https://www.bls.gov/cps/aa2018/cpsaat50.htm
Employment status of the civilian noninstitutional population by certification and licensing status...
Employment status of the civilian noninstitutional population by certification and licensing status and selected characteristics
certification and licensingemployment statuscivilianpopulation
https://tc.canada.ca/en/aviation/commercial-air-services/certification-licensing-air-operators
Certification and licensing for air operators
Getting certified as an air operator, including foreign air operators and all-weather air operators, and getting an air carrier licence or a charter permit.
certification and licensingair operators