Delta Air Lines (DL, Atlanta Hartsfield Jackson) could likely lose its Seattle Tacoma International to Tokyo Haneda route allocation after the US Department of Transportation (DOT) this week reaffirmed an earlier ruling calling for a Tokyo Haneda route case to be opened.

The announcement is a victory for American Airlines (AA, Dallas/Fort Worth) and Hawaiian Airlines (HA, Honolulu) which have both claimed that Delta's decision to operate only 17 planned rotations between Seattle and Tokyo Haneda over a 182-day period, lasting from October 1, 2014, until March 28, 2015, represents a gross underutilization of the much-prized slot.

“The Department has determined that, in light of Delta’s extensive winter-season cutbacks, and the submissions filed on the record in this case, the public interest requires a fresh examination of whether the best use of the Seattle-Haneda opportunity is to allow Delta to retain its underlying authority to operate the slot pair for Seattle-Haneda service, or whether the public interest would be better served by reallocating the slot pair for service from another U.S. city by another U.S. carrier or by Delta,” it said. "Delta has presented no information that would lead the Department to alter that conclusion. The Department has instituted this proceeding under its general powers to review the public interest bases of current awards.”

Both American and Hawaiian have put forward their own individual proposals for the Haneda slot, should they secure it. American plans to offer a year-round daily B777-200 service from Los Angeles International to Tokyo Haneda flight while Hawaiian would provide a daily year-round A330-200 service from Kona to Haneda with full utilization of the slot pair. Delta has offered to return its Seattle - Tokyo Haneda route a year-round daily B767-300(ER)service should it retain the right.

The case is expected to be resolved by month-end.