Misinterpreted descent clearance while operating in foreign airspace.

Attributes
ACN	92937
Time
Date	198808
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : kae
State Reference	FO
Altitude	msl bound lower : 27600 msl bound upper : 28000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : tae tower : pkd
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 3 Turbojet Eng
Navigation In Use	Other
Flight Phase	descent other
Route In Use	enroute : pacific
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : flight engineer pilot : instrument
Experience	flight time last 90 days : 200 flight time total : 4000
ASRS Report	92937
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : commercial pilot : instrument pilot : atp
ASRS Report	92705
Events
Anomaly	altitude deviation : overshoot non adherence : clearance
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

I, first officer, was flying on autoplt. Requested descent when 30 NM east of kae VOR. Received descent to FL210. (Had been at FL390). I dialed in 21000' on altitude alert select and captain read back FL210. At 28200' taegu control told us to stop descent. I disconnected autoplt to immediately stop descent. Leveled off initially at 27600', then climbed to 28000'. Taegu informed us we had clearance to FL310, not FL210. They then descended us to FL270, then further descent to approach and uneventful landing. No further comments from taegu or seoul approach. All 3 crew heard descent to FL210.

Original NASA ASRS Text

Title: MISINTERPRETED DESCENT CLRNC WHILE OPERATING IN FOREIGN AIRSPACE.

Narrative: I, F/O, WAS FLYING ON AUTOPLT. REQUESTED DSCNT WHEN 30 NM E OF KAE VOR. RECEIVED DSCNT TO FL210. (HAD BEEN AT FL390). I DIALED IN 21000' ON ALT ALERT SELECT AND CAPT READ BACK FL210. AT 28200' TAEGU CTL TOLD US TO STOP DSCNT. I DISCONNECTED AUTOPLT TO IMMEDIATELY STOP DSCNT. LEVELED OFF INITIALLY AT 27600', THEN CLBED TO 28000'. TAEGU INFORMED US WE HAD CLRNC TO FL310, NOT FL210. THEY THEN DSNDED US TO FL270, THEN FURTHER DSCNT TO APCH AND UNEVENTFUL LNDG. NO FURTHER COMMENTS FROM TAEGU OR SEOUL APCH. ALL 3 CREW HEARD DSCNT TO FL210.

Data retrieved from NASA's ASRS site as of August 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.