FAQ - FREQUENTLY ASKED QUESTIONS
PERFORMANCE HISTORY REPORT
4) THE DATA DOES NOT MATCH AN OAG FROM THE ERA?
6) WHAT DO THE COLORS OF LOAD FACTOR INDICATE?
8) WHAT AIRLINES ARE INCLUDED?
9) WHY NO DEPARTURE AND ARRIVAL TIMES?
10) WHY DOES THIS DATA HAVE FLIGHT NUMBER AND YOUR OTHER SIMILAR DATA DOESN'T?
2) WHAT IS INCLUDED?
This data is available 1970-1977 by month at this time. It includes historical traffic performance at a flight number level. Departure time and arrival time are very sadly not available in this database. This data was originally entered by hand in the 1970s and then eventually sent to magnetic tape, and then decoded by me from tape records which was extremely painful. There will be errors. The routing information is truncated to fit and may have errors, it is also commonly reversed in direction. Some flight numbers may have a trailing zero added by CAB/DOT.
3) HOW DO I READ THE DATA?
ROUTE : The Origin and Destination IATA airport codes joined back to back
AL FLT : The IATA airline code for the airline followed by the flight number (note digits may be added after the flight number)
ELAP TIME : Since we don't have departure and arrival time, I was able to retrieve the elapsed time in hours:minutes
A/C EQP : The aircraft equipment is the IATA/OAG equipment code most often used for the flight number that month
OB PAX : Onboard passengers per departure. e.g. 86 means 86 passengers on the plane per departure on average
TOTAL SEATS : The average number of seats on the plane per departure
SKD DPT : Scheduled departures. 1.0 means a daily roundtrip. 0.7 likely means the flight did not operate on weekends.
A/C ROUTING : This is a portion of the flight number routing for the flight. For example, EA0117 BDLATL shows PVD|BDL|ATL|FLL|BHM. This apparently means the plane arrived from PVD and continued on to FLL after ATL. If the full routing does not fit it may be truncated.
4) THE DATA DOES NOT MATCH AN OAG FROM THE ERA?
This is very likely to happen. This data involved getting data from the National Archives that I was tipped to by a DOT employee and then figuring out how to salvage the data from magnetic tape. This data was originally entered by hand in the 1970s and then eventually sent to magnetic tape, and then decoded by me from tape records which was extremely painful. There will be errors. Routing information is routinely out of order and flights numbers often include an extra trailing digit such as 417 becoming 4170 or 4171. This was done by the airline.
5) IS INTERNATIONAL INCLUDED?
It appears to be included, although I do not know what rules apply to what was included or excluded.
6) WHAT DO THE COLORS OF LOAD FACTOR INDICATE?
The colors are just a quick way of seeing performance based on load factor only.
GREEN: 80%+
BLUE: 70%+
GRAY: 55%+
ORANGE: 40%+
RED: worse than 40%
7) WHAT AIRPORT IS BAL?
In this era Baltimore was known as BAL rather than BWI which it was later changed to.
8) WHAT AIRLINES ARE INCLUDED?
Only certain airlines filed this data. At the top of each report in the header is a list of included airlines.
9) WHY NO DEPARTURE AND ARRIVAL TIMES?
The answer is simple. They didn't ask airlines to report them, so we don't have them. It is available in paper form in OAGs from the era, but in digital form it is only available to Harvard/MIT alumni through their digital library and I do not have access.
10) WHY DOES THIS DATA HAVE FLIGHT NUMBER AND YOUR OTHER SIMILAR DATA DOESN'T?
This data comes from a CAB/DOT reporting requirement called SERVICE SEGMENT. When this requirement was replaced with T100 in the 1980s the airlines successfully argued that in the deregulated era it was too detailed and allowed competitors to know too much information. Thus, the reporting of flight number along with routing was dropped.