Blog Archive

Total Pageviews


Web site terms and conditions

Copyright of material on all the pages of this site is vested in the SAMAA or the original authors. You may use the material in terms of the Creative Commons license for non-commercial purposes on the condition that you acknowledge its origin.

This work is licensed under a Creative Commons License

The views expressed on this web site, or on any directly or indirectly linked site, are not necessarily those of the SAMAA Committee, or the web editor. The information provided on this site is provided for recreational purposes only. The SAMAA and the authors of presented content assume no liability whatsoever on the use of information contained in this site. The information on this site is provided on an "as-is" basis, without warrantee of any kind. Links provided on this site will let you leave the SAMAA web site. The linked sites are not under the control of the SAMAA, and the SAMAA is not responsible for the contents of any linked site, or any link contained within a linked site, or updates to such sites.