Narrative:

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.

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Original NASA ASRS Text

Title: Flight crew was unaware of VFR crossing altitude at BYGON in the Havana FIR due to ambiguous chart information.

Narrative: 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.

Data retrieved from NASA's ASRS site 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.