Most of you reading the Delta forum probably have noticed that the underground tram at ATL announces the concourses as "A as in alpha," "B as in bravo," etc., following the convention used for communication between pilots and the ground (or other aircraft). Following that convention, the D concourse should be announced "as in Delta." But instead, the tram says "as in David."

When I first heard this, I thought, "Man, how did Airtran get that little dig at Delta implemented?" But it seems more likely perhaps, that it's to avoid having an infrequent flyer hear "Delta" and think, "My flight's on Delta, I guess this is where I get off."

But either of those is just conjecture. Anyone know for sure why it's David and not Delta at concourse D?