The world's total fleet of 50 787s has been grounded since Jan. 16 as Boeing and investigators try to figure out why one aircraft battery caught fire and another smoldered, forced an emergency landing. Each 787 has two lithium ion batteries.
Recent test flights performed in search of the root cause of battery ignition were carried out with no incidents.
LOT president Sebastian Mikosz said he could not schedule his airline's two 787s for summer season flights as long as the cause of the technical problems has not been determined and the U.S. aviation authorities' order to keep them grounded remains in force.
The decision is "the result of uncertainty," said LOT spokesman Marek Klucinski said. "We want to carry our passengers in a foreseeable and safe way."
The decision is a blow to Poland's national carrier, which is cutting costs and planning mass layoffs in an effort to survive. LOT is Europe's first airline to have Dreamliners, which it had hoped would improve its financial results and position.
It also shows carriers are preparing for their 787s to be grounded for an extended period of time.
Japan Airlines, which had one of its 787 suffer a battery fire while parked at Boston's Logan International Airport last month, has said its fleet of six Dreamliners will remain idled through March. The other troubled 787, which was forced to make an emergency landing on Jan.16 in Japan due to a smoldering battery, belongs to All Nippon Airways, which is not flying its Dreamliners either.
In Europe, Norwegian Air Shuttle has been warned by Boeing of possible delays in the deliveries of its first 787 aircraft scheduled for April and June. Boeing also suspended delivery of three more 787s planned for LOT this year.
For Poland's LOT, the grounding means it will need to extend a lease on three Boeings 767s it currently uses and lease another two for the summer season, Klucinski said. He added LOT is also talking to Boeing about the costs generated by the idling.
One of LOT's Dreamliners remains in Chicago, the other in Warsaw. Both are safe to fly, Klucinski said.
The 787, dubbed the Dreamliner by Boeing, is the first airliner to make extensive use of lithium ion batteries, which are lighter weight, charge faster and contain more energy than conventional batteries similar in size.