Before the alarming emergency in Boston involving Boeing’s 787 Dreamliner catching fire lies one far scarier moment-the closest call any jet can have. In November 2010, after a six-hour test flight, a 787 was on approach to the airport at Laredo, Texas. Suddenly an electrical fire broke out in the rear of the plane. The pilot found himself without his primary controls to fly down to a landing. The 787 and the 30 or so technicians and crew aboard were saved only by a last-resort device, a small turbine that drops below the fuselage to snatch power from the slipstream, working like a windmill. Even then, all aboard were evacuated on the runway by emergency slides-extremely rare for a test flight.
Boeing played down the seriousness of this episode as a problem that would be fixed. But it pinpointed a vulnerability unique to the 787. In other jets, the power for flight controls and other systems comes from the engines. In the 787, critical parts of the system depend on electrical power generated by equipment in two bays beneath the cabin. One of these bays was the origin of the fire in a Japan Airlines 787 while parked at a gate in Boston this week and of problems experienced by other 787 operators, including United Airlines and Qatar Airways.
Smoke and fire are an absolute no-no for airliners. Even on the ground they should be intolerable. So why did Boeing make the Dreamliner seemingly so dependent on having its own kind of in-flight electrical power plant?
In theory, the idea complemented the whole thrust of the airplane’s ambition to be a greener, cleaner jet. Not calling on the engines for many of the systems meant both more efficient engines and lower-exhaust emissions.
Before the 787, Boeing was noted for being conservative in its designs. However, stung by the reputation its rival Airbus was getting for having bet the company on one big idea, a far more automated flight-control system, Boeing’s engineers were allowed to be more daring.
As a result, the Dreamliner was actually packed with dreams: a radical change from metal to composites for the structure, a new generation of “green” engines-and far greater use of electrical power. Putting all this together in one airplane was problematic. Plants had to learn to handle composites from scratch, the supply chain seized up because of too much outsourcing, and the first 787s were more than three years late reaching the airlines.
For a while the gamble seemed to pay off. The first customer, All Nippon Airways, had flown 1.8 million passengers in its 787s in the year up to November 2012 and said it was “delighted” with the airplane, as were the passengers, with its brighter, roomier, and better ventilated cabins.
But now the Boston incident has revived earlier concerns. Boeing says, “Nothing that we’ve seen in this case indicates a relationship to any previous 787 power-system events, which involved power-panel faults elsewhere in the aft electrical equipment bay,” and that they still have “extreme confidence” in the plane. The fact is whether it comes from the battery or the power panel, fire on a plane is very bad news, and after the NTSB’s preliminary finding that the plane’s auxiliary-power-unit battery had severe fire damage, the question has become whether the 787 has, all along, been harboring a serious problem that will take a lot of money and time to fix.
Source: THE DAILY BEAST