Answer Guide: Airline slots limit the number of departures, so larger plans can maximise slot capacity. However, the failure of the A380 has, in part, been driven by the choice of the traveller to use smaller regional airports with point to point operations, ahead of larger hub-and-spoke models of operations that are needed to feed passengers into seats on larger planes.

For the A380, operational costs were less efficient than operating smaller planes. Furthermore, the vast plane required airport adaptations (larger holding rooms for boarding passengers and reinforced runways) which came at a cost; some airports would not pay, restricting where the plane could land.

Answer Guide: Capacity is controlled by landings and take-off slots. Maximising their use can help maximise capacity. More slots can be added if night flights are allowed (or, if not through the night, then earlier in the morning and later in the evening). Air traffic control also limits the number of take-offs and landings by restricting the time between each aircraft movement. At Heathrow, the gap is currently about 45 seconds, but technology is being trialled to try and reduce this time gap to less than a minute.

Capacity levels are also determined by the number of runways and terminals (to process passengers) and thus construction of new infrastructure can also expand capacity.

Answer Guide: Private jet hire may work out to be cheaper than multiple business-class flight tickets. It will also mean that the flights will depart at a time convenient to the company (rather than to an airline schedule). It also allows a route that may not be offered by commercial airlines. Furthermore, companies may choose to use a private jet to make use of the cargo capacity of an aircraft, to ship equipment alongside its passengers.