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“Winter Warmer – Just for Fun!” E20 Worldwide Postal Competition

A warm-up event for World Cup Trophy next year.


Nov 1st 2023 and March 31st 2024


The Rules


Fixed Category: E20


  1. Model Eligibility:

  2. The projected wingspan shall not exceed 20” (508mm).

  3. No auto-surfaces are allowed, except dethermalizers

  4. The minimum total model weight including battery shall be at least 1 ounce (28.35grms)

  5. Models shall use a single 8.5 mm x 20 mm coreless electric motor. No gear drives are allowed.

  6. The propeller shall not exceed 2.7 inches (68.58mm) in diameter.

  7. The battery shall be one standard single cell LiPo battery of any capacity (mAh) (1s is nominally 3.7V - The max charge of a single cell is approx 4.2V) a battery of any capacity (mAh) may be used, however, HV batteries are specifically not allowed in the fixed category.*

*Supply of LiPo batteries varies in different countries and regions. If you are unable to easily obtain a standard LiPo it is permissible to use a HV LiPo in the Fixed Category, however, it must be charged to a maximum of 4.2V only (not the full voltage of 4.35V) 


Open E20 Category

Open E20 incorporates both the Fixed Category and the rules flown as the Peterborough Open E20 Class which has been flown in the UK and in NZ. The rules are:

  1. Models must have a maximum 20" projected wingspan (508mm)

  2. Any motor, propeller, battery and timer are permitted. (note, any battery, thus HV LiPos are allowed in open Cat!)

  3. The motor run will be up to a  maximum of 10 secs (Hence, models configured to 8 sec may also be used)

  4. Models must have a dethermalizer fitted.

  5. No minimum or maximum model weight.

  6. The competition comprises three flights to a 60 second Max  


* The Open Category means two styles of E20 models can be flown competitively against each other.


A model which is legal for the Fixed Category may also fly in this Open Category





The motor run for all flights and fly-off(s) shall be 20s maximum in Fixed Category and 10 Sec in Open Category.


The motor time starts on the release of the model and ends when power to the motor ceases.


The maximum for each flight shall be 90 Sec in Fixed Category and 60 Sec in Open Category and three flights will be flown.

Two attempts are allowed for each flight in cases of flights under 20s or motor runs over 20s or 10s respectively.

In the event of a full score, the contestant is invited to record an additional  Fly-off flight, which is unlimited.

Motor run for the fly-off will be10 seconds for both Fixed Category and Open Category

All flights can be recorded by the flyer (self-timed or by a timekeeper)


A flight is deemed to have ended when the model lands or when the timekeeper can no longer see the model whichever occurs first.


The contestant is allowed to use two models, including any fly-off(s).

How to enter?

Entry is free, simply make your flights on a day in November or December 2023 or January, February or March 2024 and submit your flight times, rounded down in whole seconds, with your name, country, model and timekeeper to:  


Example of a perfect score with a fly-off:

Fixed Category (Same for Open Cat', but with 60 Sec Max) 

Graham Green, USA, Flight 1:  90 sec, Flight 2: 90 sec   Flight 3: 90 sec Fly/Off 184 sec (Model: Own Design) 

Example of dropped flights:

John Jonson, UK, Flight 1: 80 Sec Flight 2: 90 Sec Flight 3: 88 Sec (Model: E-Buzzard)

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