SEN 3437

1. 2 Joules/gram and Junior flying Q in American Cup Contests
2. Editor’s Q observation

 

2 Joules/gram and Junior flying Q in American Cup Contests

By Aram Schlosberg / Feb 28, ’26/ 398

1/ Regular rounds

With 2 Joules/gram most Q models reach 80 meters with a 20 second motor run. At 3 J/gr models reach 120 meters, to glide 3:30 minutes after a 30 second motor run for a 4-minute max. This is equivalent to using 75-meter lines in A, 45-gram motors in B or 6 second engine runs in C in the regular rounds. In Europe, all World Cup Q contests are flown with 2 J/gr on a 20 second motor run. In February, all the 3 Q World Cup contests were flown with 2 J/gr in the regular rounds.

The 3 J/gr default is an ancient sporting code requirement that was never erased.  Stating “The contest organizer can reduce the allowed energy amount to 2 joules per gram and the motor run to 20 seconds in specific rounds or all rounds if this has been announced in advance in the contest bulletin.” It can be overruled if all flyers consent to fly with 2 J/gr, difficult to reach in practice, particularly with an inexperience or literal CD. [1]
1/ All Q flights flights will be flown with 2 J/gr with 20 second motor runs. oules in all the regular rounds.
But there is an important exception!

2 Juniors
Most juniors fly direct drive Q, typically assembled from A and sometime B model components.  Direct drive models lack a prop stop, typically using 12″ props with half the diameter of geared Q models. (I’ve flown a Q model based on a B-model for years, occasionally reaching 80% altitude of Q geared models. A 10% energy bonus is lean, a 25% energy bonus generous in respect. Being generous, one can state:

2/ Juniors flying direct drive Q models (with no prop stop, mounted directly on the model’s fire wall) could use 25% more energy, namely 2.5 J/gr with 20 second motor run in all their flights. [2]
I also recommend identifying juniors (J) and whether they are flying direct drive models (J+DD) models in contest results. ///
————————————————————————————————————
[1] CIAM will probably fix the 3 J/gr by January 2028 at the earliest!
[2] One can have a low ration gear screwed onto the front of the motor that is mounted onto the fire wall. But these setups are rare and lack prop stop.

Editor’s Q observation

It is probably better to go through the regular rule change process.  This was discussed at the Feb SCAT meeting and rejected.

SCAT’s position is that the America’s Cup  object is to promote travel to participate in FAI FF events across North America. Not promote changes in the rules by requiring a specific deviation/option be applied at all contests.  In addition the general opinion was having special rules for juniors was counter productive and would essentially require a separate contest and would exclude them from World Cup events and not prepare them for World Champs. They do believe that a change to 2 joules is the right thing to do. They also think some other things need changing too but are not requiring those be applied either.

The FabFeb CDs are aware that failure to make this position clear soon enough this  did generate an excessive amount of communications traffic of all genre, except perhaps  semaphore, they plan to make this clearer for FabFeb 2027 sooner in the year. Well how about now, no that  would be over doing it and we are not 100% certain who will be CD next year. Well thank you fo the suggestion anyway.

BTW the proposal talked about the American Cup, we assumed that it referred to the America’s Cup, if that is not the case we are not aware how to find the American Cup.

SEN Status

Our new web site is online with archives of SEN going back to 1997 plus many items about FAI Free Flight. It can be found at http://www.faifreeflight.org

Existing SEN subscribers can update their preferences by following the update your preferences link at the bottom of this page.

New users can sign up at  this link http://eepurl.com/crOnvj
or at the SEN website