Key points to note include the following: • a person’s flight begins when the person first boards the aircraft and ends when the person finally disembarks from it: a flight does not end nor a new flight begin if, for example, a person disembarks from an aircraft temporarily while it refuels (see section 4); • an agreement for carriage need not be formal or commercial in nature (see section 5); accordingly, the operators of a private jet would be liable for ADT if the jet is a chargeable aircraft and carries passengers who are chargeable passengers, even if the passengers are carried on an informal basis and do not have tickets for their travel; • whether a passenger is carried on an aircraft in standard class travel (which is relevant to the structure of the tax in section 9) depends on the seat pitch...