"Runways, all runways, have a 2-digit number that represents the magnetic heading of the runway to the nearest 10 degrees. If the runway's heading is 265 — 274 degrees, then the runway number is 27 — always drop the last “0.” The opposite end of the runway is 180 degrees apart, so Runway 09 (90 degrees)."
How to represent a runway number in XML?
As ever, “it depends”. Without knowing more about the context, I can only appeal to my aesthetic sense and intuition.
What do you think? Which form is better?
Given that the computer doesn’t care if it’s 9 or 09, I’d probably store the value as 09. That will be familiar and natural to a human pilot familiar with reading runway signs. Or an experienced technical writer used to documenting airport designs.
Don’t confuse the human is always a good design choice.
To make things a bit more interesting, pilots don't speak it as
"Oh-nine". They say "nine". When I learned to fly at Honolulu
International, there were two parallel runways 04. We would call them
"four-left" and "four-right". The tower controller would say things
like "Piper zero-six-zero cleared for intersection takeoff runway four
left".
