Glossary

The airline industry’s own terms and codes, as used in delay reporting. Flight Dispatch 98 uses only some of them; see Flights and passengers for the delay codes that appear on your flights.

Delay measures

TTF: Total flights.
TRF: Total regulated flights.
TDF: Total delayed flights.
PRF: Percentage of regulated flights.
PDF: Percentage of delayed flights.
TDM: Total delay in minutes.
ADM: Average delay per movement.
ADR: Average delay per regulated flight.
ADD: Average delay per delayed flight.

Punctuality measures

Departure usually means off-blocks: the moment the aircraft starts moving from the stand, not take-off. An ops board shows A15 as well, and often D0 for just the first wave of the day: if the first wave leaves on time, the rest of the day tends to hold together.

D0: Departure zero: the percentage of flights that leave at or before their scheduled time, with no delay allowed. The strictest on-time measure, and the one ops managers tend to watch most closely, because a late first departure knocks on to everything after it.
D15: The percentage that leave less than 15 minutes late: the industry’s usual definition of on time.
A0, A15 (sometimes A14): The same for arrivals, which is what passengers and published league tables care about.

Terms

ACC: Area Control Centre.
AEA: Association of European Airlines.
AHM: Airport Handling Manual.
ATFM: Air Traffic Flow Management (used by IATA in the standard delay codes).
ATFCM: Air Traffic Flow and Capacity Management (used by the Network Manager as a fuller name for the function).
ATS: Air Traffic Services.
BTO: Block Time Overshoot.
CODA: Central Office for Delay Analysis.
DCS: Departure Control System: the station’s system for check-in, boarding and closing a flight.
DDI-F: Delay Difference Indicator, Flight.
DNM: Directorate Network Management.
ECAC: European Civil Aviation Conference.
FDPS: Flight Data Processing System.
FMP: Flow Management Position.
IACA: International Air Carrier Association.
IATA: International Air Transport Association.
NMOC: Network Manager Operations Centre.

Movement messages

From OAG’s guide to IATA’s Airport Handling Manual formats. See Movement messages.

MVT: Aircraft movement message.
AD: Actual departure: off-block, then airborne.
AA: Actual arrival: touchdown, then on-block.
EA: Estimated touchdown, and the airport. On its own in a later message, a revised estimate.
In range: The crew’s radio call to the airport they’re coming to, shortly before landing, with when they’ll land.
ED: Estimated departure.
NI: Next information: when more word will be given.
SI: Supplementary information.
ASM: Ad hoc schedule message: a change to a flight on one date.
TIM: In an ASM, a change of time.
CNL: In an ASM, a cancellation.
DL: Delay codes and their durations.
EDL: Extra delay codes.
DLA: Delay sub-codes.
PX: Passengers on board.
MVA: The same messages, sent by the aircraft itself over its datalink.

Aircraft datalink

ACARS: Aircraft Communications Addressing and Reporting System: short messages between an aircraft and the ground, sent by the aircraft’s own avionics.
OOOI: Out, Off, On, In: the four movement events an aircraft reports itself. Out of the gate, off the ground, on the ground, in at the gate.
Downlink, uplink: A message from the aircraft to the ground, and one from the ground to the aircraft.
VHF: Very high frequency radio: line of sight, so within about 200 nautical miles of a ground station for an aircraft at cruise.
SATCOM: Satellite communications: wherever the satellites over the equator can be seen, which is not near the poles.
HF: High frequency radio: reaches anywhere, by way of the upper atmosphere, but slowly and not always.
POS: Position report: where the aircraft is, its flight level, fuel on board and estimate of touchdown.
RQP: Request for a position report.
FOB: Fuel on board.

Airport Collaborative Decision Making

From IATA’s A-CDM recommendations (2018) and airports’ A-CDM guides. See Movement messages.

A-CDM: Airport Collaborative Decision Making: the airport, airlines, handlers and air traffic control sharing one set of times for each flight.
TOBT: Target Off-Block Time: the time an aircraft operator or ground handler estimates that an aircraft will be ready, all doors closed, boarding bridge removed, pushback vehicle available, and ready to start up or push back immediately on receipt of ATC clearance. Owned by the airline.
TSAT: Target Start-up Approval Time: the time provided by ATC at which an aircraft can expect start-up or pushback approval, from the tower’s pre-departure sequence.
TTOT: Target Take-Off Time: the forecast take-off time, from the TSAT plus the taxi time.
EXOT: Estimated Taxi-Out Time.

Standard IATA delay codes

Others

00-05: Airline internal codes.
06 (OA): No gate or stand available because of the airline's own activity.
09 (SG): Scheduled ground time less than the declared minimum ground time.

Passenger and baggage

11 (PD): Late check-in, acceptance after the deadline.
12 (PL): Late check-in, congestion in the check-in area.
13 (PE): Check-in error, passenger and baggage.
14 (PO): Oversales, booking errors.
15 (PH): Boarding, discrepancies and paging, missing checked-in passenger.
16 (PS): Commercial publicity or passenger convenience, VIP, press, ground meals and missing personal items.
17 (PC): Catering order, late or incorrect order given to the supplier.
18 (PB): Baggage processing, sorting and so on.
19 (PW): Reduced mobility, boarding or deboarding of passengers with reduced mobility.

Cargo and mail

21 (CD): Documentation, errors and so on.
22 (CP): Late positioning.
23 (CC): Late acceptance.
24 (CI): Inadequate packing.
25 (CO): Oversales, booking errors.
26 (CU): Late preparation in the warehouse.
27 (CE): Documentation, packing and so on (mail only).
28 (CL): Late positioning (mail only).
29 (CA): Late acceptance (mail only).

Aircraft and ramp handling

31 (GD): Aircraft documentation late or inaccurate: weight and balance, general declaration, passenger manifest and so on.
32 (GL): Loading or unloading: bulky or special load, cabin load, lack of loading staff.
33 (GE): Loading equipment, lack of or breakdown, such as a container pallet loader; lack of staff.
34 (GS): Servicing equipment, lack of or breakdown, such as steps; lack of staff.
35 (GC): Aircraft cleaning.
36 (GF): Fuelling or defuelling, fuel supplier.
37 (GB): Catering, late delivery or loading.
38 (GU): ULD (unit load devices), lack of or serviceability.
39 (GT): Technical equipment, lack of or breakdown, such as pushback; lack of staff.

Technical and aircraft equipment

41 (TD): Aircraft defects.
42 (TM): Scheduled maintenance, late release.
43 (TN): Non-scheduled maintenance, special checks or additional work beyond the normal maintenance schedule.
44 (TS): Spares and maintenance equipment, lack of or breakdown.
45 (TA): AOG spares, to be carried to another station.
46 (TC): Aircraft change, for technical reasons.
47 (TL): Stand-by aircraft, lack of a planned stand-by aircraft for technical reasons.
48 (TV): Scheduled cabin configuration or version adjustments.

Damage to aircraft and automated equipment failure

51 (DF): Damage during flight operations: bird or lightning strike, turbulence, heavy or overweight landing, collision during taxiing.
52 (DG): Damage during ground operations: collisions other than during taxiing, loading or off-loading damage, contamination, towing, extreme weather.
55 (ED): Departure control.
56 (EC): Cargo preparation or documentation.
57 (EF): Flight plans.
58 (EO): Other automated system.

Flight operations and crewing

61 (FP): Flight plan, late completion or change of flight documentation.
62 (FF): Operational requirements, fuel, load alteration.
63 (FT): Late crew boarding or departure procedures, other than connection and standby (flight deck or entire crew).
64 (FS): Flight deck crew shortage: sickness, awaiting standby, flight time limitations, crew meals, valid visa, health documents and so on.
65 (FR): Flight deck crew special request, not within operational requirements.
66 (FL): Late cabin crew boarding or departure procedures, other than connection and standby.
67 (FC): Cabin crew shortage: sickness, awaiting standby, flight time limitations, crew meals, valid visa, health documents and so on.
68 (FA): Cabin crew error or special request, not within operational requirements.
69 (FB): Captain's request for an extraordinary security check.

Weather

71 (WO): Departure station.
72 (WT): Destination station.
73 (WR): En route or alternate.
75 (WI): De-icing of aircraft, removal of ice or snow, frost prevention, excluding unserviceable equipment.
76 (WS): Removal of snow, ice, water and sand from the airport.
77 (WG): Ground handling impaired by adverse weather.

Air traffic flow management restrictions

81 (AT): ATFM due to ATC en-route demand or capacity, standard demand and capacity problems.
82 (AX): ATFM due to ATC staff or equipment en route: reduced capacity from industrial action, staff shortage, equipment failure, military exercise or extraordinary demand because capacity is reduced in a neighbouring area.
83 (AE): ATFM due to restriction at the destination airport: airport or runway closed by obstruction, industrial action, staff shortage, political unrest, noise abatement, night curfew, special flights.
84 (AW): ATFM due to weather at the destination.

Airport and governmental authorities

85 (AS): Mandatory security.
86 (AG): Immigration, customs, health.
87 (AF): Airport facilities: parking stands, ramp congestion, lighting, buildings, gate limitations and so on.
88 (AD): Restrictions at the airport of destination: airport or runway closed by obstruction, industrial action, staff shortage, political unrest, noise abatement, night curfew, special flights.
89 (AM): Restrictions at the airport of departure, with or without ATFM restrictions: air traffic services, start-up and pushback, airport or runway closed by obstruction or weather (weather only under an ATFM regulation, otherwise code 71), industrial action, staff shortage, political unrest, noise abatement, night curfew, special flights.

Reactionary

91 (RL): Load connection, awaiting load from another flight.
92 (RT): Through check-in error, passenger and baggage.
93 (RA): Aircraft rotation, late arrival of the aircraft from another flight or previous sector.
94 (RS): Cabin crew rotation, awaiting cabin crew from another flight.
95 (RC): Crew rotation, awaiting crew from another flight (flight deck or entire crew).
96 (RO): Operations control: re-routing, diversion, consolidation, aircraft change for reasons other than technical.

Miscellaneous

97 (MI): Industrial action within the airline.
98 (MO): Industrial action outside the airline, excluding air traffic services.
99 (MX): Other reason, not matching any code above.

IATA delay sub-codes

A letter after a code gives more detail.

73 (WR) Weather: en route or alternate

Z: Outside aircraft limits.
Y: Outside crew limits.
X: ETOPS.

81 (AT) ATFM due to ATC en-route demand or capacity

Z: ATC routeings.
Y: High demand or capacity.

82 (AX) ATFM due to ATC staff or equipment en route

Z: Industrial action.
Y: Equipment failure.
X: Staff shortage.
W: Military activity.
V: Special event.

83 (AE) ATFM due to restriction at the destination airport

Z: High demand or ATC capacity.
Y: Industrial action.
X: Equipment failure.
W: Staff shortage.
V: Accident or incident.
U: Military activity.
T: Special event.
S: Noise abatement or night curfew.
R: Other.

87 (AF) Airport facilities

Z: Lack of parking stands.
Y: Ramp congestion.
X: Lighting or buildings.
W: Gate limitation or no gate available.
V: Baggage sorting system down or slow.
U: No pushback clearance because of infrastructure.
T: Jet bridge inoperative.
S: Lack of check-in counters.
R: Electrical system failure.
P: Passenger transport system failure.
N: Public address or flight information display failure.
M: Insufficient fire cover.
L: Ground communication system failure.
K: No pushback clearance because of construction.
J: Breakdown of the airport fuelling system.
H: Late or lack of follow-me for pushback.
G: Any of the above at the destination airport.

89 (AM) Restrictions at the airport of departure

Z: ATC capacity.
Y: ATC industrial action.
X: ATC staffing.
W: ATC equipment.
V: ATC accident or incident.
U: ATC due to de-icing.
T: ATC special event.
S: ATC weather.
R: ATC restrictions due to curfew.
P: ATC political unrest.
N: ATC environmental.
M: Airport closure.
L: Runway closure.
K: Start-up or pushback clearance delay (local ATC).
J: Flight plan lost by ATC.
H: Construction work or maintenance.
G: Other.

93 (RA) Aircraft rotation

Z: Late arrival from a departure delay at the previous station.
Y: Late arrival from an en-route delay.
X: Late arrival from a delay after landing.
W: Late arrival from high demand at the destination station.
V: Late arrival from weather at the destination.
U: Late arrival for technical reasons.

Flow regulations and IATA codes

The reason an air traffic flow regulation gives, and the IATA code it counts as, by where it applies.

C: ATC capacity: at departure 89, en route 81, at arrival 83. For example: Demand exceeds the capacity.
I: ATC industrial action: at departure 89, en route 82, at arrival 83. For example: Controllers' strike.
R: ATC routeings: en route 81. For example: Phasing in of new procedures.
S: ATC staffing: at departure 89, en route 82, at arrival 83. For example: Illness, traffic delays on the highway.
T: ATC equipment: at departure 89, en route 82, at arrival 83. For example: Radar failure, RTF failure.
A: Accident or incident: at departure 89, at arrival 83. For example: Runway 23 closed by an accident.
G: Aerodrome capacity: at departure 87, at arrival 87. For example: Lack of parking, taxiway closure, areas closed for maintenance; demand exceeds the declared airport capacity.
D: De-icing: at departure 89. For example: De-icing.
E: Equipment, non-ATC: at departure 87, at arrival 87. For example: Runway or taxiway lighting failure.
N: Industrial action, non-ATC: at departure 98, at arrival 98. For example: Firemen's strike.
M: Military activity: at departure 89, en route 82, at arrival 83. For example: Exercises such as Brilliant Invader or ODAX.
P: Special event: at departure 89, at arrival 83. For example: European football cup, heads of government meetings.
W: Weather: at departure 89, en route 73, at arrival 84. For example: Thunderstorm, low visibility, crosswinds.
V: Environmental issues: at departure 89, at arrival 83. For example: Noise.
O: Other: at departure 89, en route 81, at arrival 83. For example: Security alert.

From EUROCONTROL's CODA Digest, Delays to Air Transport in Europe, September 2012, which takes its delay codes from IATA's Airport Handling Manual (AHM 730 and 731).