A B737 crew, departing sea, neglected to notice their altimeters had defaulted to qnh 29 pt 92, resu...

Attributes
ACN	545678
Time
Date	200204
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : sea.vortac
State Reference	WA
Altitude	msl bound lower : 5000 msl bound upper : 5500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : s46.tracon
Operator	common carrier : air carrier
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Navigation In Use	other other vortac
Flight Phase	climbout : intermediate altitude
Route In Use	departure : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : multi engine pilot : atp
Experience	flight time last 90 days : 220 flight time total : 19000 flight time type : 10000
ASRS Report	545678
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : overshoot non adherence : published procedure non adherence other other anomaly other
Independent Detector	atc equipment other atc equipment : radar other controllera
Resolutory Action	controller : issued alert flight crew : returned to assigned altitude other
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

During preflight, cockpit altimeters were set to 30.43. Before start, an anomaly was noticed on the engine and system electronic display. This required some entries on the maintenance portion of the FMC to reset. This procedure is in the amplified portion of our flight handbook but I elected to use my short-hand notes written in my logbook. As I read aloud, the first officer typed in the appropriate commands. The display reset to the normal mode and we continued preparing for pushback. After takeoff, we were cleared to 9000 ft then clearance was changed to 4000 ft and then 5000 ft by ATC. After leveloff at 5000 ft, ATC asked our altitude limit. Not knowing what he meant, I thought he was asking the ceiling of the aircraft, I told the copilot to say FL410. We were eventually cleared to our cruising altitude, but I sensed there was some confusion between us and ATC. We later realized that when we reset our display, the altimeters default to 29.92. We did not notice this, so when we leveled off at 5000 ft we were approximately 500 ft off. After landing, the copilot talked to ATC by telephone to explain the situation. If we had looked at the flight handbook instead of using my notes, we would have been warned that the altimeter defaults to 29.92 and must be reset to local setting. WX was good and we weren't being rushed, just a major oversight. Supplemental information from acn 545676: we ran procedure to recover the compass display. We didn't notice this caused our altimeters to revert to 29 pt 92. They had previously been set at 30.43. There was some confusion from the departure controller about what altitude we were given and what we went to. At this point, I noticed our altimeters were set at 29.92. This would make us about 500 ft off. We reset to 30.43 and continued without further discussion. After landing, we called the controller and explained what happened.

Original NASA ASRS Text

Title: A B737 CREW, DEPARTING SEA, NEGLECTED TO NOTICE THEIR ALTIMETERS HAD DEFAULTED TO QNH 29 PT 92, RESULTING IN A 500 FT ERROR AT LEVELOFF.

Narrative: DURING PREFLT, COCKPIT ALTIMETERS WERE SET TO 30.43. BEFORE START, AN ANOMALY WAS NOTICED ON THE ENG AND SYS ELECTRONIC DISPLAY. THIS REQUIRED SOME ENTRIES ON THE MAINT PORTION OF THE FMC TO RESET. THIS PROC IS IN THE AMPLIFIED PORTION OF OUR FLT HANDBOOK BUT I ELECTED TO USE MY SHORT-HAND NOTES WRITTEN IN MY LOGBOOK. AS I READ ALOUD, THE FO TYPED IN THE APPROPRIATE COMMANDS. THE DISPLAY RESET TO THE NORMAL MODE AND WE CONTINUED PREPARING FOR PUSHBACK. AFTER TKOF, WE WERE CLRED TO 9000 FT THEN CLRNC WAS CHANGED TO 4000 FT AND THEN 5000 FT BY ATC. AFTER LEVELOFF AT 5000 FT, ATC ASKED OUR ALT LIMIT. NOT KNOWING WHAT HE MEANT, I THOUGHT HE WAS ASKING THE CEILING OF THE ACFT, I TOLD THE COPLT TO SAY FL410. WE WERE EVENTUALLY CLRED TO OUR CRUISING ALT, BUT I SENSED THERE WAS SOME CONFUSION BTWN US AND ATC. WE LATER REALIZED THAT WHEN WE RESET OUR DISPLAY, THE ALTIMETERS DEFAULT TO 29.92. WE DID NOT NOTICE THIS, SO WHEN WE LEVELED OFF AT 5000 FT WE WERE APPROX 500 FT OFF. AFTER LNDG, THE COPLT TALKED TO ATC BY TELEPHONE TO EXPLAIN THE SIT. IF WE HAD LOOKED AT THE FLT HANDBOOK INSTEAD OF USING MY NOTES, WE WOULD HAVE BEEN WARNED THAT THE ALTIMETER DEFAULTS TO 29.92 AND MUST BE RESET TO LCL SETTING. WX WAS GOOD AND WE WEREN'T BEING RUSHED, JUST A MAJOR OVERSIGHT. SUPPLEMENTAL INFO FROM ACN 545676: WE RAN PROC TO RECOVER THE COMPASS DISPLAY. WE DIDN'T NOTICE THIS CAUSED OUR ALTIMETERS TO REVERT TO 29 PT 92. THEY HAD PREVIOUSLY BEEN SET AT 30.43. THERE WAS SOME CONFUSION FROM THE DEP CTLR ABOUT WHAT ALT WE WERE GIVEN AND WHAT WE WENT TO. AT THIS POINT, I NOTICED OUR ALTIMETERS WERE SET AT 29.92. THIS WOULD MAKE US ABOUT 500 FT OFF. WE RESET TO 30.43 AND CONTINUED WITHOUT FURTHER DISCUSSION. AFTER LNDG, WE CALLED THE CTLR AND EXPLAINED WHAT HAPPENED.

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.

A B737 crew, departing sea, neglected to notice their altimeters had defaulted to qnh 29 pt 92, resulting in a 500 ft error at leveloff.