3.4. CLASS F1D - INDOOR MODEL AIRCRAFT

3.4.1. Definition
Model aircraft which can only be flown in an enclosed space and which are powered by extensible motors and in which lift
is generated by aerodynamic forces acting on surfaces remaining fixed in flight, except for changes of camber or incidence.
3.4.2. Characteristics of Indoor Model Aircraft F1D
Maximum wingspan of the monoplane model ................550 mm,
Maximum chord of the lifting surfaces ...........................200 mm
Maximum tail span .........................................................450 mm,
Minimum weight without rubber motor ...........................1,2 g,
Maximum weight of the lubricated rubber motor ...........0,6 g.
3.4.3. Number of Flights
The competitor shall be allowed 6 flights of which the best 2 flights will be taken for classification. If the organisers specify
rounds for the competition then the competitor is entitled to one official flight in each round. The duration of rounds must
be announced in advance.
3.4.4. Definition of an Official Flight
Only flights of 60 seconds or more will be considered as official. A flight may be terminated by any physical means within
the first 60 seconds. A flight of less than 60 seconds duration will be considered an attempt and there will be one attempt
flight allowed for each of the six official flights; the attempts will not be accumulative.
3.4.5. Number of Model
There is no limit to the number of model that a competitor may use at an indoor contest.
3.4.6. Collision Rule
In the event of a collision between two models in flight, each competitor must choose, in the time span between the collision
and two minutes following the termination of his flight, either to retain the time of flight as an official time, or to have a reflight.
The reflight must be flown before his next official flight.
3.4.7. Steering
a) A balloon(s) with its line attached, or a rod, may be used to alter the course of the model, or to reposition it in another part of
the flying space. There will be no time limit or restriction to the number of steering attempts, except that all steering shall be
done from the front end of the model and never from behind.
b) Steering must only be used to avert collision with the structure of the building, its contents or other models. Movements of
the model must be primarily in a horizontal plane
Note: If, in a timekeeper's opinion, a model's altitude change is approaching one half metre, or one metre for each 25 m of
altitude (whichever is larger) he will warn the competitor. Continued disregard of the timekeeper's warning will result in a
terminated flight.
c) During steering the propeller may get caught by the line/balloon(s)/rod and stop revolving. As soon as the propeller stops,
a third watch should be used (preferably a double button watch,that records accumulative time) to determine the total of
propeller stopped time, which is deducted from the running total time shown on the other two watches. If the steerer cannot
disengage the propeller after steering, all three watches are to be stopped together, and the
total prop-stopped time deducted as is detailed above.