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Safety Recommendation Details

Safety Recommendation A-86-081
Details
Synopsis: ON AUGUST 2, 1985, AT 1805:52 CENTRAL DAYLIGHT TIME, DELTA AIR LINES (DELTA) FLIGHT 191, A LOCKHEED L-1011-385-1, N726DA, CRASHED WHILE APPROACHING TO LAND ON RUNWAY 17L AT THE DALLAS/FORT WORTH INTERNATIONAL (DFW) AIRPORT, TEXAS. WHILE PASSING THROUGH THE RAIN SHAFT BENEATH A THUNDERSTORM, FLIGHT 191 ENTERED A MICROBURST WHICH THE PILOT WAS UNABLE TO TRAVERSE SUCCESSFULLY. THE AIRPLANE STRUCK THE GROUND ABOUT 6,300 FEET NORTH OF THE APPROACH END OF RUNWAY 17L, HIT A CAR ON A HIGHWAY NORTH OF THE RUNWAY KILLING THE DRIVER, STRUCK TWO WATER TANKS ON THE AIRPORT, AND BROKE APART. EXCEPT FOR A SECTION OF THE AIRPLANE CONTAINING THE AFT FUSELAGE AND EMPENNAGE, THE REMAINDER OF THE AIRPLANE DISINTEGRATED DURING THE IMPACT SEQUENCE, AND A SEVERE FIRE ERUPTED DURING THE IMPACT SEQUENCE. OF THE 163 PERSONS ABOARD, 134 PASSENGERS AND CREWMEMBERS WERE KILLED; 26 PASSENGERS AND 3 CABIN ATTENDANTS SURVIVED.
Recommendation: THE NTSB RECOMMENDS THAT THE NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION: DEVELOP DEFINITIVE AVIATION WEATHER WARNING CRITERIA BASED ON RADAR WEATHER ECHO INTENSITIES AND THE PROXIMITIES OF RADAR WEATHER ECHOS TO AIRPORT APPROACH AND DEPARTURE CORRIDORS, AND IMPLEMENT A MEANS TO COMMUNICATE THIS INFORMATION IMMEDIATELY TO FEDERAL AVIATION ADMINISTRATION TERMINAL RADAR APPROACH CONTROL AND TOWER FACILITIES.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Unacceptable Action
Mode: Aviation
Location: DALLAS/FT WORTH, TX, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: DCA85AA031
Accident Reports: Delta Air Lines, Inc., Lockheed L-1011-385-1, N726DA
Report #: AAR-86-05
Accident Date: 8/2/1985
Issue Date: 9/3/1986
Date Closed: 4/15/1998
Addressee(s) and Addressee Status: United States Department of Commerce, National Oceanic and Atmospheric Administration (Closed - Unacceptable Action)
Keyword(s): Weather, Weather Equipment/Products/Reports

Safety Recommendation History
From: NTSB
To: United States Department of Commerce, National Oceanic and Atmospheric Administration
Date: 4/15/1998
Response: The NWS has stated that in the 9 years since its last response to this safety recommendation, advanced technology has significantly improved the weather data acquisition and dissemination capabilities at all NWS offices. Unlike former NWS weather radars, current WSR-88D Doppler weather radars can provide detailed and accurate information on convective weather echoes, including a measure of the windshear associated with the echo. The limitations of the former NWS weather radars, in recording the intensity and location of convective weather echoes, were concerns expressed in a June 1, 1987, NWS letter. However, even with the new and improved technology, the NWS does not have detailed aviation weather warning criteria based on the intensity and location of convective weather echo activity. Because the NWS plans no further action on this recommendation, Safety Recommendation A-86-81 is classified "Closed--Unacceptable Action."

From: United States Department of Commerce, National Oceanic and Atmospheric Administration
To: NTSB
Date: 11/17/1997
Response: The NWS fully addressed this recommendation in its previous responses of June 1, 1987 and July 22, 1988. In the 9 years since the last response, advanced technology has significantly improved the weather data acquisition and dissemination capabilities at all NWS offices, including Center Weather Service Units (CWSU). The implementation of the Doppler weather surveillance radar (WSR-88D) system, in particular, has enhanced the ability of the NWS meteorologist to detect and interrogate thunderstorm echoes. Additionally, the Federal Aviation Administration (FAA) has expended considerable resources to improve and upgrade the weather detection and dissemination capabilities within the air traffic control network. Some of this activity is detailed below. -- Weather and Radar Processor (WARP) System: the deployment of the first-generation WARP system, now installed in CASUS, allows air traffic controllers to receive forecasts and other weather information much more rapidly. The WARP system includes the capability to loop radar mosaics, lightning data, and satellite pictures. The information is entered by the CWSU meteorologist and sent from the main WARP processor to each of the briefing terminals. Each of the briefing terminals contain high-speed processing and storage capability. In future updates to WARP, controllers will have direct displays of radar mosaics and other information on their Display System Replacement scopes. Information will get to the controllers at the same time the meteorologist receives it. -- Integrated Terminal Weather System (ITWS): detailed information concerning weather in the terminal environment will be available with the installation of ITWS. It is our understanding that terminals will be provided to the CWSU, air traffice management, and the TRACON. ITWS permits the detection and tracking of small-scale weather phenomena such as low-level winds shear and, in turn, allows air traffic control to issue the appropriate alerts to aircraft. -- SIGMET/NOTAM Patch ("Minneapolis Patch"): the patch automatically routes weather messages to appropriate FAA facilities. A National Change Proposal currently being managed and tested by the FAA will increase the file size of the patch. A coinciding increase in the speed at which messages are transmitted will enable FAA facilities to react more quickly to disseminated weather information. The enhanced patch is expected to be implemented early in 1998. --- Terminal Doppler Weather Radar (TDWR): the automated Doppler radar-based system is being implemented at the Nation's busiest airports. The TDWR is designed to detect weather hazards in the airport terminal area and enable air traffic controllers to assist pilots in avoiding these hazards when landing or departing. The TDWR detects small-scale weather features such as microbursts, gust fronts, and wake vortices. The NWS appreciates and shares the concerns of the Board in this matter. We are convinced that the purpose of this Safety Recommendation can best be met with the effective utilization of the latest technology now in place or scheduled to be implemented, together with the continued reliance on the experience and prudent judgment of operational NWS personnel.

From: United States Department of Commerce, National Oceanic and Atmospheric Administration
To: NTSB
Date: 7/31/1997
Response:

From: NTSB
To: United States Department of Commerce, National Oceanic and Atmospheric Administration
Date: 6/2/1997
Response: OUR RECORDS INDICATE THAT ALTHOUGH THE BOARD INITIALLY RECEIVED A REPONSE FROM YOUR AGENCY CONCERNING THESE RECOMMENDATIONS, WE HAVE NOT SINCE RECEIVED ACKNOWLEDGMENT THAT THESE RECOMMENDATIONS HAS BEEN IMPLEMENTED. IF WE DO NOT RECEIVE A RESPONSE FROM YOU WITHIN 45 DAYS, THIS RECOMMENDATION WILL BE CLASSIFIED "CLOSED--UNACCEPTABLE ACTION."

From: NTSB
To: United States Department of Commerce, National Oceanic and Atmospheric Administration
Date: 1/19/1990
Response:

From: United States Department of Commerce, National Oceanic and Atmospheric Administration
To: NTSB
Date: 7/22/1988
Response: A RECENT SURVEY OF OUR CWSU OFFICES CONFIRMS THAT THE INFORMATION RELATED TO RADAR WEATHER ECHO INTENSITIES, AND THE PROXIMITY OF THOSE ECHOES TO MAJOR AIRPORT APPROACH DEPARTURE CORRIDORS, IS CURRENTLY USED BY OUR METEOROLOGISTS IN THEIR THOUGHT PROCESS AS TO THE NEED FOR THE ISSUANCE OF A CENTER WEATHER ADVISOROY.

From: NTSB
To: United States Department of Commerce, National Oceanic and Atmospheric Administration
Date: 10/19/1987
Response:

From: United States Department of Commerce, National Oceanic and Atmospheric Administration
To: NTSB
Date: 6/1/1987
Response: CONCERNING THE PORTION OF THE RECOMMENDATION TO DEVELOP DEFINITIVE AVIATION WEATHER WARNING CRITERIA, I BELIEVE THAT THE PRESENT WARNING PROGRAM UTILIZED BY THE NWS, IS THE BEST AVAILABLE WITHIN THE STATE OF THE ART OF WEATHER FORECASTING AND WITHIN THE LIMITATIONS OF CURRENT COMMUNICATIONS AND DETECTION EQUIPMENT TECHNOLOGY. ...THE DEVELOPMENT OR DEFINITIVE CRITERIA BASED SOLELY ON RADAR WEATHER ECHO INTENSITIES WOULD REPRESENT A COLLECTION OF MANDATORY ECHO INTENSITIES WOULD REPRESENT A COLLECTION OF MANDATORY REGULATIONS HAVING QUESTIONABLE METEOROLOGICAL BASIS AND BE CONTRARY TO PROVEN OPERATIONAL PRINCIPLES. IT WOULD RESULT IN CONSIDERABLE MISINFORMATION AND/OR OVERWARNING, AND THUS, SEVERELY IMPAIR THE OVERALL EFFECTIVENESS AND CREDIBILITY OF OUR WARNINGS AND ADVISORIES. ...I BELIEVE THAT THE PRESENT NWS OPERATIONAL GUIDELINES AS EXPRESSED IN WSOM CHAPTERS C-66, D-20, D-22, D-25, AND D-26, AND RELATED REGIONAL AND LOCAL INSTRUCTIONS, SATISFY THE INTENT OF THIS RECOMMENDATION.