Skip Ribbon Commands
Skip to main content
Safety Recommendation Details

Safety Recommendation A-11-049
Details
Synopsis: On August 9, 2010, about 1442 Alaska daylight time, a single-engine, turbine-powered, amphibious float-equipped de Havilland DHC-3T airplane, N455A, impacted mountainous, tree-covered terrain about 10 nautical miles (nm) northeast of Aleknagik, Alaska.1 The airline transport pilot and four passengers received fatal injuries, and four passengers received serious injuries. The airplane sustained substantial damage, including deformation and breaching of the fuselage. The flight was operated by GCI Communication Corp. (GCI), of Anchorage, Alaska, under the provisions of 14 Code of Federal Regulations (CFR) Part 91. About the time of the accident, meteorological conditions that met the criteria for marginal visual flight rules (MVFR)2 were reported at Dillingham Airport, Dillingham, Alaska, about 18 nm south of the accident site. No flight plan was filed. The flight departed about 1427 from a GCI-owned private lodge on the shore of Lake Nerka and was en route to a remote sport fishing camp about 52 nm southeast on the Nushagak River. The National Transportation Safety Board (NTSB) determined that the probable cause of this accident was the pilot’s temporary unresponsiveness for reasons that could not be established from the available information. Contributing to the investigation’s inability to determine exactly what occurred in the final minutes of the flight was the lack of a cockpit recorder system with the ability to capture audio, images, and parametric data.
Recommendation: TO THE FEDERAL AVIATION ADMINISTRATION: Correct the deficiencies with the in-service automated weather sensor system (AWSS) stations, specifically the known problems with present weather sensors and ceilometers, to ensure that the AWSS stations provide accurate information as soon as practical.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Action
Mode: Aviation
Location: Aleknagik, AK, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: ANC10MA068
Accident Reports: Collision into Mountainous Terrain, GCI Communication Corp. de Havilland DHC-3T, N455A
Report #: AAR-11-03
Accident Date: 8/9/2010
Issue Date: 6/9/2011
Date Closed: 5/4/2017
Addressee(s) and Addressee Status: FAA (Closed - Acceptable Action)
Keyword(s): Weather,Weather Equipment/Products/Reports

Safety Recommendation History
From: NTSB
To: FAA
Date: 5/4/2017
Response: We note that you completed a technical refresh of all 24 AWSS stations located in Alaska, retrofitting each station to use a modified backplane to correct radio frequency interfaces and upgrading the present weather sensors and ceilometers to ensure they provide accurate weather information. These actions satisfy Safety Recommendation A-11-49, which is classified CLOSED--ACCEPTABLE ACTION.

From: FAA
To: NTSB
Date: 3/28/2017
Response: -From Michael P. Huerta, Administrator: The Federal Aviation Administration (FAA) Air Traffic Organization completed the technical refresh of all 24 A WSS stations located in Alaska. Each A WSS station has been retrofitted to use a modified backplane to correct radio frequency interfaces. This technical refresh also included upgrading the present weather sensors and ceilometers to ensure these weather stations provide accurate weather information. We note that the identified A WSS issue did not exist in the 48 contiguous United States. Therefore, the action taken is specific to AWSS stations in Alaska. I believe that the FAA has effectively addressed this safety recommendation and consider our actions complete.

From: NTSB
To: FAA
Date: 9/26/2014
Response: We are encouraged by the progress that you are making to implement this recommendation; specifically, that you have retrofitted all AWSS stations to use a modified backplane to correct radio frequency interference. Pending completion of the upgrade to address the ceilometer deficiency, Safety Recommendation A 11 49 remains classified OPEN—ACCEPTABLE RESPONSE.

From: FAA
To: NTSB
Date: 8/19/2014
Response: -From Michael P. Huerta, Administrator: The federal Aviation Administration (FAA) deployed a modified backplane that corrected the radio frequency interference with AWSS, and since November 18, 2013, all AWSS stations have been retrofitted. As previously indicated, the ceilometer deficiency is scheduled to be corrected as part of the Automated Surface Weather Observation Network Technical Refresh Program, which began in Fiscal Year (FY) 2013 when funding was approved. The FAA plans to complete the system upgrade addressing the ceilometer deficiency in FY 2016. I will keep the Board informed on the FAA's progress on this recommendation and provide an update by July 2015.

From: NTSB
To: FAA
Date: 7/8/2013
Response: We are encouraged by the progress the FAA is making to implement this recommendation. Pending completion of the recommended action, Safety Recommendation A 11 49 remains classified OPEN—ACCEPTABLE RESPONSE.

From: FAA
To: NTSB
Date: 4/8/2013
Response: -From Michael P. Huerta, Administrator: The Federal Aviation Administration (FAA) formed a cross-organizational workgroup to address the Board's concern about deficiencies with the A WSS. The workgroup identified the radio frequency interference problem with the A WSS present weather sensor backplane. All Weather, Inc., will deploy a new backplane to correct the deficiencies with the AWSS with a scheduled completion date by December 2015. The AWSS ceilometer deficiency will be corrected as part of the Automated Surface Weather Observation Network Tech Refresh program. Work recently began in fiscal Year (FY) 2013 as a result of approved funding. I will keep the Board informed of the FAA's progress and provide an update to this recommendation by January 2014.

From: NTSB
To: FAA
Date: 12/16/2011
Response: The FAA’s plan to establish a cross-organizational workgroup to collaboratively determine the modifications required to address this recommendation is the first step in responding to this recommendation. Pending completion of the recommended action, Safety Recommendation A-11-49 is classified OPEN—ACCEPTABLE RESPONSE.

From: FAA
To: NTSB
Date: 8/19/2011
Response: CC# 201100331: - From J. Randolph Babbitt, Administrator: The FAA will establish a cross-organizational workgroup comprised of subject matter experts to address this recommendation. The workgroup will consist of members from Technical Operations, System Operations, and Air Traffic Organization Safety. Each representative will be asked to work collaboratively in determining modifications required to address deficiencies with the in-service AWSS stations. The group will review the organizational assessments and determine the appropriate course. I will keep the Board informed of the FANs progress and provide an updated response to this recommendation by January 2012.