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105 votes
Accepted

Why are Gatwick's runways too close together?

Historically, Gatwick had only one runway (08R/26L) with a taxiway to the north, but this obviously would cause problems if that runway was out of use for any reason - emergency, scheduled maintenance,...
CatchAsCatchCan's user avatar
36 votes
Accepted

What does "Independent visual approach" mean, at airports with parallel runways?

Consider an airport with only one runway. In order to keep aircraft safely apart (and to give them time to exit the runway), all aircraft must be separated by some distance as they are on final ...
randomhead's user avatar
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32 votes
Accepted

When a parallel runway is closed at an uncontrolled field, does the notation change for the operating runway?

There is no guidance that runway/tower closure status should change the name of a runway in the AIM, Airplane Flying Handbook, 7110.65, or anything else I've ever read. If such guidance exists ...
TypeIA's user avatar
  • 14.4k
32 votes

Why was the second runway at Sea-Tac Airport built so close to the first?

TL;DR/Abstract - Political, financial, and social expedience are often the dominant forces in the development of infrastructure projects - Sea-Tac is no exception. The history of Sea-Tac is messy, as ...
William Walker III's user avatar
18 votes

How many US airports have 4 or more parallel runways?

Based on my current navigation database (AIRAC 1909, valid from 2019-08-15), I found 7 US airports with 4 (or more) parallel runways: KATL (Hartsfield–Jackson Atlanta International Airport): 5 ...
Bianfable's user avatar
  • 56.5k
16 votes
Accepted

How does a pilot select the correct ILS when the airport has parallel runways?

The two ILS approaches on parallel runways will have a different ILS Localizer frequency. The pilots will select the correct approach from the charts and then either manually tune in the correct ...
Bianfable's user avatar
  • 56.5k
14 votes

How does a TCAS system avoid unnecessary (RAs) resolution advisories when aircraft are operating on separate closely spaced parallel runways?

The TCAS logic is adjusted when the aircraft is in the terminal area. It does this through the following inputs: Radio Altitude - Controls TCAS parameters when below 2350 feet AGL Landing Gear, Flaps,...
Gerry's user avatar
  • 20k
13 votes
Accepted

Why is there no numbering system for more than three parallel runways?

"Because those are rules." ICAO Annex 14 (volume 1) provides the following guidance: 5.2.2.4 A runway designation marking shall consist of a two-digit number and on parallel runways shall be ...
60levelchange's user avatar
12 votes

When a parallel runway is closed at an uncontrolled field, does the notation change for the operating runway?

The "chewing out" instructor is an deeply misguided and a danger to his students: a runway's name is basically permanent. It can be changed, but everything associated with it, like approach ...
Ralph J's user avatar
  • 51.8k
10 votes

Do we have orange runway markings?

Do we have orange runway markings? Yes. We do, apparently. Longer answer: I didn't expect aviation.stackexchange would be similar to geoguessr, but this appears to be New Chitose Airport in Japan. ...
300D7309EF17's user avatar
  • 2,400
8 votes
Accepted

How is separation managed when there are only two parallel runways in a very busy airport?

With two runways, usually, one is dedicated to arrivals, and the other is dedicated to departures. That's the simplest way to handle separation -- only in-trail separation is involved. That's ...
user14736's user avatar
  • 126
8 votes

Why is there no numbering system for more than three parallel runways?

There are only a handful of airports with 4+ parallel runways, and it's simpler to just accept them as exceptions than to add complexity to a naming system that works just fine for thousands of other ...
StephenS's user avatar
  • 27.8k
7 votes

How does a pilot select the correct ILS when the airport has parallel runways?

ILS works with radio waves, just like voice communications, or other navigation aids like VOR. This means a specific approach will use a specific frequency for its navigation signal. When the pilot ...
fooot's user avatar
  • 73.4k
7 votes

Why would an airport use an L/R runway combination and a second number instead of L/C/R?

While it is going to be very hard to pinpoint the exact reason for KPHX, there are several logical reasoning for why it is done in general (I must disagree with your observation that XL/C/R is more ...
DeepSpace's user avatar
  • 4,505
3 votes

Why do simultaneous-ops parallel runways need to be so far apart?

The simple answer seems to be for wake turbulence. This FAA document, ORDER JO 7110.308C, seems to say it is for wake turbulence reasons in para. 9: The geometry of the approach, as well as the ...
CrossRoads's user avatar
  • 8,795
2 votes
Accepted

Do we have orange runway markings?

White runway markings that turn orange are affected by a contaminant in the aggregate of the asphalt. There are modifications that can be made to the paint to resist the rust-staining. A study by ...
Donna Speidel's user avatar
2 votes

How does a TCAS system avoid unnecessary (RAs) resolution advisories when aircraft are operating on separate closely spaced parallel runways?

To add to previous answers, TAs, and RAs when above 1000ft, are based on predicted collision time. On general when flying parallel approaches standard 1000 ft separation applies until both aircraft ...
busdriver's user avatar
  • 3,340
2 votes

Why is one of two parallel runways sometimes closed in foggy weather?

It's not. Precise enough, that is. There's a point in the ILS landing process called "Minimums". At that point the pilots must see the runway or throttle up and go-around. Assuming they have ...
Harper - Reinstate Monica's user avatar
2 votes

How to find runway Centerline spacing on airport diagrams?

The scale is usually depicted on the chart. Just take a ruler and measure.
60levelchange's user avatar
1 vote
Accepted

How to find runway Centerline spacing on airport diagrams?

Here is the airport diagram for Denver International Airport, which has numerous parallel runways. I don't see any scale that could be used to measure distances. Looks to me that one would have to ...
CrossRoads's user avatar
  • 8,795
1 vote

Why do simultaneous-ops parallel runways need to be so far apart?

It is usually to guarantee sufficient aircraft separation when visual separation is not available (bad weather). See also Why is one of two parallel runways sometimes closed in foggy weather? It ...
BowlOfRed's user avatar
  • 5,621
1 vote

Why would the runway separation for parallel triple simultaneous precision approaches be dependent on airport elevation?

The 4300 ft separation is to allow wingtip vortices to dissipate from one runway to the next. This was posted about fairly recently. Why do simultaneous-ops parallel runways need to be so far apart?
CrossRoads's user avatar
  • 8,795

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