william
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Joined: Thu Jun 10, 1999 1:31 pm

What Is An ORD "S" Turn?

Wed Dec 10, 2003 2:36 pm

Sometimes ATC will tell an aircraft to S turn to gain separation. How far off the approach is this turn? Or is this like a "lazy" S turn? Is it a 90 degree turn off the approach?

Thanks
 
JBirdAV8r
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Joined: Sun Jun 24, 2001 4:44 am

RE: What Is An ORD "S" Turn?

Wed Dec 10, 2003 2:51 pm

Here's a nutshell description.

If separation between aircraft is not good on approach, to avoid a go-around, sometimes ATC will request that an aircraft S-turn. All this basically consists of is turning a little bit left and then back right again, so you're making a very lazy-looking S across the approach path. It basically reduces the speed you're closing on the runway, thereby increasing separation.

It's nothing like S-turns across a road.

Interesting point though...I don't know how many airline guys will do S-turns below 1000'AGL because most airlines I know require that the aircraft be stabilized on approach by that altitude...and I wouldn't consider an aircraft doing S-turns to be doing a "stabilized" approach.

Hope this helps  Smile/happy/getting dizzy
I got my head checked--by a jumbo jet
 
Ralgha
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RE: What Is An ORD "S" Turn?

Wed Dec 10, 2003 2:57 pm

Slow flight on downwind and base with S-turns all the way down final because some joker is flying bomber patterns in a 172 (and busting a football TFR) is the best. Wait...
09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0
 
InnocuousFox
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RE: What Is An ORD "S" Turn?

Thu Dec 11, 2003 11:42 am

The reason for it is that the lead aircraft can't speed up and the trailing aircraft is already at its approach speed. Most of the time it will be near the OM. Farther out and it would have just been a vector change or speed change, farther in and it would be dangerous as mentioned previously.

When I was on final at STL for the right side, I looked out the left window back at another aircraft who looked like he was cutting in behind us... by only a few hundred feet! I was quite alarmed until I realized that he was doing S-turns for the left side runway.
Dave Mark - Intrinsic Algorithm - Reducing the world to mathematical equations!
 
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fanoftristars
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Joined: Mon Jul 17, 2000 9:03 am

RE: What Is An ORD "S" Turn?

Fri Dec 12, 2003 2:57 am

This helps explain our weird approach last week on the way into SLC from LAX. I thought maybe we were changing runways, but lined back up for the same runway.  Smile
"FLY DELTA JETS"
 
InnocuousFox
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Joined: Sat Dec 06, 2003 1:30 am

RE: What Is An ORD "S" Turn?

Fri Dec 12, 2003 9:11 am

Well, I've had it that way too. One time into PHX, we switched from the regular arrival runway to the parallel, then back again. A departure had positioned and held and didn't go when told to, then finally decided to before it was too late. We did this slalom thing and our pilot said "Hey... this is kinda fun".  Big grin
Dave Mark - Intrinsic Algorithm - Reducing the world to mathematical equations!

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