Tough testing awaits the Boeing 787 Dreamliner once it takes to the air
The first flight of Boeing's new 787 Dreamliner, likely this week, will kick off nine months of intense aerial testing. The plane must prove itself through months of harrowing drills, from tail-scraping takeoffs to steep dives and possible lightning strikes.
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At the end of a painful year for Boeing's 787 Dreamliner program and for aerospace workers in Washington — a year of technical trouble, costly delays and a management decision to build a second assembly line outside the state — the new airplane is finally set to fly.
If all goes according to plan, the jet will take off Tuesday from Paine Field in Everett, swing out over the ocean, then turn inland and pass over Moses Lake and other eastern parts of the state. It is expected to land at Boeing Field in Seattle about five and a half hours later.
The flight will kick off about nine months of intense aerial testing intended to map the boundaries of the jet's performance.
Five more Dreamliners will join the first test plane, to be stress-tested far beyond the limits that passenger jets would normally encounter.
The test pilots will take them up and do airframe-rattling dives.
Moving at full tilt down a runway, they'll slam on the brakes.
In the middle of takeoff, they'll deliberately cut an engine and keep going. Later, they'll fly for 5 ½ hours on one engine.
They'll park overnight in 55-below-zero cold, then turn on the engines the next morning.
And they're almost guaranteed that one of the jets will be hit by lightning.
At the controls of a jet still officially classified as experimental, the test pilots will go looking for trouble.
"Finding a problem is what we do," said John Cashman, 777 project pilot, who flew the maiden flight of Boeing's last new airplane 15 years ago. "Those are good things to find. We'd rather find them than our customers [find them]."
Most Boeing test pilots have engineering degrees as well as a license to fly, which may account for their matter-of-fact approach to the work.
Their job calls on them to be steady as they land in a vicious crosswind or momentarily free fall after a deliberate stall in midair. And they must keep their cool through unexpected incidents such as the loss of cabin pressure on a 777 test flight in 1995, or a runway fire on a 747 test flight in 1974.
Yet make no mistake, these are the jocks, not the nerds, of the company.
"We've had experiences most people would dream about," Cashman said. "We had a great time doing it."
Around the clock
In the early weeks of the Dreamliner test-flight program, just five test pilots — led by chief 787 pilot Mike Carriker — will do most of the flying out of Boeing Field.
Eight additional test pilots will be assigned specifically to the 787. And a team of 24 more will be shared with the concurrent 747-8 flight-test program, to be available as needed.
That flight-test team will be backed up by an additional 50 or so Boeing test pilots, those who usually do the more routine work of evaluating new features on airplanes or commanding the service test flights on every aircraft that leaves the factory.
The 787 flight-test program is a round-the-clock operation that will cost tens of millions of dollars.
On the ground at the north end of Boeing Field, an operations center will monitor every flight, instantly receiving detailed data from the airplane's many systems.
About 600 engineers will analyze the data, with thousands more specialists available to troubleshoot any issue. Some 400 mechanics will do maintenance on the airplanes at night to ensure they are ready to fly every morning.
Boeing faces a tight schedule to complete the flight tests in time to deliver the airplane to its first customer late next year. Yet executives insist that the tightly choreographed test plan will leave time to deal with whatever problems crop up.
If all goes well, the Federal Aviation Administration will certify the 787 to fly and Boeing will deliver the first to Japan's All Nippon Airways in late 2010, with scheduled passenger flights starting probably in early 2011 — about 2 ½ years behind Boeing's original schedule.
Risk is always there
Most of the drama in test flights happens far from public view. But sometimes not.
In February 1995, on a 777 test flown by Boeing's chief test pilot at the time, Jim McRoberts, a clamp on an 11-inch air-conditioning duct came loose at 43,000 feet, causing the plane to suddenly lose air pressure.
Several engineers manning computer workstations in the back of the plane didn't get to their oxygen bottles in time and, after the rapid descent to the ground, four had to be treated in a hyperbaric chamber at Virginia Mason Hospital for symptoms of the bends.
Boeing's only commercial test-flight disaster occurred in 1959 — not in the development phase of a jet program but on a pre-delivery test flight — when a 707 for Braniff International Airways crashed along the Stillaguamish River near Arlington.
The Braniff captain, overseen by a Boeing test pilot, banked the jet beyond the maximum angle allowed and lost control. Four of the eight crew died in the crash.
In 1994, an Airbus A330 crashed during a flight test that required the pilot to cut one engine during an autopilot takeoff in poor weather. All seven people aboard were killed, including Airbus' chief test pilot. An investigation attributed the crash partly to pilot error.
While no flight test is routine, among the more hazardous are the early "flutter tests" that will take up the first couple of weeks of the Dreamliner's trials.
Flutter, which occurs when natural vibration is amplified to violent levels by wind or airflow, is what caused the original Tacoma Narrows Bridge to flail to destruction in 1940.
Seeking to detect any such flutter that could rattle a plane out of the sky, electronic devices pulse the flight controls at varying frequencies to generate shaking. The pilot also slaps the steering column rhythmically with his palm and rapidly vibrates his foot on the rudder control to shake the movable control surfaces as the jet dives from about 40,000 feet.
The tests are repeated with different weight distributions in the plane — changes accomplished by shifting water around within a series of large, connected kegs.
The airplane must be shown to be flutter-free at all speeds up to nearly the speed of sound, which at 30,000 feet is almost 680 mph.
To reach those speeds in the older 737s McRoberts tested, he had to dive at an angle of 45 degrees. With the more powerful thrust of today's engines, the 787 dive angle should be no steeper than 10 degrees.
Burning up the brakes
Another heart-racing test is the Maximum Energy Refused Takeoff, also known as max-energy RTO.
Before the test, the brake pads are intentionally ground down to the minimum allowed before they'd have to be replaced in regular service. Then, loaded to its maximum weight and full of fuel, the jet races down the runway up to a pre-calculated top speed before the pilot slams on the brakes.
When a pilot "dynamites the brakes" in this way, in the words of Joe MacDonald, former chief 747 test pilot, it generates so much heat that on earlier planes typically the steel brakes melted and the wheels caught fire, popping fuse plugs that deflated the tires. Fire personnel standing by were required to hold off dousing the flames for five full minutes in a successful test, to show that no wider fire would ensue.
In July 1974, a max-energy RTO ended with all the landing gear ablaze and bits of exploding tires and wheels shooting up over the wings. The pilots had to evacuate that plane, a customized 747 designed to be an airborne command post for the president and U.S. military leadership in a national emergency.
Boeing engineers had miscalculated the preset maximum speed, and the brakes just couldn't handle the energy poured into them. The jet wasn't severely damaged, but the wheels had to be replaced and the test rerun.
On the Dreamliner, however, the carbon composite brakes aren't expected to melt, so a fire is much less likely.
MacDonald said a max-energy RTO test, even when it goes as planned, can cost Boeing upward of $1 million. To mitigate all the risks involved, this test and several others will be done at Edwards Air Force Base in California, which has a 15,000-foot runway and a dry lake bed beyond.
Lightning vs. plastic
One area of some public concern has been the Dreamliner's lightning-protection system, because its largely plastic airframe doesn't dissipate a lightning strike as readily as today's aluminum jets.
Mike Delaney, chief project engineer on the 787, said his engineering team has done more detailed work on lightning than on any other contingency — analyzing the potential impact at "every fastener, every bracket, every spacing, every material."
Delaney said that in the coming nine months of constant flying, lightning strikes are highly likely, and he's hoping that will offer the public reassurance.
"My personal wish is that these test airplanes get struck a lot," Delaney said.
If so, Boeing's indefatigable test pilots will have another story to relate.
Not all of them are hair-raising, though.
In March, at a presentation at the Museum of Flight, Ken Higgins, Boeing's former head of flight operations and Cashman's co-pilot on that first 777 flight in 1994, recalled the biggest problem he encountered on the almost four-hour flight: bracing himself unsteadily over one of the jet's new toilets, the seats of which were designed not to slam down. But this one wouldn't stay up.
"I'd had a number of coffees," Higgins told his laughing audience. "It was a three-handed operation."
Dominic Gates: 206-464-2963 or firstname.lastname@example.org
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