Dreamliner Performs Like A ... Dream ... In Stalls

It's a routine part of any aircraft evaluation, and yet you might not think about stalling an airliner. But Boeing's 787 Dreamliner pilots conducted the program's first stall tests late last week as part of the initial airworthiness program for the airplane. Additional stall tests will take place throughout the flight test period.

The testing went "very well and there were no surprises," said 787 Chief Pilot Mike Carriker.

The purpose of the testing is to demonstrate that in the rare event a pilot encounters a stall during flight, the airplane reacts benignly and allows for a smooth recovery.

In a video on a Boeing website, Carriker said the test showed the airplane could fly from it's stall speed to a "moderate speed", which he defined as about mach .65 at FL300.  "During the course of initial airworthiness, we probably flew 50-60 stalls in the airplane," Carriker said. "For stall speed, you stall the airplane with the center of gravity forward. For flying qualities, how well the airplane flies, you do it with the center of gravity full aft. So we had to do both of them, and you do it every flap setting, you get quite a few of them."

Carriker said the stall series began with slowing the airplane down to just before it stalled to be sure it had the ability to recover from the stall, and then progress to full stalls. "You're putting enough in the airplane to make the airplane bounce up and down at 1.5g's. So you're getting thrown about a lot, it's far more than any roller coaster you'll ride. And then [from] the outside airplane you watch the wing start to shake, and that's what's driving the airplane to buffet so badly."

Carriker said the airplane is built in such a way that "we hope it never gets into a stall condition," but it obviously has to be able to recover from a stall should one occur. "We'll probably do about another 200-some-odd tests," said Carriker. "It was great fun."

FMI: www.boeing.com