Why does United Airlines put letters at the end of their flight numbers? This makes tracking the flights from, say, ORD, really difficult since you have to use the “Don’t Know The Flight Number Feature.”
This has been discussed here before. The search button is handy for instances such as these, and can be found at the top of the page.
This is usually done when there are two aircraft in the air operating at the same flight number at the same time. Even if it is just for a few minutes, any portion of the two flights being in the air together will result in this addition.
It helps avoid errors and confusion within the ATC system.
I’m sure you have seen flights on here where the two flights operate at the same time, and there is the large zigzag line which is an error in the tracking as a result. I saw this mostly when EGF aircraft did not use the leading “4” in the flights out of KORD.
It’s so they don’t have two flights in the air at the same time with the same flight number. In the case of 639 on 20 June the flight routed PVD-ORD-OMA flight. The flight from PVD to ORD was scheduled to leave PVD at 1718 and arrive in ORD at 1855. However, it didn’t leave until 1945 and didn’t arrive until 2104.
It looks like they decided to keep the ORD-OMA segment on time. Because it was scheduled to leave 35 minutes earlier than the arriving flight from PVD they had to put a new number on the flight for ATC purposes. (The scheduled departure from ORD was 2029 (actually left at 2024). Arrival in OMA was scheduled for 2157 and it actually arrived at 2143.
691 was scheduled to fly LGA-ORD-PHX. Scheduled departure from LGA was 1800 but it left an hour lat. It was scheduled to arrive in ORD at 1941 but didn’t get there until 2039. The departure from ORD was 2100 (it left at 2108). The aircraft arrived in ORD at Terminal 1 Concourse B and departed from Terminal 1 Concourse C. There was a note that said “schedule change due to Customer Service.”
In the case of 691 it may be an internal UAL reason why they changed the flight number.
Note: The times from the UAL web site are the gate times.
It may have been close enough to the arriving flight that they changed it. They file the flight plans well ahead of time, and can receive their clearance 30 minutes before scheduled departure time. It looks like 30 mins before 2100 the inbound was still in the air.
They ALL do it when it’s necessary to maintain the integrity of their schedule system.
They can’t as it then compromises everything in the schedule system that relies on the ID properties of the flight number. And virtually everything in the daily schedule of an airline operation is based on a flight number.
Actually, Delta will have the second plane change it’s flight number to one of the charter flight numbers (9000+) but all the regionals follow the same process of dropping the last number and adding a letter.
T is used a lot and it happens to be the first letter of the first name of the guy who assigns the letter suffixes.
There’s no real system to the letters they use (other than not using D to avoid ambiguity [United Five Four Three Delta?]). They also use flight numbers in the 8100-8299 range sometimes for domestic flights instead of appending a letter.
I’ve heard mouthfuls like Lifeguard United Niner Six Five Tango Heavy on channel 9.
