An air carrier flight crew descending into uaaa dipped below their cleared altitude.

Attributes
ACN	787681
Time
Date	200805
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : uaaa.airport
State Reference	FO
Altitude	agl single value : 1500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : uaaa.tracon
Operator	common carrier : air carrier
Make Model Name	MD-11
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : approach
Route In Use	approach : visual arrival star : desor
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : commercial
Experience	flight time last 90 days : 150 flight time total : 9000 flight time type : 4000
ASRS Report	787681
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : flight engineer pilot : multi engine
Experience	flight time last 90 days : 118 flight time total : 7255 flight time type : 1798
ASRS Report	787996
Events
Anomaly	altitude deviation : overshoot non adherence : clearance
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : returned to original clearance flight crew : exited adverse environment
Supplementary
Problem Areas	Chart Or Publication Flight Crew Human Performance ATC Human Performance
Primary Problem	Ambiguous

Narrative:

Asked to maintain high speed arrival due to 2 planes arriving behind us. WX VMC in all sectors. Runway and terrain in sight for the entire approach. Expected and briefed runway 23 but given runway 5. Kept us high and hot so needed to pull idle descent as well as spoilers and slats to make approach altitude. Given descent to 800 meters. Set qnh on altimeters but neglected to set ft in fcp altitude. Went below qnh altitude of 4850 ft/QFE 800 meters. Realized our mistake and leveled off to climb back up. Asked controller to confirm altitude he wanted and he told us to continue descent to 800 meters. We then asked him to confirm that the altitude restrs on the approach were canceled. He replied 'no restr' and again told us to continue descent. Since we were already 200 ft below 800 meter and in radar contact; we questioned whether or not we were flying the correct qnh/QFE procedure; especially after the NOTAM for uaaa that read 'fly normal qnh altimetry procedure.' also; since we were VMC; and because I had been into uaaa where they had descended me to VFR pattern altitude for a short turn on; I elected to descend to 1500 ft AGL. When it became apparent we were not going to be vectored; we became uncomfortable with our altitude and started a climb. At the same time; the controller called us and told us to climb to 800 meters QFE. We complied and continued the approach and landing uneventfully. Supplemental information from acn 787996: preflight and en route reviewed cfm procedures and NOTAMS regarding new procedures in effect for this airport for our company. (Formerly our company operated on QFE procedures at this airport). Company airport briefing guide was dated 2+ yrs and contained outdated QFE procedures. We relied on the NOTAM to fly normal qnh procedures and the cfm bulletin regarding the same. We believed the controller was lowering us to an MVA to turn us in visually as the field was in sight; ceiling and visibility unrestr. When the turn wasn't forthcoming; the captain and I simultaneously realized the 'trees were getting too big' and initiated a climb.

Original NASA ASRS Text

Title: AN ACR FLT CREW DESCENDING INTO UAAA DIPPED BELOW THEIR CLEARED ALTITUDE.

Narrative: ASKED TO MAINTAIN HIGH SPD ARR DUE TO 2 PLANES ARRIVING BEHIND US. WX VMC IN ALL SECTORS. RWY AND TERRAIN IN SIGHT FOR THE ENTIRE APCH. EXPECTED AND BRIEFED RWY 23 BUT GIVEN RWY 5. KEPT US HIGH AND HOT SO NEEDED TO PULL IDLE DSCNT AS WELL AS SPOILERS AND SLATS TO MAKE APCH ALT. GIVEN DSCNT TO 800 METERS. SET QNH ON ALTIMETERS BUT NEGLECTED TO SET FT IN FCP ALT. WENT BELOW QNH ALT OF 4850 FT/QFE 800 METERS. REALIZED OUR MISTAKE AND LEVELED OFF TO CLB BACK UP. ASKED CTLR TO CONFIRM ALT HE WANTED AND HE TOLD US TO CONTINUE DSCNT TO 800 METERS. WE THEN ASKED HIM TO CONFIRM THAT THE ALT RESTRS ON THE APCH WERE CANCELED. HE REPLIED 'NO RESTR' AND AGAIN TOLD US TO CONTINUE DSCNT. SINCE WE WERE ALREADY 200 FT BELOW 800 METER AND IN RADAR CONTACT; WE QUESTIONED WHETHER OR NOT WE WERE FLYING THE CORRECT QNH/QFE PROC; ESPECIALLY AFTER THE NOTAM FOR UAAA THAT READ 'FLY NORMAL QNH ALTIMETRY PROC.' ALSO; SINCE WE WERE VMC; AND BECAUSE I HAD BEEN INTO UAAA WHERE THEY HAD DSNDED ME TO VFR PATTERN ALT FOR A SHORT TURN ON; I ELECTED TO DSND TO 1500 FT AGL. WHEN IT BECAME APPARENT WE WERE NOT GOING TO BE VECTORED; WE BECAME UNCOMFORTABLE WITH OUR ALT AND STARTED A CLB. AT THE SAME TIME; THE CTLR CALLED US AND TOLD US TO CLB TO 800 METERS QFE. WE COMPLIED AND CONTINUED THE APCH AND LNDG UNEVENTFULLY. SUPPLEMENTAL INFO FROM ACN 787996: PREFLT AND ENRTE REVIEWED CFM PROCS AND NOTAMS REGARDING NEW PROCS IN EFFECT FOR THIS ARPT FOR OUR COMPANY. (FORMERLY OUR COMPANY OPERATED ON QFE PROCS AT THIS ARPT). COMPANY ARPT BRIEFING GUIDE WAS DATED 2+ YRS AND CONTAINED OUTDATED QFE PROCS. WE RELIED ON THE NOTAM TO FLY NORMAL QNH PROCS AND THE CFM BULLETIN REGARDING THE SAME. WE BELIEVED THE CTLR WAS LOWERING US TO AN MVA TO TURN US IN VISUALLY AS THE FIELD WAS IN SIGHT; CEILING AND VISIBILITY UNRESTR. WHEN THE TURN WASN'T FORTHCOMING; THE CAPT AND I SIMULTANEOUSLY REALIZED THE 'TREES WERE GETTING TOO BIG' AND INITIATED A CLB.

Data retrieved from NASA's ASRS site as of May 2009 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.