Delta Air Lines has requested a waiver from the US Department of Transportation (DOT) that its slots used for service to Tokyo-Haneda from its Detroit hub be exempt "from the slot use-or-lose condition until June 1, 2012".
The slots are currently subject to a 90-day dormancy condition.
The carrier had launched service to Haneda from Detroit and Los Angeles in February, but flights were suspended in response to the earthquake that struck Japan in March. Delta's service to Haneda from Los Angeles resumed last week.
Delta told DOT it expects after effects of the earthquake will cost the airline "between $250 and $400 million this year".
"US-Tokyo demand remains far below normal levels and forward bookings on Delta's Detroit-Haneda flight are unusually weak", said Delta. The carrier also stated that "flexibility is needed to judiciously manage the re-introduction of capacity over the off-peak winter months and shoulder season in the early spring".
Daily service between Detroit and Haneda is slated to resume on 16 June, according to the airline's filing. Delta said it plans to operate daily service "for a portion of the current summer season, but would temporarily reduce or suspend service until Tokyo business demand returns to more normal levels".
"The requested waiver period will enable the resumption of daily Detroit-Haneda service in time for next year's peak travel season," according to the airline.
The Atlanta-based airline also said that it "is willing and prepared to operate the slots on an interim basis for beach market service, should the Department be inclined to allow the temporary use of slots at alternative gateways".