2025-05-17
Spent some time looking at the TWA SST in Open Rocket. In the "Flight
#1" configuration the rocket had a Stability of 1.37 cal / 7.01%.
By adding offset front nose weight / pod those numbers increase to a Stability of 2.26 cal / 11.6%.
Being offset, hanging below C/L, also helps to correct the rockets CG, pulling it down closer to the C/L.
What the heck, I'll go ahead and add the nose weight / pod and see how she flies.
Nose Cone Weight Pod
Turned the front nose weight pod from
some 1" dia. poplar, bored it out to accept some 1/2" steel threaded
rod, and then modified the nose cone to accept the pod.
2025-05-14 And... with the help of a Gorilla.... she's all back together again.
I was going to repaint the repairs... but hey, flight scars are cool.
Launch Report: TWA SST
Date: 2025-05-08
Background
This is a single stage scratch design / built rocket. It is similar in shape to the World Air Force Supersonic Transport.
This rocket is a standard front eject parachute style.
This rocket has Altimeter Two stowage.
On Site Preparations
For a parachute I used a 24” Nylon chute.
The Altimeter was set to Flight #2 and then installed in it’s POD.
An igniter was installed in the motor and secured via a rubber band.
The rocket was slid onto the 5/16" launch rod and the controller wires were attached to the igniter leads.
The site was clear and no outside observers were present.
Launch
Wind was out of the West / Southwest and was about 4 mph.
The Aerotech G74-4 motor ignited and the rocket leaped off the pad.
It
flew stable off the rod to about 206 feet and then weathercocked
severely to a near horizontal trajectory. When the thrust stopped and
the coast started it fell from the sky.
It ground hit (12.9 g’s) on its flat belly and broke into 4 pieces.
While on the ground ejection occurred and the chute deployed.
The rocket landed 162 feet from the launch pad, to the Southwest.
Condition of rocket after the flight
All four breaks were in the four plywood “ring fin” pieces. The pieces can easily be wood glued back together.
Altimeter Readings
Altitude: 206 feet, Top Speed: 254 mph, Thrust: 1.42 sec, Peak Acceleration: 12.9 g’s
Average Accel: 8.1 g's, Coasts to Apogee: -0.4 sec, Apogee to Eject: 0 sec Ejection Altitude: 206 feet,
Descent Rate: 46 mph, Duration: 4 sec.
Conclusions
The rocket was stable, but experienced severe weather-cocking due to its design.
What I learned
This was a spectacular flight.
The Altimeter Two is one durable little device.
The photos and launch video reflected this flight accurately.
This Scratch Build / Scratch Design started out as a World Air Force SST, but morphed into a TWA Supersonic Transport. Single 29mm Motor, with an option of (3) 24mm motors just for giggles.
First Flight: Pending
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