Medium Transport; Low Wing; 2 Turbojet Eng
Flight Crew Air Transport Pilot (ATP)
Workload; Time Pressure; Confusion; Communication Breakdown
ATC Issue All Types; Deviation - Altitude Overshoot; Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued Advisory / Alert; Flight Crew Returned To Clearance; Flight Crew Became Reoriented
Procedure; Manuals; Chart Or Publication
MIA Center advised us to descend and maintain 17;000 approximately 80 NM from the BYGON Intersection (we were at FL350). The Center Controller did not give us any specific crossing restrictions or requirements; therefore we set up the aircraft in an optimum descent to meet the crossing restriction for the arrival waypoint SOUTHP (at 3;000 FT). At approximately 70 NM to BYGON; we contacted Havana Center on 123.70 and advised our intentions and reporting points. Havana Center advised that after BYGON; we can continue our descent at our discretion; as long as we did not enter Cuban airspace. Approximately 8.0 NM from BYGON at 22;000 FT in an optimum descent; MIA Center advised us that he had a requirement that we be at a VFR altitude (below 18;000) crossing BYGON. I advised him we were not given a crossing restriction. However; he advised that it should have been in our briefing; and that it is a requirement on his end. I stepped up the descent immediately to max effort to cross BYGON at a VFR altitude. Simultaneously; I advised him that I was in contact with Havana Center and they gave us pilot's discretion after BYGON to cross SOUTHP at 3;000. In his response he advised that it did not make a difference what Havana says; it was a requirement from MIA Center to be at a VFR altitude over BYGON. The aircraft smart turned over BYGON. At the rate I was descending; I was unable to calculate the precise moment and altitude of the crossing; but at that speed and rate; it was well within an acceptable range. He asked twice my altitude. The first just prior to the aircraft turning over BYGON (1.0 NM) it was 18;500 FT and the second was 37.5 NM to the next waypoint (1.5 mile inside of BYGON); EASTP; the aircraft was at 16;500. That places the aircraft; in my own scientific guess; at a VFR altitude at BYGON and thus fulfilling his requirement. I apologized for the confusion and regained communication with Havana Center and we complied with our descent and VFR requirements. He advised I should contact our flight department and perhaps that information should be in our ops briefing for the arrival. I read the ops briefing to the arrival procedures and it does not specifically say that there is a crossing restriction. The only indication that a VFR altitude could be interpreted is by the line stating the Havana FIR is to VFR only. This can be contradictory if Havana Center gives us a discretionary descent after BYGON; and MIA Center does not give us any crossing restriction.To prevent this from occurring again ; I have suggestion: A update our operations pages to reflect this restriction; to alert crews that BYGON should be crossed at or below 17;000; or at least make it suggestion. Have ATC give a hard crossing restriction at this fix if that is what they expect/or require.
I believe there was confusion with the ATC clearance and what we did. As stated above we were cleared to descend; not told we had to cross a certain fix (which happens EVERY day during normal flight operations!). If we were given a restriction then we could have made it. We are being controlled and monitored by three different people; all wanting reports to be made at the same fix etc. This restriction needs to be displayed on our charts. Or at least needs to be issued by ATC. Other aircraft on our way back were told to cancel by the fix. That would have been a verbal clue to us to be at a VFR altitude as to cancel. Also we were told by ATC that the common altimeter setting is 29.92 over BYGON which would not make sense. Transition altitude is 18;000 which I mistook for different air rules like in other ICAO countries where transition altitude is 3;000 FT above the ground and you use standard until that point. It is a very busy time for the pilot not flying! I would have appreciated a solid crossing restriction by ATC. There are no ifs and buts' about it we didn't do what he expected us to do; even though he never requested it directly. I think more training for international operations would also be very valuable. Going to this destination is nerve racking in the first place because it is completely different from normal operations. Also better communication from the Controller would have helped. The last thing I would like to say is that in the operations page it refers us to an area chart. I use the EFB so it did take me a while to find the actual chart but when you read the Havana FIR is from the ground to FL195. The reference could be updated for EFB pilot's chart 39-1 took me a while to search for. Over all I am going to try and write a briefing for other pilots as to what is expected from us. And hopefully others can learn from my possible mistake.
Flight crew was unaware of VFR crossing altitude at BYGON in the Havana FIR due to ambiguous chart information.