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Safety Recommendation Details

Safety Recommendation A-78-001
Details
Synopsis: ON APRIL 4, 1977, SOUTHERN AIRWAYS, INC., FLIGHT 242, A DC-9-3 CRASHED AT NEW HOPE, GEORGIA, AS ITS CREW ATTEMPTED AN EMERGENCY LANDING ON A HIGHWAY. THE NATIONAL TRANSPORTATION SAFETY BOARD'S INVESTIGATION DISCLOSED THAT THE FLIGHT HAD ENTERED AN INTENSE PRECIPITATION AREA WHICH RESULTED IN THE FAILURE OF BOTH OF THE AIRCRAFT'S ENGINES.
Recommendation: THE NTSB RECOMMENDS THAT THE FEDERAL AVIATION ADMINISTRATION: INITIATE RESEARCH TO DETERMINE THE ATTENUATING EFFECTS OF VARIOUS LEVELS OF PRECIPITATION AND ICING ON AIRBORNE RADOMES OF BOTH X- AND C- BAND RADAR, AND DISSEMINATE TO THE AVIATION COMMUNITY ANY DATA DERIVED CONCERNING THE LIMITATIONS OF AIRBORNE RADAR IN PRECIPITATION.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Action
Mode: Aviation
Location: New Hope, GA, United States
Is Reiterated: Yes
Is Hazmat: No
Is NPRM: No
Accident #: DCA77AA015
Accident Reports: Southern Airways, Inc., DC-9-31, N1335U
Report #: AAR-80-15
Accident Date: 4/4/1977
Issue Date: 1/30/1978
Date Closed: 6/30/1986
Addressee(s) and Addressee Status: FAA (Closed - Acceptable Action)
Keyword(s): Weather, Thunderstorms/Rain/Snow

Safety Recommendation History
From: NTSB
To: FAA
Date: 7/1/1986
Response: On receipt of your May 20, 1985, response in which you enclosed a copy of National Aeronautical and Space Administration's (NASA) final report, an investigation of the existence of a surface water layer on aircraft radomes during simulated flight in heavy precipitation NTSB and FAA staff met to discuss the NASA study which was both limited and inconclusive. Following this meeting, we kept this recommendation open as we were advised that there was a possibility that the FAA might be able to provide additional funding to NASA for further research efforts. We are now advised that the FAA will not have the funds to support further research efforts in this area. Although NASA's research efforts proved inconclusive, we wish to thank the FAA for initiating the research, as recommended, and for the efforts extended by the FAA and NASA to determine the attenuating effects of rain on aircraft radomes. This recommendation is now classified as closed-- acceptable action.

From: FAA
To: NTSB
Date: 6/30/1986
Response: "THE FAA INITIATED A JOINT RESEARCH EFFORT WITH THE NATIONAL AERONAUTICS AND SPACE ADMINISTRATION. THE PURPOSE OF THE RESEARCH WAS TO EXAMINE WHETHER AIRCRAFT WEATHER RADOMES, HAVING VARIOUS SURFACE QUALITIES AND SUBJECTED TO CONDITIONS SIMULATING FLIGHT IN HEAVY PRECIPITATION WOULD SUPPORT A WATER LAYER ON THE SURFACE. ENCLOSED FOR THE BOARD'S INFORMATION IS A COPY OF NASA'S FINAL REPORT, "AN INVESTIGATION OF THE EXISTENCE OF A SURFACE WATER LAYER ON AIRCRAFT RADOMES DURING SIMULATED FLIGHT IN HEAVY PRECIPITATION." NASA INDICATES THAT WITHOUT FURTHER STUDIES THE RESULTS OF THESE TESTS ARE INCONCLUSIVE AND DO NOT POINT TO ANY CORRECTIVE ACTION. WE PLAN NO FURTHER ACTION ON THIS RECOMMENDATION UNTIL MORE CONCLUSIVE SCIENTIFIC EVIDENCE BECOMES AVAILABLE ON THIS SUBJECT."

From: FAA
To: NTSB
Date: 5/20/1985
Response: FAA LTR: THE FAA INITIATED A JOINT RESEARCH EFFORT WITH THE NATIONAL AERONAUTICS AND SPACE ADMINISTRATION. THE PURPOSE OF THE RESEARCH WAS TO EXAMINE WHETHER AIRCRAFT WEATHER RADOMES, HAVING VARIOUS SURFACE QUALITIES AND SUBJECTED TO CONDITIONS SIMULATING FLIGHT IN HEAVY PRECIPITATION WOULD SUPPORT A WATER LAYER ON THE SURFACE. ENCLOSED FOR THE BOARD'S INFORMATION IS A COPY OF NASA'S FINAL REPORT, "AN INVESTIGATION OF THE EXISTENCE OF A SURFACE WATER LAYER ON AIRCRAFT RADOMES DURING SIMULATED FLIGHT IN HEAVY PRECIPITATION." NASA INDICATES THAT WITHOUT FURTHER STUDIES THE RESULTS OF THESE TESTS ARE INCONCLUSIVE AND DO NOT POINT TO ANY SPECIFIC CORRECTIVE ACTION. WE PLAN NO FURTHER ACTION ON THIS RECOMMENDATION UNTIL MORE CONCLUSIVE SCIENTIFIC EVIDENCE BECOMES AVAILABLE ON THIS SUBJECT.

From: NTSB
To: FAA
Date: 6/15/1981
Response: We are pleased to note that a joint FAA/NASA study will be conducted to determine the effects of precipitation on airborne radomes, and that this study will be followed by flight tests if deemed necessary. We thank the FAA for this responsive action they offer to keep us informed of significant progress as the program continues. A-78-1 is classified in an Open--Acceptable Action.

From: FAA
To: NTSB
Date: 4/7/1981
Response: FEDERAL AVIATION ADMINISTRATION LTR: FUNDING HAS BEEN APPROVED THROUGH THE FAA TECHNICAL CENTER IN THE AMOUNT OF $25,000 TO FUND A JOINT FAA/NASA STUDY EXPECTED TO CULMINATE IN A FLIGHT TEST LATER THIS SUMMER. THE NASA-LANGLEY RESEARCH CENTER'S FLIGHT ELECTRONICS DIVISION IS FABRICATING INSTRUMENTATION FOR TEST UTILIZING A RADOME FOR THE FAA/NASA T-39 RESEARCH AIRCRAFT. ASSUMING STATIC GROUND TESTS SHOW THAT MEASUREMENT OF A WATER LAYER CAN BE MADE, FLIGHT TESTING WILL BE CONDUCTED AT EDWARDS AIR FORCE BASE, CALIFORNIA, USING A KC-135 WATER SPRAY TANKER WITH THE T-39 IN FORMATION FLIGHT BEHIND. THIS PROJECT IS ENTITLED "ASSESSMENT OF THE EXISTENCE OF WATER LAYERS ON AIRBORNE RADOMES DURING FLIGHT IN PRECIPITATION," THE PROCUREMENT AND FABRICATION PHASE IS SCHEDULED FOR COMPLETION IN MID APRIL 1981, WITH FLIGHT TESTING SCHEDULED TO TAKE PLACE IN MID-SUMMER. WE PLAN TO HAVE USEABLE DATA AVAILABLE BY EARLY AUTUMN OF 1981.

From: NTSB
To: FAA
Date: 12/9/1980
Response: From the aircraft accident report of Air Wisconsin, Inc. Swearingen SA-226 Metro, N650S in Valley, Nebraska on June 12, 1980. The Board adopted this report on 12/9/1980. As a result of this investigation, the Safety Board reiterates the following recommendations: A-75-51, A-77-63, A-77-68, and A-78-1.

From: NTSB
To: FAA
Date: 7/28/1980
Response: Your letter of July 20, 1979, indicated that the FAA was reviewing the basis of its April 9, 1979, response, and that the Safety Board would be advised in the near future. In order to evaluate the progress of this recommendation, we would appreciate an updated status report.

From: FAA
To: NTSB
Date: 7/20/1979
Response: FAA LTR: THE BOARD RESPONSE ON JUNE 7, 1979, PROVIDING THE RATIONALE FOR ITS BELIEF THAT THE ACTUAL EXTENT OF ATTENUATION DUE TO PRECIPITATION ON AIRBORNE RADOMES SHOULD BE DETERMINED, AND SUGGESTING THAT FAA FURTHER CONSIDER THE MATTER. THIS MATTER WAS DISCUSSED BRIEFLY DURING THE NTSB/FAA QUARTERLY MEETING HELD JULY 13, 1979. FAA OFFERED TO REVIEW THE BASIS FOR THE 4/9/79 RESPONSE.

From: NTSB
To: FAA
Date: 6/7/1979
Response:

From: FAA
To: NTSB
Date: 4/9/1979
Response: FAA LTR: WE DO NOT HAVE EVIDENCE OF SERIOUS PROBLEMS CAUSED BY THE ACCUMULATION OF ICE AND WATER ON RADOMES. ATTENUATION EFFECTS OF ICE AND WATER ARE WELL-KNOWN. WE DO NOT BELIEVE THAT RESEARCH IS NECESSARY. TO ENSURE THAT AIR CARRIER TRAINING PROGRAMS ARE SATISFACTORY IN THIS AREA, WE WILL REQUEST THAT EACH PRINCIPAL OPERATIONS INSPECTOR CHECK THE TRAINING PROGRAM OF HIS ASSIGNED CARRIER TO ENSURE THAT ALL PILOTS ARE BEING GIVEN INFORMATION ON THE LIMITATIONS OF AIRBORNE WEATHER RADAR WITH SPECIAL EMPHASIS ON THE ATTENUATION EFFECTS OF PRECIPITATION.

From: NTSB
To: FAA
Date: 3/14/1979
Response:

From: NTSB
To: FAA
Date: 5/9/1978
Response: Open--acceptable action.

From: FAA
To: NTSB
Date: 4/17/1978
Response: FAA LTR: PRELIMINARY INFO INDICATES THAT EXTENSIVE RESEARCH MAY NOT BE NECESSARY. A LARGE PORTION OF THE DATA NEEDED IS ALREADY AVAILABLE IN THE AVIATION COMMUNITY. WE HAVE REQUESTED THE ASSISTANCE OF THE AIR TRANSPORT ASSOCIATION IN GATHERING THESE DATA.