Can anyone explain why runway lengths are sometimes "X thousand and
ONE feet" in length? I was just looking through a list of Iowa's
approximately 110 airports and 7 of them have runways that are "X
thousand and one feet" long.

Do runway manufacturing companies offer special deals like "Buy 5,000
feet of runway, get your next foot free!!!"

There's got to be a logical explanation - anyone know it?

According to FAA data, here is a count of runways grouped by the last digit
of the Runway Length.

Sorted by frequency
digit, count, %
0, 4333, 57.6%
5, 582, 7.7%
1, 549, 7.3%
9, 385, 5.1%
2, 379, 5.0%
8, 311, 4.1%
3, 274, 3.6%
7, 241, 3.2%
4, 234, 3.1%
6, 230, 3.1%

There does seem to be a statistically high percentage of runways with an
extra foot. Perhaps it's the 'fudge factor' the construction contractor
used to ensure they met specifications.

Chris
http://wayhoo.com/