See also 7.3.
7.7.1 Open Class No special rules.
7.7.2 18 Metre Class The only limitation is a maximum span of 18,000 mm (7.1.3).
7.7.3 15 Metre Class The only limitation is a maximum span of 15,000 mm (7.1.3).
a. WINGS
The span (7.1.3) must not exceed 15,000 mm. Any method of changing the wing profile other than by normal use of the ailerons is prohibited. Lift increasing devices are prohibited,
even if unusable.
b. AIRBRAKES
The glider must be fitted with airbrakes which cannot be used to increase performance. Drag parachutes are prohibited.
c. UNDERCARRIAGE
The undercarriage may be fixed or retractable. The main landing wheel shall be at least 300 mm in diameter and 100 mm in width.
d. BALLAST
Water ballast which may be discharged in flight is permitted.
The World Class glider is the PW-5 design which was the winner of the 1994 World Class design competition. All gliders must be built to the IGC specifications for the World Class and must conform to all applicable IGC rules. No modifications are permitted except as approved and circulated in writing by FAI to all NACs on behalf of the IGC.
a. ALTERATION TO AIRFLOW
Any alteration affecting airflow around the glider is prohibited. This includes, but is not limited to, the use of turbulation devices, fairings, and special surface treatment. The only exceptions are:
(i) a yaw string,
(ii) a total energy probe,
(iii) adhesive tape to seal gaps between wings, fuselage and tail. Sealing between moveable control surfaces and the airframe is not permitted.
b. ELECTRICAL DEVICES
Electrical and electronic devices are allowed, including instruments and navigational aids.
c. BALLAST
Ballast which can be jettisoned in flight is prohibited. In a World Class competition, a mass shall be specified by the Competition Director between the maximum gross mass and the lowest takeoff mass attainable by the heaviest entrant. To attain the specified mass each glider shall incorporate a fixed ballast system approved by the IGC, which may include tail ballast.
d. CENTRE OF GRAVITY CONTROL
Any device capable of altering the centre of gravity location of the glider during flight is prohibited.
The purpose of the Club Class is to preserve the value of older high performance gliders, to provide inexpensive but high quality international championships, and to enable pilots who do not have access to gliders of the highest standard of performance to take part in contests at the highest levels.
a. ENTRY
The only limitation on entry of a glider into a Club Class competition is that it is within the range of handicap factors agreed for the competition.
b. BALLAST
Water ballast is not permitted.
c. SCORING
A Club Class championship shall be scored using formulas which include handicap factors (7.4).
7.7.7 20 Metre Multi-Seat Class
a. ENTRY
The 20m multi-seat class consists of multi-seat gliders having a crew of two persons. If handicaps are to be used the glider must have a handicap factor within the range agreed for the competition.
b. CREW
The crew shall consist of two pilots who must represent the same NAC and have a Sporting Licence issued by that NAC. The winning crew shall jointly hold the title, Champion.
c. WINGS
The span must not exceed 20,000mm.
d. BALLAST
Water ballast that may be discharged in flight is permitted.
(See Annex A 4.2.1)
e. SCORING
The 20 metre multi-seat class may be scored using formulas that include handicap factors (see 7.4).