An air carrier medium large transport had a confusing set of commands from its TCASII in the traffic...

Attributes
ACN	260053
Time
Date	199401
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : lax
State Reference	CA
Altitude	msl bound lower : 1200 msl bound upper : 1200
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : lax
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	cruise other descent : approach
Route In Use	approach : visual
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	descent : approach
Route In Use	approach : straight in
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : cfi pilot : flight engineer
Experience	flight time last 90 days : 60 flight time total : 7800 flight time type : 100
ASRS Report	260053
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 100 flight time total : 8000 flight time type : 200
ASRS Report	260054
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : clearance other anomaly other other spatial deviation
Independent Detector	aircraft equipment other aircraft equipment : unspecified other controllera other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course flight crew : took evasive action other
Consequence	faa : reviewed incident with flight crew
Miss Distance	vertical : 600
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

After turning right base for visual approach to runway 24R we were approaching centerline of runway 24R from the north when TCASII RA commanded climb for traffic at 600 ft. This was followed immediately by TCASII RA to descend. After unsuccessfully trying to visually identify traffic, I observed that we were south of runway 24R centerline and approaching runway 25R centerline from the north. I advised the captain (PF) of our locations. Tower requested our intentions. I informed tower we were correcting back to runway 24L. He informed us the traffic (which had given us TCASII RA's) was on approach to runway 25L. Supplemental information from acn 260054: I corrected back to centerline for 24R. Talked to tower supervisor on telephone on arrival at gate, he advised no separation was lost with traffic on final to 25L.

Original NASA ASRS Text

Title: AN ACR MLG HAD A CONFUSING SET OF COMMANDS FROM ITS TCASII IN THE TFC PATTERN.

Narrative: AFTER TURNING R BASE FOR VISUAL APCH TO RWY 24R WE WERE APCHING CTRLINE OF RWY 24R FROM THE N WHEN TCASII RA COMMANDED CLB FOR TFC AT 600 FT. THIS WAS FOLLOWED IMMEDIATELY BY TCASII RA TO DSND. AFTER UNSUCCESSFULLY TRYING TO VISUALLY IDENT TFC, I OBSERVED THAT WE WERE S OF RWY 24R CTRLINE AND APCHING RWY 25R CTRLINE FROM THE N. I ADVISED THE CAPT (PF) OF OUR LOCATIONS. TWR REQUESTED OUR INTENTIONS. I INFORMED TWR WE WERE CORRECTING BACK TO RWY 24L. HE INFORMED US THE TFC (WHICH HAD GIVEN US TCASII RA'S) WAS ON APCH TO RWY 25L. SUPPLEMENTAL INFO FROM ACN 260054: I CORRECTED BACK TO CTRLINE FOR 24R. TALKED TO TWR SUPVR ON TELEPHONE ON ARR AT GATE, HE ADVISED NO SEPARATION WAS LOST WITH TFC ON FINAL TO 25L.

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.

An air carrier medium large transport had a confusing set of commands from its TCASII in the traffic pattern.