FAI A PD Multi-Round
Overview of Rules:
The goal is to consistently fly a specific size of parachute duration model over 5 minutes 3 times. You only get 2 models, so you'll want to get one back to make your third flight. If there are ties, you'll be able to use a third model for the final flyoff round, per Pinkbook rule 15.12.2
Design Considerations:
Per Pinkbook 9.3, "First, the minimum length of the enclosed airframe of the model must be 500 millimeters and at least 50 percent of this airframe length must have a minimum diameter of 40 millimeters in the launch configuration". In other words, you must use a body tube that is at least 40mm for at least half the airframe must be that diameter. Additionally, your airframe must be longer than 500mm.
Once that design is consideration is met, you'll realize you have room for a very large parachute!
Tips for Beginners:
The biggest issue with this event is reliable parachute deployment and finding thermals. Both require practice!
Advanced Tips: https://sites.google.com/site/xnarcompetition/duration-events/parachute-duration
These tips are for FAI event, but many are relevant: https://sites.google.com/site/xfaispacemodeling/wsmc-events/s3a---parachute-duration
Rules Link:
The link to the rules:
- Size of the FAI Model: http://nar.org/pinkbook/9_Entries.html
- Parachute Duration Scoring: http://nar.org/pinkbook/30_PD.html
Links to Companies which sell kits:
- FAI 40mm S3/S6 Mandrel from NARTS (make your own body tubes)
- International Thermal Sailor from Apogee Components
- RKT-005 40mm Spacemodel Kit
- Just in time for NARAM building, Aerospace Specialty Products has enormous 1/4mil mylar chute material back in stock. 1 sheet. 3 sheets.
- In a pinch, the Estes Big Bertha kit would qualify under the rules. Reduce the weight as much as possible, as it has to fly on an "A" engine.