Vallier Racing

ok this combat plane is simple it's a pice of down spout from home depot with a foam wing and ply spars elevon mixing required. this plane was designed for the .25 engine but everyone here in Calgary like to put .40 in them so i in a .48. well flying time came along the weather was nice light wind my dad was flying his zagi 400 landed after about 15min in the air we fired the grimlen up pre-flighted her she runs nice motor is broken in well. hereis the good stuff he lightley launches the plane it takes off stright vertical so i giver her some down stick nose goes down a bit then all of a sudder she is flopping around end over ene and then came to a crash upside down i feel that i missed the cg placement. i had a set of plane but wheni went to CG the plane i could't find the plans so i CG around the spar she took 8oz in the tail but it was weried how she just went end over end. i will be rebulding all i need is some balso elevons and some down spout and 3 hrs.