PARIS — A massive weight has been lifted from Boeing’s 787 Dreamliner inventory and transferred to Ethiopian Airlines as the carrier agreed to terms here today to acquire six of the “terrible teens” aircraft, ultimately bringing its fleet to 19.

These planes were early line numbers (hence the “teens” part of the moniker) and were some of the most significantly affected by rework efforts as flaws and shortcomings were found in the initial designs (hence the “terrible”). They have been parked at Paine Field outside the assembly line awaiting a customer for nearly five years now.

For Ethiopian Airlines, the 787 is a true game changer. Its hub at Addis Ababa sits at 7600 feet above sea level, making the increased performance of the 787 critical to meeting international growth plans for the carrier. North American routes have had the Rome tech stop removed, service to South America has been added and expansion further into Asia has been possible. And, while these Terrible Teens planes are heavier than later deliveries, to the tune of an estimated 1000 nautical mile-range penalty, they should still fit well within the carrier’s growth and modernization plans.

In a statement today Tewolde GebreMariam, CEO of Ethiopian Airlines, spoke to the benefits the Dreamliner brings to the fleet, “This new addition to our fleet will not only benefit Ethiopian because of its unmatched operating costs, but will also help us to enhance overall travel experience of our customers,” he said.

It is possible that this subfleet may be limited from the longest routes because of the weight penalty and high altitude, but the carrier appears OK with that potential limitation right now. Also, by choosing these planes, delivery can happen much more quickly. And Ethiopian wants the planes quickly even though they are less efficient; adding “regular” 787s today would likely require waiting until the end of the decade or beyond for delivery slots.

And, for Boeing, unloading these aircraft is a milestone moment. They have remained a visible reminder of the early troubles the Dreamliner had and the challenges it has faced in getting to overall profitability for the line. Which is not to say that selling these aircraft has solved those problems, but at least now they will no longer be a visible reminder alongside the flight line in Everett.