Center of gravity - What may happen if you don`t calculate correctly? - Curt Lewis

Improper cargo loading blamed in 2013 Soldotna air taxi crash that killed 10

National Transportation Safety Board investigators on the scene a plane crash in Soldotna in July 2013 that killed 10. The NTSB released a report Wednesday concluding that improperly loaded cargo was likely to blame for the crash.

An investigation into a July 2013 air taxi crash in Soldotna that killed all nine passengers and the pilot has concluded that issues with the weight and balance of cargo and baggage were directly to blame, the National Transportation Safety Board said in a new report released this week.

Inaction by the Federal Aviation Administration also contributed to the crash, the NTSB concluded. The FAA doesn't require documentation of the weight-and-balance configuration for air taxi and commuter services operating single-engine planes, even though it's a requirement for multi-engine aircraft. The NTSB has been urging the FAA to change that since 1989.

"It seems likely that if the FAA had taken the recommended action in the 26 years since the NTSB first recommended it, the accident in Soldotna would have been prevented," the NTSB said in an Aug. 21 safety recommendation to the FAA.

The flight, which crashed on takeoff July 7, 2013, was operated by Rediske Air Inc., an on-demand charter service based in Nikiski. The plane had too much weight in the rear, "which resulted in an uncontrollable nose-up pitch leading to an aerodynamic stall," said the report, posted on the NTSB website Tuesday and publicized on Wednesday.

Two families from Greenville, South Carolina, were killed when the plane went down seconds after takeoff. The two couples with five children between them were headed across Cook Inlet to Bear Mountain Lodge for an overnight trip that included bear watching. The 42-year-old pilot, Walter "Willie" Rediske, was an experienced airman, son of the air charter's founder and its co-owner when he was killed.

The NTSB put the direct cause of the crash on Rediske Air's failure to determine the actual weight of cargo, including groceries for the lodge, and properly load it onto the single-engine, turbine-powered de Havilland DHC-3 Otter. The plane ended up slightly overloaded but significantly off-balance, the NTSB said in its final report on the crash.

Because the cargo and passengers weren't weighed beforehand, the NTSB used a variety of means to figure weights. For instance, investigators went to the store where grocery items were bought and, using a receipt provided by the lodge, weighed the items.

"This was a very exhaustive, very labor-intensive investigation," said Clint Johnson, chief of the NTSB regional office in Alaska. The NTSB released about 400 pages of key documents in September 2014, including the results of several tests and studies, but only now is announcing its conclusions.

The flight load manifest listed the weight of the lodge's cargo at 300 pounds, but the NTSB investigation found it was more than double that.

In all, the NTSB estimated that the loaded Otter likely exceeded the 8,000-pound maximum weight by just 21 or so pounds. But the center of gravity was off by at least 5.5 inches -- and that was enough to doom the flight, under the NTSB's analysis. The NTSB couldn't determine where all the cargo and bags were placed.

The center of gravity on a plane is like the fulcrum on a teeter-totter. If there is a large child on one end and a small child on the other, the latter end will go up, Johnson said.

Key evidence came from a smartphone video shot during takeoff, which investigators used to determine the plane's angle and air speed. The video also revealed that the flaps were down, in the landing position. The improperly loaded plane would have crashed even with the flaps in the correct position, the report said.

Efforts to reach Rediske Air directly were unsuccessful. An Anchorage attorney representing the Rediske family group that owned the plane said that the NTSB report is inconclusive.

"Willie Rediske was a very, very fine pilot," said the attorney, Robert Richmond. "We are not aware of anything he did that was inappropriate."

The NTSB first recommended the FAA require weight-and-balance documentation for single-engine planes in 1989 and did so again 10 years later. In August, as a result of the Rediske crash, the NTSB once again pushed the FAA to act and it underscored the issue in the new investigative report.

The FAA provided a brief statement Wednesday.

"The FAA will evaluate the report to determine if we need to take any safety actions," the agency said in an emailed response to questions. "Further, we take NTSB recommendations very seriously and will respond to them within the required 90 days."

Rediske Air did not weigh the passengers or cargo, and it didn't add 10 pounds to each passenger's estimated weight, another approved method, the NTSB said.

"The NTSB's investigation found that the load manifest that was prepared for the accident flight was grossly inaccurate," the August NTSB safety recommendation said.

The operator also didn't perform balance calculations, the NTSB said.

Had an accurate manifest been required, "it would have been clear that the airplane was loaded beyond its operational limitations," the NTSB said in August.

The crash has generated a number of lawsuits in state and federal court, most of which were filed just before the two-year statute of limitations ran out and are in early stages.

Representatives of the passengers have sued Rediske Air, the family partnership and the pilot's estate, and, in a separate but parallel suit, sued Bear Mountain Lodge, the plane manufacturer and companies involved with converting the original Otter to a turbine plane. Among other issues, they claim defects in the plane. The pilot's estate -- represented by his sister, Lyla -- is suing, too, in a case that names the manufacturers, Bear Mountain Lodge and even the family partnership for which she's still the agent.

The NTSB investigation didn't name any manufacturing defect or maintenance issue as a factor in the Otter crash.

The Otter is considered a reliable and versatile plane for Alaska air taxi and commuter services and not one especially tricky to load correctly, said Paul Roderick, owner of Talkeetna Air Taxi, which has four Otters in its fleet.

A requirement for operators to document the weight and balance of each flight would mean extra paperwork but wouldn't be too burdensome, he said.

Before the fatal crash, the Bear Mountain Lodge owner had brought supplies to load onto the plane in Nikiski. The pilot then made the short flight to Soldotna to pick up the passengers.

Seconds after takeoff, the plane's nose pitched up and it stalled. Even when the pilot pushed the control column all the way forward, he couldn't bring the nose down, the NTSB found.