Commercial Fixed Wing
Flight Crew Air Transport Pilot (ATP)
Communication Breakdown
ATC Issue All Types
Air Traffic Control Issued New Clearance; Flight Crew Returned To Clearance
ATC Equipment / Nav Facility / Buildings; Human Factors; Procedure
After takeoff in a climb to FL270 we were advised to contact Yangon on 127.65 passing FL190. As one knows we had difficulty contacting Yangon till we were level at FL270 approaching CHILA Intersection. We asked for a climb to FL390 as filed. Yangon cleared us to FL370. This clearance was hard to understand due to radio quality and person speaking. The First Officer tried to confirm 3 times this clearance. Once sure of the altitude cleared to we started our climb to FL370. Now we are lightweight at 190;000 lbs so our climb gradient was around 3000 FPM. Once the climb had been started Yangon amended the level off to FL290 as we were passing FL300. At this time we expeditiously stopped the climb and returned to FL290 reaching FL305 as a high point. I don't consider this an altitude deviation since we did not go thru an assigned altitude but was given a revised level off after a clearance to climb to FL370. But with our climb rate and the time the clearance was given we were already above the new assigned altitude. After leveling at FL290 we were given a clearance to FL310 which we complied with. After that we did climb to FL370 and the rest of the flight was uneventful.Yangon is the problem. The radio quality is always bad and understanding the controller is always a challenge. Other aircraft receiving instructions would reply unreadable. With the amount of traffic thru there I wonder why no one requires better communication with better radios. They are CPDLC now; that helps; but we were not connected yet. Better radios would alleviate any possible misunderstanding of clearances; as well as timely communication when needed since contactability can be an issue.
Captain describes the routine communication difficulties encountered when in communication with Yangon Control; this time resulting in a possible altitude assignment misunderstanding. The problem is due to both poor communications equipment and poor English speaking ability.