WASHINGTON, D.C. (KTUU) - 12:00 p.m. Update:
During the board hearing, the NTSB said the probable cause involved the crew's decision to fly lower to the ground and "inhibit" a warning signal that would notify the cabin that the plane was dropping closer to the surface.
These rules, called visual flight rules or VFR, are sometimes used in lieu of IFR, or instrument flight rules, for local or sight-seeing flights, or depending on weather conditions.
The weather conditions during the flight between Quinhagak and Togiak was cloudy, so flying below the cloud cover was warranted. However, the NTSB investigators said Tuesday, the crew had inhibited warning signals due to the plane flying so close to the ground that they would continually sound if not inhibited.
The NTSB said the crew failed to properly avoid hazards while flying in VFR mode, and the crash resulted due to this.
Specifically, the board identified Hageland's pilot history, which have in the past similarly crashed due to a switch to VFR. While the point was made that the loud warning from flying below altitude would itself be a hazard, officials said simply inhibiting the warning signal indefinitely was not a good alternative.
The inhibiting of the warnings directly disables TAWS, or the terrain avoidance system, that pilots need to safely navigate aircraft, the board said.
“This crash involved a well-equipped airplane with not one but two professional pilots on board,” said Robert L. Sumwalt, the chairman of the NTSB. “But the many layers of protection against controlled flight into terrain failed to protect the pilots and their passenger.’’
A hearing today in Washington, D.C. will aim to discover the cause of a fatal airplane crash in Alaska on Oct. 2 headed to Togiak.
Two pilots, Drew Welty, 29, and Timothy Cline, 43, as well as a passenger, perished in that crash in southwest Alaska, miles outside of its destination.
For the most part, NTSB hearings which convene to investigate crashes like these take place in Alaska, where the crashes occur. This is the first investigation in almost 20 years to take place in D.C.
The hearing can be viewed live here.
The flight, operated by Hageland Aviaiton Services, Inc., was doing business as Ravn Connect. The turbine-powered Cessna 208 B left Quinhagak at 11:33 a.m., and never arrived at its Togiak destination.
The plane hit rocky mountain face 20 minutes after take-off, leaving none alive on board.
While an NTSB hearing was held on a preliminary basis in Anchorage, the final results on the crash investigation are expected at the D.C. hearing.
The National Transportation Safety Board will hear sworn testimony from subpoenaed witnesses, providing analysis of the crash's cause and complications experienced prior to its crash.