Need to understand basics of runway alignment and use
Hello
I understand next to nothing about flying so these are very basic questions.
I understand that the direction of takeoff and landing depends on wind direction. However I am not sure of the basic principles at work. If, e.g. I am coming into London City how does the wind direction affect whether (coming in from Prague) we come straight in down the river, - or alternatively do that epic twirl round the Shard? - which seems to happen more rarely. Does a plane ideally want the wind behind it when taking off?
Then, questions about my now home airport, which is Prague. It has two runways. The most regularly used one has the designation 6/24. It seems to be used in both directions like the single London City one. But it also has another one, with the designation 12/30. This runs at a tangent across the main runway. Presumably it is used when the wind is in a certain direction, but does that designation indicate which wind direction would require this runway to be used?
Finally Prague Airport is talking about building a runway parallel to the main one (6/24), and it says that if they build it, then they can cancel use of 12/30, which has a flightpath taking it over densely populated areas of Prague . But then my question is, what will they do if the wind direction is such that today they would use 12/30?
Looking forward to learning stuff, many thanks in advance