Monday, May 17, 2010

Fire in the cockpit causes United Airlines Boeing 757 diversion

by B. N. Sullivan

United Airlines B757Last night, May 16, 2010, United Airlines flight UAL 27 from New York-JFK to Los Angeles diverted to Washington Dulles International Airport (IAD) after a fire broke out in the cockpit. According to press reports, the fire may have originated in a windshield heater on the Boeing 757-200 aircraft (registration N510UA). The incident began about 30 minutes into the flight. The aircraft diverted to IAD where it landed safely. No injuries were reported.

In its account of the incident, reports that the pilots "noted the faint smell of smoke before hearing a 'sizzle' and seeing flames coming from a phenolic block that holds wires that carry power to the windshield heaters."
After donning oxygen masks, the crew extinguished the fire with a halon fire extinguisher, declared an emergency and diverted to Dulles.

Inbound to Dulles at approximately 500ft altitude on the final approach to Runway 19L, the Boeing 757's left front windshield apparently shattered with a "boom", according to a report from the crew. Despite the disruption, the pilots landed the aircraft without incident as fire and rescue crews looked on.
A preliminary report posted this morning on the FAA website said only that the aircraft diverted to IAD after reporting fire in the cockpit. No further details about the incident were provided.

The National Transportation Safety Board (NTSB) has opened an investigation.

UPDATE May 21, 2010: In a press release today, the NTSB provided the following factual information about this incident:
On Sunday, May 16, 2010, about 9:17 pm (EDT) the pilots on United Airlines flight 27, a Boeing 757, N510UA, noted a strong acrid smell and observed smoke from the Captain's lower front windshield. The incident occurred about 30 minutes into the flight while the aircraft was level at 36,000 feet MSL. On board the aircraft were 7 crew members and 105 passengers.

The Captain and First Officer reported that they donned their oxygen masks and smoke goggles immediately after observing the smoke and fire. The Captain then gave control of the airplane to the First Officer and discharged a halon fire extinguisher. The smoke and fire dissipated but then re-ignited. The Captain obtained a second bottle from the Purser. The fire remained extinguished after this second bottle was discharged. At approximately 500 feet MSL on final approach to Runway19L at IAD, the Captain’s windshield cracked. The landing was uneventful. The airplane cleared the runway, after which ARFF (Aircraft Rescue Firefighting) entered the aircraft to check for residual heat and fire. None was found and the airplane was towed to the gate for deplaning. There were no evacuation and no injuries to the flight crew or passengers.

Preliminary examination of the cockpit area revealed that the inner pane of the Captain’s windshield had cracked. One of the five terminal blocks attached to the inside of the lower left windshield was consumed by fire and the portion of the wire harness associated with this terminal block was significantly damaged by fire. There was significant sooting and paint peeling to the left hand side of the windshield air frame support.

The Captain’s windshield was moved and will be examined by Board investigators at the manufacturer.

Two previous windshield fire events on B757-200 aircraft prompted the NTSB to issue Safety Recommendation A-07-50 The Safety Board investigators will look closely at the recovered hardware to determine if this latest event is related.
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