Altitude deviation. Altitude overshot. Missed crossing restriction.

Attributes
ACN	142775
Time
Date	199004
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : sea
State Reference	WA
Altitude	msl bound lower : 11000 msl bound upper : 12000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : sea
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	descent other
Route In Use	arrival other arrival star : star
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : flight engineer pilot : atp pilot : instrument
Experience	flight time last 90 days : 200 flight time total : 5000 flight time type : 200
ASRS Report	142775
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : crossing restriction not met altitude deviation : overshoot non adherence : clearance other anomaly other
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued new clearance none taken : detected after the fact
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were given the following clrncs during the first 71 mi of the jawbn arrival vancouver transition. Cross vancouver at FL280 or below 250 KTS to maintain 16000' then cross diggn at 16000' to maintain 12000' then maintain 12000' until alkia descend and maintain 7000'. As PF I did not understand or hear clearly the third clearance given at approximately diggn. I thought I asked the other two crew members if we were to cross alkia at 7000' and thought they said yes. 7000' was set in awi (altitude warning indicator) by the captain. The procedure at air carrier a airlines is to set the lowest altitude that you are cleared to at that time. At approximately 13 mi from alkia I began my descent to cross alkia at 7000' (the clearance I thought we had been given). At approximately 11000' the captain and second officer, restated that we were to maintain 12000' until alkia. I leveled off at 11000' and the captain contacted approach and reaffirmed the clearance, then stated that we may have initially misunderstood it when given and asked if we could maintain 11000' to alkia. Approach approved. I think several factors contributed to this situation. I was flying an large transport model new to me as a result of the air carrier a and B merger. We had only recently started mixing crews and flying old large transport models. The autoplt was significantly different and throughout the descent I was trying to learn its capabilities. The captain was also my first ex-air carrier B captain and was knowledgeable in its use and was showing me how to use it. I had flown the model previously but he was the first captain to know its features. So at the time of the misunderstood clearance I was preoccupied with leveling the aircraft using the unfamiliar autoplt and did not hear it clearly for myself. Seeing 7000' set in the awi (not quite correct according to procedure) led me to further believe I was to descend. Also the previous tower clrncs were to be at a certain altitude at the fix which further had my thoughts toward that end if you will. The rest of the flight went west/O occurrence.

Original NASA ASRS Text

Title: ALT DEVIATION. ALT OVERSHOT. MISSED CROSSING RESTRICTION.

Narrative: WE WERE GIVEN THE FOLLOWING CLRNCS DURING THE FIRST 71 MI OF THE JAWBN ARR VANCOUVER TRANSITION. CROSS VANCOUVER AT FL280 OR BELOW 250 KTS TO MAINTAIN 16000' THEN CROSS DIGGN AT 16000' TO MAINTAIN 12000' THEN MAINTAIN 12000' UNTIL ALKIA DSND AND MAINTAIN 7000'. AS PF I DID NOT UNDERSTAND OR HEAR CLRLY THE THIRD CLRNC GIVEN AT APPROX DIGGN. I THOUGHT I ASKED THE OTHER TWO CREW MEMBERS IF WE WERE TO CROSS ALKIA AT 7000' AND THOUGHT THEY SAID YES. 7000' WAS SET IN AWI (ALT WARNING INDICATOR) BY THE CAPT. THE PROC AT ACR A AIRLINES IS TO SET THE LOWEST ALT THAT YOU ARE CLRED TO AT THAT TIME. AT APPROX 13 MI FROM ALKIA I BEGAN MY DSNT TO CROSS ALKIA AT 7000' (THE CLRNC I THOUGHT WE HAD BEEN GIVEN). AT APPROX 11000' THE CAPT AND S/O, RESTATED THAT WE WERE TO MAINTAIN 12000' UNTIL ALKIA. I LEVELED OFF AT 11000' AND THE CAPT CONTACTED APCH AND REAFFIRMED THE CLRNC, THEN STATED THAT WE MAY HAVE INITIALLY MISUNDERSTOOD IT WHEN GIVEN AND ASKED IF WE COULD MAINTAIN 11000' TO ALKIA. APCH APPROVED. I THINK SEVERAL FACTORS CONTRIBUTED TO THIS SITUATION. I WAS FLYING AN LGT MODEL NEW TO ME AS A RESULT OF THE ACR A AND B MERGER. WE HAD ONLY RECENTLY STARTED MIXING CREWS AND FLYING OLD LGT MODELS. THE AUTOPLT WAS SIGNIFICANTLY DIFFERENT AND THROUGHOUT THE DSNT I WAS TRYING TO LEARN ITS CAPABILITIES. THE CAPT WAS ALSO MY FIRST EX-ACR B CAPT AND WAS KNOWLEDGEABLE IN ITS USE AND WAS SHOWING ME HOW TO USE IT. I HAD FLOWN THE MODEL PREVIOUSLY BUT HE WAS THE FIRST CAPT TO KNOW ITS FEATURES. SO AT THE TIME OF THE MISUNDERSTOOD CLRNC I WAS PREOCCUPIED WITH LEVELING THE ACFT USING THE UNFAMILIAR AUTOPLT AND DID NOT HEAR IT CLRLY FOR MYSELF. SEEING 7000' SET IN THE AWI (NOT QUITE CORRECT ACCORDING TO PROC) LED ME TO FURTHER BELIEVE I WAS TO DSND. ALSO THE PREVIOUS TWR CLRNCS WERE TO BE AT A CERTAIN ALT AT THE FIX WHICH FURTHER HAD MY THOUGHTS TOWARD THAT END IF YOU WILL. THE REST OF THE FLT WENT W/O OCCURRENCE.

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.