NTSB Identification: DCA85AA015.
The docket is stored on NTSB microfiche number 27874.
Scheduled 14 CFR operation of CHINA AIRLINES (D.B.A. SUNG SHAN AIRPORT )
Accident occurred Tuesday, February 19, 1985 in SAN FRANCISCO, CA
Aircraft: BOEING 747 SP-09, registration: N4522V
Injuries: 2 Serious,271 Uninjured.

WHILE ABV A CLOUD LAYER (TOP AT FL 370) NR THE JET STREAM, AUTOPLT WAS ENGAGED & WAS IN THE PERFORMANCE MNGMNT SYS (PMS)MODE. THE PMS PROVIDED PITCH GUIDANCE TO HOLD FL 410, ROLL GUIDANCE TO AILERONS & SPOILERS FOR ROLL CTL & AUTOTHROTTLE TO MAINT .85 MACH (254 KIAS). ACFT ENCOUNTERED CLR AIR TURBC & AIRSPEED BGN TO VARY BTN .84 & .88 MACH. PMS BGN MOVING THROTTLES FORE & AFT TO HOLD .85 MACH. DRG AUTOTHROTTLE ADJUSTMENTS, #4 ENG THRUST DECREASED & 'HUNG' AT APRX 1.0 EPR & AIRSPEED BGN DECREASING. FLT ENGINEER ATMTD TO MANUALLY RCVR THE #4 ENG THRUST, BUT DID NOT CLOSE THE BLEED AIR VLV BFR ADJUSTING THE #4 THROTTLE. THE #4 ENG REMAINED AT APRX 1.0 EPR. AS THE ACFT SLOWED, AUTOPLT TRIMMED TO HOLD ALT & HDG TIL THE PLT DISENGAGED IT. AT THAT TIME, ACFT ROLLED/YAWED RGT & ENTERED AN UNCTLD DSCNT INTO THE CLOUDS. AS IT BROKE OUT OF THE CLOUDS AT 11,000', CREW RCVRD & LVLD AT 9500'. DRG DSCNT/RCVRY, ACFT WAS DMGD BY ACCELLERATION FORCES & HI SPEED. THERE WAS EVIDENCE THE PLT WAS PREOCCUPIED WITH ENG PRBLM, DIDN'T MONITOR INSTRUMENTS & OVER-RELIED ON AUTOPLT.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

FLIGHT/NAVIGATION INSTRUMENT(S)..INATTENTIVE..PILOT IN COMMAND

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

DIVERTED ATTENTION..PILOT IN COMMAND

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

AIRSPEED..NOT MAINTAINED..PILOT IN COMMAND

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

FLIGHT CONTROLS..IMPROPER USE OF..PILOT IN COMMAND

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

AIRCRAFT HANDLING..NOT MAINTAINED..PILOT IN COMMAND

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

DESIGN STRESS LIMITS OF AIRCRAFT..EXCEEDED..PILOT IN COMMAND


Contributing Factors

WEATHER CONDITION..UNFAVORABLE WIND


Contributing Factors

WEATHER CONDITION..WINDSHEAR


Contributing Factors

WEATHER CONDITION..TURBULENCE,CLEAR AIR



Contributing Factors

OVERCONFIDENCE IN AIRCRAFT'S ABILITY..PILOT IN COMMAND

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