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Safety Recommendation Details

Safety Recommendation A-83-021
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: USE THE DATA OBTAINED FROM THE JOINT AIRPORT WEATHER STUDIES (JAWS) PROJECT AND OTHER RELEVANT DATA AS A BASIS TO (1) QUANTIFY THE LOW-LEVEL WIND SHEAR HAZARD IN TERMS OF EFFECT ON AIRPLANE PERFORMANCE, (2) EVALUATE THE EFFECTIVENESS OF THE LOW LEVEL WIND SHEAR ALERT SYSTEM AND IMPROVEMENTS WHICH ARE NEEDED TO ENHANCE PERFORMANCE AS A WIND SHEAR DETECTION AND WARNING SYSTEM, AND (3) EVALUATE THE AERODYNAMIC PENALTIES OF PRECIPITATION ON AIRPLANE PERFORMANCE.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable 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: 6/18/1990
Addressee(s) and Addressee Status: FAA (Closed - Acceptable Action)
Keyword(s): Low Level Windshear, Weather, Wind

Safety Recommendation History
From: NTSB
To: FAA
Date: 6/18/1990
Response: (PER GREEN SHEET A-90-83 THRU -85) The Safety Board is reclassifying this recommendation based on the rationale cited for closing Safety Recommendations A-83- 19 and -20 and the FAA's coordinated program with the National Aeronautics and Space Administration (NASA) to evaluate the aerodynamic effects of heavy precipitation on airplane wing lift and drag characteristics. The Safety Board believes that the tangible results from this program will be incorporated into the Windshear Training Aid to provide a higher safety margin to aircraft encountering microburst windshear. (Recommendation A-83-21, issued March 25, 1983, is reclassified as "Closed-- Acceptable Action.")

From: FAA
To: NTSB
Date: 12/12/1988
Response: The National Aeronautics and Space Administration (NASA), in conjunction with the FAA, has completed the quantification of low-level windshear hazards in terms of the effect on airplane performance. The results have been made available to all of the manufacturers through the process of public meetings and technical reports. The FAA has sponsored extensive research to evaluate and improve low level windshear alert system (LLWAS) performance. The FAA is evaluating expanded systems at Denver and New Orleans, and plans are being developed to implement expanded systems at all LLWAS locations. Additionally, NASA has completed wet wind tunnel tests on the effect of heavy rain on aircraft performance. As a result of these tests, NASA and the FAA are conducting large-scale tests at the Langley Research Center using the Aircraft Landing Dynamics Facility. The first launch of the heavy rain experiment was August 1988. Experiments will continue through the summer of 1989, at which time reports will be made regarding the results. I believe that the FAA has met the intent of this safety recommendation, and I consider the FAA's action to be completed.

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 classified 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 Data Source: NTSB Recommendations to FAA and FAA Responses 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 avoidance, and in the dissemination of information on windshear.

From: NTSB
To: FAA
Date: 8/21/1986
Response: The Safety Board is encouraged by the FAA's efforts to perform the research necessary to address the issues raised in this recommendation. The Safety Board believes that the research actions proposed in your letter will have a significant effect in reducing the hazard of windshear encounters. The Safety Board would appreciate being periodically informed as to the status of the FAA's research activities. Pending completion of actions proposed, Safety Recommendation A-83-21 has been classified as "Open--Acceptable Action."

From: FAA
To: NTSB
Date: 7/10/1986
Response: THE FAA, IN ITS CONTINUING EFFORT TO UNDERSTAND THE HAZARDS POSED BY WIND SHEAR ON AIRCRAFT, IS WORKING IN ALL OF THE AREAS REGARDING THIS RECOMMENDATION. THE FAA HAS JOINED WITH NASA TO APPLY ITS UNIQUE CAPABILITIES TO SUPPORT THIS ISSUE. ANALYSES ARE BEING MADE USING WIND FIELD DATA FROM THE JAWS PROGRAM, AS WELL AS WIND FIELD DATA EXTRACTED FROM MESO-SCALE MATHEMATICAL MODELS OF THE ATMOSPHERE. ACTION IS UNDER WAY TO UPGRADE THE LLWAS PERFORMANCE IN AN INCREMENTAL FASHION, INCLUDING IMPROVEMENTS TO THE SIX SENSOR LLWAS WHICH WILL BE TESTED IN MID TO LATE 1986. JAWS DATA WILL BE USED TO DEVELOP AND REDEFINE LLWAS ALGORITHMS TO BE EMPLOYED IN THE ENHANCED LLWAS TO BE IMPLEMENTED IN FY-89. IN ORDER TO RESOLVE THE AERODYNAMIC PERFORMANCE PENALTY DUE TO HEAVY RAIN, THE FAA AND NASA WILL BE JOINTLY SUPPORTING FULLSCALE TESTS USING NASA'S AIRCRAFT LANDING DYNAMICS FACILITY.

From: NTSB
To: FAA
Date: 5/29/1984
Response: The studies presently being performed by the National Academy of Science and the National Aeronautics and Space Administration (NASA) in addition to the test of the LLWAS at the New Orleans International Airport are responsive to this recommendation. Pending review of the results of the National Academy of Science, the NASA study, and the LLWAS test at New Orleans, Safety Recommendation A-83-21 will be maintained in an "Open--Acceptable Action" status.

From: FAA
To: NTSB
Date: 7/21/1983
Response: FAA LETTER: THE EFFECT OF LOW LEVEL WIND SHEAR ON AIRCRAFT PERFORMANCE IS A SUBJECT OF THE NATIONAL ACADEMY OF SCIENCE STUDY ADDRESSED IN RESPONSE TO RECOMMENDATION A-83-20. THE PURPOSE OF THE STUDY IS TO REVIEW THE STATE OF KNOWLEDGE OF LOW LEVEL WIND SHEAR AND VARIABILITY THAT IS POTENTIALLY HAZARDOUS TO AVIATION IN THE TERMINAL AREA, INCLUDING DETECTION AND MEASUREMENT OF WIND HAZARDS, COMMUNICATION OF INFORMATION, WARNINGS TO PILOTS AND AIR TRAFFIC CONTROL PERSONNEL, PILOTING PROCEDURES AND TRAINING NEEDS, AND IMPLICATIONS FOR AIRCRAFT DESIGN, CONSTRUCTION, AND OPERATION. THE FINAL REPORT OF THIS STUDY IS SCHEDULED TO BE AVAILABLE IN SEPTEMBER 1983. THE RECOMMENDATIONS OF THE NATIONAL ACADEMY OF SCIENCE WILL BE USED TO EVALUATE OUR CURRENT PROGRAMS AND FURTHER RESPOND TO THE BOARD'S RECOM MENDATIONS. THE JOINT AIRPORT WEATHER STUDIES DATA ARE BEING USED TO ASSIST IN SITING THE ADDITIONAL LLWSAS SENSORS AT NEW ORLEANS INTERNATIONAL AIRPORT. THIS SITE THEN WILL ALSO BE USED TO EVALUATE RECOMMENDED IMPROVEMENTS TO THIS AND OTHER LLWSAS SITES. WITH REGARD TO THAT PORTION OF THE RECOMMENDATION CONCERNING AERODYNAMIC PENALTIES OF PRECIP ITATION ON AIRPLANE PERFORMANCE, THE NATIONAL AERONAUTICS AND AND SPACE ADMINISTRATION IS CURRENTLY PERFORMING A STUDY ON THIS SUBJECT.