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Guidelines for Slope Combat Flying

British Association of Radio Control Soarers

The purpose of Slope Combat is to encourage an improvement in the flying skills of pilots particularly in the ability to judge their model's separation from the ground, its position relative to other models, or obstructions while flying. Slope Combat encourages its participants to appreciate the suitability of the sites which they fly their models with due consideration for the topographical features, other flyers and any spectators.

The following guidelines are put forward as a basis for safe and fair Combat Flying whether for fun or in competition.


Models must be unpowered gliders not fitted with I/C engines, electric motors, rockets or other form of propulsion.

    Maximum Span 50 inches 1,270 mm
    Maximum Wing Loading 12 oz/sq.ft 49 gm/sq.dm
    Maximum Model Weight 35 ounces 1,008 grams

No ballast, other than that required to establish either the fore and aft or lateral center of gravity of the model, may be added either temporarily or permanently to increase flying speed. Where ballast is added to adjust the center of gravity of the model, the maximum total weight of ballast added must not exceed 4 ounces or 115 grams.


  • Models should be of generally all foam construction, preferably Expanded Polypropylene Foam (EPP), and, where covered, the covering should be of flexible plastic or parcel tape type materials. No rigid covering material, wood, GRP or vacuum formed plastic are permitted.
  • The fuselage may have longerons of any material provided the total cross section area of all longerons does not exceed 1/2 sq. in, 161 sq.mm, and their forward end(s) are not less than 2 inches, 50.8 mm, from the nose of the model. The nose block should have a minimum radius of 1/2 inch, 12.7 mm, vertically and 1/2 inch, 12.7 mm, laterally and not be made of wood, rigid plastic or other hard material. Only foam, RTV (silicone), polysulphide rubber, cork etc. are allowed.
  • Wings may have main spars of any material as above. The total cross section area of all spars must not exceed 3/4 sq.in, 363 sq.mm. There must be no rigid structural member, i.e. wood or cfk leading edge or leading edge sheeting, ahead of the mainspar and the mainspar must not be located less than 20% of the chord from the leading edge of the wing at any point. Ideally the forward 20% of the wing should be made of EPP foam covered with a flexible material.
  • All wing spar outer ends must stop not less than 2 inches, 50.8 mm, from each wing tip. No rigid materials i.e. wood, GRP or vacuum formed plastic are to be used for the wing tips. Flying wings fitted with tip fins made of fluted plastic material should have the fin edges 'rounded' by application of a silicone bead or by securing flexible tubing to the edges.
  • Servos should be securely fixed, not just wedged into place. Where quick links are exposed, either at the control horn or servo arm end, the quick link should be sleeved or taped to prevent accidental disconnection. It is recommended that steering servo savers, as used on electric model racing cars, be used on servo outputs connected to the two primary steering controls. Where push rods are exposed for any distance, i.e. on top or bottom of wing, then a suitable guard should be fitted to minimize the chance of the rod being bent or detached so causing loss of control.
  • Special care must be taken with the location and fixing of heavy items such as the radio battery or balance weight(s). All parts of the battery, balance weight(s) and any box or structure to secure them must be located not less than 2 inches, 50.8 mm, from the nose of the model. With swept flying wings having no fuselage, no part of any such heavy item or supporting structure may be located less than 2 inches, 50.8 mm, from the nearest point on the leading edge measured perpendicular to the leading edge of the wing.
  • All batteries and balance weight(s) must be secured by an adequate safety strap which, in turn, is secured to a 'strong point' within the model (wing fixing or fuselage keel for instance) to ensure that there is no likelihood of such heavy items falling away from the model while in flight.


  • Not all slope sites will be suitable for Combat flying. The following aspects should be given careful consideration when assessing their suitability.
    • a) The proximity of a road, railway line, footpath, picnic area, public viewing or observation point or car park in the area ahead of, to each side of or behind the proposed flying site where a models may come to earth.
    • b) The proximity of private houses and gardens, schools, factories or other structures or enclosed areas immediately ahead or to the side of or behind the proposed flying site where a models may come to earth.
    • c) Access to the proposed flying site by the general public. If the general public have unrestricted access do 'you' have the necessary authority to establish a 'safe' spectator area? If you do not have the authority to establish such an area that site should be considered unsuitable for Combat Flying.
  • If any of the above conditions apply then the site being evaluated is unlikely to be suitable for Combat Flying.
    • A. Where a site is deemed suitable for Combat Flying the following guidelines should be followed:
      i) A Safety Line as for F3B and F3F should be established along the line of the hill.
      ii) The Pilot's Operating line should be behind the Safety Line.
      iii) A second Safety (Spectator) Line should be established at least 10 yards or 9 metres, behind the Pilots Operating line. Any public footpaths, spectator area and pits should be located behind this line.
      iv) Where possible, polite notices should be placed at either end of this Spectator Line to indicate to passers by the 'safe' side of the line on which to pass or from where to watch.
      v) All combat challenges must be made to windward of the Safety Line.
    • B. Where a site is shared between combat and general flying an agreement about flying combat within 'exclusive slots' should be made unless the working slope is long enough to allow combat flying to be restricted to a defined area.
    • C. Whatever agreement is reached concerning the exclusive or shared use of a slope an agreement on the allocation of frequencies between the two groups must be reached.
    • NOTE 1: Most National Trust sites are unlikely to be suitable for Combat Flying because of unrestricted public access and 'your' inability to control this access.
    • NOTE 2: Where the site is on 'Common Land' it is against Common Law to establish any area, even to ensure the safety of individuals, which seeks to deny access to any part of that area of common land to any person without the express permission of the controlling conservators or commoners.
    • NOTE 3: While Slope Combat Flying is a legitimate model flying activity, it is known that the CAA are concerned about the possible consequences of the activity. Before embarking on Combat Flying we strongly recommend that every pilot should carefully consider how they would defend their flying if an action is taken against them by the CAA under ANO 56, following receipt of a complaint of endangering from a member of the general public. Please remember you do not have to hit and injure a person to endanger them!
    • NOTE 4: Before commencing to fly any model in combat both the flyer, and anyone organizing a combat event, must ensure that they are adequately covered by a THIRD PARTY PUBLIC LIABILITY INSURANCE CERTIFICATE giving a minimum of $5,000,000 or £4,000,000 liability protection.
    • NOTE 5: The holding of an appropriate third party liability insurance policy in no way diminishes a pilot's or organisers' responsibility to operate at all times within the Air Navigation Orders applicable to the flying of Small (model) Aircraft and the guidance issued by the CAA in their publication CAP 658, Small (Model) Aircraft: A guide to Safe Flying.



Remember: Slope Combat is a legitimate model flying activity but it does have safety implications beyond that of flying the models. Great care must be taken selecting the flying site for combat flying to safeguard your sport and to minimize the possibility of any action being taken against you by the CAA.