Skip Ribbon Commands
Skip to main content
Safety Recommendation Details

Safety Recommendation A-72-059
Details
Synopsis: DURING THE NATIONAL TRANSPORTATION SAFETY BOARD'S INVESTIGATION OF AN IN-FLIGHT TURBULENCE ACCIDENT INVOLVING A NATIONAL AIRLINES BOEING MODEL B-747 AIRCRAFT NEAR GRAND ISLE, LOUISIANA, ON JANUARY 4, 1972, WE DETERMINED THAT THE SUNDSTRAND DATA CONTROL ARINC 542 FLIGHT DATA RECORDER INSTALLED ON THE SUBJECT AIRCRAFT WAS NOT RECORDING VERTICAL ACCELERATION PROPERLY. BENCH CHECKS AND CALIBRATION TESTS OF THE SUBJECT ACCELEROMETER TRANSDUCER AND FLIGHTRECORDER SHOWED NO ABNORMALITIES.
Recommendation: ISSUE AN AIRWORTHINESS DIRECTIVE REQUIRING MODIFICATION OF THE SUNDSTRAND RECORDER VERTICAL ACCELEROMETER SYSTEM TO CONFORM TO THE FEDERAL AVIATION REGULATIONS.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Action
Mode: Aviation
Location: Lake Charles, LA, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: LAX72AL043
Accident Reports: National Airlines, Inc., Boeing 747-135, N77722
Report #: AAR-72-21
Accident Date: 1/4/1972
Issue Date: 4/19/1972
Date Closed: 9/1/1972
Addressee(s) and Addressee Status: FAA (Closed - Acceptable Action)
Keyword(s):

Safety Recommendation History
From: NTSB
To: FAA
Date: 8/7/1972
Response: Closed--acceptable action.

From: FAA
To: NTSB
Date: 7/20/1972
Response: It appears to us that the sundstrand flight data recorder meets the existing tso requirements, and that there is no evidence that this recorder as installed in the b-747 airplane will not continue to meet those requirements. It is also our belief that the flight recorder installation in the nal 747 which experienced the severe turbulence near grand isle, louisiana, on 4 january 1972 was not functioning correctly. The cause for this malfunctioning cannot be ascertained since both nal 747's have been retrofitted with expanded parameter flight data recorders. The only other u.S. 747 operator having this type of sundstrand flight data recorder is american airlines. They are required by amendment 66 to far 121 to retrofit to the expand parameters recorder no later than 18 september 1973. In conclusion, based on the above information, we do not feel that any further action on the part of the faa is warranted.

From: FAA
To: NTSB
Date: 5/19/1972
Response: 5/19/72 - THE FAA RESPONDED STATING THEY ARE AWARE OF THE SITUATION OUTLINED BY THE BOARD WHEREIN THE VERTICAL ACCELERATION PARAMETER DID NOT APPEAR TO BE RECORDING PROPERLY ON THE SUNDSTRAND FDR. THEY HAVE BEEN WORKING WITH BOEING ON THE SUNDSTRAND BUT HAVE NOT YET BEEN ABLE TO DETERMINE IF THIS IS SOLELY A RECORDER PROBLEM, AN AIRCRAFT RECORDER SYSTEM INSTALLATION PROBLEM OR A COMBINATION OF BOTH. THE BOARD WILL BE ADVISED OF CORRECTIVE ACTIONS TAKEN. 7/20/72 - FURTHER TO THEIR LETER OF 5/19/72, THE FAA STATED THAT SUNDSTRAND HAD TESTED A NUMBER OF FLIGHT RECORDERS. ALL MEET THE MINIMUM REQUIREMENTS OF TSO-C51A. HOWEVER, SOME TESTED WERE MARGINAL. MODIFICATIONS CONSISTING OF RESISTOR CHANGES WILL BE MADE TO INCREASE SENSITIVITY OF THE FLIGHT RECORDERS. THIS CHANGE WILL BE DESCRIBED IN A SERVICE BULLETIN. EVALUATION WAS ALSO MADE OF THE RECORDERS INSTALLATION IN THE B-747. APPROXIMATELY 35 TAPES WERE EXAMINED FROM FLIGHT TESTS WHERE A NUMBER OF MANEUVERS WERE PERFORMED. IN ALL CASES, THE ACCELERATION TRACES EXHIBITED THE INTELLIGENCE EXPECTED FROM SUCH MANUEVERS. IT IS FAA BELIEF THAT THE FLIGHT RECORDER INSTALLATION IN THE NAL 747 WAS NOT FUNCTIONING CORRECTLY. ALL RECORDERS IN 747'S ARE NOW REQUIRED TO BE RETROFITTED WITH EXPANDED PARAMETERS NOT LATER THAN SEPTEMBER 18, 1973.