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Safety Recommendation Details

Safety Recommendation A-83-015
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: RECORD OUTPUT DATA FROM ALL INSTALLED LOW LEVEL WIND SHEAR ALERT SYSTEM SENSORS AND RETAIN SUCH DATA FOR AN APPROPRIATE PERIOD FOR USE IN RECONSTRUCTING PERTINENT WIND SHEAR EVENTS AND AS A BASIS FOR STUDIES TO EFFECT SYSTEM IMPROVEMENTS.
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: 12/11/1991
Addressee(s) and Addressee Status: FAA (Closed - Acceptable Action)
Keyword(s): Low Level Windshear, Records, Weather, Wind

Safety Recommendation History
From: NTSB
To: FAA
Date: 12/11/1991
Response: The Safety Board notes that the FAA contracted with Climatronics Corporation to install LLWAS Six Sensor Improvements, which incorporate data and alarm archiving, at another 51 airports. The last installation in Lexington, Kentucky, marks the 110th LLWAS in the country and completes the installation program. Based on the above information, the Safety Board classifies Safety Recommendation A-83-15 as "Closed--Acceptable Action."

From: FAA
To: NTSB
Date: 7/10/1991
Response: ON 5/31/91 CLIMATRONICS CORPORATION INSTALLED LOW LEVEL WINDSHEAR ALERT SYSTEM (LLWAS) SIX SENSOR IMPROVEMENT INSTALLATIONS AT 51 AIRPORTS. THE LAST INSTALLATION IN LEXINGTON, KENTUCKY, MARKS THE 110TH LLWAS IN THE COUNTRY AND COMPLETES THE LLWAS INSTALLATION PROGRAM. THE LLWAS SIX SENSOR IMPROVEMENT INCORPORATES DATA AND ALARM ARCHIVING WITHIN LLWAS AS REQUESTED IN THIS SAFETY RECOMMENDATION.

From: NTSB
To: FAA
Date: 6/18/1990
Response: (PER GREEN SHEET A-90-83 THRU -85) The Safety Board understands that about 43 of the LLWAS purchased from Climatronics have not yet been modified to record wind velocity data. Although the FAA expected to have interim recording capability by June 1989 for all LLWAS, staff has indicated that this enhancement will likely be accomplished in early 1990. The status of the recommendation will be evaluated when the Safety Board is notified that all LLWAS have been modified. (Recommendation A- 83-15, issued March 25, 1983, is classified as "Open--Acceptable Action.")

From: FAA
To: NTSB
Date: 2/15/1989
Response: In 1986, the FAA installed an interface between the 59 Fairchild Weston-type Low Level Windshear Alert Systems (LLWAS) and the time-coded voice tape primarily used to record air traffic control ground-to-air transmissions. This interface served as an interim measure until a self-contained unit associated with the LLWAS Six-Sensor Improvement (LLWAS Phase II) was procured and installed in 1988. All 59 Fairchild Weston-type LLWAS now have the self-contained recording unit. Of the 51 Climatronics-type LLWAS, 44 have been installed and seven have not. Of the 44 Climatronics-type LLWAS systems, 43 are in the Phase I configuration (no recording capability) and one is in the Phase II configuration (self-contained recording unit). The upgrade of the 43 Phase I systems to Phase II has been delayed until certain logistical support items can be procured. In the interim, the FAA will install the interface to the time-coded voice tape at these airports. This Data Source: NTSB Recommendations to FAA and FAA Responses temporary recording measure will be implemented in April 1989 and will be completed by June 1989. Installation of the Phase II upgrade, which includes the self- contained recording unit, is scheduled to begin in August 1989 and will be completed by February 1990. At that time, all operational LLWAS will have the self-contained recording capability. Data acquisition at all LLWAS sites using portable recorders for a performance assessment has been completed, and the data from most of the airports have been analyzed. It is anticipated that all data analyses will be completed in early 1989. I believe that the FAA has satisfied the intent of this safety recommendation, and I urge the Safety Board to classify this safety recommendation as "closed."

From: FAA
To: NTSB
Date: 9/16/1986
Response:

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 avoidance, and in the dissemination of information on windshear.

From: NTSB
To: FAA
Date: 8/21/1986
Response: The Safety Board is pleased to learn that the FAA has implemented a recording system for the Low Level Wind Shear Alert System (LLWAS). The Safety Board is additionally pleased to learn that the FAA is planning to use data recorded from the LLWAS sensors to assess sensor performance and evaluate sensor siting. The Safety Board believes that the actions described in your letter, when fully implemented, will help prevent additional windshear accidents. Therefore, pending completion of the FAA's planned actions, Safety Recommendation A-83-15 has been classified as "Open-- Acceptable Action."

From: FAA
To: NTSB
Date: 7/10/1986
Response: THE FAA IS PROVIDING RECORDING CAPABILITY FOR THE LLWAS IN SEVERAL STAGES. (1) THE FAA HAS IMPLEMENTED A RECORDING SYSTEM WHICH RECORDS THE INPUTS THAT ARE USED TO DRIVE TOWER CAB DISPLAYS. (2) SENSOR OUTPUTS FROM EACH SENSOR AT EACH OPERATIONAL SITE WILL BE RECORDED FOR A PERIOD OF ONE MONTH TO ASSESS SENSOR PERFORMANCE AND EVALUATE SENSOR SITING AND SHEILDING. (3) THE FAA'S DATA RECORDING PLAN IS TO INTEGRATE A RECORDING CAPABILITY INTO THE ENHANCED LLWAS. THIS DATA WILL BE USED TO ESTABLISH A WIND SHEAR CLIMATOLOGY DATA BASE, SUPPORT MAINTENANCE ACTIONS, AND SUPPORT ANALYSES FOR SYSTEM IMPROVEMENTS.

From: NTSB
To: FAA
Date: 5/29/1984
Response: We are pleased that the FAA is developing a plan to install data recorders on the LLWAS. We urge the FAA to ensure that this plan requires the data to be recorded in sufficient detail to allow the reconstruction of wind shear events and the development of system improvements. Pending review and implementation of the final plan to record LLWAS data, Safety Recommendation A-83-15 will be maintained in an "Open--Acceptable Action" status.

From: FAA
To: NTSB
Date: 7/21/1983
Response: FAA LETTER: THE FAA IS DEVELOPING A PLAN TO INSTALL DATA RECORDERS ON LLWSAS. THE DATA RECORDED WILL TABULATE THE NUMBER OF TIMES WIND SHEAR ALERTS OCCURRED, THE SHEAR VELOCITY, AND THE DURATION OF THE EVENT. THIS PLAN, INCLUDING THE ENGINEERING DESIGN, WILL BE AVAILABLE IN JANUARY 1984.