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TCC Competition Primer:  USMRSC Rule 55, Plastic Model Conversion Competition (PMC)


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This primer presents, in one place, all the information you need to succeed in NAR model rocket competition in this event.

TCC has provided a link to the official rules whenever we discuss a rule.


All Entries

Your entry must:

* Comply with the NAR Model Rocket Safety Code: USMRSC 2.2

* Be a model rocket as described by the United States Model Rocket Sporting Code. USMRSC 3.1-3.9

* Use NAR Contest Approved motors: USMRSC 4.1, 4.4

* NOT eject its motor casing(s) without a recovery system. USMRSC 9.2

* Have your NAR number or your name on the outside, large and clear enough that the contest officials can easily read it. Teams must use the Team number or name. USMRSC 9.4

* Have been constructed by yourself or by one or more members of your Team. You may not enter Ready-To-Fly rockets (no construction required) in NAR sanctioned competition. USMRSC 9.9


Know the rules

Your having a grasp of the bigger picture can increase your enjoyment of NAR competition. You can read the Pink Book Lite to see only the rules for competitors, not for Contest Directors or other contest officials. Read the full USMRSC (Pink Book) to see all the rules.

* Pink Book Lite:

* Full USMRSC:


General Competition Tips:

TCC NAR Competition 101

TCC NAR Competition Strategy and Tactics

Contest Etiquette by Kevin Paul Wickart, NAR 59720, cr 1998, the author

Beginning Competition -- The RSVP Principle by Kevin Paul Wickart, NAR 59720, cr 1998, the author

Guide to NAR Contest Rocketry Information for Beginners by Jeff Vincent, NAR 27910, Northeast Regional Contest Chair


Which are the Main USMRSC Rules for This Event?

* The main rules are 9, 16 and 55.


Does TCC Have Supporting Documents?

TCC’s Judging Form Pack includes a blank judging form, instructions for using the form, and tips from Peter Always on awarding Mission Points.


What is the Goal?

* The goal of Plastic Model Conversion (PMC) is to convert a plastic model into a model rocket and make a safe, stable flight. USMRSC 55.4, 55.7


Does it Qualify for PMC?

* The plastic model you choose to convert must meet two main criteria. USMRSC 55.1

1. Be a guided missile, rocket vehicle, space vehicle, or jet whose engine(s) are in or spaced apart to the rear of the fuselage.

2. Not be intended by the manufacturer to be flown.


Are There Any Special Considerations?

* No one can catch the model. If anybody catches the model as it descends instead of letting it hit the ground, the judges will award maximum damage points as a penalty. USMRSC 16.7


Do I Have to Return My Entry?

* You must return your entry to the judges so they can award damage points. USMRSC 16.8, 55.6.2, TCC Plastic Model Conversion Judging Form

* The Contest Director can require that you return your entry. USMRSC 9.10


How Many Flights Can I Make?

* You can make two flights, but the judges will use only the best flight for scoring. USMRSC 10.1, TCC Plastic Model Conversion Judging Form


How is the Competition Scored?

There are two sections for scoring. Contest officials will add the Static score to your best Flight score to determine your score.  USMRSC 55.6 & 55.6 , TCC Plastic Model Conversion Judging Form

* STATIC      In static scoring, the judges award points for craftsmanship and appearance, taking into consideration the difficulty of converting the model to fly. USMRSC 55.5 , TCC Plastic Model Conversion Judging Form

* FLIGHT      In flight scoring, the judges award points for conducting a ‘mission’, for achieving a safe and stable flight, and deduct points for damage (damage points) the model receives on landing. If you cannot return your model to the judges after its flight, the judge will award maximum damage points which will be subtracted from your final score. USMRSC 55.6 , TCC Plastic Model Conversion Judging Form


What Will Disqualify My Entry?

Your entry will be disqualified if it fails to make a safe and stable flight. USMRSC 55.4


How About Some Suggestions for New Competitors?

Build a commercial kit or use plans for a proven design. Qualified Competition Rockets has two kits.


Here are some plans from Model Rocketry Magazine circa 1970. Even if the plastic kits they mention are no longer available, they still show the concepts for Plastic Model Conversion.

Plastic Conversions

Jupiter-C (Hawk), Stine, G. Nov 69 pg 31 il

LM (Revell), Milkie, T. Mar 70 pg 31 il dw

Saturn-V (Countdown), Parks, B. Jun 70 pg 9 il dw

Vostok Capsule (Revell), Parks, B. Sep 70 pg 35 il dw

What are Some Candidates for PMC?

(Excerpt from “AARG!”, newsletter or the Austin Area Rocketry Group #585, 1999, James Duffy.


Glencoe Jupiter (Juno) 1 ($10) - Almost perfect! Centuri ST- 20 tubing fits neatly into the booster. This kit will require a fair amount of nose weight to move the center of gravity forward far enough for a safe flight. Mission Points: The tub and Explorer 1 satellite on the prototype were rotated at 500 RPM before launch. On your model, the motor and batteries could do double duty as nose weight!


Monogram 1/144 Saturn V ($20) - Clustering, staging, and payload-this kit offers it all. This would be a remarkable achievement if done successfully, or it could be simplified to operate as an impressive single stage rocket. This kit will require a substantial amount of rework in order to fly safely.


Shanghai Dragon 1/35 V2 ($25) - A beautiful model that should be an easy conversion. Captured V2’s launched at White Sands required huge amounts of weight to replace the warheads in their nose cones, and your model should be no different. This should be one of the simplest, most straightforward models to convert to flying status. You’ll fall short on flight points, though, unless you bomb London or a Juarez cemetery.


Several jet fighters lend themselves to the task of conversion to rocket flight, such as the US F-104, F-16, and a personal favorite, the US Navy F4D1. The problems inherent in preparing a asymmetrically shaped jet should endear your model to the judges. Note that the US F-15 and the Russian MiG 29 have the performance necessary to accelerate straight up, a possible mission points coup! The Concorde supersonic jetliner would also be a stunning conversion (although tricky to recover), and four mini engines will look great at launch!


More Candidates

1:48 Hawk/Glencoe Jupiter C conversion. Hint - fly it with a C6-3.


Monogram 1:144 Saturn V conversion. Hint - toss the cluster, fly with a D12-3 or E9-4.


AMT 1:200 Saturn V conversion. Hint - Better on a single D12-3 or maybe D12-5.


…and still more


Tips for flying PMC


What Else & What Next?

Good info on building and packing competition parachutes:


TCC NAR Competition Bibliography


Yahoo group for discussing model rocket competition:


Yahoo group for discussing Plastic Model Conversion:


Use computer simulations to determine altitude and sink rate for various rocket/motor/parachute combinations.

* Free altitude simulations: 


wRASP 32 -

* Free sink rate simulation:


US Spacemodeling (International Competition Tips):


US Spacemodeling Home Page (International Competition):


Texas Competition Consortium PMC Judging Form:

TCC Plastic Model Conversion Judging Form


George Gassaway’s NARAM Tips:


George Gassaway’s PMC Tips:


rmr Frequently Asked Questions – Part 9: Competition and Records:



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