AHPRA Handicapped Altitude, Formula-AHPRA

Formula-AHPRA

Handicapped Altitude

Working Name, may be changed.

This is all tentative. Is posted here to get feedback.

At this time the contest in not in effect.

Comments?

          This is an event where any motor may compete on an even footing against any other by having motor impulse and burn time figured into a handicapping formula.

    In other altitude contests the optimum motors, the ones at the top of the impulse class range and with long burn times, are difficult to obtain or no longer made.

        This will allow the contestant to use their favorite motor and/or stay in a budget while competing and not be at a great disadvantage if the other guys favorite motor and wallet are the biggest ones made. The rocket that is best designed and constructed with a good flight will be the winner. Airframe may be any shape, long skinny, short fat. Boat tails and any other drag reducing devices are encouraged.

          Formula comes up with a number that is the minimum volume in cubic inches the airframe may be.

          Higher impulse and longer burn time require a larger volume airframe.

          A “standard” 3FNC, CD 0.45 rocket will go to 3700-4000’ using the formula. Streamlined boat tailed rocket will go to about 6000’.

          Simulations using Winroc have shown it to be fairly accurate from AT F22 to Vulcan O4000.

        The rocket for the Aerotech F21 in a standard 3FNC configuration is 1.25" dia., 17" tall. For the Ceseroni O5100 it would be 40" diameter and over 24' tall. But they will go to the same altitude!

Tripoli Safety code will be enforced.

All entrants must be members in good standing of Tripoli.

4 to 1 minimum thrust to weight. Unless higher is stated elsewhere.

Parachute must be sized so no part descends faster than 21 f/s.

Altitude is by barometric or visual tracking only. Accelerometers may be used for ejection.

Rockets must pass RSO and conform to all site rules.

This is intended to be a fun event, anyone may be declared permanently disqualified by AHPRA for violating this.

Certified motors only. Volumes are calculated from certification data.

Airframe Volumes for each motor.

Higher impulse and longer burn time require a larger volume airframe.

These are the minimum volumes, may be larger. Airframe may be any shape, long skinny, short fat. Boat tails and any other drag reducing devices are allowed.

Some motors are missing data, indicated by a "0" volume. Missing numbers were not calculated due to differences manufacture's and actual test data. There may be errors that will be corrected. Data is from the TRA TMT lists.

This is the formula used, Impulse in Newton seconds, burn time in seconds. Formula may be modified after receiving comments

=(((Impulse/587)^1.5 POWER)X600)*((Burn time/1.8)^0.3 POWER)

F Class Motors

Manufacture Motor Nsec sec Cubic Inches

AT F21W-4/6/8 55 2.5 19.0

AT F62T-S/M/L 51 1.1 13.4

G Class Motors

Manufacture Motor Nsec sec Cubic Inches

AT G12-RC 80 0.0

AT G25-5/10/15 120 0.0

AT G33-5/7 100 0.0

EM G35-6/10 124 3.9 73.5

AT G40-4/7/10 120 0.0

AT G54-6/10/14 85 0.0

AT G55-5/10/15 125 0.0

CS G60-12A 139.4 2.2 73.2

AT G64-4/8/10 120 0.0

CS G69-12A 128.8 1.9 63.0

NC G70-5/7/10 90 0.0

AT G75J-S/M 135.6 2.4 72.9

CS G79SS-13A 129 1.6 60.0

AT G80T-4/7/10 120 0.0

AT G101W-S/M/L 85 1 27.7

AT G104T-S/M/L 81.5 1 26.0

H Motors

Manufacture Motor Nsec sec Cubic Inches

AT H45W-10/15 289 6 297

EM H48-8,P 249 4 217

EM H50-6/10 264 5 246

AT H55W-6/10/14 162 2 96

AT H70W-6/10/14 215 2 137

PP H70-P 237 3 182

RT H70 208 4 155

AT H73J-S/M 186 2.6 118

EM I69-10 369 5 406

AT H97J-S/M 177.3 2 106

CS H110-13A 266 2.1 192

AT H112J-6/10/14 261.1 3 206

AT H123W-6/10/14 223.6 1.8 140

AT H125W-S/M/L 299 3 244

AT H128W-S/M/L 173 1 86

CS H143SS-13A 247 2 162

AT H148R-S/M/L 206 1.4 116

CS H153-13A 258 2 173

AT H165R-M/L 165 1 75

AT H180W-S/M/L 218 1 125

AT H210R-6/10/14

Manufacture	Motor	Nsec	sec	Cubic Inches
AT	F21W-4/6/8	55	2.5	19.0
AT	F62T-S/M/L	51	1.1	13.4