6. Where the CAA or an authorised person has reason to believe that an aeroplane is intended to be operated by any person without the noise certificate required to be in force in respect of that aeroplane by regulation 4 above, the CAA or the authorised person may—
(a)give to the person appearing to the CAA or the authorised person to be in command of the aeroplane a direction that he shall not permit the aeroplane to take off until the CAA or the authorised person has informed him that the direction is cancelled,
(b)whether or not the CAA or the authorised person has given such a direction, detain the aeroplane until the CAA or the authorised person is satisfied that the aeroplane will not be so operated,
and a person, who, without reasonable excuse, fails to comply with a direction given to him in pursuance of this regulation shall be guilty of an offence.