Tom,

My post-flight look-thru turned up some interesting news...my (backyard) engineering of the battery mount seems to have been the cause of my unfortunate mistreatment of your fine product.

I had been puzzled why the plane had behaved so unpredictably...completely out of character.

Radio interference was not an option (the only other guy at the field was a HAM-band)...

It turns out that the tray I had constructed to mount the battery pack appears to have come loose part way through the last flight...evidently the 'dynamically determined' CG was not a good choice. [:'(]