Night cargo flight has altitude deviation due to disputed clearance in foreign airspace.

Attributes
ACN	330050
Time
Date	199603
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : rjtg
State Reference	FO
Altitude	msl bound lower : 31000 msl bound upper : 33000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : rjtg
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 300 flight time total : 14000 flight time type : 3000
ASRS Report	330050
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : flight engineer
Events
Anomaly	altitude deviation : excursion from assigned altitude other anomaly other
Independent Detector	other controllera
Resolutory Action	flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Air Traffic Incident	other

Narrative:

Requested FL330 from tyo radio on HF 2932. Later bell called and cleared to maintain mach .84 then climb to FL330. Read back same. Called FL330. Tyo said negative! Maintain FL310. Descended to FL310 and called level. Original clearance was also heard by reserve first officer and he verified altitude setting on fcp. Captain was on scheduled break in back of aircraft. At this time I fully believe clearance given was to FL330. Extenuating circumstances would be back side of clock flying and HF radios. Our company has sat communication available and installed in one airplane now.

Original NASA ASRS Text

Title: NIGHT CARGO FLT HAS ALTDEV DUE TO DISPUTED CLRNC IN FOREIGN AIRSPACE.

Narrative: REQUESTED FL330 FROM TYO RADIO ON HF 2932. LATER BELL CALLED AND CLRED TO MAINTAIN MACH .84 THEN CLB TO FL330. READ BACK SAME. CALLED FL330. TYO SAID NEGATIVE! MAINTAIN FL310. DSNDED TO FL310 AND CALLED LEVEL. ORIGINAL CLRNC WAS ALSO HEARD BY RESERVE FO AND HE VERIFIED ALT SETTING ON FCP. CAPT WAS ON SCHEDULED BREAK IN BACK OF ACFT. AT THIS TIME I FULLY BELIEVE CLRNC GIVEN WAS TO FL330. EXTENUATING CIRCUMSTANCES WOULD BE BACK SIDE OF CLOCK FLYING AND HF RADIOS. OUR COMPANY HAS SAT COM AVAILABLE AND INSTALLED IN ONE AIRPLANE NOW.

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.