Altitude deviation on arrival at yyz.

Attributes
ACN	480168
Time
Date	200007
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : cyyz.airport
State Reference	ON
Altitude	msl bound lower : 10500 msl bound upper : 12000
Environment
Flight Conditions	IMC
Weather Elements	Thunderstorm
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : czyz.artcc
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : vacating altitude
Route In Use	arrival : profile descent
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain
Qualification	pilot : commercial pilot : private pilot : instrument pilot : flight engineer pilot : atp pilot : multi engine
Experience	flight time last 90 days : 95 flight time total : 10000 flight time type : 95
ASRS Report	480168
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial
Events
Anomaly	altitude deviation : overshoot altitude deviation : crossing restriction not met non adherence : clearance other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : became reoriented flight crew : returned to original clearance
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Approaching cyyz, ATC issued us routing to include guelf (found on runway 23/24L profile descent). ATC gave us an initial descent to FL200, then cleared us the runway 5/6R profile descent. We had changed controllers/frequencys before the runway 5/6R profile descent was given. As guelf is not on the runway 5/6R arrival, I took manual control of the aircraft while we asked the controller for verification. He changed our arrival routing point to ricki and the runway 5/6R profile descent. A short time later, the controller then issued us another clearance to descend and maintain 7000 ft. The first officer was placing new routing in the FMC. I continued our descent with some thunderstorms in the area on radar. While descending to 7000 ft, I realized (just before the 15 DME arc) that subsequent altitude clrncs given in canadian airspace do not negate our requirement to meet the altitudes shown on the profile descent. As soon as I recognized my error, I leveled the aircraft between 10500-11000 ft, then continued our descent to 7000 ft. (The 15 DME restr is ywt 15 DME arc at or between 12000-14000 ft). No conflicts were encountered and no adverse effects. I am a relatively new captain, and new to this aircraft. Feel that the conflict in clrncs given, and my workload management (watching for thunderstorms, checking the first officer's FMC work, and manually flying the aircraft) along with the confusion/difference in united states/canadian procedures contributed to my missing the restr.

Original NASA ASRS Text

Title: ALTDEV ON ARR AT YYZ.

Narrative: APCHING CYYZ, ATC ISSUED US ROUTING TO INCLUDE GUELF (FOUND ON RWY 23/24L PROFILE DSCNT). ATC GAVE US AN INITIAL DSCNT TO FL200, THEN CLRED US THE RWY 5/6R PROFILE DSCNT. WE HAD CHANGED CTLRS/FREQS BEFORE THE RWY 5/6R PROFILE DSCNT WAS GIVEN. AS GUELF IS NOT ON THE RWY 5/6R ARR, I TOOK MANUAL CTL OF THE ACFT WHILE WE ASKED THE CTLR FOR VERIFICATION. HE CHANGED OUR ARR ROUTING POINT TO RICKI AND THE RWY 5/6R PROFILE DSCNT. A SHORT TIME LATER, THE CTLR THEN ISSUED US ANOTHER CLRNC TO DSND AND MAINTAIN 7000 FT. THE FO WAS PLACING NEW ROUTING IN THE FMC. I CONTINUED OUR DSCNT WITH SOME TSTMS IN THE AREA ON RADAR. WHILE DSNDING TO 7000 FT, I REALIZED (JUST BEFORE THE 15 DME ARC) THAT SUBSEQUENT ALT CLRNCS GIVEN IN CANADIAN AIRSPACE DO NOT NEGATE OUR REQUIREMENT TO MEET THE ALTS SHOWN ON THE PROFILE DSCNT. AS SOON AS I RECOGNIZED MY ERROR, I LEVELED THE ACFT BTWN 10500-11000 FT, THEN CONTINUED OUR DSCNT TO 7000 FT. (THE 15 DME RESTR IS YWT 15 DME ARC AT OR BTWN 12000-14000 FT). NO CONFLICTS WERE ENCOUNTERED AND NO ADVERSE EFFECTS. I AM A RELATIVELY NEW CAPT, AND NEW TO THIS ACFT. FEEL THAT THE CONFLICT IN CLRNCS GIVEN, AND MY WORKLOAD MGMNT (WATCHING FOR TSTMS, CHKING THE FO'S FMC WORK, AND MANUALLY FLYING THE ACFT) ALONG WITH THE CONFUSION/DIFFERENCE IN UNITED STATES/CANADIAN PROCS CONTRIBUTED TO MY MISSING THE RESTR.

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.