Holtville - April 2016 launch report

In looking at my todo list in the entry below I must admit I recall little from the February launch but I remember much about last month's launch.  Here are a few photos of Ron Rickwald's M flight, my M2080 Skidmark, and Larry Hermanson's L1000.  Thanks to Mark Treseder for shooting the away photos.  And here's the GoPro vid of Ron and my flights:

In honor of Mike "Sparky" Jerauld's lengthy service to the DART club many folks flew Skidmarks, Dark Matters, or Metalstorm motors.  I elected to bust out the CTI Pro75/6GXL 6827M2080 Skidmark purchased during last fall's Wildman sale.  As always the prep took much of the morning but I felt good about the setup.  Thanks to Darrel for helping out at the pad and that was a fine, joltingly quick liftoff:

Mark Treseder later shared that he thought the motor had cato'd but I had used the stock CTI igniter and I'm guessing it was the high aspect ratio, 7G motor that caused the quick pressure up.  I never saw it after burnout but had GPS lock from about 14,000 feet until it landed. Later Darrel and I drove right up to it on the concrete runway about three feet North of the dirt.  It was clear that the apogee ejection had worked but there had been no main ejection at 800 feet.  Having flown this rocket based on a recipe that had served me well for about nine flights I was shocked and saddened at the recovery failure.  I forgot to shoot a photo but the booster was on the runway painfully close to the dirt (which would have saved it) and the payload section was in the dirt.  I'm guessing that the payload section had bounced off the concrete, however, as it's nearly totaled as well.  The booster clearly landed at an angle as the AeroPack motor retainer has a huge dent in it, the epoxy sealing the retainer in is mostly fractured out, and I can see that the casing itself is dented.  I will publish a separate entry on the failure analysis but I'm quite certain the new M-tek 'initiators' are to blame.  Kenny Harkema spoke to the folks at electricmatch dot com and they told him there was a defective batch of pyrogen material for these new matches.   Friggin' sheer awesomeness.  I should note that their J-teks have never failed me.
   The flight had sim'd to 14,800' AGL.  I still need to pull the ARTS2 data but the Raven 2 and Big Red Bee Beeline GPS appear to have survived the impact:

• [Addendum] ARTS (graph, tabular, motor performance (7192M2197), CD)
• Baro altitude: 14,263'
• Max velocity: 1,510 fps (1,029 MPH)
• Max acceleration: 657 ft/s^2 (20.5 Gees)
• Raven2 (graph, tabular):
• Baro altitude: 14,281'
• Max velocity: 956 MPH
• Max acceleration: 29.1 Gees
• Beeline GPS (Google Earth screen grab)
• Max altitude: 4,513m AGL => 14,803'
• [Addendum] Averages:
• Altitude: 14,449'
• Velocity: 993 MPH
• Acceleration: 24.8 Gees

Tomorrow's Holtville launch will be small but I'm gonna head out anyway in search of better luck.  Wish that for all of us. Thanks for reading.