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.
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-6/10/14 220 1 115 AT H220T-6/10/14 220 1 115 AT H238T-S/M/L 167.8 0.9 75 AT H242T-6/10/14 231.7 1.1 127 AT H268R-M/L 320 1 212 I Motors
Manufacture Motor Nsec sec Cubic Inches AT I65W-P 665 8.1 1136 PP I80 460 5.8 590 RT I80 359.5 5.8 408 RT I90 493.8 8.3 732 WC I110-P 413 3.8 442 HT I130 470.6 3.6 529 EM I130 597.6 4.4 808 AT I132W-M/L 610.7 4.8 856 EM I134-15 444.9 5.2 543 HT I136 507 3 561 HT I145FX 541 3.7 661 EM I150-20,P 346.2 2.8 309 AT I154J-6/10 378 3 361 PP I160 484 3.1 530 EM I160-20,P 462.7 3.5 513 AT I161W-S/M/L 329 1.8 252 CS I170-15A 418.5 2.1 378 KBA I170S-L 374 2 315 AT I195J-6/10/14 426.5 1.7 364 AT I200W-6/10/14 324.5 1.7 240 CS I205-13A 380.9 1.9 318 HT I205 469 2.3 461 AT I211W-6/10/14 441.6 1.7 386 CS I212SS-14A 364 1 246 HT I222 519 2 515 HT I225FX 527.5 2.4 555 EM I230-20,P 540 3.1 621 CS I240-15A 556 2 571 HT I260 570.4 2.2 610 KBA I280F-L 382 1 264 AT I284W-6/10/14 607.3 1.9 646 CS I285-15A 510.1 1.9 495 CS I287SS-15A 486 1 379 AT I300T-6/10/14 440 0 KBA I310S-S/L/P 633.8 2.1 705 CS I350SS-15A 60 1 16 AT I357T-S/M/L 360.4 1.4 266 CS I360-15A 625.5 1.8 657 AT I366R-M/L 539 1 443 KBA I370F-P 634.3 1.7 663 AT I435T-6/10/14 565 1.1 490 KBA I450F-L 633 1 563 J Motors
Manufacture Motor Nsec sec Cubic Inches AT J90W-S/M/L 707 6.9 1184 HT J115 674 6.85 1102 HT J120FX 758 6.2 1278 AT J135W-S/M/L 1069 6.8 2200 PP J140 664 4.9 976 AT J145H 825.7 5.7 1411 EM J160 667.7 5.1 995 HT J170 728 4.3 1072 AT J180T-S/M/L 764 4.5 1173 HT J190FX 827 4.3 1306 CS J210-16A 836 4 1295 HT J220 721 3.3 980 HT J250 745 3 1000 HT J270FX 802 3 1114 EM J270-20,P 648.5 3.5 848 AT J275W-S/M/L/XL 774 3.3 1090 CS J280SS-16A 716.5 2.5 897 CS J285-15A 684 2.3 808 CS J295-16A 1196 4 2218 HT J295 655 2.2 751 CS J300-15A 694 2.1 802 HT J315 999 3.2 1583 AT J315R-L/P 763 0 HT J317 998.8 3.2 1583 CS J330-16A 765 2.5 985 HT J330FX 1051 3.2 1708 EM J330-20,P 737.8 3.6 1044 AT J350W-S/M/L 697.4 1.8 774 AT J350W-S/M/L (MOD) 670.1 1.5 693 AW J357WW-P 1000 0 CS J360-15A 826 1.9 1018 AW J370GG-P 1040 0 CS J380SS-16A 1043 2.7 1610 AT J390H 1280 0 CS J400SS-16A 700 1.7 774 KBA J405S-L 722 1.9 836 AT J415W-S/M/L 1232 2.9 2100 AT J420R-S/M/L 658 1.4 655 AW J450ST-P 1070 0 AT J460T-S/M/L 805.5 1.8 966 AW J500ST-20A 660 1.3 649 AT J540R-S/M/L/P 1161 2.4 1826 AT J570W-S/M/L 973.1 1.9 1304 KBA J605F-L 737 1.3 766 AT J800T-S/M/L/XL 1278 1.9 1953 K Motors
Manufacture Motor Nsec sec Cubic Inches AT K185W-S/M/L 1417 6.9 3364 HT K240 1292 5.6 2754 RT K240 1845 8.1 5240 AT K250W 2484 9.3 8540 KBA K400S-S/M/L 1386 3.5 2658 CS K445-17A 1636 3.7 3458 AW K450BB-PS 1845 0 AT K458W-P 2465 6 7408 AW K470ST-P 1679 3.7 3603 AW K475WW-P 1400 0 AT K485H 1687 3.5 3568 AW K530GG-P 1410 0 CS K530SS-18A 1412 5.3 3093 AT K550W 1568 2.9 3032 AT K560W 2520 4.5 7023 CS K570-17A 2063 3.6 4862 AW K570WW-P 1700 0 CS K575SS-P 2493 4.3 6824 AW K600WW-PS 2500 0 KBA K600F-S/M/L/P 1429 2.4 2477 CS K650SS-16A 1750 2.7 3471 AT K650T-P 2406 3.7 6164 CS K660-17A 2437 3.7 6295 AW K670GG-P 1751 0 AT K680R-P 2358 3.5 5892 AT K695R-M/L/P 1514 2.4 2713 AT K700W-P 2261 3.5 5542 AW K950ST-P 1860 0 AW K975WW-PS 2450 0 KBA K1000S-P 2593 2.6 6219 AT K1050W-P 2530 2.3 5763 AW K1075GG-PS 2400 0 AT K1100T- 1472 1.6 2304 KBA K1400F-P 2640 1.9 5798 L Motors
Manufacture Motor Nsec sec Cubic Inches HT L200 2639 13 10350 HT L225FX 2789 12 10978 EM L330-P 2911 8 10366 HT L350 3043 8 11078 HT L355FX 2851 8 10047 HT L475 2774 5 8375 HT L535FX 2994 5 9390 HT L540 4615 8 20692 HT L550 3095 5 9869 HT L570FX 4716 8 21375 HT L575 4831 8 22161 RT L600 3152 7.1 11269 EM L600-P 4995 8 23302 HT L610FX 3131 5 10042 HT L625FX 4951 7 22089 AW L700BB 2590 0 HT L740FX 5033 6.8 22444 AW L777WW- 3140 0 AT L850W-P 3736 4.4 12624 CS L890SS-P 3762 4.2 12570 AT L952W-P 4656 6.2 19377 HT L970 5098 5.3 21196 KBA L1000S-P 2592 2.6 6217 AW L1060GG-PS 3622 0 CS L1090SS-P 4815 4.4 18468 AW L1111ST-P 3480 3.1 10234 AT L1120W-P 4947 4.4 19233 AT L1300R-P 4567 3.6 15977 KBA L1400F-P 2640 1.9 5798 AT L1420R-P 4603 3.2 15716 AT L1500T-P 5089 3.5 18651 M Motors
Manufacture Motor Nsec sec Cubic Inches HT M740 5143 7 23356 AT M845H 6159 0 RT M900 6463 12 39020 HT M956 6421 6.7 32199 HT M960FX 5126 5.3 21444 EM M1000-P 7320 7 39711 HT M1000 9155 9 59893 HT M1001 9835 9 66688 HT M1010FX 9114 9 59491 HT M1015FX 6334 6 30519 HT M1040FX 10098 9 69381 AT M1315W-P 6714 5.4 32267 AW M1350WW-PS 5725 0 AT M1419W-P 7756 7.1 43492 AT M1550R-P 5600 3 20608 AT M1600R-P 7084 4 31963 AW M1850GG-P 5920 3 22399 AT M1939W-P 10482 6.2 65609 AT M2000R-P 9218 4 47444 AT M2400T-P 7717 3.2 33985 AT M2500T-P 9671 3.9 50403 AW M2500GG-PS 7800 0 CS M2505-P 7450 3 31590 AW M3000ST-P 7367 2.5 29404 N motors
Manufacture Motor Nsec sec Cubic Inches AT N2000W-P 13347 6.9 97353 AT N4800T-P 19361 4.4 149,011 O Class Motors
Manufacture Motor Nsec sec Cubic Inches CS
O5100-P 29,990 5.9 312,210