Altitude undershoot when altimeter is not set passing through FL180.

Attributes
ACN	489620
Time
Date	200010
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : rdu.airport
State Reference	NC
Altitude	msl bound lower : 18500 msl bound upper : 19000
Environment
Flight Conditions	VMC
Light	Dawn
Aircraft 1
Controlling Facilities	artcc : zdc.artcc
Operator	common carrier : air taxi
Make Model Name	Super King Air 200/Huron
Operating Under FAR Part	Part 135
Flight Phase	climbout other cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air taxi
Function	flight crew : captain
Qualification	pilot : atp
Experience	flight time last 90 days : 75 flight time total : 5400 flight time type : 100
ASRS Report	489620
Person 2
Affiliation	company : air taxi
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : multi engine
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : undershoot non adherence : published procedure non adherence : clearance non adherence : far
Independent Detector	other controllerb
Resolutory Action	controller : issued advisory flight crew : returned to assigned altitude
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

The event occurred while on an IFR flight from rdu to mmu. During climb out, an environmental control system failed to a full hot condition. The first officer and myself were distraction by our attempt to control the cabin temperature. We used the normal and emergency checklists to control the cabin temperature. However, during the climb we ran both the climb and cruise checklists. However, we missed the 1800 ft check to reset our altimeter to 29.92 after leveling off at FL190 but set to rdu's pressure, center inquired as to our altitude. We corrected this and advised center. Through our distrs with the environmental control system we had failed to set our altimeters correctly to 29.92 causing us to be below FL190. After this was corrected the flight continued with no further incident. I feel that better CRM procedures and running the FL180 check with the climb check may help prevent this.

Original NASA ASRS Text

Title: ALT UNDERSHOOT WHEN ALTIMETER IS NOT SET PASSING THROUGH FL180.

Narrative: THE EVENT OCCURRED WHILE ON AN IFR FLT FROM RDU TO MMU. DURING CLBOUT, AN ENVIRONMENTAL CTL SYS FAILED TO A FULL HOT CONDITION. THE FO AND MYSELF WERE DISTR BY OUR ATTEMPT TO CTL THE CABIN TEMP. WE USED THE NORMAL AND EMER CHKLISTS TO CTL THE CABIN TEMP. HOWEVER, DURING THE CLB WE RAN BOTH THE CLB AND CRUISE CHKLISTS. HOWEVER, WE MISSED THE 1800 FT CHK TO RESET OUR ALTIMETER TO 29.92 AFTER LEVELING OFF AT FL190 BUT SET TO RDU'S PRESSURE, CTR INQUIRED AS TO OUR ALT. WE CORRECTED THIS AND ADVISED CTR. THROUGH OUR DISTRS WITH THE ENVIRONMENTAL CTL SYS WE HAD FAILED TO SET OUR ALTIMETERS CORRECTLY TO 29.92 CAUSING US TO BE BELOW FL190. AFTER THIS WAS CORRECTED THE FLT CONTINUED WITH NO FURTHER INCIDENT. I FEEL THAT BETTER CRM PROCS AND RUNNING THE FL180 CHK WITH THE CLB CHK MAY HELP PREVENT THIS.

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.