During the routine schedule update for the weekend of 29MAR14, DELTA has closed reservation for Chicago – London Heathrow winter 2014/15 operation, due to start from 26OCT14. The Skyteam member opened reservations for this flight on 15FEB14.
Previously planned operational schedule as follow.
DL040 ORD1730 – 0735+1LHR 76W D
DL039 LHR0930 – 1245ORD 76W D
Reservation for this flight gradually closed overnight 28/29MAR14 (Eastern Time). Around 0900GMT, Airline Route on twitter account noted that only full-fare booking class was available at that time. DL removed this flight completely from the GDS in the early-morning hours on 29MAR14 (Eastern Time).