Originally Posted by
amanuensis
Would going to five digits break Delta's IT so badly that expanding the pool of numbers is simply beyond any possibility of it being a solution?
Yes. Yes it would. Not to mention the thousands of flight monitors that only have room to show 4 digits.
And undoubtedly DL would charge us a 5 digit flight number "convenience" fee for the privilege. Of course this would be waved for Delta 360 members, or anyone who spends 100K annually on their DL cobranded Amex.