Actually, not sure what others do, but I set my DG (Directional Gyro or heading indicator) to the runway heading when I line up for takeoff. (learned this diddy from the KLEX accident!)
Therefore, the runway number is my heading and I am cross checking that I am indeed on the right runway…
When you take off, and ATC asks you to fly runway heading, you wouldn’t fly 268 as in your example, but 270.
What you say is true for assigning numbers to runways, but not for flying a heading instruction by ATC.
Don’t get me wrong, 2 degrees is barely noticeable, just wanted to keep it clear that runway numbers match flight headings which would be rounded to the 10 degree headings. (I.E. 010, 020, 090, 140 and so on).
Note, headings are based on magnetic, not ground track. ATC will account for any winds aloft, so we do not use GPS ground track for heading assignments.
I bring this up as by the time I am over the opposite end of the runway, there is a good chance I am not physlcally over the runway on Xwind takeoffs.
On instrument approaches (landing) the opposite is true. We fly the magnetic heading down to the individual degree (157 heading to land on runway 16) to maintain runway centerline.
For obvious reasons, precision on landing is ramped up to the umteenth degree so we can find ourselves between the edges of the runway when the wheels meet terra firma after breaking out of the clouds.
For visual approaches, runway heading 160 heading for runway 16) will work just fine for landing as you don’t have to fly as precise to find the runway (you have it in sight, just fly toward it)…
Allen