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On July 26, 2002, about 0537 eastern daylight time, Federal Express flight 1478, a Boeing 727-232F, N497FE, struck trees on short final approach and crashed short of runway 9 at the Tallahassee Regional Airport (TLH), Tallahassee, Florida. The flight was operating under the provisions of 14 Code of Federal Regulations Part 121 as a scheduled cargo flight from Memphis International Airport, in Memphis, Tennessee, to TLH. The captain, first officer, and flight engineer were seriously injured, and the airplane was destroyed by impact and resulting fire. Night visual meteorological conditions prevailed for the flight, which operated on an instrument flight rules flight plan.
TO THE FEDERAL AVIATION ADMINISTRATION: Conduct research to determine the effectiveness of each of the current Federal Aviation Administration-approved color vision test protocols (including the color signal light test) at effectively screening out pilot applicants with color vision deficiencies that could impair their ability to perform color-related critical aviation tasks including (but not limited to) correct interpretation of glideslope information and in-cockpit displays that use color to convey information. The research should take into account the time typically available to perform each task, particularly under emergency conditions, and the potential effect of mild hypoxia (as might occur at typical cabin altitudes) on color vision deficiencies.
Original recommendation transmittal letter:
Closed - Acceptable Action
Tallahassee, FL, United States
Collision With Trees on Final Approach Federal Express Flight 1478, Boeing 727-232
Addressee(s) and Addressee Status:
FAA (Closed - Acceptable Action)
Safety Recommendation History
Thank you for the description of the extensive research program on color vision testing that the FAA completed. We also appreciate receiving the summary of the findings provided in the FAA’s letter. Conclusion of this research program completes the recommended action; accordingly, Safety Recommendation A-04-46 is classified CLOSED—ACCEPTABLE ACTION.
-From J. Randolph Babbitt, Administrator: The Federal Aviation Administration (FAA) conducted a series of studies in response to Safety Recommendation A-04-46. Concerning current pilot color vision screening, our findings suggest that subjects who can pass clinical color screening make few or no errors in discriminating colors in signal lights, approach lighting (including precision approach path indicator lights). airport surface lighting, and cockpit displays. This is true whether those tasks make use of incandescent or light-emitting diode (LED) lights. The FAA Office of Aerospace Medicine revised its approved list of initial color vision screening tests in 2010. However, these studies raise concerns about the operational performance based testing process for those who fail current pilot clinical color screening. Color use in airport surface lighting glide path signaling systems, and cockpit displays is changing. Surface and signaling systems are moving 10 LED lighting to increase energy efficiency. Aircraft manufacturers arc increasing use of color in cockpit display systems. Signal Light Guns (SLOs), used operationally for communication ill the absence of radio and as a certificatioJ110ol to predict safe performance of airmen with deficient color vision, have also changed. Older SLOs (e.g., Crollse-Ilinds Type \V-I Signal Light Gun) were able to identify which color vision deficient (CYD) individuals were also able to discriminate the various surface lighting requirements. The result of our studies show that older SLGs predicted well who could not discriminate airport surface lighting glide path signaling systems, and cockpit displays, using both incandescent and LED lights. Newer SLGs (e.g.. ATS Aerospace, Inc. Model 901) produce colors that arc easier to discriminate by color deficient individuals. Approximately two-thirds of research subjects with color vision deficiencies pass newer SLGs. This is beneficial for operational use. If communication by signal light is necessary, more CYD pilots would be able to do so. However, the error rate among those who pass the newer SLG test but fail the older SLG test is elevated for airport surface lighting, glide path signaling systems, and cockpit displays. Between 20 and 48 percent of those who pass only the newer SLGs failed to make required discriminations in these areas, as compared to subjects with normal color vision. Therefore, the new SLGs cannot be used as a stand alone test to predict one's ability to perform other color-based cockpit tasks. This suggests that the concerns articulated in this recommendation arc well founded. In December 2010, the Federal Air Surgeon recommended the decertification of the older Crouse-Hinds Type W-I SLG for operational use out of concern that a pilot cleared on a newer SLG might encounter and fail to discriminate operational signals from an older SLG. Continuing work in this area is described in our response to Safety Recommendation A-04-47. Concerning the impact of mild hypoxia, three divisions at the FAA's Civil Aerospace Medical Institute (Aerospace Human Factors, Aeromedical Research, and Aeromedical Education divisions) collaboratively examined the effects of mild hypoxia (chamber environment equivalent to altitudes of 8,000 feet and 12,400 feet) to determine whether hypoxia induced color perception decrements that would render pilots with marginal color vision incapable of interpreting color-coding in the cockpit or airport environment. Results indicated that hypoxia has no measurable effect among color vision normal or deficient subjects at altitudes experienced in a pressurized cabin or at the allowable limits for extended unpressurized flight. On color identification, color naming, and color discrimination tasks and measurements by high precision clinical tests, participants performed no worse at the measured altitudes than they did at ground level, regardless of their color vision status. Only a slight decrease in sensitivity to green light among color vision normal and anomalous trichromat (mildest deficient) subjects was documented (Hovis and Milburn, 2011). Other research (Richalet, Duval-Arnould, Darnaud, Kerollles, and Rutgers, 1988) has documented color vision loss in color vision normal subjects at altitudes above 14,000 feet and color vision loss is routinely described by participants in high altitude training above 18,000 feet. No action is required regarding color vision relative to mildly hypoxic flight conditions. I believe that the FAA has effectively addressed this recommendation and I consider our actions complete.
Pending the results of the FAA's color vision testing research program and appropriate revisions to the color vision testing protocols used for recurrent medical examinations and certifications, Safety Recommendations A-04-46 and -47 are classified OPEN -- ACCEPTABLE RESPONSE.
Letter Mail Controlled 9/22/2004 9:38:22 AM MC# 2040571 - From Marion C. Blakey, Administrator: The Federal Aviation Administration (FAA) has reviewed the Federal Express accident and the two other accidents in the Board's database where pilots with valid medical qualifications were involved in accidents where deficient color vision was cited as a contributing cause. On August 5, 1980, a Navy F-4J was lost 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 an impending collision. On August 29, 1992, the pilot of a Mooney 20F, with a "waiver for partial color-blindness to red and green," was startled by a near miss, and decided to land on the first runway he had in sight. The runway he chose was marked ''closed'' with orange crosses on the soil 50 feet beyond each end. The pilot stated that he had checked the NOTAMs and was aware that the N-S runway was closed. The Board listed his limited ability to detect the orange closed marking as a factor. The FAA recognizes that color vision testing methods and the relevance of color vision deficiencies to aviation safety are controversial, both in the United States and worldwide. The FAA is also aware that efforts are underway in some countries to assess color vision testing methods for airmen and possibly develop a color vision test that may be more appropriate than those presently in use. The FAA accepts several color vision screening tests for airmen and employs practical testing with signal lights to determine whether an airman should be permitted to perform aviation duties without limitations. While the FAA does not believe the above mentioned accidents provide compelling evidence that the current color vision discrimination tests are deficient, because a number of these tests were validated years ago and the demands for color vision perception in aviation are changing, the FAA believes it is appropriate to conduct the research recommended by the Board. The FAA anticipates that the research necessary to identify, develop, and validate a new color vision screen that is in compliance with existing Federal regulations will be a substantial effort. Careful consideration will be given to the added risk associated with any performance differences between pilots with normal color vision and those with varying degrees of color vision deficiency. In pursuing this research, FAA must consider other safety research priorities and the availability of resources. The following is a tentative schedule for pursuing the research initiative: · Conduct an extensive review of the literature related to color vision and performance on color-coded displays, with particular attention to the flight environment. (Estimated time for completion is 6 months.) · Establish a group of subject matter experts from the aviation community to review existing and emerging aviation displays and the flight environment to identify systematically the use of color, to identify instances where color is used as a non-redundant cue, and determine whether pilots who have a color vision deficiency may respond in a manner that may compromise safety. (Estimated time for completion is 1 year.) · Use results of the review and analysis to develop a research study that assesses the ability of color vision deficient individuals to respond to information from cockpit displays and the aviation environment, as well as respond to simulated red-white VASI/PAPI lights under time constricted conditions. (Estimated time for completion is 2.5 years.) · These results, along with those of research currently ongoing in other countries, will provide the necessary information regarding the modification of existing standards and the development of a revised testing protocol, including practical tests. (Estimated time for completion is 2.5 years) I will keep the Board informed of the FAA's progress on these safety recommendations.
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