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Altitude deviation altitude overshot. Descending arrival traffic, a B737-400 uses incorrect altimeter setting, has potential conflict with departure traffic from pit.
| Attributes | |
| ACN | 361560 |
| Time | |
| Date | 199702 |
| Day | Thu |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | airport : pit |
| State Reference | PA |
| Altitude | msl bound lower : 5000 msl bound upper : 6000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tracon : pit |
| Operator | common carrier : air carrier |
| Make Model Name | B737-400 |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | Other Other |
| Flight Phase | descent other |
| Route In Use | arrival other enroute : on vectors enroute other |
| Flight Plan | IFR |
| Aircraft 2 | |
| Operator | common carrier : air carrier |
| Make Model Name | Commercial Fixed Wing |
| Operating Under FAR Part | Part 135 |
| Flight Phase | climbout : intermediate altitude |
| Route In Use | departure other enroute : on vectors |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : flight engineer pilot : commercial pilot : atp pilot : instrument |
| Experience | flight time last 90 days : 188 flight time total : 18031 flight time type : 5779 |
| ASRS Report | 361560 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 125 flight time total : 8300 flight time type : 4000 |
| ASRS Report | 361995 |
| Events | |
| Anomaly | altitude deviation : overshoot conflict : airborne less severe non adherence : far non adherence : clearance non adherence : published procedure other anomaly other |
| Independent Detector | aircraft equipment other aircraft equipment : unspecified other controllera other flight crewa |
| Resolutory Action | flight crew : became reoriented flight crew : took evasive action other |
| Consequence | Other |
| Miss Distance | horizontal : 1000 vertical : 1000 |
| Supplementary | |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation |
Narrative:
Descending from aco to cutta intersection, we began to discuss crosswind limitations at pit. ATIS winds were 240 degrees 26 KTS gusting to 41 KTS. ZOB issued a clearance to cross cutta intersection at 10000 ft. Previously we had been given a descent to 15000 ft and I thought the controller issued an altimeter setting of 30.62. In reality the altimeter setting was 29.62. As we descended through 18000 ft, I set and called out FL180, 30.62. We then did the preliminary checklist using the incorrect altimeter settings. After checking in with pit approach, we advised we would not make the crossing restr at cutta intersection, not because of our altimeter setting, but because of a late descent clearance and strong tailwinds. Pit approach gave us a vector to 170 degrees and clearance to 6000 ft. I do not believe the controller reissued an altimeter setting. As we descended to 6000 ft the controller issued a TA for a second aircraft climbing to 5000 ft. We did have the second aircraft visually and on TCASII. We then received an RA. I instructed the first officer to reduce our rate of descent (as per the RA) even though we had him visually. After the traffic went by and we leveled at 6000 ft, approach control indicated that our altitude was indicating 5000 ft -- to check our altitude. At this point I said we were level at 6000 ft but asked for an altimeter setting. When he issued 29.62 I realized either we were given the wrong setting from ZOB or I flipped the numbers somehow. Landing uneventful. Although we both reset our altimeters descending through FL180, this problem may have started with our distraction over the crosswind component chart. Also, if approach had given us the local altimeter setting when we checked in, this might have broken the chain of misinfo. Supplemental information from acn 361995: first officer was flying the visual approach into pit, so the captain went off the approach control frequency to get the pit ATIS. When he returned he briefed the pit altimeter setting as 30.64. It was an unusual descent in that we never leveled off from the time we departed FL310 until we reached 6000 ft, and found out from pit approach control that we were actually closer to 5000 ft, due to an incorrect altimeter setting.
Original NASA ASRS Text
Title: ALTDEV ALT OVERSHOT. DSNDING ARR TFC, A B737-400 USES INCORRECT ALTIMETER SETTING, HAS POTENTIAL CONFLICT WITH DEP TFC FROM PIT.
Narrative: DSNDING FROM ACO TO CUTTA INTXN, WE BEGAN TO DISCUSS XWIND LIMITATIONS AT PIT. ATIS WINDS WERE 240 DEGS 26 KTS GUSTING TO 41 KTS. ZOB ISSUED A CLRNC TO CROSS CUTTA INTXN AT 10000 FT. PREVIOUSLY WE HAD BEEN GIVEN A DSCNT TO 15000 FT AND I THOUGHT THE CTLR ISSUED AN ALTIMETER SETTING OF 30.62. IN REALITY THE ALTIMETER SETTING WAS 29.62. AS WE DSNDED THROUGH 18000 FT, I SET AND CALLED OUT FL180, 30.62. WE THEN DID THE PRELIMINARY CHKLIST USING THE INCORRECT ALTIMETER SETTINGS. AFTER CHKING IN WITH PIT APCH, WE ADVISED WE WOULD NOT MAKE THE XING RESTR AT CUTTA INTXN, NOT BECAUSE OF OUR ALTIMETER SETTING, BUT BECAUSE OF A LATE DSCNT CLRNC AND STRONG TAILWINDS. PIT APCH GAVE US A VECTOR TO 170 DEGS AND CLRNC TO 6000 FT. I DO NOT BELIEVE THE CTLR REISSUED AN ALTIMETER SETTING. AS WE DSNDED TO 6000 FT THE CTLR ISSUED A TA FOR A SECOND ACFT CLBING TO 5000 FT. WE DID HAVE THE SECOND ACFT VISUALLY AND ON TCASII. WE THEN RECEIVED AN RA. I INSTRUCTED THE FO TO REDUCE OUR RATE OF DSCNT (AS PER THE RA) EVEN THOUGH WE HAD HIM VISUALLY. AFTER THE TFC WENT BY AND WE LEVELED AT 6000 FT, APCH CTL INDICATED THAT OUR ALT WAS INDICATING 5000 FT -- TO CHK OUR ALT. AT THIS POINT I SAID WE WERE LEVEL AT 6000 FT BUT ASKED FOR AN ALTIMETER SETTING. WHEN HE ISSUED 29.62 I REALIZED EITHER WE WERE GIVEN THE WRONG SETTING FROM ZOB OR I FLIPPED THE NUMBERS SOMEHOW. LNDG UNEVENTFUL. ALTHOUGH WE BOTH RESET OUR ALTIMETERS DSNDING THROUGH FL180, THIS PROB MAY HAVE STARTED WITH OUR DISTR OVER THE XWIND COMPONENT CHART. ALSO, IF APCH HAD GIVEN US THE LCL ALTIMETER SETTING WHEN WE CHKED IN, THIS MIGHT HAVE BROKEN THE CHAIN OF MISINFO. SUPPLEMENTAL INFO FROM ACN 361995: FO WAS FLYING THE VISUAL APCH INTO PIT, SO THE CAPT WENT OFF THE APCH CTL FREQ TO GET THE PIT ATIS. WHEN HE RETURNED HE BRIEFED THE PIT ALTIMETER SETTING AS 30.64. IT WAS AN UNUSUAL DSCNT IN THAT WE NEVER LEVELED OFF FROM THE TIME WE DEPARTED FL310 UNTIL WE REACHED 6000 FT, AND FOUND OUT FROM PIT APCH CTL THAT WE WERE ACTUALLY CLOSER TO 5000 FT, DUE TO AN INCORRECT ALTIMETER SETTING.
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.