MD-11
Flight Crew Air Transport Pilot (ATP)
No Specific Anomaly Occurred All Types
General None Reported / Taken
Airspace Structure; Procedure
ATC would not allow a descent to FL280 on airway N892 after we notified them of 'negative ADS-B'.
Initial climb was FL350. ATC asked if we were ADS-B and we responded negative. We initially were assigned FL350; by Manila but asked Ho Chi Minh for lower altitude due to NOTAM requiring FL290 or below in their airspace. They denied the request. We asked several times for lower; but were not given lower for about an hour. Remove altitude restriction in VVTS airspace.
MD11 flight crew reports that VVTS airspace has a NOTAM requiring flight at FL290 and below for aircraft not equipped with ADS-B. When a descent is requested to comply with the NOTAM; the request is denied.