Potential conflict sensed by TCASII RA, twice in a row.

Attributes
ACN	208929
Time
Date	199204
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : lax
State Reference	CA
Altitude	msl bound lower : 9500 msl bound upper : 11000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdv
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	descent other
Route In Use	approach : straight in arrival other arrival star : star enroute airway : lax
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	climbout : intermediate altitude
Route In Use	enroute : direct
Flight Plan	VFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 155 flight time total : 7500 flight time type : 2400
ASRS Report	208929
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation
Situations
ATC Facility	procedure or policy : unspecified

Narrative:

TCASII TA given as other aircraft (possibly a VFR pop-up who was climbing out near the localizer) was at 2 O'clock position and 1000 ft below climbing. First TCASII RA given as aircraft was under right wing at minus 300 ft on TCASII screen. Climb command given by TCASII. Climbed from 9500-10500 and got 'clear of conflict.' as my aircraft leveled off at 10500 and started to descend to the profile altitudes, another TCASII RA occurred as another aircraft was behind our wing at minus 100 ft. A second climb command was issued, and this time I climbed to 11000 MSL before clear of conflict. We never received an ATC advisory on this aircraft and we never made visual contact; however, I do believe that an aircraft was there as the controller did acknowledge an aircraft off our right side after the event. The remainder of the flight was uneventful.

Original NASA ASRS Text

Title: POTENTIAL CONFLICT SENSED BY TCASII RA, TWICE IN A ROW.

Narrative: TCASII TA GIVEN AS OTHER ACFT (POSSIBLY A VFR POP-UP WHO WAS CLBING OUT NEAR THE LOC) WAS AT 2 O'CLOCK POS AND 1000 FT BELOW CLBING. FIRST TCASII RA GIVEN AS ACFT WAS UNDER R WING AT MINUS 300 FT ON TCASII SCREEN. CLB COMMAND GIVEN BY TCASII. CLBED FROM 9500-10500 AND GOT 'CLR OF CONFLICT.' AS MY ACFT LEVELED OFF AT 10500 AND STARTED TO DSND TO THE PROFILE ALTS, ANOTHER TCASII RA OCCURRED AS ANOTHER ACFT WAS BEHIND OUR WING AT MINUS 100 FT. A SECOND CLB COMMAND WAS ISSUED, AND THIS TIME I CLBED TO 11000 MSL BEFORE CLR OF CONFLICT. WE NEVER RECEIVED AN ATC ADVISORY ON THIS ACFT AND WE NEVER MADE VISUAL CONTACT; HOWEVER, I DO BELIEVE THAT AN ACFT WAS THERE AS THE CTLR DID ACKNOWLEDGE AN ACFT OFF OUR R SIDE AFTER THE EVENT. THE REMAINDER OF THE FLT WAS UNEVENTFUL.

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.