WASHINGTON — Speculation over the crash of a single-engine turboprop plane into a cemetery shifted to ice on the wings Monday after it became less likely that overloading was to blame, given that half of the 14 people on board were small children.
While descending Sunday in preparation for landing at the Bert Mooney Airport in Butte, Mont., the plane passed through a layer of air at about 1,500 feet that was conducive to icing because the temperatures were below freezing and the air "had 100 percent relative humidity or was saturated," according to AccuWeather.com, a forecasting service in State College, Pa.
Safety experts said similar icing condition existed when a Continental Airlines twin-engine turboprop crashed into a home near Buffalo Niagara International Airport last month, killing 50.
A possible engine stall created by ice, and the pilot's reaction to it, has been the focus of the Buffalo investigation.
"It's Buffalo all over again, or it could be," said John Goglia, a former member of the National Transportation Safety Board. "Icing, given those conditions, is certainly going to be high on the list of things to look at for the investigators."
Mark Rosenker, acting NTSB chairman, told reporters in Montana that investigators would look at icing on the wings as a factor.
"We will be looking at everything as it relates to the weather," he said.
The plane, designed to carry 10 people, crashed 500 feet short of the Montana airport runway Sunday, nose-diving into a cemetery and killing seven adults and seven children aboard. Relatives said the victims were headed to an exclusive resort on a ski vacation, and gave the children's ages as 1, 3, 5, 7 and 9, plus two 4-year-olds.
The victims were members of three California families traveling to the exclusive Yellowstone Club for a skiing vacation.
"We were going on a vacation with all the grandkids," said Bud Feldkamp, who lost two daughters and their families in the crash. "They were all excited about skiing."
Feldkamp leased the airplane that crashed Sunday in Butte. He said he, his wife and another daughter had driven to Montana for the vacation.
"We were at the entrance to the Yellowstone Club when I got a cell phone call" from my nephew, Feldkamp said. "He saw it on CNN. He said, 'Nobody survived.' And we knew it was our plane."
Feldkamp spoke shortly after he, his wife and two children along with Bob Ching and his wife spent about 45 minutes at the crash site.
Buddy Feldkamp said the victims included his sisters Amy Jacobson of St. Helena, Calif., and Vanessa Pullen of Lodi, Calif. Jacobson's husband, Erin, and their children Taylor, 4; Ava, 3; Jude, 1, also died in the crash as did Pullen's husband, Michael, and their children Sydney, 9, and Christopher, 7.
Buddy Feldkamp said Bob Ching' son, Brent Ching, of Durham, Calif., was killed in the crash along with his wife, Kristen and their children, Heyley, 5 and Caleb, 4.
Vanessa Pullen was a pediatrician, Michael Pullen was a dentist, Erin Jacobson was an opthalmologist and Amy Jacobson was a dental hygienist. Brent Ching was an orthopedic surgeon.
Buddy Feldkamp identified the pilot as Buddy Summerfield.
Safety experts said finding the cause of the crash is likely to be significantly complicated by the absence of either a cockpit voice recorder or a flight data recorder, which isn't required for smaller aircraft that don't fly commercial passengers like airlines and charter services.
Former NTSB chairman Jim Hall pointed to similarities between the Montana crash and a March 26, 2005 crash near Bellefonte, Pa., in which a pilot and five passengers were killed.
The plane in both cases was the Pilatus PC 12/45 and was on approach to an airport. In both cases there were reports of conditions conducive to icing at lower elevations and witness reports that the plane appeared to dive into the ground.
"I'm certain they are also going to look at the weather conditions at the time and the pilot's training," Hall said. He pointed to a recommendation on NTSB's "most wanted list" of safety improvements that FAA test the ability of turboprop planes to withstand a particular type of icing condition called "super cooled liquid drops" before certifying the aircraft design for flight. FAA officials have said they're working on that recommendation.
"If you had some precipitation and the temperature was in the right range, that again is an area that investigators would look at," Hall said.