NTSB Identification: SEA93GA041.
The docket is stored on NTSB microfiche number 51009.
Accident occurred Friday, December 18, 1992 in BILLINGS, MT
Probable Cause Approval Date: 12/09/1993
Aircraft: CESSNA 550, registration: N6887Y
Injuries: 8 Fatal.
: NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this public aircraft accident report.DURING DESCENT INTO BILLINGS, THE CITATION WAS SEQUENCED BEHIND A BOEING 757, AND BOTH AIRPLANES WERE EVENTUALLY CLEARED FOR VISUAL APPROACHES. ABOUT 1-1/2 MI FROM THE RUNWAY THE CITATION WAS OBSERVED TO ROLL RAPIDLY TO THE INVERTED POSITION & DESCEND ALMOST VERTICALLY INTO THE GROUND. ACCORDING TO ATC TRANSCRIPTS AND THE AIRPLANES'S COCKPIT VOICE RECORDER, THE CREW OF THE CITATION HAD MAINTAINED VISUAL AWARENESS OF THE POSITION OF THE B-757 THROUGHOUT THE APPROACH. AT THE TIME OF THE UPSET, THE VERTICAL SEPARATION BETWEEN AIRPLANES WAS 600-1000 FT, AND THE HORIZONTAL SEPARATION WAS DECREASING BELOW 2.6 MI. ONE OF THE CITATION CAPTAIN'S LAST COMMENTS WAS 'ALMOST RAN OVER A SEVEN FIFTY SEVEN.' WINDS WERE 5 KTS.
The National Transportation Safety Board determines the probable cause(s) of this accident to be:
THE PILOT-IN-COMMAND'S FAILURE TO FOLLOW ESTABLISHED VORTEX AVOIDANCE PROCEDURES, AS PUBLISHED IN THE AIRMAN'S INFORMATION MANUAL, TO PROVIDE HIS OWN WAKE TURBULENCE SEPARATION. Index for Dec1992 | Index of months