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37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
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A B734 crew descending into sea, planning to cross the fix at 16000 ft for a south landing was unable, at ATC's request, to cross at 12000 ft for a north landing. A 360 degree turn was performed to get into the flow of things.
| Attributes | |
| ACN | 518370 |
| Time | |
| Date | 200107 |
| Day | Fri |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | navaid : olm.vortac |
| State Reference | WA |
| Altitude | msl single value : 17000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zse.artcc tower : bdl.tower |
| Operator | common carrier : air carrier |
| Make Model Name | B737-400 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | descent : approach |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 150 flight time total : 2400 flight time type : 150 |
| ASRS Report | 518570 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Events | |
| Anomaly | altitude deviation : undershoot non adherence : published procedure other anomaly other |
| Independent Detector | other flight crewa other flight crewb |
| Resolutory Action | controller : issued new clearance |
| Consequence | faa : reviewed incident with flight crew |
| Supplementary | |
| Problem Areas | Flight Crew Human Performance Chart Or Publication Airport ATC Human Performance |
| Primary Problem | Flight Crew Human Performance |
Narrative:
Flying lax direct seattle and cleared the 'olympia 2 arrival, descend via the olympia 2,' there was nonstandard clearance terminology by ATC as to what altitude to arrive at olm fix. We expected to cross olm 16000 ft for runway 16R at sea, per our latest ATIS. Center thought we were to cross olm at 12000 ft per new ATIS and a runway change that we were unaware of. In summary: prior to our clearance limit at olm, center called us and asked if we would make 12000 ft at olm. We said no, and thought we were landing runway 16R to cross olm 16000 ft. Center said 'no problem, make a left 360 degree turn prior to olm and descend to 12000 ft via the olympia 2 arrival landing runway 34.' there was no conflict or event, other than less than optimum communication between center and our airplane. Cause: nonstandard terminology for olympia 2 arrival clearance. Center did not use the expected standard clearance term 'descend via the olympia 2, cross at or 16000 ft (or 12000 ft) landing south (or north).' instead, they used the term 'north flow' which I, as a new first officer, misunderstood to mean fly north on the 340 degree heading for landing runway 16R (south). Nonstandard terminology along with new first officer made unclr communication.
Original NASA ASRS Text
Title: A B734 CREW DSNDING INTO SEA, PLANNING TO CROSS THE FIX AT 16000 FT FOR A S LNDG WAS UNABLE, AT ATC'S REQUEST, TO CROSS AT 12000 FT FOR A N LNDG. A 360 DEG TURN WAS PERFORMED TO GET INTO THE FLOW OF THINGS.
Narrative: FLYING LAX DIRECT SEATTLE AND CLRED THE 'OLYMPIA 2 ARR, DSND VIA THE OLYMPIA 2,' THERE WAS NONSTANDARD CLRNC TERMINOLOGY BY ATC AS TO WHAT ALT TO ARRIVE AT OLM FIX. WE EXPECTED TO CROSS OLM 16000 FT FOR RWY 16R AT SEA, PER OUR LATEST ATIS. CTR THOUGHT WE WERE TO CROSS OLM AT 12000 FT PER NEW ATIS AND A RWY CHANGE THAT WE WERE UNAWARE OF. IN SUMMARY: PRIOR TO OUR CLRNC LIMIT AT OLM, CTR CALLED US AND ASKED IF WE WOULD MAKE 12000 FT AT OLM. WE SAID NO, AND THOUGHT WE WERE LNDG RWY 16R TO CROSS OLM 16000 FT. CTR SAID 'NO PROB, MAKE A L 360 DEG TURN PRIOR TO OLM AND DSND TO 12000 FT VIA THE OLYMPIA 2 ARR LNDG RWY 34.' THERE WAS NO CONFLICT OR EVENT, OTHER THAN LESS THAN OPTIMUM COM BTWN CTR AND OUR AIRPLANE. CAUSE: NONSTANDARD TERMINOLOGY FOR OLYMPIA 2 ARR CLRNC. CTR DID NOT USE THE EXPECTED STANDARD CLRNC TERM 'DSND VIA THE OLYMPIA 2, CROSS AT OR 16000 FT (OR 12000 FT) LNDG S (OR N).' INSTEAD, THEY USED THE TERM 'N FLOW' WHICH I, AS A NEW FO, MISUNDERSTOOD TO MEAN FLY N ON THE 340 DEG HDG FOR LNDG RWY 16R (S). NONSTANDARD TERMINOLOGY ALONG WITH NEW FO MADE UNCLR COM.
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.