Boeing’s New B787 Suffers Electrical Fire in Flight

Thu, Nov 11, 2010 — David Evans


One of Boeing’s new B787 airliners had to curtail its test flight and make an emergency landing due to an uncontrolled electrical fire.

The B787 at Laredo after the fire was extinguished. Emergency escape slides have already been removed.

The B787 at Laredo after the fire was extinguished. Emergency escape slides have already been removed.

One of the six B787s experienced a cascading series of electrical failures, and smoke filled the cabin, prompting a hasty landing at Laredo, Texas, near the end of a 6-hour test flight on 6 November. The 42 test flight personnel on board, including a Federal Aviation Administration (FAA) contingent, evacuated the airplane via emergency slides. This hasty evacuation suggests that smoke filled the cabin to the point where those aboard were perhaps blinded and choking and had to get off the airplane the fastest way possible.

The airplane was painted in All Nippon Airways (ANA) livery. ANA is slated as the first airline to receive the B787 in the first quarter of 2011. That date may slip while the cause of the onboard fire is investigated and corrective actions are taken. Further late delivery will put the program, for which Boeing has 847 orders, even further behind the three-year delay existing before the incident.

The plane had departed Yuma, AZ for a flight to assess the functioning of the fuel tank inerting system. In this system, intended to improve fuel tank safety, nitrogen enriched air is pumped into the fuel tanks to lessen the danger of fuel-vapor explosion of the type that destroyed TWA flight 800, a B747-100, in 1996. The B787 is built of composite materials, which could be more vulnerable to lightning strikes penetrating the fuel tanks. With inerting and other features, Boeing plans to blunt the hazard of a fuel tank explosion.

According to a Boeing official, the fire started in a power control panel in the rear electronics bay on the test airplane. It is not clear whether the fire started in equipment that is a permanent part of the B787 or equipment installed for purposes of the test flight.

Boeing’s certification and delivery schedule could be in jeopardy if the fire’s cause and subsequent electrical failures cannot be isolated to an item of test equipment on this specific airplane.

“There could be a fundamental issue with the electrical system, which could require redesign of a specific system or subsystem,” Douglas Harned, an aerospace analyst with Bernstein Research in New York, wrote in a note to investors 10 November. “Such a situation would be much more serious because it could significantly delay certification while a solution is developed.”

Boeing will delay further test flights of the B787 aircraft until the cause of the fire is known definitively.

The electrical fire triggered a series of cascading electrical failures that affected a number of computerized systems and flight controls, a person familiar with the matter said. The ram air turbine (RAT) was deployed to provide power.

Three issues immediately come to mind:

1. The absence of built-in fire suppression and perhaps even fire detection in the rear of the cabin. There are whole sections of a modern jetliner that are unprotected by smoke warning and fire detection. Given that the fire ultimately was extinguished by Laredo airport fire and rescue personnel, it appears that such was the case here. If the fire was in an area not accessible to personnel armed with portable fire extinguishes, a major vulnerability exists.

2. Electrical power that feeds a fire should have been terminated by one or more circuit breakers. If the breakers did not function, why not? If they did, why was the fire continuing?

Electrical arcing; very hazardous in flight.

Electrical arcing; very hazardous in flight.

3. Was other flammable material contributing to the fire? Recall that after the 1998 Swissair flight 111 crash in Nova Scotia, the Transportation Safety Board of Canada recommended that airliners not be built with flammable material

The FAA is investigating and the incident and the National Transportation Safety Board (NTSB) is monitoring the situation.

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