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Safety Recommendation Details

Safety Recommendation A-92-027
Details
Synopsis: ON APRIL 5, 1991, ATLANTIC SOUTHEAST AIRLINES, INC., FLIGHT 2311, AN EMBRAER EMB-120, N270AS. CRASHED DURING A LANDING APPROACH TO RUNWAY 07 AT THE GLYNCO JETPORT, BRUNSWICK, GEORGIA. THE FLIGHT WAS SCHEDULED COMMUTER FLIGHT FROM ATLANTA TO BRUNSWICK, GEORGIA, OPERATING UNDER THE PROVISIONS OF TITLE 14 CODE OF FEDERAL REGULATIONS (CFR) PART 135, AND WAS BEING CONDUCTED UNDER INSTRUMENT FLIGHT RULES. THE AIRPLANE WAS OPERATING VISUAL METEOROLOGICAL CONDITIONS AT THE TIME OF THE ACCIDENT. THE AIRPLANE WAS DESTROYED; AND THE TWO PILOTS, THE FLIGHT ATTENDANT, AND ALL 20 PASSENGERS RECEIVED FATAL INJURIES.
Recommendation: THE NTSB RECOMMENDS THAT THE FEDERAL AVIATION ADMINISTRATION: ESTABLISH A PERIODIC INSPECTION TIME REQUIREMENT FOR THE TRANSFER TUBE SPLINES, SERVO BALLSCREW AND BALLSCREW QUILL ON HAMILTON STANDARD MODEL 14RF PROPELLERS AND OTHER PROPELLER SYSTEMS OF SIMILAR DESIGN.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Action
Mode: Aviation
Location: BRUNSWICK, GA, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: DCA91MA033
Accident Reports: Atlantic Southeast Airlines, Inc. Flight 2311 Uncontrolled Collision with Terrain an Embraer EMB-120, N270AS
Report #: AAR-92-03
Accident Date: 4/5/1991
Issue Date: 5/14/1992
Date Closed: 3/20/1997
Addressee(s) and Addressee Status: FAA (Closed - Acceptable Action)
Keyword(s):

Safety Recommendation History
From: NTSB
To: FAA
Date: 3/20/1997
Response: A-92-27 ASKED THE FAA TO ESTABLISH A PERIODIC INSPECTION TIME REQUIREMENT FOR THE TRANSFER TUBE SPLINES, SERVO BALLSCREW, & BALLSCREW QUILL ON HAMILTON STANDARD MODEL 14RF PROPELLER & OTHER PROPELLER SYSTEMS OF SIMILAR DESIGN. BECAUSE THIS ACTION MEETS THE INTENT OF THE RECOMMENDATION, A-92-27 IS CLASSIFIED "CLOSED--ACCEPTABLE ACTION."

From: FAA
To: NTSB
Date: 2/12/1997
Response: THE FAA ISSUED AIRWORTHINESS DIRECTIVE 96-25-20, EFFECTIVE 2/7/97, WHICH REQUIRES INITIAL & REPETITIVE INSPECTIONS OF THE CRITICAL CONTROL COMPONENTS IN HAMILTON STANDARD 14RF & 14SF & HAMILTON STANDARD/BRITISH AEROSPACE MODEL 6/5500F PROPELLERS.

From: NTSB
To: FAA
Date: 4/16/1996
Response: (FOLLOWUP FOR BOTH LETTERS 10/26/96 & 1/17/96) THE BOARD NOTES THAT ON 12/13/95, THE FAA ISSUED A NOTICE OF PROPOSED RULEMAKING TO REQUIRE INITIAL & REPETITIVE INSPECTIONS OF CRITICAL COMPONENTS IN HAMILTON STANDARD 14RF, 14SF, & 6/5500/F SERIES PROPELLERS. FOR THESE SERIES PROPELLERS, THE NPRM PROPOSES AN INSPECTION INTERVAL OF 10,500 HOURS, ONCE AGAIN,GIVEN THE CRITICAL NATURE OF THE PCU COMPONENTS, THE BOARD BELIEVES THAT IT WOULD BE PRUDENT TO INITIALLY ESTABLISH A SHORTER REPETITIVE INSPECTION PROGRAM UNTIL THE BALLSCREW QUILL DAMPER & THE SECONDARY DRIVE QUILL HAVE BEEN INSTALLED & PROVEN IN SERVICE. ONCE THIS HAS BEEN DONE & INSPECTIONS DETERMINE THAT THERE IS NO UNUSUAL WEARING OF THE COMPONENTS, THE INSPECTION PERIOD COULD BE INCREASED. PENDING FURTHER CORRESPONDENCE ON THIS ISSUE & THE BOARD'S REVIEW OF THE FINAL RULE A-92-27 IS CLASSIFIED "OPEN--ACCEPTABLE RESPONSE."

From: FAA
To: NTSB
Date: 1/17/1996
Response: THE FAA ISSUED A NOTICE OF PROPOSED RULEMAKING PROPOSING TO ADOPT AN AD APPLICABLE TO HAMILTON STANDARD 147RF, 247F, 14SF, & 6/5500/F SERIES PROPELLERS. THIS NPRM PROPOSES TO REQUIRE INITIAL & REPETITIVE INSPECTIONS OF CRITICAL COMPONENTS & REPLACEMENT WITH SERVICEABLE PARTS OF THOSE CRITICAL COMPONENTS THAT DO NOT MEET THE RETURN TO SERVICE CRITERIA. I HAVE ENCLOSED A COPY OF THE NPRM FOR THE BOARD'S INFO. I WILL PROVIDE THE BOARD WITH A COPY OF THE AD AS SOON AS IT IS ISSUED.

From: FAA
To: NTSB
Date: 10/26/1995
Response: THE FAA AGREES WITH THE ABOVE RECOMMENDATIONS & HAS TAKEN EXTENSIVE ACTIONS TO ADDRESS THESE ISSUES. IN JUNE 1992, THE FAA'S HAMILTON STANDARD CERTIFICATION REVIEW TEAM COMPLETED ITS CERTIFICATION REVIEW OF THE HAMILTON STANDARD 14RF PROPELLER SYSTEM & OTHER MODEL PROPELLER SYSTEMS THAT HAVE THE SAME DESIGN CHARACTERISTICS AS THE HAMILTON STANDARD 14RF. THE FAA REVIEWED THE VIBRATION SPECTRUM THAT WOULD BE ENCOUNTERED IN FLIGHT ON THOSE AIRCRAFT FOR WHICH THE PROPELLERS ARE CERTIFICATED. THE REVIEW ALSO INCLUDED AN EXAMINATION OF THE DESIGN & CERTIFICATION PROCESS USED TO APPROVE THE HAMILTON STANDARD 14RF, 14SF, & 6/5500/F-1 MODEL PROPELLERS. THE TEAM CONCLUDED THAT EACH OF THE PROPELLER MODELS WAS IN COMPLIANCE WITH 14 CFR PART 35 & HAD BEEN CERTIFICATED CORRECTLY. BASED ON THE INFO THAT THE CERTIFICATION REVIEW TEAM COMPLIED, FOUR RECOMMENDATIONS WERE DEVELOPED. THE FOLLOWING IS A STATUS OF FAA ACTIONS ACCOMPLISHED TO DATE TO ADDRESS THESE RECOMMENDATIONS. THE FAA ACTIONS ENCOMPASS ALL SAFETY CONCERNS OUTLINED A-92-25 THROUGH -27. 1. REVISE AIRWORTHINESS DIRECTIVE 92-08-03, DATED 4/27/92, WHICH REQUIRES A 900-HOUR REPETITIVE INSPECTION OF THE SERVO BALLSCREW INTERNAL SPLINE TO EXTEND ITS APPLICABILITY TO INCLUDE ALL MODELS OF THE HAMILTON STANDARD 14RF, 14SF, & 6/5500/F SERIES PROPELLERS.

From: NTSB
To: FAA
Date: 10/11/1994
Response: THE BOARD NOTES THAT THE FAA HAS ISSUED TWO AIRWORTHINESS DIRECTIVES (AD): ONE REQUIRES THE REMOVAL OF ALL TITANIUM NITRIDED TRANSFER TUBES & REPLACEMENT OF WORN BALLSCREW QUILLS & THE OTHER REQUIRES INITIAL & REPETITIVE INSPECTION OF THE SERVO BALLSCREW. WHILE DISASSEMBLY OF THE PCU TO INSPECT THE SERVO BALLSCREW WOULD PROVIDE AN OPPORTUNITY TO INSPECT THE TRANSFER TUBE & BALLSCREW QUILL, THE AD DOES NOT SPECIFY A PERIODIC INSPECTION REQUIREMENT FOR THOSE COMPONENTS. ALTHOUGH IT COULD BE INFERRED THAT MAINTENANCE PERSONNEL WOULD INSPECT THE TRANSFER TUBE & BALLSCREW QUILL WHILE INSPECTING THE SERVO BALLSCREW, THE BOARD BELIEVES THAT THE POTENTIAL CONSEQUENCES OF A LOSS OF ENGAGEMENT BETWEEN THE TRANSFER TUBE & THE BALLSCREW QUILL ARE SO GREAT THAT SUCH INSPECTIONS MUST BE REQUIRED & NOT LEFT TO CHANCE. THEREFORE A-92-27 IS CLASSIFIED "OPEN--UNACCEPTABLE RESPONSE," PENDING THE FAA'S ISSUANCE OF AN AD THAT REQUIRES PERIODIC INSPECTION OF THE TRANSFER TUBE & BALLSCREW QUILL ON HAMILTON STANDARD MODEL 14RF PROPELLERS & OTHER PROPELLER SYSTEMS OF SIMILAR DESIGN.

From: FAA
To: NTSB
Date: 7/26/1994
Response: THE FAA ISUED TWO AIRWORTHINESS DIRECTIVES IN RESPONSE TO THIS RECOMMENDATION. ON 5/18/93, THE FAA ISSUED AD 93-06-06 APPLICABLE TO HAMILTON STANDARD 14RF & 14SF SERIES PROPELLERS & HAMILTON STANDARD BRITISH AEROSPACE MODEL 6/5500/F-1 PROPELLERS. THIS AD REQUIRES REMOVAL OF ALL TITANIUM NITRIDED TRANSFER TUBES & REPLACEMENT OF WORN BALLSCREW QUILLS. ON 8/13/93, THE FAA ISSUED AD 93-16-02 TO REQUIRE INSPECTIONS FOR TOOTH WAR & REPLACEMENT, AS NECESSARY, OF PROPELLER CONTROL UNIT SERVO BALLSCREW INTERNAL SPLINE ASSEMBLIES.

From: NTSB
To: FAA
Date: 10/6/1992
Response: THE BOARD NOTES THAT THE FAA'S SPECIAL CERTIFICATION REVIEW TEAM EXAMINED THE DESIGN & CERTIFICATION PROCESS USED TO APPROVE THE HAMILTON STANDARD 14RF SERIES PROPELLERS & AS A RESULT OF THAT REVIEW, THE FAA PLANS TO REVISE TWO AIRWORTHINESS DIRECTIVES (AD), ISSUE A NEW AD, & ADVISE HAMILTON STANDARD TO INCORPORATE A FAIL-SAFE FEATURE INTO THE DESIGN OF 14RF, 14SF, & 6/5500/F-1 MODEL PROPELLERS. PENDING FURTHER INFORMATION, RECOMMENDATIONS A-92-25 THROUGH -27 ARE CLASSIFIED AS "OPEN--ACCEPTABLE RESPONSE."

From: FAA
To: NTSB
Date: 7/22/1992
Response: THE FAA SPECIAL CERTIFICATION REVIEW TEAM EXAMINED THE DESIGN AND CERTIFICATION PROCESS USED TO APPROVE THE HAMILTON STANDARD 14RF SERIES PROPELLERS. THE TEAM ALSO EXAMINED THE HAMILTON STANDARD 14SF AND 6/5500/F SERIES PROPELLERS. AS A RESULT OF THIS REVIEW, THE FAA WILL TAKE THE FOLLOWING ACTIONS TO ADDRESS THESE RECOMMENDATIONS: REVISE AIRWORTHINESS DIRECTIVE (AD) 92-08-03, WHICH REQUIRES A 900 HOUR REPETITIVE INSPECTION OF THE SERVO BALLSCREW INTERNAL SPLINE, TO EXTEND ITS APPLICABILITY TO INCLUDE ALL MODELS OF THE 14RF, 14SF, AND 6/5500/F MODEL PROPELLERS. ISSUE AN AD TO MANDATE PROPELLER DISASSEMBLY AND INSPECTION OF ALL CRITICAL ITEMS. REVISE AD T91-11-51 TO HAVE ALL TITANIUM-NITRATED OIL TRANSFER TUBES REMOVED FROM SERVICE AND NO LONGER ALLOWED TO BE USED. ADDITIONALLY, THE FAA WILL REVIEW ALL DESIGN CHANGES TO CRITICAL COMPONENTS SINCE JANUARY 1987. ADVISE HAMILTON STANDARD TO INCORPORATE A FAIL-SAFE FEATURE INTO THE DESIGN OF 14RF, 14SF, AND 6/5500/F-1 MODEL PROPELLERS. THE FAIL-SAFE DESIGN FEATURE WILL BE CERTIFICATED WITHIN 2 YEARS WITH INCORPORATION IN ALL IN-SERVICE PROPELLER UNITS WITHIN 3 YEARS THEREAFTER.