ASF Cautions Against "Jumping To Conclusions"

ANN REALTIME UPDATE 03.25.09 0001 EDT: Investigators with the National Transportation Safety Board recovered a piece of evidence Tuesday they hope might shed new light on why a Pilatus PC-12/45 crashed near an airport in Butte, MT this weekend: the engine performance recorder.

The device, reports The New York Times, measures engine data once every minute, and might disclose whether the aircraft's Pratt & Whitney Canada PT6A-67B turboprop powerplant suffered any problems that might have led to the accident.

Such a discovery would appear to be a longshot, but with little other information to go on -- like many small corporate planes, the PC-12 was not equipped with flight data or cockpit voice recorders -- investigators hope to catch a break.

Acting NTSB Chairman Mark Rosenker said the Board will consider numerous possible scenarios in working to determine why the aircraft crashed, claiming the lives of the 14 people onboard. Among the many questions is why the plane's pilot opted to divert to Butte when the aircraft was within 20 minutes of its planned destination of Bozeman.

"There are some interesting attributes to this [investigation]. One is the question of the 25,000-foot request for diversion to come to Butte," Rosenker said. "There are a lot of questions, but it begins with that question. That's where we believe -- that's where we're beginning to look at things."

The Los Angeles Times reports investigators also want to know why the plane impacted where it did: about 500 feet away from its intended landing point, nearly abeam midfield. Further, the aircraft wasn't fully configured for landing -- investigators say the landing gear was down, but flaps were not deployed.

Though this -- like nearly every theory at this point -- is pure speculation, the NTSB says the impact point might indicate the pilot was attempting to turn a very tight downwind for Runway 33 at Bert Mooney Airport (BTM). That turn may have been complicated by the weight of the passengers and baggage onboard the plane... or possibly ice accumulated on the airframe from descending through a freezing layer on approach to the airport.

The NTSB also noted Tuesday that an airworthiness directive was issued by the FAA two weeks ago, requiring PC-12 operators to check whether the rear stick-pusher cable clamp had shifted forward on the elevator cable, a condition that could hamper pitch control authority.

It's not clear whether that AD had been complied with on the accident aircraft, as the directive doesn't go into effect until March 30, and gives operators 150 flight hours to comply. However, NTSB Investigator-In-Charge Dennis Hogenson told the Associated Press investigators were able to establish control continuity at the crash site, and at this point it's unlikely that issue was a factor in Sunday's crash.

Original Report

03.24.09 1000 EDT: As investigators worked Monday to identify the victims of Sunday's downing of a Pilatus PC-12/45 near Bert Mooney Airport (BTM), speculation about possible causes for the crash continued to run the gamut -- including theories the aircraft (type shown below) was overweight and/or out of CG range, that it may have suffered some kind of mechanical failure, or that the plane picked up severe airframe icing on its descent into Butte, MT.

Such speculation is the norm when dealing with a high-profile aviation accident... particularly when the crash attracts the attention of the general media, and involves the loss of families or children. Whether that's right or wrong is a discussion for another time -- though the AOPA Air Safety Foundation cautioned Tuesday against anyone jumping to conclusions regarding causes, when the investigation has barely started.

"It's important to remember that except for the extremely rare single-point catastrophic failure, aviation accidents are almost invariably the result of a chain of events and decisions," said Air Safety Foundation President Bruce Landsberg. "The National Transportation Safety Board is extremely good at accident reconstruction, but it will take them months to find and then unravel all the links in this accident's chain."

Landsberg's comments followed statements made by a number of aviation analysts Monday. John Goglia, a former National Transportation Safety Board official, told The Associated Press icing may very well emerge as a leading theory among investigators, given weather conditions at the time and witness accounts the plane nosedived into the ground.

"It's Buffalo all over again, or it could be," Goglia said, referring to last month's downing of a Bombardier Q400 regional aircraft as it approached Buffalo, NY, that many believe was at least partly due to significant airframe icing. (Of course, it's also worth noting THAT investigation is still underway, as well -- Ed.)

Officials have confirmed the PC-12 had 14 individuals onboard, seven adults and seven children. Those children ranged in age from 1 to 9... meaning that despite having more persons onboard the plane than number of seats available -- the accident aircraft was in a commuter configuration with either 10 or 11 pilot and passenger seats, according to reports -- it's likely some of those youths were seated on adult passengers' laps, which FAA regs allow up to the age of 2.

It's still too soon to determine whether the aircraft was operating within its specified weight range. Investigators may also never know whether the aircraft was within its accepted center-of-gravity range, particularly as fuel burned off during the flight.

"I'm convinced, even at this early stage, that one of the areas they need to look at the closest is weight and balance," said ABC News aviation consultant John Nance, adding it's possible the adults or children onboard were moving about the cabin during the approach to BTM, possibly throwing off the aircraft's weight balance at a critical moment.

"The fact that you've got children onboard, they may see something out of the airplane at the last minute," Nance said. "People unstrap their seat belts, get up and move, and your center of gravity could shift."

Officials have identified the plane's pilot, as well as the owner of the PC-12. Buddy Summerfield, 65, was a former military pilot with 2,000 hours in the PC-12, according to authorities. Summerfield was apparently flying three families on a skiing trip, for the plane's owner, Dr. Bud Feldkamp.

Feldkamp was not onboard the aircraft... but he said two of his daughters, their husbands and five of his grandchildren were onboard the plane.

Investigators also aren't sure why Summerfield opted to divert to Butte over the plane's intended destination of Bozeman. No emergency call was made; Nance said it's possible Summerfield opted to land sooner to give his passengers a bathroom break... a plausible theory, given the plane was airborne for 2 1/2 hours prior to the crash, and the commuter-configured PC-12 was likely not equipped with a lavatory.

During press conferences Monday, acting NTSB Chairman Mark Rosenker stressed the investigation was only just beginning. "This will be a long and tedious investigation, extremely thorough," he said. "We will look at every factor which could affect the performance of this aircraft."

"To say that icing is becoming the lead focus is not true at this point," NTSB spokesman Keith Holloway told The Associated Press. "We're looking at mechanical issues. We're looking at weather. We're looking at the structure of the aircraft. We're looking at human performance, weight and balance issues."

Those sentiments were echoed Tuesday by ASF's Landsberg (shown above). "The briefings and the preliminary report are nothing more -- or less -- than a listing of the facts collected," said Landsberg. "They give no relative weight to any of the facts, nor do they draw any conclusions about possible causes."

FMI: www.ntsb.gov, www.aopa.org/asf