NTSB Identification: LAX94FA073.
The docket is stored in the Docket Management System (DMS). Please contact Records Management Division
Nonscheduled 14 CFR
Accident occurred Wednesday, December 15, 1993 in SANTA ANA, CA
Probable Cause Approval Date: 10/06/1994
Aircraft: Israel Aircraft Industries 1124A, registration: N309CK
Injuries: 5 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 aircraft accident report.

A BEECH LINER, BOEING 757 & ISRAEL WESTWIND (WW) WERE VECTORED FOR LANDINGS ON RWY 19R. THE 757 & WW WERE SEQUENCED FOR VISUAL APCHS BEHIND THE BEECH. BEFORE BEING CLEARED FOR VISUAL APCH, THE WW WAS CLOSING 3.5 MI FROM THE 757 ON A CONVERGING COURSE. THE 757 & WW CREWS WERE TOLD TO SLOW TO 150 KTS. THE 757 SLOWED BELOW 150 KTS & WAS HIGH ON FINAL APPROACH WITH A 5.6 DEG DESCENT. THE WW CONTINUED TO CONVERGE TO ABOUT 2.1 MI BEHIND THE 757 ON A 3 DEG APCH. ATC DID NOT SPECIFICALLY ADVISE, AND WAS NOT REQUIRED BY ATC HANDBOOK TO ADVISE, THE WW PILOTS THAT THEY WERE BEHIND A BOEING 757. CAPT DISCUSSED POSSIBLE WAKE TURBULENCE, FLEW ILS 1 DOT HIGH, NOTED CLOSENESS TO THE 757 & INDICATED THERE SHOULD BE NO PROBLEM. WHILE DESCENDING THRU APRX 1100 FT MSL, THE WW ENCOUNTERED WAKE TURBULENCE FROM THE 757, ROLLED INTO A STEEP DESCENT & CRASHED. THE CREW LACKED SPECIFIC WAKE TURBULENCE TRAINING. CHLORPHENIRAMINE (COMMON OVER-THE-COUNTER ANTI-HISTAMINE; NOT APPROVED FOR FLYING) DETECTED IN PILOT'S LUNG TISSUE (0.094 UG/ML). (SEE SPCL STUDY NTSB/SIR-94/01)

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

THE PILOT-IN-COMMAND'S FAILURE TO MAINTAIN ADEQUATE SEPARATION BEHIND THE BOEING 757 AND/OR REMAIN ABOVE ITS FLIGHT PATH DURING THE APPROACH, WHICH RESULTED IN AN ENCOUNTER WITH WAKE VORTICES FROM THE 757. FACTORS RELATED TO THE ACCIDENT WERE: AN INADEQUACY IN THE ATC PROCEDURE RELATED TO VISUAL APPROACHES AND VFR OPERATIONS BEHIND HEAVIER AIRPLANES, AND THE RESULTANT LACK OF INFORMATION TO THE WESTWIND PILOTS FOR THEM TO DETERMINE THE RELATIVE FLIGHT PATH OF THEIR AIRPLANE WITH RESPECT TO THE BOEING 757'S FLIGHT PATH.

Full narrative available

Index for Dec1993 | Index of months