Date: 201812
Local time of day: 1201-1800
Location: ZSWX.Airport, FO
Aircraft: B747 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Second reporter function: Pilot Flying; Captain
Anomaly: Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Became Reoriented
Contributing factors: Chart Or Publication; Procedure
Primary problem: Chart Or Publication

Narrative: Departing ZSWX/WUX from Runway 03 on the EKI11D SID; Tower assigned an initial climb to 900m/3;000 feet. In the air were handed over to 'Shanghai Approach'; which gave us the local altimeter setting (1034 hpa) and instructed us to climb 'via SID' and to climb to 2;700m/8;900 feet. The chart for the EKI11D SID specified a transition altitude of 5;930 feet. As we passed 5;930 feet; the Pilot Flying and Pilot Monitoring changed their altimeter to STD and the aircraft leveled-off at the assigned altitude. Shortly after this ATC forcefully told us to stop climb immediately and to turn to a heading to avoid traffic. The controller then again told us that the QNH was 1034 hpa. As 'Third Pilot' I verified with the conversion chart that we were in fact at the assigned altitude and above the transition level from the SID chart. The Captain/Pilot Monitoring asked that I next check a chart for ZSPD/PVG for their transition level; which was 10;830 feet. and thus above our current level. Pilot Flying and Pilot Monitoring returned their altimeters to the local setting; which put our plane about 500 feet. higher than with STD setting. Although we were instructed to follow the ZSWX/WUX SID; ATC in Shanghai's airspace expected us to follow the transition altitude as it appears on ZSPD/PVG charts; not on ZSWX/WUX charts. There was nothing in the Jeppesen charts preparing us for this 'trap.' A vague note on company page 10-10 points out that ZSWX/WUX and ZSPD/PVG are using different transition altitudes; but then says to 'use procedures per ATC and as charted per SID/STAR'; which is what we did. At no point did we have a loss of separation; and the traffic ATC vectored us away from was still 2;000 feet above our altitude; and we were not climbing at that time.ZSWX/WUX does not have a taxiway parallel to the only Runway 03/21 suitable for a B747. As we park towards the north end of the airport; the preferred method is to land on '03' and takeoff from '21.' Due to traffic and wind we departed '03;' which immediately put us into Shanghai's airspace. The standard departure off '21' has a climbing turn back towards the airport and likely avoids our situation by entering Shanghai's airspace above either transition altitudes. A note to this regard in the ZSWX/WUX REF pages or SIDs in the Jeppesen app would alert crews to this - easily avoided - problem.


Second narrative: After departure from WUZ; we were assigned to climb and maintain 2;700 meters. At the time; we were on the transition altitude for WUZ. Shanghai Departure on climb out to us to stop climb and maintain 2;700 meters; we were at 2;700 meters apparently after further figuring it out the transition altitude for Shanghai airspace was different than WUZ. Thus; causing us to fly above assigned flight level. We then descended to the proper flight level and had no further issues with altitudes and ATC.This a real 'gotcha' because when you take off to the north from WUZ you are in Shanghai's airspace and nowhere on the plates does it tell you to change transition altitudes. Only in the station guides is there a note. A station guide is just a guide.


Synopsis: B747 flight crew reported critical need of departure warning to flight crews of dissimilar transition levels.