Commuter light transport altitude deviation overshot during climb.

Attributes
ACN	122649
Time
Date	198909
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : gmn
State Reference	CA
Altitude	msl bound lower : 15000 msl bound upper : 15500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zla
Operator	common carrier : air carrier
Make Model Name	Light Transport, Low Wing, 2 Turboprop Eng
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : atp
Experience	flight time last 90 days : 150 flight time total : 6000 flight time type : 1200
ASRS Report	122649
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	altitude deviation : overshoot non adherence : required legal separation non adherence : clearance
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Ambiguous
Air Traffic Incident	other

Narrative:

After departing bur for smf, we were given vectors to gmn. We were given a climb from 12000 to 16000'. Both my first officer and I clearly heard 16000'. I also put 16000' in the altitude alerter. Additionally, 16000' was the correct altitude for the direction of flight. When we were passing through 15500', the controller (different sector from the one who climbed us to 16000') told us, 'descend and maintain 15000...immediately.' by the time the controller said descend, I was thinking, 'the controller has got our call sign confused again.' it wasn't until he said immediately that I realized he did mean us. Apparently the second controller thought the first controller had climbed us to only 15000'. There was conflicting traffic. This was set up by either: 1) both my first officer and I hearing (and expecting an even altitude) 16000' instead of 15000'; 2) controller #1 issuing the wrong altitude; 3) controller #2 incorrectly assuming we had been cleared to 15000'. This was made worse by: 1) the frequent occurrence of incorrect/similar call sing; 2) the 'immediately' so late in the transmission.

Original NASA ASRS Text

Title: COMMUTER LTT ALT DEVIATION OVERSHOT DURING CLIMB.

Narrative: AFTER DEPARTING BUR FOR SMF, WE WERE GIVEN VECTORS TO GMN. WE WERE GIVEN A CLB FROM 12000 TO 16000'. BOTH MY F/O AND I CLEARLY HEARD 16000'. I ALSO PUT 16000' IN THE ALT ALERTER. ADDITIONALLY, 16000' WAS THE CORRECT ALT FOR THE DIRECTION OF FLT. WHEN WE WERE PASSING THROUGH 15500', THE CTLR (DIFFERENT SECTOR FROM THE ONE WHO CLBED US TO 16000') TOLD US, 'DSND AND MAINTAIN 15000...IMMEDIATELY.' BY THE TIME THE CTLR SAID DSND, I WAS THINKING, 'THE CTLR HAS GOT OUR CALL SIGN CONFUSED AGAIN.' IT WASN'T UNTIL HE SAID IMMEDIATELY THAT I REALIZED HE DID MEAN US. APPARENTLY THE SECOND CTLR THOUGHT THE FIRST CTLR HAD CLBED US TO ONLY 15000'. THERE WAS CONFLICTING TFC. THIS WAS SET UP BY EITHER: 1) BOTH MY F/O AND I HEARING (AND EXPECTING AN EVEN ALT) 16000' INSTEAD OF 15000'; 2) CTLR #1 ISSUING THE WRONG ALT; 3) CTLR #2 INCORRECTLY ASSUMING WE HAD BEEN CLRED TO 15000'. THIS WAS MADE WORSE BY: 1) THE FREQUENT OCCURRENCE OF INCORRECT/SIMILAR CALL SING; 2) THE 'IMMEDIATELY' SO LATE IN THE XMISSION.

Data retrieved from NASA's ASRS site as of August 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.