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Minimum Color Vision Requirements for Professional Flight Crew, Part III: Recommendations for New Color Vision Standards

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Federal Aviation Administration DOT/FAA/AM-09/11 Office of Aerospace Medicine Washington, DC 20591 Minimum Color Vision Requirements for Professional Flight Crew, Part III: Recommendations for New Color Vision Standards John Barbur Marisa Rodriguez-Carmona Applied Vision Research Centre Northampton Square London, EC1V 0HB, UK Sally Evans Civil Aviation Authority Gatwick Airport South Gatwick, RH6 0YR, UK Nelda Milburn Civil Aerospace Medical Institute Federal Aviation Administration Oklahoma City, OK 73125 June 2009 Final Report OK-09-0434-JAH NOTICE This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The United States Government assumes no liability for the contents thereof. ___________ This publication and all Office of Aerospace Medicine technical reports are available in full-text from the Civil Aerospace Medical Institute’s publications Web site: www.faa.gov/library/reports/medical/oamtechreports Technical Report Documentation Page 1. Report No. 2. Government Accession No. 3. Recipient's Catalog No. DOT/FAA/AM-09/11 4. Title and Subtitle 5. Report Date Minimum Color Vision Requirements for Professional Flight Crew, June 2009 6. Performing Organization Code Part III: Recommendations for New Color Vision Standards 7. Author(s) 8. Performing Organization Report No. 1 1 2 3 Barbur J , Rodriguez-Carmona M , Evans S , Milburn N 9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) 1Applied Vision Research Centre 3FAA Civil Aerospace Medical Institute Northampton Square P.O. Box 25082 11. Contract or Grant No. London EC1V 0HB, UK Oklahoma City, OK 73125 06-G-003 2Civil Aviation Authority Gatwick Airport South Gatwick, RH6 0YR, UK 12. Sponsoring Agency name and Address 13. Type of Report and Period Covered Office of Aerospace Medicine Federal Aviation Administration 800 Independence Ave., S.W. Washington, DC 20591 14. Sponsoring Agency Code 15. Supplemental Notes Work was accomplished under approved task AM-521. 16. Abstract This report describes the findings of the third phase of the project sponsored by the United Kingdom Civil Aviation Authority on “Minimum Color Vision Requirements for Professional Flight Crew.” This third part of the project, “Recommendations for New Color Vision Standards,” involved collaboration and co-sponsorship by the Federal Aviation Administration. Minimum color vision requirements for professional flight crew have been established by assessing the level of color vision loss above which subjects with color deficiency no longer perform the most safety-critical, color- related tasks within the aviation environment with the same accuracy as normal trichromats. The new CAD (Color Assessment & Diagnosis) test provides accurate assessment of the applicant’s color vision. The results of the test establish with high specificity whether the subject’s red-green and yellow-blue color vision performance falls within the normal range and the class and severity of color vision loss in subjects with color deficiency. The results of the test also indicate whether the applicant’s color vision meets the minimum requirements for safe performance that have emerged as necessary from this investigation. If the new, experiment-based, pass/fail color limits were adopted as minimum requirements for professional flight crew, 36% of deutan subjects and 30% of protan subjects would be classified as safe to fly. Given the higher prevalence of deutan deficiencies, these findings suggest that 35% of color deficient applicants would be classified as safe to fly. 17. Key Words 18. Distribution Statement Color Vision, Pilot Screening, Colour Deficiency, CAD Document is available to the public through the Defense Technical Information Center, Ft. Belvoir, VA Test, PAPI Lights, Signal Lights 22060; and the National Technical Information Service, Springfield, VA 22161 19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No. of Pages 22. Price Unclassified Unclassified 47 Form DOT F 1700.7 (8-72) Reproduction of completed page authorized ACKNOWLEDGMENTS We thank Dr. Anthony Evans (ICAO) for hs actve partcpaton n ths project and contnued support wth many aspects of ths nvestgaton. We also acknowledge the valuable contrbuton each of the persons lsted below has made to the project through progress revew meetngs, valuable crtcsm, and comments on the final report: Ms. J. Brch Cty Unversty, UK Mr. A. Chorley CAA Chef Optometrst, UK Dr. D. Connolly Qnetq Ltd., UK Dr. H. Courteney CAA, UK Dr. A. Evans ICAO Montreal, Canada Mr. S. Grffin CAA, UK Mr. A. Harlow Cty Unversty, UK Dr. I. Moorhead Qnetq Ltd., UK Ms. M. O’Nell-Bba Cty Unversty, UK Dr. J. Ptts CAA Consultant Ophthalmologst, UK Dr. R. Scott RAF Consultant Ophthalmologst, UK Mr. S. Wllams CAA, UK EXECUTIVE SUMMARY Ths report descrbes the findngs of the thrd phase plots, although many of these subjects may well be able of the project sponsored by the Unted Kngdom Cvl to perform safety-crtcal tasks, as well as normal trchro- Avaton Authorty (CAA) on “Mnmum Color Vson mats, when presented wth the same, suprathreshold color Requrements for Professonal Flght Crew.” Parts I and sgnals. In prncple, these subjects should be allowed to II have already been publshed and cover “Use of Color fly. To nclude some ndvduals wth mnmum color Sgnals and Assessment of Color Vson Requrements,” deficency that may well be safe to fly, some authortes and “Vsual Task Analyss,” respectvely. Ths thrd part have ether relaxed the pass lmts on tests desgned to of the project, “Recommendatons for New Color Vson screen for normal color vson (e.g., Ishhara, Dvorne) Standards,” nvolved collaboraton and co-sponsorshp or they have ntroduced less demandng tests that ap- by the Federal Avaton Admnstraton (FAA). plcants wth mld color vson deficency can pass. Ths Mnmum color vson requrements for professonal approach does justce to some applcants but not to others. flght crew have been establshed by assessng the level of Exstng, conventonal color screenng tests employed by color vson loss above whch subjects wth color deficency most authortes cannot be used to quantfy accurately no longer perform the most safety-crtcal, color-related the severty of color vson loss, and ths makes t dfficult tasks wthn the avaton envronment wth the same to set relable pass/fal lmts. Wth very few exceptons, accuracy as normal trchromats. The new CAD (Color no red/green color deficent applcants pass ether the Assessment & Dagnoss) test provdes accurate assess- Ishhara or the Dvorne color screenng tests wth zero ment of the applcant’s color vson. The results of the errors. The same apples to anomaloscope matches when test establsh wth hgh specficty whether the subject’s strct crtera are employed (e.g., when the applcant sets red-green and yellow-blue color vson performance falls an approprate red/green mxture field to match the color wthn the normal range and the class and severty of appearance of a yellow, monochromatc field, as n the color vson loss n subjects wth color deficency. The Nagel anomaloscope). In ths respect, these tests are ex- results of the test also ndcate whether the applcant’s cellent, but as has been shown n several studes, nether color vson meets the mnmum requrements for safe the anomaloscope results (Barbur et al., 2008) nor the performance that have emerged as necessary from ths Dvorne/Ishhara plates (Squre et al., 2005) can be used nvestgaton. If the new, experment-based, pass/fal to quantfy relably the severty of color vson loss. color lmts were adopted as mnmum requrements When the pass lmts are relaxed, the outcome of such for professonal flght crew, 36% of deutan subjects and tests no longer guarantees normal trchromatc perform- 30% of protan subjects would be classfied as safe to fly. ance n the most safety-crtcal, color-related tasks. The Gven the hgher prevalence of deutan deficences, these FAA gudelnes for avaton medcal examners (www.faa. findngs suggest that 35% of color deficent applcants gov/about/office_org/headquarters_offices/avs/offices/ would be classfied as safe to fly. aam/ame/gude/) n relaton to color vson tests, test- ng procedures, and pass lmts are dfferent from those BacKGROUND practced n Europe. The JAA member states employ the Ishhara screenng test to dentfy applcants wth red/green The use of color n avaton for codng of sgnals and deficency. No errors on any of the first 15 plates of the nformaton s mportant, hence the need to set adequate 24-plate Ishhara set are allowed n order to pass. Most color vson requrements to ensure that flght crew are color deficent observers (both deutan and protan) fal able to dscrmnate and recognze dfferent colors, both ths strngent use of the Ishhara test, except for a very on the flght deck and externally. Concern has, however, small number of mnmum deuteranomalous that pass. been expressed durng the past few years that the cur- In addton, ~15% of normal trchromats (an estmate rent color vson standards, at least wthn JAA (Jont based on 202 normal trchromats examned at Appled Avaton Authortes) member states, are not approprate Vson Research Centre (AVRC)) also fal the Ishhara, snce most tests and pass lmts only screen for normal when one employs the strct CAA/JAA pass/fal crtera. red/green color vson. Snce the ncdence of congental Secondary tests such as the Holmes-Wrght Type A (HW) yellow/blue deficency s extremely low (see Table 1), the lantern (used n the Unted Kngdom) are employed, absence of red/green deficency s vrtually equvalent and although some color deficent observers (mostly to normal trchromacy. Subjects wth mnmal color deuteranomalous subjects, see dscusson secton) pass deficences often fal normal trchromacy tests, and the these tests, the severty of ther color vson loss remans great majorty are therefore prevented from becomng unknown. One advantage of usng the HW lantern as a v secondary test s that normal trchromats pass ths test Although such occurrences have not passed unnotced, no and are therefore not dsadvantaged when they fal the adequate solutons have emerged to set mnmum lmts Ishhara test.
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