Very low altimeter setting.

Attributes
ACN	295350
Time
Date	199502
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : pvd airport : bos
State Reference	RI
Altitude	msl bound lower : 10000 msl bound upper : 10000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zbw
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	descent other
Route In Use	enroute airway : zbw
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Experience	flight time last 90 days : 200 flight time total : 9000 flight time type : 4000
ASRS Report	295350
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : overshoot inflight encounter : weather non adherence : clearance
Independent Detector	other controllera
Resolutory Action	flight crew : became reoriented flight crew : returned to intended course or assigned course other
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Weather
Air Traffic Incident	Pilot Deviation

Narrative:

On descent to boston, I was flying the B-737-300. Out of 18000 ft I asked the captain for the altimeter setting and I heard him say 30.51. We were discussing personal experiences throughout the descent and I delayed calling for the 'preliminary landing checklist,' a standard procedure for our company. In doing so, I delayed the process whereby the PNF goes off frequency to get the ATIS. Therefore, I was relying on the altimeter setting given to me passing through 18000 ft. I had not heard the controller's setting when the descent was issued and had no reason to suspect we were off by 1 inch of mercury, which equates to 1000 ft. 'High to low -- look out below ran through my mind later. In actuality, the altimeter was 29.51 (not 30.51), so I really leveled off the airplane at 10000 ft. ZBW came back once on the radio and said to maintain 11000 ft and since I was at 11000 ft (at 30.51) I said, 'roger, we're at 11000 ft.' at this time the captain returned to the interphone with the correct ATIS altimeter, and remarked to me 'the altimeter is 29.51.' I was shocked because somehow I was told, heard or interpreted the altimeter to be 30.51. I then reset the altimeter and climbed up 1000 ft as the captain announced to ZBW that we were 'maintaining 11000 ft on 29.51.' there was no traffic conflict and no TCASII alert, as if we were all alone (and lucky) at that time. ZBW made no more comment to us about the altitude. Pure and simple: cockpit resource management, good habits and procedures broke down and bit me! I realize why we harp on it and try my best to comply. It was a potentially serious lesson to learn! Callback conversation with reporter revealed the following information: the reporter flies the B-737-300 for a major united states air carrier. This crew has known each other for some time and are 'loose on the checklist.' the reporting first officer heard what he thought was correct (30.51) and the captain did no correct him. The crew was distracted by good company and conversation.

Original NASA ASRS Text

Title: VERY LOW ALTIMETER SETTING.

Narrative: ON DSCNT TO BOSTON, I WAS FLYING THE B-737-300. OUT OF 18000 FT I ASKED THE CAPT FOR THE ALTIMETER SETTING AND I HEARD HIM SAY 30.51. WE WERE DISCUSSING PERSONAL EXPERIENCES THROUGHOUT THE DSCNT AND I DELAYED CALLING FOR THE 'PRELIMINARY LNDG CHKLIST,' A STANDARD PROC FOR OUR COMPANY. IN DOING SO, I DELAYED THE PROCESS WHEREBY THE PNF GOES OFF FREQ TO GET THE ATIS. THEREFORE, I WAS RELYING ON THE ALTIMETER SETTING GIVEN TO ME PASSING THROUGH 18000 FT. I HAD NOT HEARD THE CTLR'S SETTING WHEN THE DSCNT WAS ISSUED AND HAD NO REASON TO SUSPECT WE WERE OFF BY 1 INCH OF MERCURY, WHICH EQUATES TO 1000 FT. 'HIGH TO LOW -- LOOK OUT BELOW RAN THROUGH MY MIND LATER. IN ACTUALITY, THE ALTIMETER WAS 29.51 (NOT 30.51), SO I REALLY LEVELED OFF THE AIRPLANE AT 10000 FT. ZBW CAME BACK ONCE ON THE RADIO AND SAID TO MAINTAIN 11000 FT AND SINCE I WAS AT 11000 FT (AT 30.51) I SAID, 'ROGER, WE'RE AT 11000 FT.' AT THIS TIME THE CAPT RETURNED TO THE INTERPHONE WITH THE CORRECT ATIS ALTIMETER, AND REMARKED TO ME 'THE ALTIMETER IS 29.51.' I WAS SHOCKED BECAUSE SOMEHOW I WAS TOLD, HEARD OR INTERPRETED THE ALTIMETER TO BE 30.51. I THEN RESET THE ALTIMETER AND CLBED UP 1000 FT AS THE CAPT ANNOUNCED TO ZBW THAT WE WERE 'MAINTAINING 11000 FT ON 29.51.' THERE WAS NO TFC CONFLICT AND NO TCASII ALERT, AS IF WE WERE ALL ALONE (AND LUCKY) AT THAT TIME. ZBW MADE NO MORE COMMENT TO US ABOUT THE ALT. PURE AND SIMPLE: COCKPIT RESOURCE MGMNT, GOOD HABITS AND PROCS BROKE DOWN AND BIT ME! I REALIZE WHY WE HARP ON IT AND TRY MY BEST TO COMPLY. IT WAS A POTENTIALLY SERIOUS LESSON TO LEARN! CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR FLIES THE B-737-300 FOR A MAJOR UNITED STATES ACR. THIS CREW HAS KNOWN EACH OTHER FOR SOME TIME AND ARE 'LOOSE ON THE CHKLIST.' THE RPTING FO HEARD WHAT HE THOUGHT WAS CORRECT (30.51) AND THE CAPT DID NO CORRECT HIM. THE CREW WAS DISTRACTED BY GOOD COMPANY AND CONVERSATION.

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.