S.L. 499.39 ст. 5Exemptions.

The Director may in certain cases exempt airports from these regulations and authorise the individual operation on an ad hoc basis of marginally compliant aircraft which would otherwise not be permitted under these regulations. Such authorisation shall, however, be limited to aircraft whose individual operations are of such an exceptional nature that it would be unreasonable to withhold a temporary authorisation, and which are being operated for non-revenue flights for alterations, repair or maintenance.