Paragraph 30 Maintaining continuous watch and complying with air traffic control instructions
(1)
Subject to rule 31, whilst flying within Class B, Class C or Class D airspace during the notified hours of watch of the appropriate air traffic control unit, the pilot-in-command of an aircraft shall—
(a)
cause a continuous watch to be maintained on the notified radio frequency appropriate to the circumstances; and
(b)
comply with any instructions which the appropriate air traffic control unit may give.