Cargo flight on climbout approaching 16000' told to climb and maintain 15000'.

Attributes
ACN	182299
Time
Date	199106
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : ont
State Reference	CA
Altitude	msl bound lower : 15000 msl bound upper : 17000
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Controlling Facilities	artcc : zla tower : las
Operator	common carrier : air carrier
Make Model Name	Heavy Transport, Low Wing, 4 Turbojet Eng
Flight Phase	climbout : intermediate altitude
Route In Use	enroute airway : zla
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : second officer
Qualification	pilot : instrument pilot : flight engineer pilot : commercial
Experience	flight time last 90 days : 150 flight time total : 2000 flight time type : 300
ASRS Report	182299
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	altitude deviation : overshoot conflict : airborne less severe non adherence : clearance
Independent Detector	other controllera
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

After takeoff during climb out the first officer was flying and the captain had the radios. As I momentarily switched my attention from the F/east's panel to the front of the cockpit. I heard the ATC controller tell us to climb and maintain 15000'. I noticed we were approaching 15000' at the time and the captain told the controller that we were passing 16000' for 17000' as previously assigned, but we could descend back to 15000'. The controller repeated his directions to maintain 15000' and called out traffic at 11 O'clock and 16000'. The copilot took immediate action to rapidly return us to 15000' as we searched for and located the traffic approaching off our left wing. Although I did not pay attention to our original altitude assignment, the captain and first officer were very confident that we had been cleared to 17000'. The remainder of the flight was unremarkable.

Original NASA ASRS Text

Title: CARGO FLT ON CLIMBOUT APCHING 16000' TOLD TO CLIMB AND MAINTAIN 15000'.

Narrative: AFTER TKOF DURING CLBOUT THE F/O WAS FLYING AND THE CAPT HAD THE RADIOS. AS I MOMENTARILY SWITCHED MY ATTN FROM THE F/E'S PANEL TO THE FRONT OF THE COCKPIT. I HEARD THE ATC CTLR TELL US TO CLB AND MAINTAIN 15000'. I NOTICED WE WERE APCHING 15000' AT THE TIME AND THE CAPT TOLD THE CTLR THAT WE WERE PASSING 16000' FOR 17000' AS PREVIOUSLY ASSIGNED, BUT WE COULD DSND BACK TO 15000'. THE CTLR REPEATED HIS DIRECTIONS TO MAINTAIN 15000' AND CALLED OUT TFC AT 11 O'CLOCK AND 16000'. THE COPLT TOOK IMMEDIATE ACTION TO RAPIDLY RETURN US TO 15000' AS WE SEARCHED FOR AND LOCATED THE TFC APCHING OFF OUR LEFT WING. ALTHOUGH I DID NOT PAY ATTN TO OUR ORIGINAL ALT ASSIGNMENT, THE CAPT AND F/O WERE VERY CONFIDENT THAT WE HAD BEEN CLRED TO 17000'. THE REMAINDER OF THE FLT WAS UNREMARKABLE.

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.