Jan 31 (Reuters) - Boeing Co CEO Dave Calhoun said on Wednesday he was convinced that the door plug issue that has sparked a safety and quality crisis at the planemaker was "completely under control."

In an interview to CNBC, Calhoun also apologized to United Airlines CEO Scott Kirby after the carrier's top boss earlier this month called the 737 MAX 9's partial grounding "the straw that broke the camel's back."

"I am going to work my tail off and our team will to satisfy Kirby," Calhoun added. (Reporting by Abhijith Ganapavaram in Bengaluru; Editing by Anil D'Silva)