The wrong altimeter setting results in an altitude undershoot above the transition level.

Attributes
ACN	496220
Time
Date	200012
Day	Sat
Local Time Of Day	1201 To 1800
Place
State Reference	OH
Altitude	msl bound lower : 30700 msl bound upper : 31000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zob.artcc tracon : lszh.tracon
Operator	common carrier : air carrier
Make Model Name	B727 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other vortac
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : multi engine pilot : atp pilot : commercial
Experience	flight time last 90 days : 90 flight time total : 5700 flight time type : 3000
ASRS Report	496220
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial
Events
Anomaly	altitude deviation : undershoot non adherence : published procedure non adherence : far non adherence : clearance other anomaly other
Independent Detector	other controllerb
Resolutory Action	controller : issued advisory flight crew : returned to assigned altitude
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Neither the captain nor the first officer set altimeters from 30.25 KG to 29.92 hg when climbing through FL180. ATC advised of 300 ft altitude deviation approximately 40 mins after leveloff into cruise. Both pilots noticed unset altimeters. The altimeters were then set to 29.92 and a climb was initiated to the assigned altitude. This error is likely attributable to high cockpit workload while passing through FL180. It is not a procedure for my airline, but having a climb checklist with altimeters as a checklist item would have possibly allowed us to avoid the problem. I will also be very alert to transition altitudes in the future.

Original NASA ASRS Text

Title: THE WRONG ALTIMETER SETTING RESULTS IN AN ALT UNDERSHOOT ABOVE THE TRANSITION LEVEL.

Narrative: NEITHER THE CAPT NOR THE FO SET ALTIMETERS FROM 30.25 KG TO 29.92 HG WHEN CLBING THROUGH FL180. ATC ADVISED OF 300 FT ALTDEV APPROX 40 MINS AFTER LEVELOFF INTO CRUISE. BOTH PLTS NOTICED UNSET ALTIMETERS. THE ALTIMETERS WERE THEN SET TO 29.92 AND A CLB WAS INITIATED TO THE ASSIGNED ALT. THIS ERROR IS LIKELY ATTRIBUTABLE TO HIGH COCKPIT WORKLOAD WHILE PASSING THROUGH FL180. IT IS NOT A PROC FOR MY AIRLINE, BUT HAVING A CLB CHKLIST WITH ALTIMETERS AS A CHKLIST ITEM WOULD HAVE POSSIBLY ALLOWED US TO AVOID THE PROB. I WILL ALSO BE VERY ALERT TO TRANSITION ALTS IN THE FUTURE.

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.