Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 200; Flight Crew Total 22400; Flight Crew Type 850
Training / Qualification; Situational Awareness; Confusion; Communication Breakdown
ATC Issue All Types; Aircraft Equipment Problem Less Severe; Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Overcame Equipment Problem; Flight Crew Became Reoriented
Aircraft
While departing from Beijing...we were cleared to climb and maintain 8;900 meters by the Chinese enroute air traffic controller. During this portion of the flight the right transponder was in use.As the pilot monitoring; I referenced a shirt-pocket meters conversion chart that had been issued to me while in training. Both the pilot flying and the relief pilot referenced the iPad Tables/Code section of the FOM on page 16.10.10. My shirt pocket reference chart indicated a conversion which resulted in me setting FL291. I was advised by both of the other pilots that this conversion was incorrect. They both showed that the correct conversion for this meters to flight level altitude should be FL292. Seeing that their reference material was a more current reference; I set FL292 in the altitude alert window and we climbed up to FL292.Once level at this altitude; ATC queried us about our altitude. They advised us that we were above the assigned altitude of 8;900 meters. They asked us if we were at FL291 and we advised them we were at FL292. They issued an immediate descent to us and a 45 degree right turn off course to avoid converging traffic. Later in the flight we determined that the right transponder was showing the aircraft altitude to be 100 feet higher than the altitude being reported by the left transponder. This was written up in the logbook and maintenance was advised.After being able to review the situation I believe we have two separate issues that caused this controller to believe we had a potential loss of separation in RVSM airspace. They are: 1. Pilots using the FOM conversion table to convert meters to Flight Levels. This resulted in the aircraft being 100 feet higher in altitude than it would be if we used the altitudes on the enroute chart; and 2. The fact that; unknown to us at the time; the right transponder was reporting 100 feet higher than the left transponder which gave the controller the impression that we were a total of 200 feet high in altitude.I suggest that the training center reinforce the correct reference for obtaining the meters to feet altitude conversion is the enroute chart and NOT the FOM tables/codes conversion chart. I also suggest that a meters to FL conversion chart be put into the FOM rather than having to rely on old and possibly outdated training material hand outs. A secondary issue is that the FOM meters conversion table FOM 16.10.10 is not pilot friendly. The single chart is broken into two pages and this is VERY confusing during a time critical analysis of an inflight situation because it appears that data is missing from what a person might assume is a single chart.
[ATC] then directed a HDG change of 90 degrees to 180 and a descent to 29200 feet/8900 meters.
Confusion between two different flight level/meter conversion tables and a small error in the altitude reporting of the transponder resulted in a small altitude deviation and a corrective clearance from ATC for the flight crew of a B747.