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Safety Recommendation Details

Safety Recommendation A-94-186
Details
Synopsis: THE NATIONAL TRANSPORTATION SAFETY BOARD'S INVESTIGATION OF A RECENT ACCIDENT INVOLVING A LANDING APPROACH, IN INSTRUMENT METEOROLOGICAL CONDITIONS, AT WASHINGTON DULLES INTERNATIONAL AIRPORT (IAD), HAS REVEALED SOFTWARE DISCREPANCIES WITH THE MINIMUM SAFE ALTITUDE WARNING SYSTEM (MSAW) AND LOW LEVEL WINDSHEAR ALERT SYSTEM (LLWAS) OPERATING AT IAD AT THE TIME OF THE ACCIDENT. THE DISCREPANCIES ARE BELIEVED TO AFFECT THE ACCURACY OF THE WARNING SYSTEMS. THE SAETY BOARD BELIEVES THAT ACTION IS REQUIRED TO CORRECT THE DISCREPANCIES AT IAD, AND MAY BE REQUIRED TO CORRECT SIMILAR DISCREPANCIES AT OTHER AIRPORTS THROUGHOUT THE COUNTRY.
Recommendation: THE NTSB RECOMMENDS THAT THE FEDERAL AVIATION ADMINISTRATION: REVIEW THE CALCULATIONS ESTABLISHING THE RUNWAY THRESHOLD COORDINATES FOR ALL RUNWAYS AT IAD WITH RESPECT TO THE AIR SURVEILLANCE RADAR TO VERIFY PROPER ALIGNMENT OF THE MSAW CAPTURE BOXES.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Action
Mode: Aviation
Location: CHANTILLY, VA, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: DCA94MA061
Accident Reports: Controlled Collision with Terrain Transportes Aereos Ejecutivos, S.A. (TAESA) Learjet 25D, XA-BBA
Report #: AAR-95-02
Accident Date: 6/18/1994
Issue Date: 11/21/1994
Date Closed: 11/20/1995
Addressee(s) and Addressee Status: FAA (Closed - Acceptable Action)
Keyword(s):

Safety Recommendation History
From: NTSB
To: FAA
Date: 11/20/1995
Response: THE BOARD NOTES THAT THE FAA HAS COMPLETED ITS REVIEW OF THE CALCULATIONS & ADAPTATION VALUES FOR RUNWAY THRESHOLD COORDINATES FOR ALL RUNWAYS AT IAD & HAS VERIFIED PROPER ALIGNMENT OF THE MSAW CAPTURE BOXES. THEREFORE, THE BOARD CLASSIFIES A-94-186 'CLOSED--ACCEPTABLE ACTION."

From: FAA
To: NTSB
Date: 9/27/1995
Response: THE FAA COMPLETED ITS REVIEW OF THE CALCULATIONS & ADAPTATION VALUES FOR RUNWAY THRESHOLD COORDINATES FOR ALL RUNWAYS AT IAD & HAS VERIFIED PROPER ALIGNMENT OF THE MSAW CAPTURE BOXES.

From: NTSB
To: FAA
Date: 5/25/1995
Response: THE BOARD NOTES THAT THE FAA WILL REVIEW THE CALCULATIONS ESTABLISHING THE RUNWAY THRESHOLD COORDINATES FOR ALL RUNWAYS AT IAD TO VERIFY PROPER ALIGNMENT OF MSAW CAPTURE BOXES BY JULY 1995. PENDING NOTIFICATION OF THE COMPLETION OF THIS PROJECT, THE RECOMMENDATION HAS BEEN CLASSIFIED "OPEN--ACCEPTABLE RESPONSE."

From: NTSB
To: FAA
Date: 4/27/1995
Response: THE BOARD NOTES THAT THE FAA IS DEVELOPING A PROGRAM TO CORRECT THE ERRORS IN THE MSAW ARRANGEMENT AT DULLES, & TO REVIEW ALL OTHER MSAW INSTALLATIONS. PENDING THE ISSUANCE OF THE PROGRAM, & CONFIRMATION OF THE PROPER MSAW INSTALLATION AT ALL U.S. AIRPORTS, A-94-186 & A-187 ARE CLASSIFIED "OPEN--ACCEPTABLE RESPONSE."

From: FAA
To: NTSB
Date: 3/20/1995
Response: THE FAA WILL CONDUCT A REVIEW OF THE CALCULATIONS FOR RUNWAY THRESHOLD COORDINATES FOR ALL RUNWAYS AT IAD TO VERIFY PROPER ALIGNMENT OF THE MSAW CAPTURE BOXES. THE REVIEW WILL BEGIN IN APRIL & CONCLUDE IN JULY 1995. I WILL KEEP THE BOARD INFORMED OF THE FAA'S PROGRESS ON THIS SAFETY RECOMMENDATION.

From: FAA
To: NTSB
Date: 1/24/1995
Response: THE FAA AGREES WITH THESE SAFETY RECOMMENDATION NA PROGRAM IS BEING DEVELOP FOR THE REVIEW OF WASHINGTON DULLES INTERNATIONAL AIRPORT & OTHER AIRPORTS WHICH USE MINIMUM SAFE ALTITUDE WARNING SYSTEMS. I WILL PROVIDE THE BOARD WITH THE FAA COURSE OF ACTION TO ADDRESS THESE RECOMMENDATION BY 3/31/95.