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37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
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A commuter flight crew flew through a pressure gradient and did not reset the altimeter quickly enough. The ARTCC radar controller notified the flight crew that they were shown on radar as 400 ft below the assigned altitude. Altitude deviation altitude excursion.
| Attributes | |
| ACN | 326311 |
| Time | |
| Date | 199601 |
| Day | Mon |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | atc facility : olm |
| State Reference | WA |
| Altitude | msl bound lower : 10600 msl bound upper : 11000 |
| Environment | |
| Flight Conditions | IMC |
| Light | Night |
| Aircraft 1 | |
| Controlling Facilities | tower : pit |
| Operator | common carrier : air carrier |
| Make Model Name | Light Transport, Low Wing, 2 Turboprop Eng |
| Flight Phase | cruise other descent other |
| Route In Use | enroute airway : zse |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 240 flight time total : 6200 flight time type : 4000 |
| ASRS Report | 326311 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp pilot : cfi |
| Experience | flight time last 90 days : 380 flight time total : 11000 flight time type : 1500 |
| ASRS Report | 326020 |
| Events | |
| Anomaly | altitude deviation : excursion from assigned altitude non adherence : clearance non adherence : far other anomaly other |
| Independent Detector | atc equipment other atc equipment : unspecified other flight crewa |
| Resolutory Action | flight crew : returned to intended course or assigned course other |
| Consequence | faa : reviewed incident with flight crew |
| Supplementary | |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation |
Narrative:
In route from pdx to sea we received clearance to descend to 11000 ft. 11000 ft was acknowledged to the center, set in the altitude alerter and verbally confirmed by both pilots. Approximately at 6 DME sse from olm VOR sea ATIS was received and the new altimeter setting set. The difference between pdx and sea altimeter made our altimeters drop approximately 200 ft which we were compensating for. Around that time, center called us to climb to 11000 ft and report, which we did. Upon arrival in sea we were notified by center that at the time they told us to climb to 11000 ft they got an altitude reading on their radar of 10600 ft. Both altitude indicators never indicated below 10800 ft, and the altitude alerter was never activated, which does when there is a 200 ft discrepancy.
Original NASA ASRS Text
Title: A COMMUTER FLC FLEW THROUGH A PRESSURE GRADIENT AND DID NOT RESET THE ALTIMETER QUICKLY ENOUGH. THE ARTCC RADAR CTLR NOTIFIED THE FLC THAT THEY WERE SHOWN ON RADAR AS 400 FT BELOW THE ASSIGNED ALT. ALTDEV ALT EXCURSION.
Narrative: IN RTE FROM PDX TO SEA WE RECEIVED CLRNC TO DSND TO 11000 FT. 11000 FT WAS ACKNOWLEDGED TO THE CTR, SET IN THE ALT ALERTER AND VERBALLY CONFIRMED BY BOTH PLTS. APPROX AT 6 DME SSE FROM OLM VOR SEA ATIS WAS RECEIVED AND THE NEW ALTIMETER SETTING SET. THE DIFFERENCE BTWN PDX AND SEA ALTIMETER MADE OUR ALTIMETERS DROP APPROX 200 FT WHICH WE WERE COMPENSATING FOR. AROUND THAT TIME, CTR CALLED US TO CLB TO 11000 FT AND RPT, WHICH WE DID. UPON ARR IN SEA WE WERE NOTIFIED BY CTR THAT AT THE TIME THEY TOLD US TO CLB TO 11000 FT THEY GOT AN ALT READING ON THEIR RADAR OF 10600 FT. BOTH ALT INDICATORS NEVER INDICATED BELOW 10800 FT, AND THE ALT ALERTER WAS NEVER ACTIVATED, WHICH DOES WHEN THERE IS A 200 FT DISCREPANCY.
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.