Air carrier medium large transport climbed 1500' above cruise altitude.

Attributes
ACN	80777
Time
Date	198801
Day	Tue
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : yyz
State Reference	ON
Altitude	msl bound lower : 17000 msl bound upper : 18500
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : cyyz
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
ASRS Report	80777
Person 2
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude inflight encounter : weather non adherence : clearance
Independent Detector	other controllera other flight crewa
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:

10 1/2 hours into the crew duty day. Climbed out in moderate turbulence and solid IFR to 17000'. Leveled off. Ride and then received a frequency change to toronto center. With the exchange came an altimeter change with an increase of about 150'. As the PNF I set my altitude after announcing the value to the captain. He reset it to the correct value and noted we then were at 17100' or thereabouts. On the medium large transport autoplt, after having leveled off at a specified altitude, to recapture the new 17000' after changing the altimeter, it is necessary to change the value in the window to 16000' or 18000' to get a vertical movement going. Exactly what the captain did next is not clear. I looked up and saw 19000' in the altitude window, the altimeter at 18500' and climbing. I immediately asked, 'what altitude are we clrd to?' thinking we must have received a clearance while I was getting the identify. The captain immediately started a des. Just as we started down toronto center called and asked our altitude. I paused a moment and said, 'we're getting bounced around pretty good (which we were) and would be back to 17000 shortly.' 3000' vvi achieved this end quickly.

Original NASA ASRS Text

Title: ACR MLG CLIMBED 1500' ABOVE CRUISE ALT.

Narrative: 10 1/2 HRS INTO THE CREW DUTY DAY. CLBED OUT IN MODERATE TURBULENCE AND SOLID IFR TO 17000'. LEVELED OFF. RIDE AND THEN RECEIVED A FREQ CHANGE TO TORONTO CENTER. WITH THE EXCHANGE CAME AN ALTIMETER CHANGE WITH AN INCREASE OF ABOUT 150'. AS THE PNF I SET MY ALT AFTER ANNOUNCING THE VALUE TO THE CAPT. HE RESET IT TO THE CORRECT VALUE AND NOTED WE THEN WERE AT 17100' OR THEREABOUTS. ON THE MLG AUTOPLT, AFTER HAVING LEVELED OFF AT A SPECIFIED ALT, TO RECAPTURE THE NEW 17000' AFTER CHANGING THE ALTIMETER, IT IS NECESSARY TO CHANGE THE VALUE IN THE WINDOW TO 16000' OR 18000' TO GET A VERT MOVEMENT GOING. EXACTLY WHAT THE CAPT DID NEXT IS NOT CLEAR. I LOOKED UP AND SAW 19000' IN THE ALT WINDOW, THE ALTIMETER AT 18500' AND CLBING. I IMMEDIATELY ASKED, 'WHAT ALT ARE WE CLRD TO?' THINKING WE MUST HAVE RECEIVED A CLRNC WHILE I WAS GETTING THE IDENT. THE CAPT IMMEDIATELY STARTED A DES. JUST AS WE STARTED DOWN TORONTO CENTER CALLED AND ASKED OUR ALT. I PAUSED A MOMENT AND SAID, 'WE'RE GETTING BOUNCED AROUND PRETTY GOOD (WHICH WE WERE) AND WOULD BE BACK TO 17000 SHORTLY.' 3000' VVI ACHIEVED THIS END QUICKLY.

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.