Phoenix Airport Close Call Between Delta A330 & United 737

PHX runways are parallel, they just call them the way they do

@ Nick -- Good catch on them being fully parallel, and not just nearly parallel. Updated the post to reflect that, thanks.

PHX runways are parallel, they just call them the way they do because before they opened the south runway (now 7R/25L), they already had 8R/26L and 8L/26R; the new one would've had to be 8R/26L (which was already taken), so instead they called it 7R/25L and renamed the old 8R/26L to 7L/25R, and then made the old 8L/26R to 8/26. See the diagram here: they're all 79.9 degrees/80 degrees https://skyvector.com/files/tpp/2413/pdf/00322AD.PDF

Minor correction: All the runways at PHX are exactly parallel at 078 degrees in this direction (258 the other way). It is common for runways that have many parallel runways to be numbered up to 20 degrees off from their real direction (ex. DFW having runways 34, 35 and 36 all being exactly identical), as some places don't want to have a center runway and some have more then three parallel runways.

TCAS saves lives again.

Wouldn't it be wonderful if we had TCAS level of awareness and protection all the time not just near miss.
Automated TCAS would save countless lives from human error.

Probably a dumb question, but how does TCAS know what to tell each plane to do? As in, it doesn't tell them both to descend or climb - are they connected somehow when the planes are close to each other?

This would have been the second unfortunate DTW-PHX flight in the Delta family

Wow great technology save the day.

Yes, they do coordinate with each other. One will always tell to climb and the other to descend.

Would it also prevent spurious comments those with an anti-Airbus, BA and British nationals?

Thanks again for your input, general public. But we'll continue to handle it like we have for the last 30+ years without killing "countless" people.

Sincerely, ATC.

Aren't the runways closer than 1200 feet to one another? In other words the aircraft are closer to "colliding" when landing than they were in this instance (1300 feet diagonally).

Does DL routinely fly an a330 on dtwphx?

DL routinely adds widebodies to major cities in the west and southwest during the winter that use narrowbodies other times of the year

There are definite rules that are encoded into the algorithm that each TCAS system is programmed to follow exactly the same. So if 2 planes are about to be in some conflicting situation to each other by a given configuration (position, altitude, speed, etc), each system knows what its own command will be, and what the other's command will be to give consistent instructions (like an air traffic controller seeing the whole picture) to get them out of the situation.

Yes. For Snowbirds.

Magnetic headings always change over time. The numbering reflects roughly where they were when they were built, but it can vary over the years. Runways can and are renumbered if needed, but there's no point in doing it if it's relatively close. Obviously it's a pretty significant expense to renumber.

PHX didn't go with a center runway because they'd always intended to build a fourth parallel. It would have been two 7/25s and two 8/26s. They numbered it the way they did so that it didn't require a full renumbering if and when the fourth parallel could be built. For a long list of reasons, the fourth parallel was scrapped from the master plan, probably because it was never going to realistically happen.

DFW doesn’t have a runway 16/34. Maybe you were thinking of the 31s.

The most premium mid-air collision!

It looks to me as if the flights got closer BECAUSE of the TCAS alerts.

I don't blame TCAS. The system on both flights didn't know that the controller had just turned the Delta to "angle" towards the final approach path instead of a pure 90 degree "base to final" turn. You can hear the Delta TCAS alert of "descend, descend" literally as Delta was acknowledging the turn instruction.

Delta was a little lower than United, thus the "descend descend" alert (I assume United's alert was to climb). The Delta pilots who got the alert just as they started the turn, immediately did what TCAS said to do while also stopping the turn that I assume they may have thought is what triggered the alarm. Initially continuing on a southerly heading reduced the lateral distance while TCAS did separate the planes vertically.

ATC could've given Delta a visual approach clearance. Then Delta could've started the easterly turn (to align with the runway) earlier. As it was, they had to continue on the heading of 170. I'm sure the Delta crew was wondering when that turn was going to be called. There was another plane on final for runway 8 (DL's runway). Before ATC could issue a visual clearance, the pilots would have to have that plane in sight. Perhaps ATC planned to delay a visual clearance until after the small plane had landed. Then the DL crew would only have to report the runway in sight. However, as Lucky noted, the conversation with UPS started instead. I do think ATC should've given DL the turn before she replied to UPS' question.