TCASII. Misunderstood communication clearance.

Attributes
ACN	315034
Time
Date	199508
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : lax
State Reference	CA
Altitude	msl bound lower : 2000 msl bound upper : 2200
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : lax
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	climbout : initial climbout : intermediate altitude
Flight Plan	IFR
Aircraft 2
Operator	general aviation : personal
Make Model Name	King Air C90 E90
Operating Under FAR Part	Part 91
Flight Phase	cruise other
Flight Plan	VFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : commercial pilot : flight engineer pilot : instrument pilot : atp
Experience	flight time last 90 days : 200 flight time total : 11600 flight time type : 2100
ASRS Report	315034
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : flight engineer pilot : commercial
ASRS Report	315032
Events
Anomaly	conflict : airborne less severe other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : took evasive action other
Consequence	Other
Miss Distance	horizontal : 1000 vertical : 250
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation other

Narrative:

Usually when taking off from lax runway 25R we are restr to 2000 ft, but almost always get 3000 ft before takeoff or in the climb. This time in the climb, I thought I heard '3000 ft' just as the TCASII went off (TA yellow alert at about 1500-1600 ft). I kept my hand on the throttles to keep them from coming back (autothrottles) at the 2000 ft MCP altitude so the first officer could change the MCP window, for the new altitude. At that point I asked if he could see the traffic, just as the red RA sounded 'descend, descend.' I started pulling the throttles back, but we rounded off at 2200 ft going back to 2000 ft. Traffic was called at 2500 ft. We saw a beech king air about 2300 ft turning away from us. The first officer said he could read the n-number at 3-4 O'clock. Center asked if we had followed a TCASII alert. We said 'affirmative.' after 25 yrs, I heard what I wanted to hear. We had not been cleared to 3000 ft. There was a lot of noise in the cockpit TA's, RA's, questions, etc. But, this is a very dangerous situation at lax: jet aircraft in a high rate climb having to level at 2000 ft for possible 2500 ft traffic. We can easily be going up 3000-4000 FPM if we are light. Our overshoot and him being a few hundred ft low, could mean a disaster. (Note: first officer who also filed a report, stated he heard 'climb, climb.' I heard 'descend, descend.') supplemental information from acn 315032: during takeoff from runway 25R at lax aug/xx/95, we received a TCASII RA alert at 1900 ft just prior to leveling off at 2000 ft. The TCASII alert was 'climb, climb.' the TCASII also showed the traffic to be at the 3 O'clock position, when I, the first officer (PNF), observed it. The captain, who was flying, immediately followed the TCASII instruction to climb which resulted in our flying through our level off altitude of 2000-2200 ft. At this point the traffic was off our 4 O'clock and passing behind. There was no warning from ATC about the traffic until I announced we were deviating on a TCASII alert. ATC said traffic was at 2500 ft, but from where we were it was at 2200 ft.

Original NASA ASRS Text

Title: TCASII. MISUNDERSTOOD COM CLRNC.

Narrative: USUALLY WHEN TAKING OFF FROM LAX RWY 25R WE ARE RESTR TO 2000 FT, BUT ALMOST ALWAYS GET 3000 FT BEFORE TKOF OR IN THE CLB. THIS TIME IN THE CLB, I THOUGHT I HEARD '3000 FT' JUST AS THE TCASII WENT OFF (TA YELLOW ALERT AT ABOUT 1500-1600 FT). I KEPT MY HAND ON THE THROTTLES TO KEEP THEM FROM COMING BACK (AUTOTHROTTLES) AT THE 2000 FT MCP ALT SO THE FO COULD CHANGE THE MCP WINDOW, FOR THE NEW ALT. AT THAT POINT I ASKED IF HE COULD SEE THE TFC, JUST AS THE RED RA SOUNDED 'DSND, DSND.' I STARTED PULLING THE THROTTLES BACK, BUT WE ROUNDED OFF AT 2200 FT GOING BACK TO 2000 FT. TFC WAS CALLED AT 2500 FT. WE SAW A BEECH KING AIR ABOUT 2300 FT TURNING AWAY FROM US. THE FO SAID HE COULD READ THE N-NUMBER AT 3-4 O'CLOCK. CTR ASKED IF WE HAD FOLLOWED A TCASII ALERT. WE SAID 'AFFIRMATIVE.' AFTER 25 YRS, I HEARD WHAT I WANTED TO HEAR. WE HAD NOT BEEN CLRED TO 3000 FT. THERE WAS A LOT OF NOISE IN THE COCKPIT TA'S, RA'S, QUESTIONS, ETC. BUT, THIS IS A VERY DANGEROUS SIT AT LAX: JET ACFT IN A HIGH RATE CLB HAVING TO LEVEL AT 2000 FT FOR POSSIBLE 2500 FT TFC. WE CAN EASILY BE GOING UP 3000-4000 FPM IF WE ARE LIGHT. OUR OVERSHOOT AND HIM BEING A FEW HUNDRED FT LOW, COULD MEAN A DISASTER. (NOTE: FO WHO ALSO FILED A RPT, STATED HE HEARD 'CLB, CLB.' I HEARD 'DSND, DSND.') SUPPLEMENTAL INFO FROM ACN 315032: DURING TKOF FROM RWY 25R AT LAX AUG/XX/95, WE RECEIVED A TCASII RA ALERT AT 1900 FT JUST PRIOR TO LEVELING OFF AT 2000 FT. THE TCASII ALERT WAS 'CLB, CLB.' THE TCASII ALSO SHOWED THE TFC TO BE AT THE 3 O'CLOCK POS, WHEN I, THE FO (PNF), OBSERVED IT. THE CAPT, WHO WAS FLYING, IMMEDIATELY FOLLOWED THE TCASII INSTRUCTION TO CLB WHICH RESULTED IN OUR FLYING THROUGH OUR LEVEL OFF ALT OF 2000-2200 FT. AT THIS POINT THE TFC WAS OFF OUR 4 O'CLOCK AND PASSING BEHIND. THERE WAS NO WARNING FROM ATC ABOUT THE TFC UNTIL I ANNOUNCED WE WERE DEVIATING ON A TCASII ALERT. ATC SAID TFC WAS AT 2500 FT, BUT FROM WHERE WE WERE IT WAS AT 2200 FT.

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.