A pilot with colour vision deficiency is challenging restrictions on his licence which he says are discriminatory.
First Officer John O'Brien is preparing to challenge the restrictions in a hearing in Brisbane next month.
He's been unable to pass what's known as the control tower signal gun test.
The test is based around the scenario of when red and green lights are used by the control tower when radio contact is lost.
It's considered outdated by some in the aviation sector because pilots can use their mobile phone to communicate with the control tower if radio contact fails.
The Civil Aviation Safety Authority has written to pilots, airlines and freight companies warning them that it's considering tightening the medical requirements for pilots with colour vision deficiency.
Dr Arthur Pape from the Colour Vision Defective Pilots Association told Greg Dyett, CASA's crackdown could be related to the pending court hearing.
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