User guide - Aviation statistics

Notes and definitions

Aircraft Movement

An aircraft take-off or landing at an airport: one arrival and one departure are counted as two movements. Air transport movements are landings or take-offs of aircraft engaged in the transport of passengers or cargo on commercial terms. All scheduled service movements, whether loaded, empty or positioning; and charter movements transporting passengers or cargo and air taxi movements are included.

Types of passengers

A terminal passenger is one who joins or leaves an aircraft at the reporting airport, excluding passengers carried on air taxi charter services. A passenger travelling between two reporting airports is counted twice, once at each airport. There are two types of terminal passenger: terminating passengers, who arrive or depart at the airport by a surface means of transport; and transfer passengers, who change aircraft at the airport. A transit passenger is one who arrives at and departs from a reporting airport on the same aircraft which is transiting the airport. Each transit passenger is counted once only.

Freight

The weight of property carried out on an aircraft including, for example the weight of vehicles, excess baggage, and diplomatic bags, but excluding mail and passengers' and crews' permitted luggage. Freight carried on air taxi services and in transit through the airport on the same aircraft is excluded.

International Services

Services to and from Scotland from places outside the UK, Isle of Man and Channel Islands.

International and Domestic Destinations

The figures in Tables 8.2 to 8.7 are based on the origin and destination of passengers as reported to UK airport authorities by the airport handling agent. Operators are required to report in respect of each service operated, the point of uplift and discharge of each passenger. The figures may not reflect a passenger's entire air journey: the point at which a passenger disembarks from a particular service may not represent his ultimate destination. In some cases the actual point of uplift or discharge is not recorded. In such cases all passengers are allocated to the end point of the service, i.e. the aircraft's origin or ultimate destination. The figures include all passengers carried on scheduled and chartered services excluding those charter passengers carried on air taxi service and passengers carried on aircraft chartered by Government Departments. In Tables 8.3 and 8.4, international traffic figures are given for each country for which scheduled traffic was reported until and including 2004 data. In cases where charter only routes carried fewer than 5,000 passengers, the countries concerned may not appear separately in Table 8.3, and may be shown under "Other international traffic" in Table 8.4. All non- air taxi is recorded individually.

Air punctuality statistics

These statistics cover both arrivals and departures. They relate solely to punctuality at the specified airport. For example, the information which is used about flights from Edinburgh relates only to the punctuality of their departure, so the statistics take no account of any subsequent delays before landing at, say, London. Similarly, the information which is used about arrivals at Edinburgh relates only to the time of arrival (no allowance is made for whether or not the flight departed on time from the airport of origin).

The calculations cover those flights for which information about the planned and the actual times of operation has been matched - for example, cancelled flights, and flights which are diverted to or from another airport, are excluded (the numbers of such flights are included in the figures which are given for unmatched flights).

The percentages early to 15 minutes late would probably be lower, and the average delays would probably be higher, if these statistics were calculated in the same way as the rail punctuality statistics (the latter are based on the time of arrival at the destination, and take account of cancellations).

All cargo and air taxi services are excluded.

Unmatched actual flights

Air transport movements which actually took place at the airport, but for which no corresponding planned flight was found. There may be a number of reasons for this, such as:

the flight was a diversion from another airport;
the flight was a short-haul flight more than one hour before the planned time;
the flight was planned to take place in the previous month;
errors in, or omissions from, the records of Airport Coordination Ltd (ACL) or the airport.

Unmatched planned flights

Flights which were reported in data supplied by ACL, but for which no corresponding air transport movement return has been found. There may be a number of reasons for this, such as:

the flight was diverted to another airport;
the flight was cancelled;
the planned time was for a short-haul flight more than one hour after the flight;
the flight took place in the following month;
errors in, or omissions from, the records of ACL or the airport.

Average delays

The averages relate to all flights – not just to the ones which were delayed. With effect from January 2000, flights which are early are counted as zero delay; prior to that they were counted as a negative delay. As a result, the average delays for 2000 onwards are not directly comparable with the figures for 1999 and earlier years. This accounts for the whole of the apparent increase in the averages for Glasgow for 2000: when the Civil Aviation Authority (CAA) recalculated the averages for 1999 on the current basis, it found that they would be two minutes more than when calculated on the original basis. A similar recalculation using the data for Edinburgh for 1999 suggested that the change had no effect on its averages, when these were rounded to the nearest whole minute.

Taxi-ing time

The CAA changed its assumption for the taxi-ing time for Edinburgh airport departures from 5 minutes to 10 minutes with effect from the start of 2001. As a result, the punctuality and average delay figures for Edinburgh for 2001 onwards are not on the same basis as the figures for 2000 and earlier years. However, when the CAA recalculated the figures for Edinburgh for 2000 on the current basis, it appeared that this change did not affect the averages or the percentage early or within 15 minutes, when these were rounded to the nearest whole number.

Route Development Fund

The Route Development Fund (RDF) formally ended on 31 May 2007 and has not been replaced. It has not proved possible to introduce a replacement route development scheme within the constraints imposed by the European Commission. However, the Scottish Government continues to work with airlines and airport operators on the development of new international air routes which improve business connectivity, encourage inward investment and make Scotland more accessible for inbound tourism. As Table 8.16 that was included in previous publications can no longer be updated it has been removed. Versions of the table and information about the RDF can be found in previous editions including STS 2011.

International and domestic passengers

A passenger is classified as domestic if his/her flight is between two points which are within the UK or the Channel Islands).

Business and leisure journeys

The business category includes purposes such as meetings with customers, conferences, trade fares, armed services and airline staff, studies paid for by an employer, overseas employment, etc. The leisure category includes holidays, visiting friends or relatives, migration, culture, sport, study (not paid for by an employer), etc.

UK and Foreign passengers

A passenger is classified as a UK resident if the UK is the country in which he/she has lived for most of the last twelve months.

Mode of transport

The mode of surface transport that was used to arrive at the airport. In cases where the journey involved the use of more than one mode of transport, it may not be the mode used for the majority of the journey.

Origins and destinations of terminating passengers

When analysing the results of the survey, the CAA used the former Regions for Scottish origins and destinations. The interviewer asks: "where did you start your journey to catch this flight?" In cases where the answer is not the person's home, the interviewer asks whether it was a transit stop - i.e. somewhere the traveller chose to break the journey to the airport (e.g. an airport hotel prior to an early morning flight, calling in on or staying with relatives, stopping somewhere to rest or for a meal, etc) - and, if it was a transit stop, asks for the proper origin of the journey.

Sources

Tables 8.1 to 8.13 are compiled from information supplied by the Civil Aviation Authority (CAA).

The punctuality statistics in Tables 8.8 are prepared by the CAA with the co-operation of the airport operators and Airport Coordination Ltd (ACL). They are produced for Edinburgh, Glasgow and some other UK airports. The first year for which information is available varies from airport to airport: for example, figures for Edinburgh are only available from April 1996, so it is not possible to provide figures for Edinburgh for 1996 as a whole, or for any earlier years. The actual times of flights' wheels on/off the runway are derived from flight air transport movement returns made by airports to the CAA. The planned times, which relate to arrival/departure from the stand, and include changes made up to 24 hours beforehand, are supplied by ACL. The CAA also uses assumptions about taxi-ing time - currently these are: arrivals - 5 minutes; departures - 10 minutes, for both Edinburgh and Glasgow.

The CAA matches the two sets of data and resolves any obvious mismatches. For example, if an airline appears to operate a series of flights significantly off slot, the CAA will substitute information from published timetables, where these are available, in place of the ACL slot. The statistics are then calculated from the information for those flights for which the data have been matched - so cancelled flights, and flights which are diverted to or from another airport, are excluded from the calculations.

Tables 8.14 to 8.16 were prepared using figures from the Civil Aviation Authority's Passenger Survey reports.

The survey only includes Scottish airports in some years: most recently 2013, and prior to that 2009. Only departing passengers are interviewed, as previous surveys found no significant differences between the characteristics of arriving and departing passengers. The information collected includes: the purpose, origin, destination and type of ticket used for the journey; the age-group, income band, job title and other details needed to determine the socio-economic group of the passenger; the number of people in the party, whether the traveller was accompanied to the airport, and whether the person has flown before; etc.

Each month's sample is weighted, using information on routes and destinations, to gross up the results to the actual level of traffic. The weighting factors therefore vary, but generally, a single survey interview will be weighted in such a way as to represent around 1,000 actual passengers.

Further information

Within Scottish Transport Statistics:

Chapter 3 - Freight includes comparison across freight modes.
Chapter 11 - Personal Travel chapter includes data on visits abroad

The Department for Transport also produce aviation statistics.

The Civil Aviation Authority produce most the statistics used in this publication.