The BGA has recently reminded clubs about published guidance describing which categories of pilots should be supervised, which includes;
Pilots under training
At BGA clubs, a pilot is under training until the pilot has qualified for the Cross-Country endorsement. All flights prior to that qualification should be supervised by an instructor approved to do so by the CFI.
First Cross-Country Flights.
A pilot intent on setting off on an early cross-country flight should be individually briefed by a suitably experienced instructor. The pilot should “brief” the instructor on at least the likely route with airspace and navigation being of primary interest. The weather for setting off and the state of the fields should be thoroughly reviewed.
Although navigation training should ensure that pilots become skilled in basic map and compass navigation techniques, it is recommended that when inexperienced pilots are flying cross-country they are equipped with a suitable GPS moving map. If the pilot intends to make use of GPS as a navigation aid (which must be in conjunction with a current chart), his or her understanding of the system should be established
Young solo pilots
Pilots under the age of 18 may have exemplary handling skills but a different attitude to risk and little experience of taking important decisions. Clubs should provide their young pilots with individual supervision. This will ensure the club’s child protection measures include awareness of young people’s needs in terms of active supervision of flying.
The full detail is described under ‘Supervision’ in the BGA publication ‘Managing Flying Risk’, which is available here.