Ed Jacoby's Successful Level 3 Flight
Conditions just couldn't get any better for a Level 3 attempt; the date was August 12th, 2001, skies were clear and temperatures were in the mid-nineties. The waiver was in place, and around 7:00 pm the winds dropped off to virtually calm. Now, it was up to Ed.
For his second Level 3 attempt, Ed chose a scratch built, 12 inch diameter Sonotube based rocket. The Sonotube was reinforced with kevlar and fiberglass, the bulkheads and fins were 1/2 inch plywood (also glass reinforced) and the basic dimensions of the rocket were based on the popular LOC Mini-Mag. Mini-Mag fliers know that the rocket is only marginally stable on larger motors, so Ed's "Maxi-Mag" carried 7 pounds of lead in the nose to counter the weight of the Kosdon M1130. The Kosdon M1130 puts out 5800 newton-seconds of thrust over it's 5.1 second burn time. Liftoff weight was 55 pounds, predicted altitude was 3400 feet at a max velocity of 400 feet/second.
After the important things (like arming the electronics) were checked and checked again, the crowd moved back to a safe distance and the countdown began. At T - 0 the button was pushed, the ignitor fired instantly, and the motor roared to life. Liftoff was slow and impressive.The rocket showed absolutely no roll as it accelerated upward on a perfectly vertical course. After burnout, the rocket was extremely easy to track due to it's large size and the Kosdon full 3 inch diameter smoke grain.
Right at apogee the twin 10 gram black powder charges fired and the 16 foot main parachute deployed quickly and perfectly. We were particularly worried about the parachute opening; the chute is so large and has so many shroud lines it is easy to get them tangled. Great care and attention was devoted to packing the chute and it paid off, the chute performed perfectly. The rocket desended gently to earth, landing undamaged in a cotton field about 1/2 mile from the pad. A perfect flight and a successful Level 3 certification!
Photos by Tom Kindel, Steve Rogers and Tom Montemayor. Click thumbnails for larger image.
The onboard Adept altimeter indicated a max altitude of 3637 feet. The backup AltAcc accelerometer indicated a max inertial altitude of 3574 feet and a peak acceleration of 4.5 Gs.
Ed Jacoby and Maxi-Mag.
Liftoff!
Perfect recovery.
The rocket is the big grey thing.
The Halls of Montezuma.
Blowing and Going!
See video of the Level 3 flight. Click here for Ed Jacoby Level 3 Video Page.