234.4—Reporting of on-time performance.

(a) Each reporting carrier shall file BTS Form 234 “On-Time Flight Performance Report” with the Office of Airline Information on a monthly basis, setting forth the information for each of its reportable flights held out in the Official Airline Guide (OAG), in the computer reservations systems (CRS), or in other schedule publications. The reportable flights include, but are not limited to, cancelled flights, mechanically cancelled flights, diverted flights, new flights and wet-leased flights. The report shall be made in the form and manner set forth in accounting and reporting directives issued by the Director, Office of Airline Statistics, and shall contain the following information:
(1) Carrier and flight number.
(2) Aircraft tail number.
(3) Origin and Destination airport codes.
(4) Published OAG departure and arrival times for each scheduled operation of the flight.
(5) CRS scheduled arrival and departure time for each scheduled operation of the flight.
(6) Actual departure and arrival time for each operation of the flight.
(7) Difference in minutes between OAG and CRS scheduled arrival times.
(8) Difference in minutes between OAG and CRS scheduled departure times.
(9) Actual wheels-off and wheels-on times for each operation of the flight.
(10) Date and day of week of scheduled flight operation.
(11) Scheduled elapsed time, according to CRS schedule.
(12) Actual elapsed time.
(13) Amount of departure delay, if any.
(14) Amount of arrival delay, if any.
(15) Amount of elapsed time difference, if any.
(16) Causal code for cancellation, if any.
(17) Minutes of delay attributed to the air carrier, if any.
(18) Minutes of delay attributed to extreme weather, if any.
(19) Minutes of delay attributed to the national aviation system, if any.
(20) Minutes of delay attributed to security, if any.
(21) Minutes of delay attributed to a previous late arriving aircraft, if any.
(22) For gate returns, first gate-departure time at origin airport.
(23) Total ground time away from gate for all gate/air returns at origin airport, including cancelled flights—actual minutes.
(24) Longest time away from gate for gate return or cancelled flight.
(25) Three-letter code of airport where diverted flight landed.
(26) Wheels-on time at diverted airport.
(27) Total time away from gate at diverted airport.
(28) Longest period of time away from gate at diverted airport.
(29) Wheels-off time at diverted airport.
(b) Repeat fields (25) through (29) for each subsequent diverted airport landing.
(c) When reporting the information specified in paragraph (a) of this section for diverted flights, a reporting carrier shall use the original scheduled flight number and the origin and destination airport codes except for item (25).
(d) A reporting carrier shall report the information specified in paragraph (a) of this section for a new flight beginning with the first day of the new scheduled operation.
(e) A reporting carrier shall not report the information specified in paragraph (a) of this section for any discontinued or extra-section flight.
(f) Actual arrival, departure and elapsed times shall be measured by the times at which the aircraft arrived at and departed from the gate or passenger loading area.
(g) The published arrival time and departure time of a flight shall be, respectively, the scheduled arrival and departure times in effect on the date of the scheduled operation of the flight, as shown in the most recent Official Airline Guide, and in computer reservations systems. Each carrier shall designate a single computer reservations system in addition to the Official Airline Guide as the sources of scheduled arrival time and departure time data in its reports to the Department and shall report the scheduled arrival times and departure times listed in those sources for each flight. Scheduled elapsed times, amount of departure and/or arrival delay, and elapsed time difference shall be calculated using the scheduled times shown in the designated CRS source.
(h) Reporting carriers should use the following codes to identify causes for cancelled flights:
Code
A—Air Carrier
B—Extreme Weather
C—National Aviation System (NAS).
D-Security
(1) Air Carrier cancellations are due to circumstances that were within the control of the air carrier (e.g., lack of flight crew, maintenance, etc.).
(2) Extreme weather cancellations are caused by weather conditions (e.g., significant meteorological conditions), actual or forecasted at the point of departure, en route, or point of arrival that, in accordance with applicable regulatory standards and/or in the judgment of the air carrier, prevents operation of that flight and/or prevents operations of subsequent flights due to the intended aircraft being out of position as a result of a prior cancellation or delay attributable to weather.
(3) NAS cancellations are caused by circumstances within the National Aviation System. This term is used to refer to a broad set of conditions: weather-non-extreme, airport operations, heavy traffic volume, air traffic control, etc.
(4) Security cancellations may be the result of malfunctioning screening or other security equipment or a breech of security that causes the evacuation of the airport or individual concourses, or the need to re-screen passengers.
(i) Reporting carriers should use the following causes to identify the reasons for delayed flights:
CAUSE
Air Carrier
Extreme weather
NAS
Security
Late arriving aircraft
(1) Air carrier delays are due to circumstances within the control of the air carrier.
(2) Extreme weather delays are caused by weather conditions (e.g., significant meteorological conditions, actual or forecasted at the point of departure, en route, or point of arrival that, in accordance with applicable regulatory standards and/or in the judgment of the air carrier, prevents operation of that flight and/or prevents operations of subsequent flights due to the intended aircraft being out of position as a result of a prior cancellation or delay attributable to weather.
(3) NAS delays are caused by circumstances within the National Aviation System. This term is used to refer to a broad set of conditions: weather-non-extreme, airport operations, heavy traffic volume, air traffic control, etc.
(4) Security delays may be the result of malfunctioning screening or other security equipment or a breech of security that causes the evacuation of the airport or individual concourses or the need to re-screen passengers.
(5) Late arriving aircraft delays are the result of a late incoming aircraft from the previous flight.
(j) When reporting causal codes in paragraph (a) of this section, reporting carriers are required to code delays only when the arrival delay is 15 minutes or greater; and reporting carriers must report each causal component of the reportable delay when the causal component is 5 minutes or greater.

Code of Federal Regulations

[Amdt. 234-1, 52 FR 34071, Sept. 9, 1987, as amended by Docket No. 48524, 59 FR 49797, Sept. 30, 1994; 60 FR 66722, Dec. 26, 1995; 67 FR 70544, Nov. 25, 2002; Doc. No. RITA 2007-28522, 73 FR 29431, May 21, 2008]