Cargo weight likely is to blame for an Alaska plane crash that killed nine people from Greenville two years ago, the National Transportation Safety Board said Wednesday.
The air taxi went into an aerodynamic stall at the Soldotna, Alaska, airport on July 7, 2013, after the operator failed to determine the actual cargo weight, which led to the loading and operation of the airplane outside of its weight and center of gravity limits, NTSB investigators said in the agency's final report on the crash.
Contributing to the accident was the Federal Aviation Administration's failure to require weight and balance documentation for that type of air taxi flight, investigators said.
Family members of the victims found little solace in the NTSB report.
"We're devastated," said Rachel Dickert, whose daughter, Stacey McManus of Greenville, and two grandchildren were killed.
FAA officials said in a statement they will evaluate the report to determine if any safety actions are needed.
The flight was headed from Soldotna to a lodge 90 miles away when the airplane stalled and crashed on takeoff. The airplane was destroyed by the impact and a post-crash fire, and the pilot and nine passengers were killed.
A video of the airplane’s taxi, takeoff roll and takeoff was recovered from a passenger’s smartphone, NTSB investigators said.
A video study by the NTSB indicated that shortly after takeoff, the airplane’s airspeed decreased from about 68 mph to about 44 mph over a period of about 8.5 seconds. About 11 seconds after takeoff, the airspeed reached a value consistent with an aerodynamic stall, investigators said. The airplane rolled right-wing-down and hit the ground several seconds later.
Pilot Walter "Willie" Rediske died, along with Greenville doctor Chris McManus, his wife, Stacey, and their two children, 17-year-old Meghan and 14-year-old Connor; and Melet and Kim Antonakos and their three children, 16-year-old Olivia, 14-year-old Mills and 11-year-old Anastacia.
The Greenville families had been on an extended Alaskan vacation, one of many trips the families shared through the years. They were on their way to a one-day bear-viewing excursion, where they would spend the night in the lodge, before flying back to Greenville.
According to the NTSB:
Before picking up the nine passengers, the pilot loaded the airplane at the operator's base in Nikiski with food and supplies for the lodge. The lodge operator estimated the cargo weighed about 300 pounds and that the passengers' baggage weighed about 80 pounds.
Estimates of the passengers' weights, provided to the lodge operator in preparation for the trip, totaled 1,350 pounds. The load manifest listed each estimate for a total of 1,730 pounds.
But the cargo wasn't weighed. The pilot didn't document any weight and balance calculations, nor was he required to.
The weight of the cargo recovered from the crash site and determination of the weight of cargo destroyed in the impact and post-crash fire showed the freight was about 418 pounds higher than what was stated on the load manifest, NTSB investigators said. That resulted in a center of gravity aft of the limits for the airplane, the investigators said.
The airplane operator didn't keep fueling records for each flight. A witness during fueling operations at the operator's base reported he saw the pilot top off the front tank then begin fueling the center tank. The first leg of the trip from the operator's base to pick up the passengers was uneventful.
According to witnesses at Soldotna Airport, after loading the passengers and their baggage, the pilot taxied for departure. There were no witnesses to the accident. The airplane hit the ground about 2,320 feet from the threshold of the departure runway and about 154 feet right of the runway centerline.
An extensive post-crash fire consumed most of the airplane's cockpit and cabin area, including an unknown amount of the baggage and cargo.
The entire airplane was accounted for at the wreckage site. Disassembly and examination of the engine and propeller revealed that both were operating during impact. Examination of the structure and flight control systems found no pre-impact malfunctions or failures that would have precluded normal operation.
The pilot was properly certificated and qualified in accordance with federal regulations. Toxicological testing of the pilot came back negative for any carbon monoxide, alcohol or drugs.
The airplane wasn't equipped, and was not required to be, with any type of crash-resistant recorder. A video recovered from a passenger's smartphone showed the accident sequence looking out of the fourth row, left seat window.
The left wing and flaps are in view for most of the sequence and the flap position doesn't change. The investigation found that the flaps were set to the full-down, or landing, position during takeoff, contrary to recommended procedures in the airplane flight manual.
The recovered video was used to estimate the airplane speed, altitude and orientation for the portion of the flight where ground references were visible, about 22.5 seconds after the start of the takeoff roll.
The ground references disappeared from the video as the airplane experienced a sharp right roll before hitting the ground several seconds later.
A woman at a campground near the airport told investigators she heard a high-pitched sound and then a pop. A man driving on a road next to the airport said he saw black smoke coming from the engine. He didn't see the crash, however, because he had driven behind a hangar.