LAUNCH REPORT 1999-006

Date:    June 9, 1999
Time:    8:00 pm
Place:   My backyard, Stow, OH
Weather: Sunny, 85 Degrees F
Winds:   SSE calm-5 mph

It's been pretty hot and breezy for several days. Yesterday afternoon the winds
started calming down and today was nearly perfect all day. I told the boys it
looked like good flying weather and my oldest said "Let's do CR4!"

I told him that it was a bit late to be taking aerial pictures but we could leave
the camera out. Kids love instant gratification, so this was no concern to him
at all! Now I became concerned about entering restricted air space with the lower
overall weight (no time for FAA notification). I double-checked with wRASP and
there was no way we were going to punch 700 feet. This is a 4" diameter rocket and
the unpainted body and fins really bump up the coefficient of drag. I loaded up an
NCR F62-6. This delay is a bit long, but with this rocket's two-piece recovery and
"beefier" recovery system I wasn't too concerned.

wRASP input: Drag Coefficient 0.750, empty weight: 0.650 kg. max diameter: 3.980 in.
Environment: Hot Day, Launch Rod Length 6.0 ft., Base Altitude 1100.0 ft.
wRASP output: max altitude: 620.9 ft. AGL, d4: 21.9 ft/sec, d6: -41.4 ft/sec

This was only the CR4's second launch, the first without a camera (the camera port
hole was plugged with a tube coupler taped inside), and my first NCR motor.

My boys went out and rounded up the neighbors. In all, over 20 moms, dads, and kids.
The boys and some of their friends helped drag the PD3L and other equipment out to
the back end of my backyard (~100 feet from the house). My wife was assigned to
capture the moment on film and everyone was moved much further back than what they
usually are.

CR4 without camera (is that R4?)
NCR F62-6
Straight boost a bit NNW
Altitude ~600' AGL
Landed ~300' NNW of the launch pad.

The kids *all* counted it out 5...4...3...2...1...LIFT OFF! The NCR smoked for a
brief moment. I kept the relay button depressed and suddenly, WHOOOOSSSSSH.

Dense black smoke around the pad and a column about 200 feet up--WOW! All this was
too much for my wife and she never got the picture. She later remarked "That rocket
was pretty cool."

The trajectory was a bit to the NNW. Away from the wind, but roughly in line with
the launch rod. The fins are rather small, the margin of stability isn't big and
the wind was so calm that weathercocking was virtually eliminated.

Perfect ejection occurred just past apogee. The booster chute popped open first,
then one of the twin chutes on the payload with its brother a second behind. The
wind came into play a bit here as the drift continued NNW, but was not too great.
Both pieces hit the same roof, across the street and two doors west, about 300
feet NNW of the pad. One of the fins on the booster took a ding, and the bulkhead
at the base of the payload got scraped and slightly separated from the coupler.
Both items an easy fix, so the launch was ruled a success.

One launch wasn't enough, so I grabbed the Maniac and a D12-7. Switched over to the
3/16" rod and we were ready to go.

Maniac
D12-7
Straight boost
Altitude ~4" AGL (yes that's inches, not feet)
Landed on the pad *exactly* where it took off from

5...4...3...2...1...LIFT OFF! NOT! This was my first "departure failure". Seems
the goofy Estes engine hook grabbed my binder-clip stand-off. It let go right at
the end of the burn and managed to get up a few inches. The kids all got to see
how an engine works. I was amazed at the amount of flame and light thrust the
engine still makes during the delay. Perfect ejection, but not enough downward
velocity (none) to open the chute.

Now there's a hole in my blast deflector and the top of my PD3L is all black.

Due to the educational value and complete damage-free recovery, this was also
ruled a success.

Lots of questions from the neighbors and quite a few kudos for the CR4. We lugged
it all in the house and called it a night.