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Safety Recommendation Details

Safety Recommendation A-76-077
Details
Synopsis: ON FEBRUARY 8, 1976, A MERCER AIRLINES DC-6, YC112A (N901MA), WAS DESTROYED AND THREE CREWMEMBERS WERE KILLED WHEN IT MADE AN EMERGENCY LANDING ON A GOLF COURSE IN VAN NUYS, CALIFORNIA. 1/THE NATIONAL TRANSPORTATION SAFETY BOARD'S INVESTIGATION OF THE ACCIDENT REVEALED THAT THE EMERGENCY WAS THE RESULT OF AN IN-FLIGHT FAILURE OF A CURTISS-WRIGHT MODEL 632S-B TYPE 744 HOLLOW STEEL PROPELLER BLADE WHICH RESULTED FROM A FATIGUE CRACK.
Recommendation: REVIEW THE OVERHAUL MANUALS FOR ALL METAL PROPELLER BLADES THAT ARE SHEATH EQUIPPED AND INSURE THAT THE MANUALS REQUIRE THAT THE SURFACES OF THESE BLADES BENEATH THE SHEATHS BE INSPECTED EITHER BY REMOVAL OF THE SHEATH OR BY AN ALTERNATE METHOD WHICH WILL DETECT CRACKS UNDERNEATH THE SHEATH. (URGENT)
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Action
Mode: Aviation
Location: Van Nuys, CA, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: DCA76AZ020
Accident Reports: Mercer Airlines, Inc., Douglas DC-6/YC-112A, N901MA
Report #: AAR-76-17
Accident Date: 2/8/1976
Issue Date: 5/13/1976
Date Closed: 3/10/1977
Addressee(s) and Addressee Status: FAA (Closed - Acceptable Action)
Keyword(s):

Safety Recommendation History
From: FAA
To: NTSB
Date: 8/30/1976
Response: WE ARE PREPARING A NOTICE TO EMPHASIZE THE NEED FOR FIELD INSPECTORSTO ASSURE THAT REPAIR STATIONS AND OPERATORS ARE USING COMPLETE AND CURRENT DATA IN INSPECTION, MAINTENANCE, AND OVERHAUL. FIELD INSPECTORS WILL BE REMINDED TO STRESS TO THE OPERATORS AND AGENCIES THEIR RESPONSIBILITY TO ASSURE THE AIRWORTHINESS OF THE AIRCRAFT AND COMPONENTS OPERATED OR MAINTAINED BY THEM. SPECIAL EMPHASIS WILL BE EXPRESSED THE NOTICE CONCERNING THE DATA USED FOR METAL, SHEATH, OR DELCER EQUIPPED PROPELLER BLADES. WE EXPECT ISSUANCE OF THIS NOTICE BY OCTOBER 1976.

From: NTSB
To: FAA
Date: 8/30/1976
Response: We are preparing a notice to emphasize the need for field inspectors to assure that repair stations and operators are using complete and current data in inspection, maintenance, and overhaul. Field inspectors will be reminded to stress to the operators and agencies their responsibility to assure that airworthiness of the aircraft and components operated or maintained by them. Special emphasis will be expressed in the notice concerning the data used for metal, sheath, or deicer equipped propeller blades. We expect issuance of this notice by october 1976.