Hello all! I have noticed that there are two runways that are somewhat close to each other. One has a regular ILS approach a which is 10C (second image) But I’ve been told that that runway 10R (first image) has an offset approach. And when I see the two approaches coming in, I see that 10R is slightly diagonal and not completely straight unlike a regular approach. You can see that in the first image. (both runways have same heading)
This is 10R, and you can see that the approach isn’t completely straight like the other runways.
From what I can tell, ORD uses 10C for the western arrivals, 10R for southern arrivals, and 9L for northern/eastern arrivals. It makes sense, because when I arrived from EWR, we landed on 9L, and the aircraft paralell to us (on 10C) was landing from HND (ANA 77W).
The approach is diagonal so that the aircraft landing on 10C and 10L can keep a safe distance from each other.
Runway 10R uses an ILS PRM approach at times. PRM is precision runway monitor which has an off course localizer guidance. It’s a simultaneous offset approach. One aircraft will be on a straight in to 10L while the pilot on the offset approach will be going to 10R.
The pilot will be advised if he breaks from the final approach course and alerted by ATC or waved off if he enters the no transgression zone.
The pilot flying the offset PRM approach must report the straight in traffic in sight.