Wrong altimeter setting results in an altitude deviation altitude overshot in climb.

Attributes
ACN	300270
Time
Date	199503
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : atl
State Reference	GA
Altitude	msl bound lower : 10000 msl bound upper : 10600
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : atl
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : atp pilot : commercial
Experience	flight time last 90 days : 150 flight time total : 5200 flight time type : 762
ASRS Report	300270
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 150 flight time total : 11000 flight time type : 3500
ASRS Report	300049
Events
Anomaly	altitude deviation : overshoot non adherence : clearance non adherence other other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Aircraft was on the first flight of the day after maintenance overnight. Ground operations were normal and there was adequate time to accomplish all required checks and still depart on schedule. Captain was flying the aircraft to assigned altitude of 10000 ft MSL. At approximately 7500 ft MSL I reached up to adjust the air conditioning system. The captain made the call 'out of 9000 ft for 10000 ft,' and I glanced at his altimeter. It was passing through 9100 ft. The altitude alert sounded at 9300 ft and I finished with the air conditioner. I noticed my altimeter now indicating 10600 ft MSL as the departure controller said 'oops, call sign xx climb maintain 14000 ft.' I looked at the captain's altimeter and it read 10000 ft but it was set to 28.87 instead of 29.87. He corrected his setting and the flight continued uneventfully. There was no traffic conflict. What happened? Maintenance had performed some checks the previous night and had set the captain's altimeter to zero. Departure field elevation was almost exactly 1000 ft MSL when he set his altimeter to the ATIS setting. We both missed the fact that his was 1000 ft low. The needle in his altimeter was slightly right of 12 O'clock and mine was slightly left of 12 O'clock. The digit in the 1000 ft drum of both altimeters was zero, the last 2 digits of the altimeter setting were correct, the first digit was also correct, the 2 altimeters appeared to be within tolerances. In short, everything looked right but it was obviously very wrong. This was a very subtle trap but we had a lot of chances to catch it. I look at altimeters a lot more closely now. Supplemental information from acn 300049: the captain's altimeter was set to zero during the night. Local altimeter setting was 29.87. The zero setting was 28.77. Atl field elevation is 1027 ft, and I also missed the 1000 ft pointer, which was zero and should have been 1000 ft. If maintenance has a procedure check that requires setting the altimeter to zero, the end of their procedure should be to reset the altimeter back to the local altimeter setting. Especially when the field elevation is in exactly 1000 ft increments.

Original NASA ASRS Text

Title: WRONG ALTIMETER SETTING RESULTS IN AN ALTDEV ALT OVERSHOT IN CLB.

Narrative: ACFT WAS ON THE FIRST FLT OF THE DAY AFTER MAINT OVERNIGHT. GND OPS WERE NORMAL AND THERE WAS ADEQUATE TIME TO ACCOMPLISH ALL REQUIRED CHKS AND STILL DEPART ON SCHEDULE. CAPT WAS FLYING THE ACFT TO ASSIGNED ALT OF 10000 FT MSL. AT APPROX 7500 FT MSL I REACHED UP TO ADJUST THE AIR CONDITIONING SYS. THE CAPT MADE THE CALL 'OUT OF 9000 FT FOR 10000 FT,' AND I GLANCED AT HIS ALTIMETER. IT WAS PASSING THROUGH 9100 FT. THE ALT ALERT SOUNDED AT 9300 FT AND I FINISHED WITH THE AIR CONDITIONER. I NOTICED MY ALTIMETER NOW INDICATING 10600 FT MSL AS THE DEP CTLR SAID 'OOPS, CALL SIGN XX CLB MAINTAIN 14000 FT.' I LOOKED AT THE CAPT'S ALTIMETER AND IT READ 10000 FT BUT IT WAS SET TO 28.87 INSTEAD OF 29.87. HE CORRECTED HIS SETTING AND THE FLT CONTINUED UNEVENTFULLY. THERE WAS NO TFC CONFLICT. WHAT HAPPENED? MAINT HAD PERFORMED SOME CHKS THE PREVIOUS NIGHT AND HAD SET THE CAPT'S ALTIMETER TO ZERO. DEP FIELD ELEVATION WAS ALMOST EXACTLY 1000 FT MSL WHEN HE SET HIS ALTIMETER TO THE ATIS SETTING. WE BOTH MISSED THE FACT THAT HIS WAS 1000 FT LOW. THE NEEDLE IN HIS ALTIMETER WAS SLIGHTLY R OF 12 O'CLOCK AND MINE WAS SLIGHTLY L OF 12 O'CLOCK. THE DIGIT IN THE 1000 FT DRUM OF BOTH ALTIMETERS WAS ZERO, THE LAST 2 DIGITS OF THE ALTIMETER SETTING WERE CORRECT, THE FIRST DIGIT WAS ALSO CORRECT, THE 2 ALTIMETERS APPEARED TO BE WITHIN TOLERANCES. IN SHORT, EVERYTHING LOOKED RIGHT BUT IT WAS OBVIOUSLY VERY WRONG. THIS WAS A VERY SUBTLE TRAP BUT WE HAD A LOT OF CHANCES TO CATCH IT. I LOOK AT ALTIMETERS A LOT MORE CLOSELY NOW. SUPPLEMENTAL INFO FROM ACN 300049: THE CAPT'S ALTIMETER WAS SET TO ZERO DURING THE NIGHT. LCL ALTIMETER SETTING WAS 29.87. THE ZERO SETTING WAS 28.77. ATL FIELD ELEVATION IS 1027 FT, AND I ALSO MISSED THE 1000 FT POINTER, WHICH WAS ZERO AND SHOULD HAVE BEEN 1000 FT. IF MAINT HAS A PROC CHK THAT REQUIRES SETTING THE ALTIMETER TO ZERO, THE END OF THEIR PROC SHOULD BE TO RESET THE ALTIMETER BACK TO THE LCL ALTIMETER SETTING. ESPECIALLY WHEN THE FIELD ELEVATION IS IN EXACTLY 1000 FT INCREMENTS.

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.