The docket is stored on NTSB microfiche number 31249.
Scheduled 14 CFR AERONAVES DE MEXICO, S.A.
Accident occurred Sunday, August 31, 1986 in CERRITOS, CA
Probable Cause Approval Date: 03/07/1988
Aircraft: McDonnell Douglas DC-9-32, registration: XAJED
Injuries: 82 Fatal, 8 Minor.
The Safety Board’s full report on this investigation is provided as Aviation Accident Report number AAR-87/07. To obtain a copy of this report, or to view the executive summary online, please see the Web site at http://www.ntsb.gov/publictn/publictn.htm
AT APRX 1140 PDT, A PIPER PA-28, N4891F, DEPARTED TORRANCE, CA ON A VFR FLT TO BIG BEAR, CA. AFTER TAKEOFF, THE PLT TURNED EASTBOUND TWD THE PARADISE VORTAC WITH HIS X-PONDER SQUAWKING 1200. AT THAT TIME, AEROMEXICO FLT 498 (DC-8, MEX REGISTRY XA-JED) WAS ON ARRIVAL, RCVG NORTHBOUND VECTORS FM LAX APCH CTL (AR-1 CTLR) FOR AN ILS APCH TO THE LAX INTL ARPT. AT 1151:04, THE CTLR ASKED FLT 498 TO RDC SPD TO 190 KTS & DSCND FM 7000′ TO 6000′. DRG THIS TIME, THE CTLR WAS CTLG OTR TRAFFIC & PROVIDING RADAR ADVISORIES, BUT DIDN’T SEE A DISPLAY FOR N4891F ON HIS SCOPE. AT 1152:09, N4891F & FLT 498 CONVERGED & COLLIDED AT APRX 6560′, THEN FELL TO THE GND. AN INV REVEALED N4891F HAD INADVERTENTLY ENTERED THE LAX TERMINAL CONTROL AREA (TCA) & WASN’T IN RADIO CONTACT WITH ATC. LAX TRACON WASN’T EQUIPPED WITH AN AUTO CONFLICT ALERT SYS & THE ANALOG BEACON RESPONSE FM N4891F’S X-PONDER WASN’T DISPLAYED DUE TO EQUIP CONFIGURATION. N4891F’S PSN WAS DISPLAYED BY AN ALPHANUMERIC TRIANGLE, BUT THE PRIMARY TARGET WASN’T DISPLAYED DUE TO AN ATMOSPHERIC INVERSION.
The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
RADAR,APPROACH/DEPARTURE..INADEQUATE
PROCEDURE INADEQUATE..FAA(OTHER/ORGANIZATION)
Contributing Factors:
IDENTIFICATION OF AIRCRAFT ON RADAR..NOT ATTAINED
PROCEDURES/DIRECTIVES..NOT FOLLOWED..PILOT OF OTHER AIRCRAFT
UNSAFE/HAZARDOUS CONDITION..INADVERTENT..PILOT OF OTHER AIRCRAFT
VISUAL LOOKOUT..INADEQUATE..PILOT OF OTHER AIRCRAFT
VISUAL LOOKOUT..INADEQUATE..PILOT IN COMMAND