WASHINGTON – WASHINGTON (AP) — Investigators are looking into whether long-known problems with the heating system in a cockpit window of the Boeing 757 played a role in a fire that forced an airliner to make an emergency landing near Washington, federal safety officials said Monday.
United Airlines Flight 27 en route from New York to Los Angeles with 112 people aboard made an emergency landing at Dulles International Airport in Virginia on Sunday night due to a cockpit fire, a spokeswoman for the Federal Aviation Administration said.
The fire aboard was extinguished before the plane landed and no injuries were reported, FAA spokeswoman Holly Baker said.
Keith Holloway, a spokesman for the National Transportation Safety Board, said the board has dispatched three investigators to examine the cockpit in an effort to determine the cause of the fire.
"We haven't narrowed down what the issues are with this incident yet," Holloway said. However, he added that the board will be investigating whether the cause of the fire was due to "a recurring problem" involved in previous 757 cockpit fires, or a new issue.
The board recommended to the FAA in 2007 that airlines be required to replace the windshield heat terminal blocks on all Boeing 747s, 757s, 767s and 777s. The FAA proposed a rule in March 2008 that gave airlines a choice of regularly inspecting the heat terminal blocks on 757s, 767s and 777s or replacing the terminal blocks. Boeing 747s were not included in the proposed order.
However, FAA records show airlines strongly criticized the proposal and it hasn't been made final. FAA spokesman Les Dorr said the rule is expected to become final in August. Airlines said in comments submitted to FAA that the agency's proposal wouldn't resolve the cause of the electrical arcing that led to the fires.
Airlines aren't required to comply with a rule until it's final, although many do.
The NTSB's recommendation was made in response to two fires that erupted in 757 cockpits in January 2004: an American Airlines flight in Dallas and an Air Greenland flight in Copenhagen.
Also, in 2006 a fire was reported on a Delta Air Lines 757 in the corner of a cockpit window. The pilots put it out with a fire extinguisher and cut power to the window heat, according to an FAA report on the incident. The plane had been en route from Tampa, Fla. to Hartford, Conn., but diverted to Savannah, Ga.
FAA said in 2008 that it was aware of nine incidents of electrical arcing at the terminal blocks, and "more than one incident" of open flames. The agency didn't specify in which Boeing model the incidents occurred.
There have been concerns about the cockpit heating systems of 757s for at least two decades. A 1990 safety directive from the FAA ordered airlines to inspect the window heating system 757s for undersized wiring. The FAA proposed a $1.45 million civil penalty against Northwest Airlines in March for failing to carry out some of those inspections until 2008. "Left uncorrected, the problem could cause overheating, smoking and possibly a fire," the FAA wrote when it fined Northwest.
None of the 757s turned out to have the wrong wires, according to Delta Air Lines Inc., which bought Northwest.
The 757s are one of the most widely used aircraft in the U.S. FAA in 2008 said that its proposal for inspecting terminal blocks would affect 1,212 Boeing planes registered in the United States.
Passenger Phil Lobel said he saw someone bring a fire extinguisher to the cockpit during the incident and other passengers later showed him pictures they took of flames in the cockpit.
United spokesman Mike Trevino said the plane took off from New York's John F. Kennedy International Airport and was diverted to Dulles, where it landed at 9:36 p.m.
Lobel, who has a public relations business in Los Angeles, told The Associated Press that about 30 minutes into the flight he detected an electrical burning smell.
He said flight attendants began going over emergency instructions with passengers in the exit rows and someone brought up a fire extinguisher from the back of the plane.
Lobel said the plane landed within about 20 minutes and a half-dozen or more emergency vehicles met the plane at Dulles. Some passengers on the flight were celebrities, he said. A publicist for the Broadway show "Jersey Boys" confirmed that star Jarrod Spector was on board.
About an hour after the plane landed, Lobel received an e-mail from United apologizing for the "experience" he had on the flight.
AP Airlines Writer Joshua Freed contributed from Minneapolis. Associated Press Writer Nafeesa Syeed contributed from Washington.