B737 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Type 3111
Communication Breakdown
ATC Issue All Types; Deviation - Altitude Overshoot; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued Advisory / Alert; Flight Crew Requested ATC Assistance / Clarification
Airspace Structure; Procedure; Human Factors
On departure from ZZZZ the controller was talking in a very low tone and his English was not too clear. He said we were number three aircraft going to the same destination; and same altitude; and climb to FL250. After he said that we continued the climb to the assigned altitude of FL250. The first officer was the pilot monitoring and is the one that checked in with ATC. Once passing 10;000 feet I elected to stay at 250 knots as we appeared to have good spacing from the airplane in front of us on the TCAS. Shortly after that he called back and was upset that we were not going 200 knots as he had assigned us. I decided to talk to him on the radio and politely told him that we did not hear that part of the clearance and what speed would he like. He said maintain 17;000 feet and you should have been doing 200 knots. I asked him again if he now wanted us at 200 knots or present speed and his reply was I told you 200 maintain 17;000 now. We NEVER read back any speed reduction the first officer just acknowledged the information about being number 3. He was talking so much about same airport; same airplane; same altitude; same type plane; etc that his speed reduction instruction was lost somewhere in the talking.
B737 Captain reported that there was miscommunication with foreign ATC regarding aircraft speed due to a language barrier.