captain420

Need help with wind speed, direction and runway information

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Posted (edited)

How does one determine what runway a plane should depart and arrive from? What are the wind conditions that need to be met? How fast does the windspeed need to be before it is considered too much. For example, what is the speed range for calm winds? is it between 0-6kts? I will use RJAA in this example.Please reference the chart I have attached below. I know when landing it is preferred to fly into the wind as it will slow the plane down and you can have better control when landing and also the same goes for departure as you want to  take off against the wind to produce lift to the wings.But what if there's crosswinds (not blowing in front of or behind but to the sides).

What runway would be used for landing/departures if the following wind conditions are:

  1. 270 @ 7+ kts
  2. 270 @ 0-6 kts
  3. 090 @ 7+ kts
  4. 090 @ 0-6 kts
  5. 210 @ 0-6 kts
  6. 210 @ 15+ kts
  7. 160 @ 20+ kts
  8. 160 @ 0-6 kts
  9. 340 @ 20+ kts
  10. 340 @ 0-6kts

16853-rjaa_airport_map_jeppessen.jpg

Edited by captain420

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caution everyone .... aaron is an XP user, hence the answer could be different & particularly if you are wanting to use AI assigned runways.

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Posted (edited)

? I am trying to replicate real world ops.It don't think it has anything to do with which platform or sim I use,

Edited by captain420

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so you are not interested in what runway AI might use ..... you can not replicate real world in any sim !!

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It's possible in X-Plane.

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Posted (edited)

Wow, didn't know such a thing existed! This will definitely help me out! Thanks a lot for this! 🙂

Now how does one determine what windspeed is too much in order to switch to another runway? Like anything about 6 knots?

Edited by captain420
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Aaron,

NRT is a difficult example to use, the reason is that they usually prefer landing aircraft to the NORTH due to noise abatement plus that they want you full configured by 11.8 NM. There is a note on the APP plates.

Besides that landing NORTH preferred rwy would be 34 R for non heavy equipment (having available 34L for dep), even they try  to squeeze the heavy ones on that one.

They assign 34L and 16R mainly for departures where t.o. wts are a factor. In our case operating heavy equipment we request 16R or 34L for dep and arr. 

Wind wise you will see using 34 L/R even with a tailwind component of 10 KTS (which is within majority of a/c limits), so you can keep in mind for what you would like to do. Just a side note rwy 16L/34R now is a bit longer.

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Arron, 

Your most welcome! Happy flights to you!

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Local procedures and considerations will have a huge impact on this, as will the aircraft type and other conditions (e.g. runway surface conditions -- is it dry/wet/icy etc?).

In an ideal world, as you say, all takeoffs and landings would be in to the wind.

In the non-ideal real world, as others have said above many airports (NRT amongst them in particular) have preferential runway configurations based on noise considerations and traffic flow implications. This means that in practice many major airports will assign those preferential runways even if that means a tailwind (as much as a 5 or 10 knot tailwind component, perhaps - NRT is probably at the extreme end at 10 kt but up to 5 would be not uncommon at some other places). The details of such preferential runway arrangements are normally detailed in the textual data section of the aerodrome charts, but again it's not necessarily 100% hard and fast because it's not always practical to change ends and any decision to use a particular runway will take the longer term forecast in to account as well as pilot feedback.

ICAO defines calm winds as < 3 kt.

How windy is too windy? Well, that will depend on the aircraft type. For a microlight, or even a C172, 8 kt of crosswind component would be notable. A B747, on the other hand, would barely notice 8 kt across! Each aircraft type will have wind speed limitations and maximum demonstrated crosswinds in published in the AFM. For jet transport types, max demonstrated crosswind values (for all intents and purposes limits) are normally in the order of 36-40kt, though the limit could be considerably less if the runway is wet or contaminated. Tailwind limits for takeoff or landing are normally in the order of 10-15kt. Crosswinds above about 20-25kt might be considered 'sporting' in a jet transport ;).

To quickly estimate the crosswind component without having to get your calculator out whilst wrestling with the controls as you fly an approach in a howling crosswind, you can use the "rule of sixths": if the wind direction is 10 degrees off the runway heading, take 1/6 of the wind speed as crosswind; 20 degrees off take 2/6; 30 degrees off take 3/6 (1/2) and so on. For 60 degrees or more you can consider the full wind speed as crosswind.

For example, if the wind is reported as 310 @ 25, that is 30 degrees off the heading of rwy 34 (340). So 3/6 of 25 is 12.5 kt crosswind component (from the left, in this case).

On the other hand, if the wind were 330 @ 25 that is 10 degrees off the runway heading so you take 1/6 of 25 = just over 4 kt crosswind component (again from the left). You get the idea!

Obviously the inverse would be true for head/tailwind component (i.e. for 10 degrees off the runway heading 5/6 is headwind and so on).

Hope that sheds a small amount of light...

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Posted (edited)

Great info Simon. Yes it does help me out. Thanks a lot! and yes I am configuring airport runway operations for a traffic AI program, Hence the reason for this info. I am working on doing AI traffic for big airports like Narita and Haneda. So most of the planes will be tubeliners, 777. 737. A320,. 747, A350, A330,etc. So for thhese planes the consideration for wind speed in order to make a change in which runways they depart and arrive from is 10knots or more and if its less 0-10 knots, then they can pretty much use any available runways that the airport permits?

Edited by captain420

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