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Safety Recommendation Details

Safety Recommendation A-83-018
Details
Synopsis: ON JULY 9, 1982, PAN AMERICAN WORLD AIRWAYS FLIGHT 759 CRASHED AFTER TAKING OFF FROM RUNWAY 10 AT NEW ORLEANS INTERNATIONAL AIRPORT, KENNER, LOUISIANA. WHEN FLIGHT 759 TOOK OFF, THERE WERE ISOLATED HEAVY SHOWERS OVER THE AIRPORT AND TO THE EAST OF THE AIRPORT ALONG THE AIRPLANE'S INTENDED DEPARTURE PATH. LOW LEVEL WIND SHEAR CONDITIONS HAD BEEN DETECTED BY THE AIRPORT'S LOW LEVEL WIND SHEAR ALERT SYSTEM (LLWSAS), AND THE SYSTEM HAD ALARMED SEVERAL TIMES, THE LAST TIME ABOUT 4 MINUTES BEFORE FLIGHT 759'S TAKEOFF. THE SYSTEM WAS NOT ALARMING AT THE TIME THE TAKEOFF CLEARANCE WAS ISSUED; HOWEVER, A WIND SHEAR ADVISORY WAS BROADCAST 2 SECONDS AFTER THE ACCIDENT.
Recommendation: THE NTSB RECOMMENDS THAT THE FEDERAL AVIATION ADMINISTRATION: EVALUATE METHODS AND PROCEDURES FOR THE USE OF CURRENT WEATHER INFORMATION FROM SOURCES SUCH AS RADAR, LOW LEVEL WIND SHEAR ALERT SYSTEMS, AND PILOT REPORTS AS CRITERIA FOR DELAYING APPROACH AND DEPARTURE OPERATIONS WHICH WOULD EXPOSE THE FLIGHT TO LOW ALTITUDE PENETRATION OF SEVERE CONVECTIVE WEATHER.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Alternate Action
Mode: Aviation
Location: Kenner, LA, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: DCA82AA028
Accident Reports: Pan American World Airways, Inc., Clipper 759, Boeing 727-235, N4737
Report #: AAR-83-02
Accident Date: 7/9/1982
Issue Date: 3/25/1983
Date Closed: 1/23/1996
Addressee(s) and Addressee Status: FAA (Closed - Acceptable Alternate Action)
Keyword(s): Weather, Air Traffic Control, Thunderstorms/Rain/Snow

Safety Recommendation History
From: NTSB
To: FAA
Date: 1/23/1996
Response: THE BOARD IS AWARE THAT THOSE TESTS HAVE BEEN COMPLETED WITH POSITIVE BENEFITS, ALTHOUGH THE FAA'S VIEWS APPARENTLY REMAIN UNCHANGED THAT THE PILOT SHOULD HAVE THE ULTIMATE AUTHORITY FOR APPROACH & DEPARTURE OPERATIONAL DECISIONS, WHILE BELIEVING THAT THE FAA SHOULD CONTINUE TO REVIEW THE CONTROLLER'S ROLE IN THE OPERATIONAL DECISION PROCESS, THE BOARD ACKNOWLEDGES THE FAA'S EFFORTS TO IMPROVE THE QUANTITY & QUALITY OF WEATHER INFO PROVIDED TO PILOTS TO HELP THEM AVOID UNINTENTIONAL ENCOUNTERS WITH HAZARDOUS CONDITIONS. TWO OF THE SIGNIFICANT ADVANCEMENTS WILL BE THE INSTALLATION OF AIRBORNE WINDSHEAR DETECTION EQUIPMENT RECENTLY OR CURRENTLY BEING CERTIFIED FOR AIR CARRIER AIRPLANES, & THE FUTURE DEPLOYMENT OF THE INTEGRATED TERMINAL WEATHER SYSTEM AT AIRPORT TRAFFIC CONTROL TOWERS. BASED ON THESE PROGRAMS, THE BOARD CLASSIFIED A-83-18 "CLOSED--ACCEPTABLE ALTERNATE ACTION."

From: FAA
To: NTSB
Date: 9/10/1990
Response: THE FAA IS CONTINUING ITS OPERATIONAL TESTING & EVALUATION OF THE ASR-9 & THE TERMINAL DOPPLER WEATHER RADAR CAPABILITIES & PROCEDURES AT ORLAND, FLORIDA AS AN EFFORT TO COMPLY WITH THE RECOMMENDATION. IN 1991, THE ORLANDO TESTS WERE EXPANDED TO INCORPORATE AN LOW LEVEL WIND SHEAR ALERTING SYSTEM (ELLWAS), RESULTING IN EVALUATION OF THE ASR-9, TDWR, & ELLWAS.

From: NTSB
To: FAA
Date: 6/18/1990
Response: (PER GREEN SHEET A-90-83 THRU -85) The Safety Board acknowledges the actions described in the FAA's May 26, 1988, response to this recommendation and generally concurs with the position that the weather data provided to tower controllers from existing systems may not be adequate for controller decisions regarding the continuation or delay of airport operations. The Safety Board believes, however, that ASR-9, TDWR, and Phase 3 LLWAS should provide sufficient information to derive definitive criteria for ceasing runway operations. Many representatives of the steering group, which included FAA personnel, who analyzed the occurrence of a microburst at Stapleton Airport on July 11, 1988, during the TDWR/LLWAS demonstration program have expressed such views. The Safety Board believes that Data Source: NTSB Recommendations to FAA and FAA Responses further study is required by the FAA. Further, the Safety Board would welcome a more comprehensive briefing on the controller procedures and responsibilities associated with use of the ASR-9 weather channels. (Recommendation A-83-18, issued March 25, 1983, is classified as "Open--Acceptable Action.")

From: FAA
To: NTSB
Date: 5/26/1988
Response: The FAA has taken various actions to address this safety recommendation. The FAA discussed the merits of this safety recommendation with the National Academy of Sciences Panel on Low Altitude Wind Shear and Its Hazards to Aviation. The FAA discussed the use of the National Weather Service (NWS) weather radars, including the concept of providing a special display in towers which would be updated by a dedicated meteorologist. The FAA also enhanced and tested the Low Level Wind Shear Alert System (LLWAS), and it is continuing evaluations of the terminal Doppler weather radar (TDWR). The FAA concluded that the current NWS weather radars and the basic LLWAS do not provide sufficient information to support reasonably reliable criteria for delaying approach or departure operations in order to avoid low altitude wind shear encounters. The enhanced LLWAS currently in operation at Denver provides better information in a form more usable by pilots, but the FAA does not yet have sufficient data to determine if it can be used for more than an advisory system. The FAA is continuing with development of the ground-based Doppler radar and now has data from three airports--Memphis, Huntsville, and Denver. This system provides reliable information concerning winds in the approach and departure paths of airports. The information is in the form of an expected gain or loss in airspeed which provides data to assist the crew in making a go/no-go decision. There is also an ongoing effort to relate the information provided by the ground-based systems, LLWAS, and Doppler weather radar to aircraft performance factors in an effort to establish more positive go/no-go criteria. This effort is being accomplished with oversight by a steering group consisting of representatives of the NTSB technical staff, National Aeronautics and Space Administration (NASA), FAA, National Center for Atmospheric Research (NCAR), Lincoln Lab, pilot user groups, aircraft operators, and the aircraft industry. The 1988 TDWR operational demonstration at Denver will provide air carrier and general aviation operating experience with the ground-based Doppler radar and will lead to additional refinements in its use. It appears that the cockpit remains the logical location for go/no-go decisions concerning wind shear, and this joint effort will result in the establishment of criteria which will allow pilots to make sound decisions concerning operations into areas of potential wind shear hazards. I believe that these actions are fully responsive to this safety recommendation as issued to the FAA. I do not agree with the Safety Board that this safety recommendation should be classified as "open" pending the completion of all ongoing efforts associated with wind shear. I believe that the FAA has met the intent of this safety recommendation, and I urge the Safety Board to classify this safety recommendation as "closed."

From: NTSB
To: FAA
Date: 9/16/1986
Response: In the course of the Safety Board's investigation of an accident involving Delta Air Lines flight 191 at Dallas/Fort Worth International Airport, Texas, on August 2, 1985, the Safety Board has performed a detailed review of all Safety Recommendations, currently clssified as open, issued to the FAA on the subject of windshear. Also addressed in this review were three Safety Recommendations that discussed the timely detection of severe weather, though not specifically related to windshear or microbursts. The Safety Board's review included past FAA responses, evaluation of the FAA's letters of September 24, 1985, and May 5, 1986, and our analysis of the FAA's Integrated Wind Shear Program Plan. A more descriptive review of the FAA's responses to these Safety Recommendations and of the program plan is contained in appendix H of the Safety Board's report of the Delta flight 191 accident. The open Safety Recommendations reviewed by the Safety Board are as follows: A-74-13 A-76-34 A-77-63 A-80-118 A-83-15 A-83-18 A-83-19 A-83-20 A-83-21 A-83-22 A-83-23 A-83-24 A-83-25 A-85-26 A-85-27 The Safety Board has carefully reviewed the Integrated Wind Shear Program Plan and the two letters from the FAA mentioned above and finds that the actions concurrently being taken and planned by the FAA will comply with the intent of all of the above Safety Recommendations when implemented. Therefore, all of the above-listed Safety Recommendations have been classified as "Open--Acceptable Action" pending completion of the FAA's planned actions. The Safety Board appreciates the FAA's actions to improve windshear detection and Data Source: NTSB Recommendations to FAA and FAA Responses avoidance, and in the dissemination of information on windshear.

From: NTSB
To: FAA
Date: 10/1/1985
Response: The Safety Board believes that pilots and controllers should be provided with the most up-to-the-minute information on severe convective weather in the terminal area in order for them to determine if additional measures should be taken to ensure flight safety. We note that the FAA is planning to investigate the feasibility of providing existing National Weather Service radar weather information to control tower cabs, and that research is continuing for improved use of the ground-based Doppler radar as a means of identifying windshear in operational settings. The Safety Board looks forward to receiving your progress reports concerning this recommendation which is classified as "Open--Acceptable Action."

From: FAA
To: NTSB
Date: 4/2/1985
Response: FAA LTR: THE FAA HAS CONSIDERED THIS RECOMMENDATION AND DISCUSSED ITS MERIT WITH THE NATIONAL ACADEMY OF SCIENCES' PANEL ON LOW ALTITUDE WIND SHEAR AND ITS HAZARD TO AVIATION. THE NATIONAL ACADEMY OF SCIENCES' ONLY RECOMMENDATION IN THIS AREA WAS THAT INFORMATION FROM EXISTING WEATHER RADARS SHOULD BE MADE AVAILABLE TO TRAFFIC CONTROLLERS IN A TIMELY AND EASILY UNDERSTOOD MANNER. WE ARE PLANNING TO INVESTIGATE THE FEASIBILITY OF PROVIDING EXISTING NATIONAL WEATHER SERVICE RADAR WEATHER INFORMATION TO CONTROL TOWER CABS SO THAT PILOTS MAY BE PROVIDED THE LATEST SEVERE WEATHER INFORMATION PRIOR TO DEPARTURE OR LANDING. IF THIS PROVES TO BE A FEASIBLE PROGRAM, WE WOULD IMPLEMENT IT, BUT ONLY TO PROVIDE ADDITIONAL INFORMATION TO PILOTS. THE AVAILABLE SENSORS ALONE OR TOGETHER DO NOT PROVIDE SUFFICIENT INFORMATION ABOUT THE WIND SHEAR PHENOMENON TO ENABLE US TO ESTABLISH OPERATIONAL CRITERIA CONCERNING IT. THE ONLY EQUIPMENT HAVING THE POTENTIAL TO PROVIDE SUFFICIENT INFORMATION IS THE DOPPLER RADAR. THE FAA IS CURRENTLY INVESTIGATING THE USE OF GROUND-BASED DOPPLER RADAR AS A MEANS OF IDENTIFYING WIND SHEAR IN OPERATIONAL PROGRAM. WE UTILIZE A NATIONAL SCIENCE FOUNDATION RESEARCH DOPLER RADAR AT THE DENVER STAPLETON AIRPORT, DENVER COLORADO, DURING THE MOST RECENT WIND SHEAR SEASON (JULY-AUGUST) WITH PROMISING RESULTS. WE ALSO HAVE DEPLOYED A TERMINAL VERSION OF A DOPPLER RADAR TO ESTABLISH OPERATING PARAMETERS AND SITING CRITERIA FOR SUCH RADAR. THIS RADAR PRESENTLY IS OPERATING IN THE MEMPHIS AIRPORT AREA, MEMPHIS, TENNESSEE. AS WE DEVELOP OPERATING STRATEGIES AND GAIN MORE DATA ON THE PERFORMANCE OF SUCH RADARS IN THE OPERTIONAL ENVIRONMENT, WE WILL BE IN A BETTER POSITION TO DETERMINE IF A GO/NO-GO DECISION CAN BE MADE ON USING THIS EQUIPMENT MORE WIDELY.

From: NTSB
To: FAA
Date: 5/29/1984
Response: Your response to Safety Recommendation A-83-18 describes the present information available to a pilot concerning severe weather, and we do not disagree that there is an abundance of information available. The Safety Board believes, however, that there is a need to evaluate methods and procedures for the use of available weather information as criteria for making go/no-go decisions in severe weather conditions. We have classified this recommendation as "Open--Unacceptable Action" pending your response to these comments.

From: FAA
To: NTSB
Date: 7/21/1983
Response: FAA LETTER: AS NOTED IN OUR RESPONSE TO RECOMMENDATION A-83-26, THE FAA HAS NUMEROUS DOCUMENTS WHICH PROVIDE A PILOT WITH INFORMATION REGARDING WEATHER ANALYSIS AND AVOIDANCE CRITERIA WHICH SHOULD ENABLE THE PILOT TO DETERMINE IF A DELAYED APPROACH OR DEPARTURE IS WARRANTED. THOSE DOCUMENTS INCLUDE ADVISORY CIRCULARS, AIR CARRIER OPERATIONS BULLETINS, THE AIRMAN'S INFORMATION MANUAL, AND AIR CARRIER TRAINING PROGRAMS. THE FAA BELIEVES THE METHODS AND PROCEDURES CURRENTLY AVAILABLE TO AIR CARRIER PILOTS USABLE FOR EVALUATION OF CONVECTIVE WEATHER PATTERNS ARE ADEQUATE IF UTILIZED WITH CONSERVATIVE DISCRETION COMMENSURATE WITH AVAILABLE TECHNOLOGY; I.E., AIRBORNE RADAR, LLWSAS.