Large Transport; Low Wing; 2 Turbojet Eng
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 24
Communication Breakdown
ATC Issue All Types; Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Aircraft; Company Policy
When Aircraft X entered my airspace I issued the aircraft a vector for spacing and the pilot did not read back or acknowledge the clearance. A few seconds later I issued the vector again and the pilot read back the clearance. I immediately issued a code change and the pilot did not answer so I waited to see if the data block reflected the code change and it did not. I reissued the code change and the pilot verbally acknowledged. I then issued an altitude clearance to Aircraft X and the pilot never acknowledged. I then called Aircraft X to see if the aircraft was still on frequency and the pilot acknowledged so I reissued the altitude clearance and the pilot read back the clearance. I then advised Aircraft X I have called him twice with every clearance except the last one and that was three times. He never acknowledged.ZLA has had a problem with these pilots not listening to the radio and not acknowledging clearances on the first call. This unnecessarily increases controller workload and needs to be addressed. I have heard that this company has ATC communications on speaker in the cockpit. This might be contributing to missed calls.
ZLA Controller reports of possible company problem with a particular airline not answering calls in a timely manner.