THE CREW WERE ADVISED THAT THE ACFT'S VACUUM PUMP SYSTEM WAS INOPERATIVE DUE TO A SHEARED PUMP DRIVESHAFT. THE COPILOT HAD STATED THAT FSS HAD FORECAST 25,000 FT BROKEN & HE DID NOT FEEL HE WOULD NEED THE PUMP. AT 1735 THE PLT CONTACTED CENTER & REQUESTED RADAR ADVISORIES TO BROWNSVILLE. AT 1812 THE PILOT REQUESTED & WAS GRANTED PERMISSION TO DEVIATE AROUND A CELL. 12 MINUTES LATER THE TARGET DISAPPEARED. WRECKAGE EXAMINATION REVEALED THAT THE TAIL & RIGHT WING HAD SEPARATED IN FLIGHT. THERE WAS A VIP LEVEL 1 ECHO WITHIN 5 MI EAST & A VIP LEVEL 3 ECHO WITHIN 10 MI SE OF THE ACCIDENT SITE. MODERATE TO SEVERE CONVECTIVE TURBULENCE & UP & DOWN DRAFTS WOULD HAVE BEEN PRESENT BELOW 10,000 FT. THE PLT'S LIVER TISSUE PRODUCED 96 MG% ETHYL ALCOHOL & MIXED TISSE FLUID PRODUCED 112 MG%.

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

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

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

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

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

Contributing Factors

WEATHER CONDITION..TURBULENCE(THUNDERSTORMS)

Contributing Factors

WEATHER CONDITION..DOWNDRAFT

Contributing Factors

OVERCONFIDENCE IN PERSONAL ABILITY..PILOT IN COMMAND

Contributing Factors

IMPAIRMENT(ALCOHOL)..PILOT IN COMMAND

Contributing Factors

VACUUM SYSTEM..INOPERATIVE

Contributing Factors

OPERATION WITH KNOWN DEFICIENCIES IN EQUIPMENT..ATTEMPTED..PILOT IN COMMAND

Index for Oct1982 | Index of months