Repercussions of the Boeing 787 groundings are becoming increasingly vexing for All Nippon Airways (ANA), as flight cancellations start to overlap with crucial peak travel periods. After initially being a competitive advantage for its launch customer, the 787 has turned into a headache that is forcing the carrier to make tough scheduling choices.

Although Boeing is working to get the 787s flying again, any certified solution will come too late for one of ANA's highest-demand weeks. To reduce uncertainty, ANA has already extended 787 flight cancellations to the end of May, encompassing Japan's traditional holiday period known as Golden Week.

ANA has also had to suspend another of the long-haul routes that were launched with the 787 in mind. This is a blow to the airline, since these flights were a key part of its international network expansion strategy. The arrival of the 787 opened up new route opportunities that were well-suited to the aircraft's range and size.

The latest round of cancellations means ANA's flight disruptions will last at least four months from when the worldwide 787 fleet was first grounded in mid-January after the discovery of serious problems with the aircraft's lithium-ion batteries.

This was certainly not the script that ANA envisaged. After enduring three years of delivery delays, the carrier had last year finally begun to gain some marketing mileage from being the 787 launch customer. Now the 787 woes have become just the latest in a string of challenges for ANA, which has already faced a serious demand slump following the March 2011 earthquake and tsunami, the revival of main competitor Japan Airlines (JAL) with the aid of government intervention, and new competition from a developing low-cost airline sector.

ANA has the largest 787 fleet of any airline, with 17 aircraft delivered. Six are configured for domestic routes only, six for international flights only and another five have been used domestically but are slated to eventually switch to Asian routes.

Since the 787 groundings, ANA has had to progressively issue updates on which flights will be canceled or changed. The latest update covers the longest period yet, March 31-May 31, as the carrier seeks to restore some stability to its schedule.

However, an airline spokeswoman tells Aviation Week that the length of the cancellations does not mean ANA is assuming the groundings will continue through May, and it has no new information about when the 787s are likely to resume service.

Rather, the airline was forced to extend the flight cancellations for another two months as a precaution, since the major Japanese holidays of Golden Week are approaching, falling in late April and early May this year. This follows a school vacation period in late March, when demand will also be high.

The ANA spokeswoman says the carrier is expecting a large number of bookings around Golden Week, so it needed to make a call on canceling flights as early as possible to minimize disruption for passengers. Leaving the cancellations until later would mean more passengers would have to be rebooked on different flights.

If the 787s are cleared to begin flying again before the end of May, the carrier would be unlikely to reinstate the canceled flights, says the spokeswoman. However, the aircraft could be used as “relief flights” to boost the domestic schedule where necessary.

The cancellations for April and May affect 1,250 domestic and 464 international flights. The 787 services that are not being canceled will be operated with other aircraft types, such as Boeing 777s on international routes.

In its domestic network, ANA is only canceling flights on routes that have multiple frequencies. To help cover some of the shortfall, it is expanding code-share arrangements with domestic carrier Solaseed Air—formerly Skynet Asia Airways—in the south of Japan, and with Air Do in the north.

In the international operation, ANA has decided to cancel flights from Tokyo's Narita Airport to Seattle and San Jose, Calif., for April and May, as well as flights to Seoul's Incheon Airport from Kansai International Airport in Osaka and Central Japan International Airport (also known as Chubu Centrair International Airport) in Nagoya.

The two Seoul flights are on the list because leisure demand on the routes has fallen. The San Jose and Seattle flights, meanwhile, are new routes that were specifically designed for the 787.

The San Jose flights had already been canceled in previous schedule updates. ANA only has authorization to fly the route with 787s; it did not apply to use other aircraft because the 787 is best-suited to projected demand. It would take months to apply to adjust the authorization to add another aircraft type, and the airline has no plans to do so.

ANA has so far been able to operate about half the scheduled Narita-Seattle flights in the weeks leading up to March 31 using alternate aircraft. However, it has now decided to suspend the service altogether through May. The ANA spokeswoman notes that it is difficult to make international routes work with just a few flights a week. Also, ANA can still offer code-share service with United Airlines on the route.

Eventually, the carrier will negotiate compensation with Boeing, but ANA says it has not yet begun such talks, as its focus is on returning the aircraft to service. The only estimate the airline has released so far is that the groundings cost it ¥1.4 billion ($15.3 million) through the end of January.

The 787 problems are expected to delay delivery schedules for many of the aircraft's customers. ANA is scheduled to receive three more 787s by the end of March, but it seems unlikely that this target will be met. The carrier says that while it has been speaking with Boeing daily, it has had no updates regarding timetable revisions for 787 deliveries. It has a total order of 66, split between the -8 and -9 versions.

Rival carrier JAL is also suffering from the 787 battery issues, having grounded its fleet of seven aircraft. Because it operates them only on international routes, fewer flights are affected, but this also means it is more complicated to find replacement aircraft.

JAL is operating alternate aircraft on all of its current 787 routes, although it is canceling selected flights from Narita to Boston, San Diego and Honolulu through May 31. The carrier has also had to postpone indefinitely the launch of its Tokyo Narita-Helsinki service, which was earmarked for the 787 and due to start on Feb. 25.

JAL estimates that the 787 groundings will cost it ¥700 million through the end of March. It is due to receive 45 787s, including both -8s and -9s.

In the long term, the question will be whether Boeing's tight relationship with the Japanese carriers will be affected. There may already be signs of openings for Airbus in Boeing's near-monopoly on Japanese orders; JAL Chairman Emeritus Kazuo Inamori recently revealed in a television interview that he has deep reservations about the carrier's reliance on a single vendor. However, Japan's ties with Boeing run deep, with several major components of the 787 manufactured there—including the troublesome lithium-ion batteries.