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Safety Recommendation Details

Safety Recommendation A-84-112
Details
Synopsis: ON NOVEMBER 24, 1983, AIR CANADA FLIGHT 965, A LOCKHEED L-1011, C-FTNJ, WITH 154 PASSENGERS AND 15 CREWMEMBERS ON BOARD, ENCOUNTERED SEVERE CLEAR AIR TURBULENCE ABOUT 105 MILES OFF THE COAST OF CHARLESTON, SOUTH CAROLINA, WHILE EN ROUTE TO TORONTO, CANADA, FROM PORT OF SPAIN, TRINIDAD. ONE FLIGHT ATTENDANT AND THREE PASSENGERS WERE SERIOUSLY INJURED DURING THE ENCOUNTER. TWO PHYSICIANS ABOARD THE FLIGHT PROVIDED IMMEDIATE MEDICAL ATTENTION TO THE INJURED. THE FLIGHT CONTINUED TO ITS DESTINATION AND LANDED WITHOUT FURTHER INCIDENT ABOUT 1 1/2 HOURS AFTER THE ACCIDENT. MEDICAL ASSISTANCE WAS ON HAND TO PROVIDE TREATMENT WHEN THE FLIGHT ARRIVED AT THE GATE. AT THE TIME OF THE TURBULENCE ENCOUNTER, THE FLIGHT WAS UNDER THE CONTROL OF THE JACKSONVILLE AIR ROUTE TRAFFIC CONTROL CENTER (ARTCC) METTA SECTOR, AND A CONVECTIVE SIGMET WAS IN EFFECT FOR A LARGE PORTION OF THE METTA SECTOR. THE METTA CONTROLLER HAD BEEN RELIEVED OF THE RESPONSIBILITY OF BROADCASTING SIGMETS UNDER THE TERMS OF THE FEDERAL AVIATION ADMINISTRATION'S HAZARDOUS INFLIGHT WEATHER ADVISORY SERVICE (HIWAS). THE FLIGHT CREW WAS NOT AWARE OF THE SIGMET.
Recommendation: THE NTSB RECOMMENDS THAT THE FEDERAL AVIATION ADMINISTRATOR: DESIGNATE COMMUNICATION FREQUENCIES WITHIN THE 118-135 MHZ BAND FOR EACH AIR ROUTE TRAFFIC CONTROL CENTER TO BROADCAST HAZARDOUS INFLIGHT WEATHER ADVISORY SERVICE INFORMATION.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Unacceptable Action
Mode: Aviation
Location: CHARLESTON, SC, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: DCA84AA008
Accident Reports: Air Canada Flight 965, Lockheed L-1011, C-FTNJ
Report #: AAR-84-13
Accident Date: 11/24/1983
Issue Date: 10/25/1984
Date Closed: 12/18/1986
Addressee(s) and Addressee Status: FAA (Closed - Unacceptable Action)
Keyword(s): Weather, Weather Equipment/Products/Reports

Safety Recommendation History
From: NTSB
To: FAA
Date: 12/18/1986
Response: The Safety Board continues to believe that the continuous broadcasting of HIWAS information is necessary to ensure that all aircraft are provided with this vital weather information. It was the Safety Board's intent in issuing this recommendation that the FAA would establish a HIWAS reporting system similar to the Automatic Terminal Information Service (ATIS). The Safety Board believes that broadcasting over the very high frequency omnidirectional range (VOR) voice channels may not provide for the continuous reporting of weather as would a discrete channel, due to the other transmissions necessary on the VOR frequency. The Board notes that in the subject incident, the aircraft was far enough off the coast that it may have been impossible to receive a usable signal from an inland VOR site. Additionally, the Board notes that many of the newer aircraft have navigational computers that automatically tune and identify the VOR to be used. In this situation the pilots may never listen to the VOR channel or the computer may select a VOR that does not provide HIWAS information. Therefore, the Safety Board continues to believe that using VOR frequencies for broadcasting HIWAS information is not a suitable response to this recommendation. Safety Recommendation A-84-112 has been classified as "Closed--Unacceptable Action."

From: FAA
To: NTSB
Date: 1/17/1986
Response: THE FAA'S SYSTEMS ENGINEERING SERVICE HAS CONDUCTED A STUDY ON THE USE OF DISCRETE VERY HIGH AIR/GROUND COMMUNICATIONS FREQUENCIES FOR VARIOUS TYPES OF WEATHER INFORMATION SYSTEMS. ADDITIONALLY, THE FAA'S TECHNICAL CENTER HAS ANALYZED THE VOICE QUALITY OF EXISTING VOR VOICE CHANNELS. BASED ON THE RESULTS OF THESE STUDIES, IT HAS BEEN DETERMINED THAT THE FAA WILL USE THE VOR VOICE CHANNEL, NOT DISCRETE VHF, FOR HIWAS. IT HAS ALSO BEEN DETERMINED THAT AS FAR AS OTHER TYPES OF WEATHER SYSTEMS (ATIS, ETC.) ARE CONCERNED, THE FAA WILL USE A COMBINATION OF VOR VOICE CHANNELS, DISCRETE VHF AIR/GROUND COMMUNICATIONS CHANNELS, AND, IN SOME CASES, NDB CHANNELS.

From: NTSB
To: FAA
Date: 5/14/1985
Response: The Safety Board is pleased to learn that the FAA has initiated a study to determine the feasibility of broadcasting HIWAS information within the 118-135 MHz band. The Safety Board realizes that the creation of HIWAS broadcasting bands could significantly increase the cost of the HIWAS program. However, the Safety Board continues to believe that such a system would be the best approach to insure that all aircraft are provided with this vital weather information. Since the results of this study are expected within 60 days, Safety Recommendation A-84-112 has been classified as "Open--Acceptable Action," pending our review of these results.

From: FAA
To: NTSB
Date: 2/11/1985
Response: FAA LTR: THE BOARD'S RECOMMENDATION TO ESTABLISH A HIWAS ADVISORY SERVICE FOR EN ROUTE FACILITIES COULD SIGNIFICANTLY INCREASE THE COST OF THE HIWAS PROGRAM; THUS, MORE CONSIDERATION MUST BE GIVEN TO THIS RECOMMENDATION. WE HAVE INITIATED ACTION TO STUDY USE OF THE BOARD'S RECOMMENDED HIWAS CONCEPT. WE WILL ADVISE THE BOARD WITHIN 60 DAYS OF OUR PROGRESS RELATIVE TO THIS RECOMMENDATION.