An aircrew mistook meters for ft leaving chinese airspace.

Attributes
ACN	271401
Time
Date	199405
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : lq airport : hkg
State Reference	FO
Altitude	msl bound lower : 5500 msl bound upper : 13000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : vhhk
Operator	general aviation : corporate
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 91
Navigation In Use	Other Other
Flight Phase	descent other
Route In Use	enroute airway : z6zv enroute airway : vhhk
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 120 flight time total : 9400 flight time type : 3445
ASRS Report	271401
Person 2
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 30 flight time total : 13000 flight time type : 1200
ASRS Report	271794
Events
Anomaly	altitude deviation : overshoot altitude deviation : crossing restriction not met non adherence : clearance other anomaly other
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued new clearance flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

During en route descent on flight from shanghai to hong kong on A461 between yingde (yin) VOR and rumet intersection, we received descent clearance to cross rumet at FL130. We were still in chinese airspace being controled by a chinese controller. All altitudes previously had been given in meters, including the initial descent clearance from cruise altitude. Due to assuming that the crossing altitude would be given in meters and very broken english on the part of the chinese controller and after several call backs for clarification on a very congested frequency we, the PIC and myself, agreed that he said to cross rumet at 1300 meters (4300 ft) vice FL130 (13000 ft). Our calls to the controller for clarification included asking if he meant meters or ft, but all we got back was to FL130 which we interpreted to be 1300 meters. During the rapid descent to be at rumet by 4300 ft, we were handed over to hong kong control. During our initial call to hong kong control it became evident that the descent clearance was to FL130, not to 1300 meters. At this point we were descending through about 5500 ft and, as soon as the error was realized, we started an immediate maximum effort climb back to FL130. We informed hong kong control of what happened whereupon they instructed us to just level where we were, which put us at about 12000 ft. Then almost immediately the hong kong controller started us back down again for our approach to hong kong. In all of our previous fir xings from united states airspace to russian airspace and then from russian airspace to chinese airspace, each controling agency was very exacting in giving altitude clrncs in their country's standards right up to the fir of the adjoining country. Rumet intersection is the fir boundary between china and hong kong. With experience established in previous country fir xings, a congested frequency and extreme language barrier, we erroneously descended well below our cleared altitude. Lessons learned: 1) know minimum en route altitudes for where you are. 2) even if you don't hear ft or meters on an altitude clearance, remember that flight levels in meters are always given using 4 numerals and flight levels in ft are always given using 3 numerals.

Original NASA ASRS Text

Title: AN AIRCREW MISTOOK METERS FOR FT LEAVING CHINESE AIRSPACE.

Narrative: DURING ENRTE DSCNT ON FLT FROM SHANGHAI TO HONG KONG ON A461 BTWN YINGDE (YIN) VOR AND RUMET INTXN, WE RECEIVED DSCNT CLRNC TO CROSS RUMET AT FL130. WE WERE STILL IN CHINESE AIRSPACE BEING CTLED BY A CHINESE CTLR. ALL ALTS PREVIOUSLY HAD BEEN GIVEN IN METERS, INCLUDING THE INITIAL DSCNT CLRNC FROM CRUISE ALT. DUE TO ASSUMING THAT THE XING ALT WOULD BE GIVEN IN METERS AND VERY BROKEN ENGLISH ON THE PART OF THE CHINESE CTLR AND AFTER SEVERAL CALL BACKS FOR CLARIFICATION ON A VERY CONGESTED FREQ WE, THE PIC AND MYSELF, AGREED THAT HE SAID TO CROSS RUMET AT 1300 METERS (4300 FT) VICE FL130 (13000 FT). OUR CALLS TO THE CTLR FOR CLARIFICATION INCLUDED ASKING IF HE MEANT METERS OR FT, BUT ALL WE GOT BACK WAS TO FL130 WHICH WE INTERPRETED TO BE 1300 METERS. DURING THE RAPID DSCNT TO BE AT RUMET BY 4300 FT, WE WERE HANDED OVER TO HONG KONG CTL. DURING OUR INITIAL CALL TO HONG KONG CTL IT BECAME EVIDENT THAT THE DSCNT CLRNC WAS TO FL130, NOT TO 1300 METERS. AT THIS POINT WE WERE DSNDING THROUGH ABOUT 5500 FT AND, AS SOON AS THE ERROR WAS REALIZED, WE STARTED AN IMMEDIATE MAX EFFORT CLB BACK TO FL130. WE INFORMED HONG KONG CTL OF WHAT HAPPENED WHEREUPON THEY INSTRUCTED US TO JUST LEVEL WHERE WE WERE, WHICH PUT US AT ABOUT 12000 FT. THEN ALMOST IMMEDIATELY THE HONG KONG CTLR STARTED US BACK DOWN AGAIN FOR OUR APCH TO HONG KONG. IN ALL OF OUR PREVIOUS FIR XINGS FROM UNITED STATES AIRSPACE TO RUSSIAN AIRSPACE AND THEN FROM RUSSIAN AIRSPACE TO CHINESE AIRSPACE, EACH CTLING AGENCY WAS VERY EXACTING IN GIVING ALT CLRNCS IN THEIR COUNTRY'S STANDARDS RIGHT UP TO THE FIR OF THE ADJOINING COUNTRY. RUMET INTXN IS THE FIR BOUNDARY BTWN CHINA AND HONG KONG. WITH EXPERIENCE ESTABLISHED IN PREVIOUS COUNTRY FIR XINGS, A CONGESTED FREQ AND EXTREME LANGUAGE BARRIER, WE ERRONEOUSLY DSNDED WELL BELOW OUR CLRED ALT. LESSONS LEARNED: 1) KNOW MINIMUM ENRTE ALTS FOR WHERE YOU ARE. 2) EVEN IF YOU DON'T HEAR FT OR METERS ON AN ALT CLRNC, REMEMBER THAT FLT LEVELS IN METERS ARE ALWAYS GIVEN USING 4 NUMERALS AND FLT LEVELS IN FT ARE ALWAYS GIVEN USING 3 NUMERALS.

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.