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Safety Recommendation Details

Safety Recommendation A-96-137
Details
Synopsis: ON 11/12/95, AT 0056 EASTERN TIME (EST), AMERICAN AIRLINES (AAL) FLIGHT 1572, A MCDONNELL DOUGLAS MD-80, REGISTERED IN THE UNITED STATES AS N566AA, STRUCK TREES ON A RIDGE LINE NORTHEAST OF THE AIRPORT, IN EAST GRANBY, CONNECTICUT, WHICH IS ABOUT 2.54 MILES FROM THE END OF RUNWAY 15, AT BRADLEY INTERNATIONAL AIRPORT (BDL) WINDSOR LOCKS, CONNECTICUT. THE TREE STRIKE OCCURRED DURING AN INSTRUMENT APPROACH TO RUNWAY 15 IN DARKNESS & IN VARIABLE WIND CONDITIONS. BOTH ENGINES SUBSEQUENTLY LOST POWER FOLLOWING INGESTION OF TREE LIMBS, BUT THE FLIGHTCREW WAS ABLE TO CONTINUE THE FLIGHT TO THE AIRPORT. THE AIRPLANE WAS SUBSTANTIALLY DAMAGED DURING THE EMERGENCY LANDING. ONE OF THE 72 PASSENGERS RECEIVED A MINOR INJURY DURING THE EMERGENCY EVACUATION, & NONE OF THE FIVE CREWMEMBERS WAS INJURED IN THE ACCIDENT. THE FLIGHT, WHICH WAS OPERATING UNDER 14 CODE OF FEDERAL REGULATIONS PART 121, ORIGINATED AT O"HARE INTERNATIONAL AIRPORT, CHICAGO, ILLINOIS, ABOUT 2 HOURS BEFORE THE ACCIDENT.
Recommendation: THE NTSB RECOMMENDS THAT THE FAA: EVALUATE THE LOW LEVEL WINDSHEAR ALERT SYSTEM (LLWAS) RECERTIFICATION PROCESS, & ENSURE THAT THE PROCESS ADDRESSES THE TOTAL FUNCTIONAL CAPABILITY OF THE SYSTEM.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Action
Mode: Aviation
Location: EAST GRANBY, CT, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: DCA96MA008
Accident Reports: Collision with Trees on Final Approach American Airlines Flight 1572, McDonnell Douglas MD-83, N566AA
Report #: AAR-96-05
Accident Date: 11/12/1995
Issue Date: 12/3/1996
Date Closed: 11/13/1997
Addressee(s) and Addressee Status: FAA (Closed - Acceptable Action)
Keyword(s): Low Level Windshear, Weather, Wind

Safety Recommendation History
From: FAA
To: NTSB
Date: 7/9/1997
Response: The Federal Aviation Administration (FAA) stated in its letter dated February 24, 1997, that Order 6560.13B, Maintenance of Aviation Meteorological Systems and Miscellaneous Aids, included a requirement to certify the alignment of the anemometer base orientation on an annual basis. This was not an accurate account of the requirement contained in Order 6560.13B. The FAA has a requirement in Order 6560.13B, to certify the anemometer directional accuracy annually (Appendix 3, Table 1) and to check the anemometer base orientation every 3 years (Appendix 2, paragraph 27). The FAA also requires certification of this facility following restoration due to an interruption of service, maintenance action, or modification. Certification is also required during the course of a postaccident/incident evaluation if the facility in question may have been in use. Additionally, the FAA certifies facilities upon initial installation and use, upon restoration after an outage or significant maintenance or modification, during a postaccident/incident evaluation, and periodically in accordance with certification requirements published in the appropriate maintenance handooks. FAA Order 6560.13B contains certification requirements for the Low Level Windshear Alert System (LLWAS) as follows: * Appendix 3, Table 1, specifies wind direction accuracy as a certification parameter and that the LLWAS shall be certified at least annually. * Appendix 2, paragraph 5.a.(1)(b), specifies standards and tolerances for wind direction accuracy for the Loral anemometer. * Appendix 2, paragraph 5.a.(2)(d), specifies standards and tolerances for the Climatronics anemometer. I believe that these current procedures address this safety issue completely, and I consider the FAA's action to be completed.

From: NTSB
To: FAA
Date: 6/26/1997
Response: HOWEVER, IN A RECENT REVIEW OF ORDER 6560.13B, BOARD STAFF WAS UNABLE TO INDENTIFY AN ANNUAL REQUIREMENT TO CHECK THE ORIENTATION OF THE LLWAS ANEMOMETER BASES/PEDESTALS. PENDING RECEIPT OF ADDITIONAL CLARIFYING INFO OR DOCUMENTATION, A-96-137 IS CLASSIFIED "OPEN--ACCEPTABLE RESPONSE."

From: FAA
To: NTSB
Date: 2/24/1997
Response: THE FAA REPLY TO THIS RECOMMENDATION INDICATES THAT FAA ORDER 6560.13C CONTAINS A REQUIREMENT TO CERTIFY THE ALIGNMENT OF THE ANEMOMETER BASE ORIENTATION ON AN ANNUAL BASIS. THE FAA ALSO CONDUCTS A SEPARATE CERTIFICATION OF THE SYSTEM WHEN CORRECTIVE MAINTENANCE IS PERFORMED TO CORRECT A MALFUNCTION OR WHEN AN ACCIDENT OR INCIDENT IS REPORTED. THE FAA CONTENDS THAT THESE PROCESSES CURRENTLY IN PLACE ENSURE THE TOTAL FUNCTIONALITY OF THE SYSTEM. HOWEVER, IN ITS RECENT REVIEW OF THE SUBJECT ORDER, OUR STAFF WAS UNABLE TO IDENTIFY AN ANNUAL OR OTHER REQUIREMENT TO CHECK THE ORIENTATION OF THE LLWAS ANEMOMETER BASES/PEDESTALS.