After flying a different rocket I decided I wanted to send this up again for its second test flight, this time with the more powerful D12. The winds continued to die down more, so I was sure this wouldn’t get lost.  Though I thought it would fly well on the way up, I didn’t want this new rocket to get lost in a drift.  The manufacturer claimed 980 feet for this motor.

The D12 burned for 1.9 seconds, its peak thrust giving the rocket 12.4 Gs of acceleration.  For the entire burn, the average acceleration was 3.1 Gs, giving the rocket enough energy to reach 131 mph on its fast, straight climb.  It then coasted for 5.6 seconds but still did not slow enough before the ejection fired slightly (2/10 sec) early as it reached 668 feet.  With the rocket opened it slowed in the next 8/10 seconds to an apogee of exactly 700 feet, having climbed an additional 32 feet.

There apparently was not enough ejection pressure because the parachute, though not stuck tight, did not leave the tube.  First the empty engine casing landed on the ground, then the rest of the rocket fell to earth at 20 mph, but it landed in the grass safely, about 80 feet upwind, with no dings or cracks.  The motor mount and engine clip appeared in fine condition and was not damaged in any way.

This same problem was happening with my Bandit II, which kept rejecting D12 casings and not deploying the parachutes all the time. Co-incidentally it also had an ejection baffle installed.  Puzzling since this rocket was built with at least a foot of empty tube space before the baffle.  I believed that was plenty of volume to prevent over-pressurization.

My current thinking is that I have learned that these baffles are not so reliable for higher power motors with their stronger ejection pressures, and I should cut/drill out the DEFCON’s baffle and use Nomex before using higher power motors.  My love affair with baffles has ended, but my love affair with the DEFCON 1 has just started – She looks great and flies well!