Project
911 Flight

Post-flight Analysis

• Good flight except the fins sheared off towards the end of the flight. Recovery still needs work but I think the results of this flight will produce a working ejection system on the next flight. The fin surface area had been increased by 24% in an effort to increase stability. However, the fin size was increased in width and not in length which caused the fins to become unstable at high speed.
• Also tested were two static J300 engines with Glycerin added to increase the flexibility of the finished fuel. The first static had 10% of the fuel as Glycerin or 4.2% of the total engine mixture. The second static had 10% of the total engine mixture as Glycerin or 25% of the fuel. The initial results were good when the fuel was made. Glycerin as 25% of the fuel made the mixture a little too flexible but 10% of the fuel made the finished fuel nicely flex able when pressure was applied to it.
• Power output was noticeably reduced with the addition of Glycerin however the pressure spike, normally present in all J300 engine, was gone.
• A 60/40 fuel ratio may be too fuel rich with a Glycerin additive, 65/35 will be tested next month.

• Static 01
• Static 02

Construction

• 6" ABS was used as the rocket body.
• 4 J300 engines were used to power the rocket.
• Fins were increased in size by 24%.

Pros

• Good stability.
• Nice power off the pad.
• Easy to construct and low cost.

Cons

• Increased fin size caused the fins to become weak at high speed.
• Recovery needs work.

Pictures

Video

• Flight 01
• Static 01 with 4.2% Glycerin
• Static 02 with 10% Glycerin

Drawings

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