# Why are some taxiways named with two characters?

The picture above is a diagram of the Taoyuan Airport, Taipei, and as you can see in the diagram, some taxiways are named with two characters like “NC, NP, WC.” My question is: Is there any good reason, if any, why some taxiways are named with two characters when, clearly, there are other single letters still available?

• Judging by the airport's layout it stands out that the leading N, S, E, W actually stand for North, South, East, West. – DeepSpace Aug 15 '18 at 7:10
• Out of curiosity what's the name of this tablet application? – kevin Aug 15 '18 at 7:37
• @kevin FliteDeck Pro – assylias Aug 15 '18 at 14:08

Coding the taxiways this way makes it easy to create mnemonics. Note that from northwest to southeast, the first letters are alphabetically increasing. From southwest to northeast the numbers are increasing.

The combination of a letter and a number gives a good indication of the location of the taxiway.

Every taxiway close to the northern runway (5L-23R) is named Nx, everything close the southern runway (5R-23L) is called Sx. Numbering is from southwest to northeast, so N1 is close to the northern runway, at the west end (5L); S10 is the southern runway close to the eastern end (23L).

Letters can also be combined:

The apron side of the N taxiway is where you park, and called NP.

You cross on the east of the terminal on the eastern crossing or EC, or you cross on the west side of the terminal on WC or W2.

• What then are R1-3? – Pilothead Aug 15 '18 at 19:32
• @Pilothead in the alphabet R is just before S and 1 is a low number. I would start my map search just north of the 5R rwy... and there they are. – DeltaLima Aug 15 '18 at 19:53
• I'd say the go to the remote stands. – DeltaLima Aug 15 '18 at 19:55

When you see NC (or WC,SC or EC) you would expect a cross taxiway.. eg..north cross. When more than 1 crossing to the north of the terminal then NC1/NC2.