last hour of buffalo flight
Investigators Look at Final Seconds of Buffalo Flight (Update1)
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By Brian K. Sullivan
Feb. 16 (Bloomberg) -- Investigators are looking at the final actions of the crew, as well as the aircraft performance, of a Continental Connection’s flight that crashed outside Buffalo four days ago killing 49 people aboard and one man on the ground.
The crew appeared to struggle with the aircraft, which went through a series of violent bucks and rolls seconds before it hit the ground in Clarence, New York. The de-icing equipment was engaged 11 minutes after taking off from Newark, New Jersey, yet the crew commented on ice buildup on the wings and windshield just before the accident, said Steve Chealander, a member of the National Transportation Safety Board.
The pilots, Captain Marvin Renslow, 47, and First Officer Rebecca Shaw, 24, had turned on the plane’s autopilot for part of their approach to Buffalo’s Niagara International Airport, Chealander said.
NTSB, Bombardier Inc., the plane’s manufacturer, and the airline, Pinnacle Airlines Corp.’s Colgan Air unit, all recommend pilots disengage autopilot features when flying in “severe icing” conditions. Chealander said a pilot has a better feel for the aircraft when the autopilot is off.
Chealander wouldn’t criticize the crew’s actions, however, saying using autopilot helps with the workload of trying to land a sophisticated commercial airliner.
“To say that they should not have been flying on autopilot is not correct,” Chealander said during a briefing held in Amherst, New York. “Thus far, we haven’t determined it was severe icing, it doesn’t seem like it was a severe icing event.”
Icing Questions
The crew on the flight voice recorder reported “significant icing.” Chealander said investigators don’t know what that means. The term “severe icing” is an official designation. However, “significant icing” isn’t.
Based on initial weather data and reports filed by other pilots flying into the airport that night, there isn’t any evidence to say the “severe icing” designation was applicable, he said.
“They viewed it as significant,” Chealander said. “We don’t know if it was severe icing. They didn’t say it was severe icing. The weather man didn’t say it was severe icing.”
The pilots had winter training suggesting they engage de- icing equipment before entering icing conditions.
The plane crashed about 6 miles (9.7 kilometers) northeast of Buffalo’s Niagara International Airport in Clarence, New York at about 10 p.m. local time Thursday. Colgan operated the plane, a Dash 8 Q400 turboprop, for Continental Airlines Inc.
The chief pilot Renslow began flying the Dash 8 model in December and had 3,379 flying hours, according to Chealander. Shaw joined the company in January 2008 and had 2,244 hours.
Sophisticated Equipment
The Q400 has a sophisticated set of ice detection equipment on board, more advanced than required by current Federal Aviation Administration rules, said Laura Brown, FAA spokeswoman in Washington. The equipment complies with a proposed FAA rule change not yet implemented.
“They have gotten ahead of the mandates,” Brown said of the aircraft manufacturer by telephone from Washington.
There was some differences between how the FAA and the NTSB approaches the subject of icing, Brown said. Yesterday, Chealander said the “FAA sees things a little differently than we do” when it comes to flying on autopilot in icing conditions.
The FAA and the NTSB agree on about 80 percent of the rules for operating in icing conditions, Brown said. However, some NTSB recommendations take time to implement to avoid creating unintended consequences.
Since 1994, the FAA has issued more than 100 directives concerning icing, Brown said.
Safety Alert
A safety alert concerning preparing a plane for takeoff and planning a flight in icing conditions was released the day before the Buffalo crash, according to the FAA Web site.
The aircraft was manufactured in April and went into service by Colgan that month, according to a company statement.
Officials are still trying to determine if the plane stalled as it approached the airport.
Chealander said the stall speed for the aircraft is still being determined. It depends on a number of factors including the gross weight of the plane at the time of the crash.
Stall Speed
He said a device that helps the plane avoid stalls in icy conditions was engaged.
Chealander said in the final seconds of flight, the airplane went through a series of up-and-down jerking motions and side-to- side rolls.
Right after that, the so-called stick pusher activating the nose of the aircraft rose to about 31 degrees, according to information recovered from the flight data recorder. The stick pusher will drop the nose of the aircraft in order to gain speed and avoid a stall.
Chealander said he wouldn’t comment on whether the sudden rise of the nose was caused by a pilot reaction to the stick pusher sending the plane into a dive. Following the nose of the airplane going up, the plane then went down to a 45 degree angle.
The plane then rolled about 46 degrees to the left followed by 105 degrees to the right, putting the aircraft onto its side.
He said passengers and crew experienced about 2 Gs of force. One G, or gravitational pull, is what a person standing still experiences.
The last radar hit showed the aircraft was at an altitude of about 900 feet traveling at about 100 knots (115 miles per hour). Radar also indicated the plane fell from 1,800 to 1,000 feet in five seconds, Chealander said.
The area around the crash site remains closed and residents in the neighborhood haven’t been allowed to return home.
Site Closed
A main road passing the crash site re-opened yesterday, however police closed it again last night after sightseers clogged the area, New York State Police Captain Steven Nigrelli said this morning at a briefing.
“As long as people create a traffic hazard it will remain closed,” Nigrelli said.“If you try to breach our lines you will be arrested.”
Nigrelli said people parked on lawns in the area and were cutting through residents’ back yards to get a look at the crash site, which is shielded from view by large tarps. Three people have been arrested since Friday.
“We are sworn to protect the sanctity of the scene,” Nigrelli said at a briefing in the Clarence Public Library.
sorrowful images. To God we belong to HIM we return
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