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General Aviation Safety
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.
TO THE FEDERAL AVIATION ADMINISTRATION: Implement a collaborative test program in Alaska among the Federal Aviation Administration, the National Weather Service (NWS), the local academic community, and private entities to establish the viability of relaying weather information collected from airborne aircraft equipped with existing data-link technology, such as universal access transceivers, to the NWS Alaska Aviation Weather Unit in real-time.
Original recommendation transmittal letter:
Closed - Unacceptable Action
Aleknagik, AK, United States
Collision into Mountainous Terrain, GCI Communication Corp. de Havilland DHC-3T, N455A
Addressee(s) and Addressee Status:
FAA (Closed - Unacceptable Action)
Weather, Weather Equipment/Products/Reports
Safety Recommendation History
We do not agree that a test using the Universal Access Transceiver (UAT) to report meteorological information from airborne sensors to the ground would be unproductive, nor do we agree that the alternative approaches undertaken by the FAA and the National Weather Service achieve the objectives of these safety recommendations. However, because the FAA has made it clear that it considers its actions in response to these recommendations to be complete and it will take no further action, Safety Recommendations A-11-50 and -51 are classified CLOSED—UNACCEPTABLE ACTION.
The FAA concurs with the Board's recommendations; however, the FAA and the NWS are currently exploring more cost-effective ways to achieve a similar safety objective. The FAA finds that a test using the Universal Access Transceiver (UAT) to report meteorological information from airborne sensors to the ground would be unproductive at this time for several reasons: • There are no significant technical unknowns about downlinking weather information from aircraft, as such services have been underway for over 20 years using various data links; • General aviation aircraft are not generally equipped with on•board sensors to reliably collect the weather information to be downlinked. Acquisition, installation, and maintenance of reliable sensor equipment for general aviation aircraft is costly; and • Standards for on•board weather sensors and for downlinking weather information arc incomplete. The RTCA Special Committee SC•206 is tasked with developing such standards and with making recommendations on utilizing existing data links for the exchange of Aeronautical Information and Meteorological Information Services data. After review of those standards, further determinations for government or commercial investments will be made. Several capabilities proposed by the Board's recommendations are already in place or planned and the FAA, in conjunction with the NWS, will substantially address the problem by: • Increasing coverage of airborne weather reports from commercial aircraft; • Enhancing surface observations at both airport and off-airport locations; • Increasing remote weather camera coverage; and • Implementing improvements to National Oceanographic and Atmospheric Administration (NOAA) Numerical Weather Prediction Models. The Meteorological Data Collection and Reporting System (MOCRS), operated by the FAA and the NWS, in collaboration with commercial airlines, provides airborne weather observations of winds and temperature (and, in some cases, water vapor) to NWS forecast models and personnel, as well as to participating airlines. Alaska Airlines (AS) was added to the MDCRS program in March 2011, adding approximately 120 reporting aircraft. These aircraft provide on the order of 25,000 observations per day, approximately 20 percent of which are low-level reports from surface to 5,000 feet above ground level (AGL). About one-quarter of the total observations from AS reporting aircraft are in the vicinity of Anchorage, with the remainder located in the regions around 19 remote airports, a number of which have service directly as a result of subsidies from the Department of Transportation under the Essential Air Services program. An example of a typical data collected over a 48-hour time period is depicted below: 48 hrs Alaska Airlines MDCRS, June 20-22, 2012. In addition, MDCRS data is near real-time. NWS personnel at the Alaskan Aviation Weather Unit (AA WU) have rapid access to the MDCRS data through the NOAA Port connection. Most of the data are available to operations within 20 minutes of their valid time. The FAA and the NWS have made improvements to surface observing capabilities as well. At Alaskan airports, the Automated Weather Observation System (AWOS), A WSS, and the Automated Surface Observing System (ASOS) programs are critical for providing data used as input to forecasting models. Over the last 10 years, 14 A WOS units and 24 A WSS units have been installed in Alaska, bringing the total number of automated observing systems in the region to 126 (44 ASOS, 24 A WSS, and 58 AWOS). More importantly for off-airport regions, the NWS is planning to replace manual part-time and limited human observations in remote villages with automated stations that report constantly under the Meteorological Automated Weather System program. Cameras are another source of weather observations currently in use. The FAA's Aviation Weather Camera program seeks to improve aviation safety by providing current visual weather information in the form of near real-time video camera images of current sky conditions at airports and strategic visual flight rule locations, such as high-use routes and high-accident areas, to aviation users. The images provide pilots, dispatchers, and flight service station specialists with up-to-date weather information on their route of flight and their destination airport. This enables them to make better-informed decisions about whether or not it is safe to fly before they become airborne, as well as during flight, via en route briefings. The images are available free of charge on the Web site: http://avcams.faa.gov. Currently, there are 182 operational cameras, with a total of221 planned by mid-2014. In addition to improving and enhancing observing capabilities, the NWS is also taking steps to increase the accuracy of the forecasts that its meteorological models predict for Alaska. On May 1, 2012, the Rapid Refresh (RAP) forecast model was implemented by NOAA as the next-generation assimilation/modeling system. The RAP, as a high-resolution model, covers Alaska for the first time and it also replaces the Rapid Update Cycle model in the lower 48 states. The RAP has a high resolution, 13 kilometer grid structure, extends 18 hours into the future, and is updated hourly, providing a valuable forecasting tool for the AA WU forecasters. In summary, the FAA finds that the alternative approaches undertaken by the FAA and the NWS, such as the expansion of the MDCRS program; additional installations of AWOS, ASOS and weather cameras; and implementing the RAP, achieve the safety objectives sought by the Board and do so in a more cost-effective manner. I believe the FAA has effectively addressed Safety Recommendations A-11-50 and -51 and consider our actions complete.
The NTSB is aware that (1) the FAA has been performing and sponsoring research and development on relaying weather information collected from airborne aircraft equipped with existing data-link technology and (2) RTCA Special Committee (SC) 206 is currently working on the delivery of downlinked meteorological data over the Automatic Dependent Surveillance-Broadcast (ADS-B) link. The work the FAA is performing with RTCA to evaluate future downlink capabilities of the universal access transceiver (UAT) is valuable, and the FAA moves toward establishing the test program recommended in Safety Recommendation A-11-50; we encourage you to continue this work. However, we disagree that it would be premature for the FAA to take the recommended action before RTCA SC 206 has completed its work. The purpose of Safety Recommendation A-11-50 is to establish a test program in Alaska to demonstrate the viability and value of relaying airborne weather information collected from aircraft equipped with existing data-link technology (like the UAT). Although downlinked meteorological data are being collected and relayed to the ground from suitably equipped airliners through Aircraft Meteorological Data Relay (AMDAR), we do not believe that these actions constitute an acceptable substitute for that specified in Safety Recommendation A-11-50. The existing AMDAR program the FAA described collects data primarily from airliners. Alaska is heavily dependent on aviation for basic transportation and has a wide variety of airplanes that fly to more locations at a greater variety of altitudes (particularly lower altitudes) than airliners do; these airplanes can be equipped for collection of meteorological data and can potentially use the existing UAT technology for data relay. The NTSB believes that benefits would be realized from establishing a test program for this technology in Alaska, because UATs are in use by many aircraft in Alaska as a result of the Capstone Program. Further, we believe there will be an immediate safety benefit of the air-to-ground relay of meteorological information if such information is provided in real time to the National Weather Service’s Alaska Aviation Weather Unit (AAWU). Providing the AAWU with real-time data from aircraft (especially those operating at lower altitudes) equipped with existing data-link technology (like the UAT), as recommended in Safety Recommendation A-11-50, would enable the AAWU to better support the Alaskan aviation community. The NTSB believes that the institution of a special program in Alaska is justified and that, consequently, the FAA’s response to A-11-50 is not acceptable. Accordingly, pending the establishment of a collaborative test program in Alaska to establish the viability of relaying weather information collected from airborne aircraft equipped with existing data-link technology (like the UAT) and the relay of such information in real time to the AAWU, Safety Recommendation A-11-50 is classified OPEN—UNACCEPTABLE RESPONSE. We point out that completion of the action in Safety Recommendation A-11-51 is contingent upon the successful completion of Safety Recommendation A-11-50. The FAA has not indicated its opposition to a program to encourage operators in Alaska to outfit their data link–equipped aircraft with weather-sensing equipment for real-time data relay. Consequently, pending completion of the recommended action, Safety Recommendation A-11-51 is classified “Open—Acceptable Response.”
CC# 201100331: - From J. Randolph Babbitt, Administrator: The FAA began researching the issue of relaying weather information collected from airborne aircraft equipped with existing data link technology prior to the issuance of Safety Recommendation A-II-50. The FAA has requested RTCA, Inc. develop appropriate technical guidance for the uplink of Aeronautical Information Services (AIS) and Meteorological Information Services (MET) data, crosslink of MET data, and the downlink of AIS and MET data. An RTCA Special Committee (SC 206) is currently working on link-agnostic delivery of downlinked MET data as well as a link-specific implementation over the Automatic Dependent Surveillance-Broadcast (ADS-B) link. Weather information is currently being collected in the United States and globally using existing data link technology. These safety recommendations focus on using the universal access transceiver (UAT) as a data link to enable the downlink of MET parameters. The FAA and RTCA are conducting additional research on this method as well as use of the ADS-B link. Until the RTCA process is completed, it would seem premature to embark upon a specific implementation path. Currently, downlink MET information is being collected from suitably equipped airliners, using commercial data links, on a global basis. This downlink of MET information is termed Aircraft Meteorological Data Relay (AMDAR), and is coordinated globally by the World Meteorological Organization. The collection of MET data using either the ADS-B link or the UAT link would be a logical expansion of this ongoing implementation. I will keep the Board informed of the FAA's progress and provide an updated response to this recommendation by January 2012.
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