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I would like to know if there are any official reports pointing Color Vision Deficiency (CVD) as a major contributing cause of an air accident/incident. Not only related to flying but also maintenance or ATC for instace.

So far, I have only come across with FedEx flight 1478, in which a CVD F/O misjudged the PAPI lights. However, the report does not point how severe was the F/O's deficiency (all crew survived the accident). And more important is that the Captain and Flight Engineer (with normal color vision) could neither detect the wrong glidepath.

My final goal is to research the topic of color-blindness in aviation with real case instances and hopefully draw some conclusions about the actual impact of this disease in aviation for candidate's medical certification.

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  • $\begingroup$ CVD is only disqualifying for night flying or "color signal control". I don't think this is one of the regulations that is "written in blood" as many others are. Many flying cues are by color and if you can't distinguish colors, you need restrictions. $\endgroup$ – Ron Beyer Feb 17 at 16:39
  • $\begingroup$ Things in general are so much more flexible now. In Canada at least you can hold a Cat 1 while blind in one eye and even with Type 1 diabetes (albeit with a lot of restrictions). $\endgroup$ – John K Feb 17 at 18:15
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    $\begingroup$ @RonBeyer Yes, there is no doubt that aviation jobs require color discrimination capabilities. The thing is that CVD varies greatly among candidates. The issue here is where to draw the line where safety is not compromised. My own experience has shown me that values are kept very conservative using empyrical tests (such as Ishihara test plate) and I am afraid that a more pragmatic approach is missing. For instance, creating simulator scenarios where color discrimination is at stake for safety. $\endgroup$ – ppinto Feb 17 at 19:54
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    $\begingroup$ @ppinto Please add country-specific tags to your question if you want country-specific answers. $\endgroup$ – Ron Beyer Feb 17 at 21:23
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    $\begingroup$ One of the flaws in this line of questioning is that until recently most regulators have largely prohibited pilots with CVD from flying, you certainly won't find 2 pilots in an airliner who both have CVD. This is slowly changing so this question is worth revisiting in maybe 15 years time. $\endgroup$ – Ben Feb 17 at 22:15
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In response to two NTSB safety recommendations, the FAA stated that it has only identified three accidents involving pilots with valid medical qualifications in which color vision deficiency (CVD) was cited as a contributing cause.

  1. As you mention above, on July 26, 2002, a Federal Express Boeing 727-200F crashed during a visual approach to Tallahassee Regional Airport in nighttime visual meteorological conditions. The three crew members were seriously injured and the airplane was destroyed in the crash, which the NTSB attributed to “the captain’s and first officer’s failure to establish and maintain a proper glide path.” Because the first officer was flying the plane at the time of the crash, the NTSB cited as one of several contributing factors “the first officer’s color vision deficiency" which interfered with his ability to discern the red and white lights of the precision approach path indicator (PAPI).

  2. On Aug. 29, 1992, an incident occurred in which the pilot of a Mooney 20F with “a waiver for partial color blindness to red and green” landed on a closed runway that was marked with orange crosses in the dirt 50 ft beyond each end. The pilot’s “limited ability to detect the orange-colored marking” was cited as a contributing factor.

  3. One incident involved a Navy F4J lost on Aug. 5, 1980, “when a severely color deficient pilot failed to interpret correctly the colored navigation lights of other aircraft in the area, leading to the false impression of a collision.”

Regarding the severity of the FO's color blindness from FedEx flight 1478, records indicate that he passed all color vision tests during his 16 years as a U.S. Navy pilot but failed a test administered during an FAA medical evaluation in 1995. This failed test indicated that he had a mild red-green deficiency. The FAA issued a first-class medical certificate with a statement of demonstrated ability (SODA), based on his years as a Navy pilot and the results of his Navy color vision tests. He was issued this SODA on all subsequent medical examinations.

After the 2002 crash, the first officer passed the Farnsworth Lantern (FALANT) color vision test, which was designed to differentiate between those with mild red-green deficiencies, who pass the test, and others with more significant red-green deficiencies, who fail. He also passed a light-gun-signal test administered by an FAA medical examiner. However, he failed seven other red-green color vision tests and was determined to have a “severe congenital deuteranomaly” — a red-green deficiency that is the most common color vision defect.

Hope this helps.

References: Werfelman, L. (2008, December). Color deficient?[PDF] Aero Safety World, 38-41. Flight Safety Foundation. Retrieved from:http://www.flightsafety.org/asw/dec08/asw_dec08_p38-41.pdf

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