Nederlandse tekst

F1L EZB or Easy B


The EZB is a simple design to build and fly with broad appeal to both beginner and expert. The weight limit is 1.2 gram; the average EZB probably weighs about 2 grams.
To keep things relatively simple the propellor must be made from balsa, bracing of wing and tail boom are not allowed and the model must be covered with paper or plastic.

Video: flying F1L in Santa Fé, 1998

F1D Rules

3.L.1. Definition:

Monoplane model aircraft powered by one (1) extensible motor, and in which lift is generated by aerodynamic forces acting on fixed surfaces.

3.L.2. Characteristics

Wingspan, maximum projected: 457.2 mm
Wing chord maximum: 76.2 mm
Stabiliser area maximum: 50% of wing

a) Structure

1) Only balsa wood and adhesive are to be used for the basic structure. Exempted are the
propeller shaft, rear hook, thrust bearing, surface holding fittings and reinforcements for
their attachments. No external bracing is allowed except balsa wood wing struts.
2) The motor stick must be a solid single piece of balsa. The tail boom must also be solid and
of one piece but may be an extension of the motor stick. Balsa splices up to one
centimetre in length may be used to repair breaks in the motor stick or boom.
3) The propeller must be all balsa except for ground adjustable pitch fittings, if used.
4) There are to be no devices for changing any part of the model's geometry or torque during
flight. Only the normal flexing of the structure due to flight loads or motor forces is allowed.

b) Covering

1) Models are to be covered with any commercially available solid sheet material such as paper or plastic.
2) Microfilm is not allowed.

c) Weight

Weight of the model aircraft without rubber motor shall not be less than 1,2 g.

3.L.3. Number of Flights

The competitor shall be allowed 6 flights of which the two best flights will be taken for classification.

3.L.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.


A good start is the HobbyShopper EZB by Larry Coslick on the IndoorDuration website.
On the same website you can download the John Tipper's Sweeps F1L Plan (Acrobat .pdf) from INAV 106.
Also a good article about building and flying EZB can be found here.
Or download the Cargolifter Loafer F1L from Indoor News and Views, a good beginning F1L by Laurie Barr.


F1L record Jan Massinkhal (ceiling less than 8 m)

11 min 52 sec
Record holder: Bob Bailey
Date of flight: March 16, IIFI 2008

F1L World record Cat I hall (ceiling less than 8 m)

19 min 39 sec
Date of flight: 06/05/2001
Record holder: Akihiro DANJO (Japan)
Course/place: Tokyo (Japan)


F1L World records Cat II, III, IV halls

Ceiling 8m - 15m: 21 min 29 sec
Date of flight: 31/08/2007
Record holder: Akihiro DANJO (Japan)
Course/place: Tokyo (Japan)

Ceiling 15m - 30m: 23 min 1 sec
Date of flight: 01/10/2005
Record holder: Akihiro DANJO (Japan)
Course/place: Saitama (Japan)

Ceiling over 30m: 32 min 22 sec
Date of flight: 11/08/2002
Record holder: Akihiro DANJO (Japan)
Course/place: Tokyo (Japan)


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