Air carrier X TCASII RA had near midair collision with VFR aircraft. Evasive action taken. See and a...

Attributes
ACN	266818
Time
Date	199403
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : lax
State Reference	CA
Altitude	msl bound lower : 9500 msl bound upper : 10000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : lax
Operator	common carrier : air carrier
Make Model Name	MD-80 Series (DC-9-80) Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	cruise other
Route In Use	arrival other
Flight Plan	IFR
Aircraft 2
Operator	general aviation : personal
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	climbout : intermediate altitude
Route In Use	enroute : direct
Flight Plan	VFR
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Experience	controller non radar : 4 controller radar : 1
ASRS Report	266818
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : nmac non adherence : clearance non adherence : far other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other controllera
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	vertical : 300
Supplementary
Primary Problem	Flight Crew Human Performance

Narrative:

I am a controller at southern california TRACON. While working the arrival sector east of lax I accepted a handoff from ZLA on a MD80 (X) bound for lax, level at 10000 ft on the reeder STAR. The center controller advised me of traffic 5 mi south of baset intersection northbound at 9500 ft. I only observed a target with no mode C. The MD80 crew advised me they had the target on their TCASII but did not have the aircraft in sight visually. I gave an update to the crew of the traffic at '12 O'clock, 2 mi, altitude unknown.' just prior to the 2 aircraft targets merging the MD80 crew responded to an RA and descended to avoid the suspect aircraft. After the crew advised me of the deviation I observed a mode C readout of the suspect aircraft at 10900 ft. Apparently the suspect aircraft climbed as the MD80 descended. The TCASII RA seemed appropriate to react upon by the MD80 crew. However, it appears there is a problem with the lax ASR-9 in not receiving the altitude of the suspect aircraft.

Original NASA ASRS Text

Title: ACR X TCASII RA HAD NMAC WITH VFR ACFT. EVASIVE ACTION TAKEN. SEE AND AVOID CONCEPT.

Narrative: I AM A CTLR AT SOUTHERN CALIFORNIA TRACON. WHILE WORKING THE ARR SECTOR E OF LAX I ACCEPTED A HDOF FROM ZLA ON A MD80 (X) BOUND FOR LAX, LEVEL AT 10000 FT ON THE REEDER STAR. THE CTR CTLR ADVISED ME OF TFC 5 MI S OF BASET INTXN NBOUND AT 9500 FT. I ONLY OBSERVED A TARGET WITH NO MODE C. THE MD80 CREW ADVISED ME THEY HAD THE TARGET ON THEIR TCASII BUT DID NOT HAVE THE ACFT IN SIGHT VISUALLY. I GAVE AN UPDATE TO THE CREW OF THE TFC AT '12 O'CLOCK, 2 MI, ALT UNKNOWN.' JUST PRIOR TO THE 2 ACFT TARGETS MERGING THE MD80 CREW RESPONDED TO AN RA AND DSNDED TO AVOID THE SUSPECT ACFT. AFTER THE CREW ADVISED ME OF THE DEV I OBSERVED A MODE C READOUT OF THE SUSPECT ACFT AT 10900 FT. APPARENTLY THE SUSPECT ACFT CLBED AS THE MD80 DSNDED. THE TCASII RA SEEMED APPROPRIATE TO REACT UPON BY THE MD80 CREW. HOWEVER, IT APPEARS THERE IS A PROB WITH THE LAX ASR-9 IN NOT RECEIVING THE ALT OF THE SUSPECT ACFT.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Air carrier X TCASII RA had near midair collision with VFR aircraft. Evasive action taken. See and avoid concept.