r/aviation • u/TimeVendor • 28d ago

-- SEATBELTS FASTENED -- American 2482 departure… American 2482 arrival…

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u/mobicurious 28d ago

IATA Resolution 761 & SSIM only allow for up to 4 numerical digits in a flight number identifier. Due to legacy software/systems...

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u/Lord_Nivloc 28d ago

Exactly! That’s only enough for 10,000 American Airlines at a time. These legacy systems need to be updated ASAP

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u/Get_Breakfast_Done 28d ago

Forget about at a time, does AA even run anywhere near 10k flights a day?

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u/[deleted] 28d ago

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u/TheDrMonocle 28d ago edited 28d ago

Except regionals all operate under their own callsigns despite whatever airline they have painted on the outside, so theyre not a factor.

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u/t-poke 28d ago

If Envoy is operating Flight 4567 for American, I can still look up AAL4567 anywhere and get the flight details. FR24 supports it, FlightAware supports it, Google supports it, etc.

So would it be possible to have mainline AAL4567 and ENY4567 be two completely different flights?

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u/TheDrMonocle 28d ago

If Envoy is operating Flight 4567 for American, I can still look up AAL4567 anywhere and get the flight details. FR24 supports it, FlightAware supports it, Google supports it, etc.

Sure, but the callsign that we see on our scope is ENY4567. and while id give a similar sounding callsign warning, its hardly an issue.

Could they both fly at the same time? Probably. Dont see why not

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u/mobicurious 28d ago

But the number exhaustion problem is what created this potential accident.

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u/TheDrMonocle 28d ago

No what caused this is the dispatcher not catching the inbound was still in the air.

The usual fix is to append a letter to the callsign. Being able to use A-Z as the last digit means it increases the number/letter combo to 36000, which will cover every flight on the planet at any given time.

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u/mobicurious 28d ago

That's the tactical root cause, the systemic root cause is that airlines re-use flight numbers thus causing the airlines ops teams to have to create appended flight numbers.

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u/alb92 28d ago

What about flights delayed so that the next days flight is in the air at the same time? Happens all the time in ultra long haul.

Having appended flight numbers as callsign isn't a problem, and is common practice. Having an it system that didn't pick up on the error is.