Hi Friends, want to share my Crashing experience involved huge learning .

I was flying my piper cub for the second time after I assembled it and tried to do some sky photography with my blackberry taped below the battery lid.

This piper is a Phoenix model aircraft with 60 inch wing span. It's a slow flying & ultra stable model. 

I was flying it very slow (almost at the threshold of being stalled) but didnt realized that I taped my blackberry below it adding extra weight.




Took a tight right turn with Rudder and ailerons (its very easy to take a very tight turn because of its slow flying character and ultra stability) ......Alas! .... extra weight added to it, suddenly without any warning it fell nosedown exactly at the place of its turn. 

It was at about 150 feets and such a sudden fall was never expected!

I was stunned looking at it falling like a stone. Bumppp!!!!! And it's over. All I imagined was a heap of balsa lying on the ground.

Running towards the site, I was planning how to collect the heap of balsa pieces and calculating the loss happened within second flight!

I was awestruck observing the scene, whole planes was unhurt except few zig-saw puzzles lying around and the motor lying on a side with propeller intact.

Now look at the photographs you can see nothing much happened but the impact was completely absorbed by the Motor mount which was nicely zig-saw puzzeled designed.

After this Crash I realized the importance of Crumple Zones and importance of well researched engineering designs.

Thanks to Amit ( Hellyflyer) who helped me to solve this puzzle and now Its almost done, except motor mount I have recovered whole front part of it.


I need a small help from the group! Can any one suggest me someone with CNC machine who can again make this kind of motor mount and I also need a fiberglass cowl for it (if someone can make it !) 

Asin.. as this structure is not much complicated, hope can cut it out from appropriate plywood, with a drill and jigsaw, while tracing the shape of each plates on a tissue paper, after glueing together..

Many thanks Krishna Ji, here is the structure I am talking about.

Asin.. if you have measurements, or crashed plate, then can cut it all easily.. its nothing complicated..

 ..Sure sir for you its a cake walk, for me its  .

Will surly try to cut or get it CNCcd from some nearby source.

All I want to share with my friends is the magic of crumple Zones an 800gm model fell nosedown from 150 feet and nothing much happened  ....all credit to Engineering and people like you..who are dedicated to R&D.

you may want to look at these mounts, very nice mounts, been using them for a while, they are adjustable in length (Read Basic AD Thread on Spin and recovery)
This crumple zone is not by design, it more of a default setting. crumple zone design is different. can talk about it some other time

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=5283

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=7388