SFCL.405 Limitation of privileges in case of vested interests
A sailplane examiner shall not conduct:
(a) a skill test or assessment of competence of an applicant for the issue of a licence, rating or certificate to whom he or she has provided more than 50 % of the required flight instruction for the licence, rating or certificate for which the skill test or assessment of competence is taken; or
(b) a skill test, proficiency check or assessment of competence whenever he or she feels that his or her objectivity may be affected.