O’hare Question

Quick Question,

Why don’t planes use runway 28L at Chicago O’hare?

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Hey @Delta419! This is a really good question. I’ve been digging into it and here’s what I’ve found.

According to FAA regulations, it is not able to have parallel approaches with 28C:

“10R-28L is positioned 3100 feet to the south of Runway 10C-28C, and that spacing is not sufficient for simultaneous independent parallel approaches on those two runways – meaning that both 28C and 28L currently cannot be used simultaneously for straight-in arrivals” (Source)

I’ve been having trouble finding out much more. I believe one possibility could be noise mitigation, but I find that a less plausible reason.

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That seems right. I assume the calculus is that three parallel approaches is a higher rate than four staggered, I’ve tried to find out more to, and only came across what you mentioned, so unless we have both missed the obvious that sounds very plausible

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I’m not sure to be honest. I know 10C and 10R are used simultaneously usually, but not sure why 28L/C can’t be used simultaneously.

Here’s an article that talks about fears of low use before it was finished, it does say it closes at night, along with its dedicated control tower, and the article discusses some things with the use cases that I honestly didn’t fully understand in my quick read since I’m not very familiar with the airports patterns, but a local may be able to make more sense of this…

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To what @Will_A said, 28L can be used with 28C for simultaneous arrivals. I don’t know where you found that FAA rule, but it is not true if you look at places like KSFO, where the runways are definitely not 3100 feet apart.

I found this chart online, and I guess it is more efficient for KORD to have the original 3 in use opposed to using the layout with the new runway.

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I got my info from FAA.gov. I may have interpreted this wrong, but here is the full response.

Why have we not used 28L for arrivals in West Flow?

FAA Response: Runway 10R-28L is open and available for arrivals/departures in East Flow and West Flow. However, 10R-28L is positioned 3100 feet to the south of Runway 10C-28C, and that spacing is not sufficient for simultaneous independent parallel approaches on those two runways – meaning that both 28C and 28L currently cannot be used simultaneously for straight-in arrivals (FAA separation standards for simultaneous independent parallel arrival operations). For the 10R approach, FAA established an “offset” instrument approach procedure that allows us to safely use 10R and 10C simultaneously for arrivals in East Flow conditions. We do not currently have a similar offset approach established for 28L. FAA is in the process of assessing the feasibility of an offset approach for 28L, similar to the 10R offset approach.”

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In the post above by @Will_A, it mentions how there is no offset approach for runway 28L to be used with 28C. 10R does have an offset approach which allows 10R and 10C to be used at the same time. This is similar to KSFO’s offset 28R approach… it’s an interesting concept.

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taxiing from 28L back to the terminals and crossing 2 other runways isn’t ideal either

What do you mean by offset approach. Like the runways aren’t exactly aligned?

I also have another question. Why do they use 28R late at night and use 28C in the daytime??

SFO has ATC monitoring, which allows them to go down to I don’t know what, but a lot lower than for standard visual separation…

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Honestly, Heathrow has 2 runways and O’Hare has 8 so I don’t see why they bothered to open 28L

Hello, as a local Chicagoan, with Ohare being my home airport, I can help answer this question:

28C is used during the day time to alleviate traffic flow. Majority of flights into Ohare are coming during the daytime, especially around noon-3pm, when the European arrivals come in, and also around 4-7 pm when some European arrivals come in and most of the European departures leave. If you look at taxi patterns for KORD, this will also correspond with the allocated runways. At night, especially after 10pm, there are not a lot of arrivals, so Ohare can afford to use 28R for approach. We can also see this very early in the morning as well, with flight such as United’s arrival from Honolulu frequently using 28R/10L for landing at around 4:30 am In short, it is to alleviate the airport congestion!

Feel free to ask anymore questions regarding KORD, I love it when people talk about my home airport, which also happens to be the third busiest in the US!

Hope this helps! 😄

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Thank you! I also have O’Hare as my home airport and feel the same way when people talk about it!

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To be honest I hate the new night patterns they are using with 22R and 22L. I loved it when they would all land on 28R at night! Now only the heavies land on 28R later at night…

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However, 28L isn’t used much, but 10R is used quite often on the busy banks when you can see them using 10R, 10C and 9L for arrivals and 9R and 10L for depatures

28L is never used, only 10R

Ohare is also one of my home airports! I love it when people talk about it!

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3rd??? its easily top 2 in the world!