Paul
The 18 foot rule refers to the Normal Flight Level at approximately 6 meter height. That is the height most of the flying is at and most maneuvers start and finish at.
Low Flight is at 2 meters, Normal Flight is at 6 meters and High Flight between 30 and 45 degrees line elevation.
To download the FAI - F4B rules:
go to:
www.fai.orgSelect: Air Sports & Technical Commissions
Select: FAI Aeromodelling Commission
Select: Documents
Select: Sporting Code Section 4 - 2010 Edition
click on the
FAI download site to download this secton of the rules in english. All 82 pages.
I then printed out pages 9 - 12, General Rules for Static Judging
pages 13 - 16, Control Line Flying Scale Models
pages 21 - 24, Annex 6A Static Judges Guide
pages 25 - 41, Annex 6B F4B Judges Guide - Flying
page 72, Annex 6E - Competitor's Declaration Form
If you want to be competitive read the rules!
Clancy