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Safety Recommendation Details

Safety Recommendation A-86-075
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 FEDERAL AVIATION ADMINISTRATION: CONDUCT, DURING THE CURRENT CONVECTIVE SEASON, AN OPERATIONAL TEST OF CURRENTLY AVAILABLE WEATHER RADAR SYSTEMS AT SELECTED AIRPORTS AND, BASED ON THE RESULTS OF THE EVALUATION, CONSIDER DEPLOYMENT OF A SYSTEM OR SYSTEMS TO SUPPLEMENT DATA DERIVED FROM THE LOW LEVEL WIND SHEAR ALERT SYSTEM AS AN INTERIM MEASURE UNTIL DEPLOYMENT OF ADVANCED DOPPLER RADAR IN TERMINAL AREAS.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable 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: 1/13/1988
Addressee(s) and Addressee Status: FAA (Closed - Acceptable Action)
Keyword(s): Low Level Windshear, RADAR, Weather, Weather Equipment/Products/Reports, Wind

Safety Recommendation History
From: NTSB
To: FAA
Date: 1/13/1988
Response: The intent of this safety recommendation was to have the FAA take a critical look at currently available weather radar systems and consider using these systems as an interim measure to the ASR-9 as well as the advanced terminal Doppler radar. Since the operative word in this recommendation is "consider" such deployment, we must, in keeping with the intent, classify A-86-75 as "Closed--Acceptable Action." The Safety Board is disappointed, however, that the evaluation performed by the FAA was not successful in identifying some application of current technology to provide an interim coverage for the detection of low level wind shear. We strongly encourage you to act as expeditiously as possible to complete the three phase program outlined in your October 19 response.

From: FAA
To: NTSB
Date: 10/19/1987
Response: THE FAA POINTS OUT THAT THE KEY REQUIREMENTS OF WEATHER RADAR INFORMATION IN THE AIR TRAFFIC ENVIRONMENT ARE (1) THAT THE RADAR SYSTEM AUTOMATICALLY INTERPRETS THE WEATHER SITUATION AND GENERATES PRODUCTS THAT CAN BE USED BY CONTROLLERS, AND (2) THAT THE INFORMATION APPEARS ON THE CONTROLLERS' DISPLAYS IN THE PROPER RELATION TO THE AIR TRAFFIC. AVAILABLE WEATHER RADARS DO NOT MEET EITHER OF THESE REQUIREMENTS AND CANNOT BE MADE TO DO SO WITHOUT A LENGTHY DEVELOPMENT ACTIVITY SIMILAR TO THAT WHICH THE FAA IS CURRENTLY COMPLETING. THE USE OF AVAILABLE WEATHER PRODUCTS WOULD REQUIRE THAT SEPARATE WEATHER DISPLAYS BE LOCATED IN THE TERMINAL RADAR APPROACH CONTROL FACILITIES AND TOWERS. IN ADDITION, METEOROLOGISTS WOULD BE NEEDED TO INTERPRET THE WEATHER INFORMATION AND PASS IT ALONG TO CONTROLLERS. THIS CONFIGURATION OF EQUIPMENT AND METHOD OF INTERPRETING AND USING THE INFORMATION IS NOT COMPATIBLE WITH THE FAST PACE OF ACTIVITY AND QUICK RESPONSE TIMES REQUIRED IN THE TERMINAL ENVIRONMENT. FINALLY THE TRACON'S AND ESPECIALLY THE TOWERS, ARE ALREADY CROWDED WITH PERSONNEL AND EQUIPMENT. THE RESPONSE GOES ON TO DESCRIBE THE FAA 3-PHASE PROGRAM FOR PROVIDING WEATHER RADAR INFORMATION FOR TERMINAL AREAS.

From: NTSB
To: FAA
Date: 7/1/1987
Response: We are pleased that the FAA is incorporating a weather display capability in their newest airport surveillance radar (ASR-9). However, installation which is to begin in late 1987 will not be completed until 1991. Because of this we believe that currently available weather radar systems must be considered as an interim measure to the ASR-9 as well as the advanced terminal Doppler radar. We therefore request that the FAA reconsider its position on the use of currently available radar information. Pending your further response, this recommendation is classified as "Open--Unacceptable Action."

From: FAA
To: NTSB
Date: 5/22/1987
Response: WEATHER RADAR SYSTEMS CURRENTLY AVAILABLE TO THE FAA PROVIDE A CAPABILITY OF DISPLAYING SIX LEVELS OF PRECIPITATION INTENSITY. THIS SAME CAPABILITY IS BEING INCORPORATED INTO THE DEDICATED WEATHER CHANNEL OF THE FAA'S NEWEST AIRPORT SURVEILLANCE RADAR (ASR-9). THE ASR-9 WILL ENABLE AIR TRAFFIC CONTROLLERS TO SELECT ANY TWO OF THE SIX STANDARD PRECIPITATION LEVELS TO APPEAR AS BACKGROUND INFORMATION IN THEIR TRAFFIC DISPLAYS. THE ASR-9 WILL PROVIDE THE SAME REFLECTIVITY INFORMATION AVAILABLE WITH EXISTING WEATHER RADARS, AND WILL HAVE THE ADVANTAGE OF DIRECT READOUT ON THE CONTROLLERS' DISPLAYS. OPERATIONAL TESTING IS PLANNED IN CONJUNCTION WITH THE FIRST ASR-9 TO BE DEPLOYED AT HUNTSVILLE, ALABAMA. NINETY-EIGHT ASR-9 SYSTEMS WILL BE INSTALLED AT MAJOR AIRPORTS TO PROVIDE IMPROVED RADAR SERVICES, INCLUDING WEATHER, TO OVER 86 PERCENT OF THE ENPLANED PASSENGERS IN THE UNITED STATES. INSTALLATION OF THESE RADARS WILL BEGIN IN LATE-1987 AND WILL BE COMPLETED BY 1991. SINCE THE FAA HAS A WELL-DEFINED, APPROVED PROGRAM ENTERING INPLEMENTATION, I CONSIDER THE FAA'S ACTION TO BE COMPLETED ON THIS RECOMMENDATION.

From: NTSB
To: FAA
Date: 3/20/1987
Response: Pending completion of the FAA's review, Safety Recommendation A-86-75 has been classified as "Open--Acceptable Action."

From: FAA
To: NTSB
Date: 12/16/1986
Response: THE FAA IS IN THE PROCESS OF REVIEWING THIS RECOMMENDATION. I WILL ADVISE THE BOARD OF THE FAA'S ACTIONS AS SOON AS THE REVIEW IS COMPLETED.