A Reddit forum post raises a practical question that recurs frequently among aspiring Canadian pilots: whether a Transport Canada Category 1 Medical Certificate obtained despite failing standard Ishihara colour-plate testing—but passing supplementary tests like the Farnsworth Lantern Test—is sufficient for airline employment, or whether individual carriers layer on their own colour vision screening during the hiring process. The poster, who self-identifies with mild red-green colour deficiency, is essentially asking whether regulatory compliance guarantees employability, a distinction that matters enormously for anyone investing years and tens of thousands of dollars into flight training before knowing if a career at a major or regional carrier is even attainable.
The underlying issue reflects a well-known tension in aviation medical certification worldwide. Regulators including Transport Canada, the FAA, and EASA have moved away from a strict pass/fail Ishihara standard toward tiered testing protocols precisely because a meaningful percentage of otherwise medically fit applicants—estimates commonly cite roughly 8% of men of European descent—have some degree of red-green colour vision deficiency. Supplementary tests like the Farnsworth Lantern (FALANT), the Colour Assessment and Diagnosis (CAD) test, or Operational Colour Vision Assessment Tests allow examiners to distinguish between deficiencies severe enough to compromise safety-critical tasks (reading approach light systems, PAPI/VASI colour cues, cockpit annunciator lights, or airport signage) and milder deficiencies that don't meaningfully impair operational performance. A pilot who fails plates but passes an operational test can be issued a medical without restriction, or in some cases with a restriction limiting operations to daylight VFR or requiring colour-normal crew pairing, depending on the jurisdiction and specific test results.
Where this gets murkier—and where the original poster's question is entirely valid—is that a medical certificate establishes regulatory eligibility, not guaranteed employability. Airlines, particularly major carriers, have historically been conservative about colour vision in their own pilot selection processes, sometimes applying screening during simulator assessments, class 1 medical review by company-designated physicians, or specific questions during pilot medical history intake, independent of what Transport Canada has already certified. Some Canadian regional and major carriers have been known to accept an unrestricted TC medical at face value, while others, especially those with international codeshare or ICAO-harmonization considerations (given some countries' regulators remain stricter on colour vision than Canada), may probe further. This inconsistency means answers genuinely vary by operator and can change over time as carriers update policy, making anecdotal crowdsourced information from working pilots, as sought in this thread, valuable but not authoritative.
For working pilots and flight instructors advising students, this topic underscores the importance of pursuing supplementary colour vision testing early—ideally before committing to expensive flight training—and obtaining explicit written documentation of any restriction or lack thereof on the medical certificate itself, since that document is what an airline's aeromedical or HR department will ultimately review. It also highlights a broader industry trend: as pilot shortages have pushed airlines to widen their talent pools, there's more institutional appetite for accommodating borderline medical cases that would have been automatic disqualifiers a generation ago, provided objective operational testing demonstrates safety isn't compromised. Prospective pilots dealing with this issue are well served by consulting directly with Transport Canada Civil Aviation Medicine, an aviation medical examiner experienced with colour vision cases, and where possible, the specific airlines they hope to eventually fly for, rather than relying solely on regulatory minimums.