EVERETT, Wash. — Boeing Co. says four of its five 787 flight test planes are far from their Seattle base this week at locations ranging from Arizona to Iceland.

One 787 is conducting cold-weather and crosswind testing at Keflavik, Iceland, while the first 787 to fly — ZA001 — is in Roswell, New Mexico, to test performance when the plane has to abort a takeoff.

A third 787 is in Yuma, Arizona, for hot-weather tests and the fourth is off to Glascow, Montana, to check how it performs when artificial ice shapes are attached to its wings and tail. The fifth plane continues to work out of Seattle.

After more than two years of delays, Boeing hopes to deliver the first of the new airliners to customers early next year. So far, the test fleet has completed more than 540 flights.