F. Defective Color Vision.
1) Applicants who fail the color vision screening test as listed in the Guide for Aviation Medical Examiners, but desire an airman medical certificate without the color vision limitation, "NOT VALID FOR NIGHT FLYING OR BY COLOR SIGNAL CONTROL," may be given, upon request, an opportunity to take and pass additional operational color perception tests. The operational tests are determined by the class of medical certificate requested (see Figure 5‑153A). Such testing is conducted solely by an ASI and may be conducted only on a LOA (see Figures 5‑153B and 5‑153C). Applicants for a first‑ or second‑ class medical certificate are required to take and pass an Operational Color Vision Test (OCVT) and a color vision Medical Flight Test (MFT). Applicants for a third class medical certificate need only to take and pass the OCVT.
2) The OCVT has two components, the Signal Light Test (SLT) and demonstration of the ability to correctly read and identify colors on aeronautical charts. (See paragraph 5‑1526E6) for instructions on how to conduct the OCVT.) Applicants for a medical certificate who have defective color vision must be initially tested in daylight conditions, and if specified in the LOA, a nighttime test may be authorized to be given only after the daylight test has been completed.
6) Observe the applicant with a color vision defect.
a) An applicant for a first‑ or second‑ class airman medical certificate who has defective color vision, must demonstrate the following:
1. The ability to pass an OCVT which includes:
· A SLT (see paragraph 5‑1527); and
· The ability to read and correctly interpret in a timely manner aeronautical charts, including print in various sizes, colors, and typefaces; conventional markings in several colors; and terrain colors. Aeronautical chart reading may be performed under any light condition where the chart will normally be read. The ASI or AST must provide the aeronautical chart.
2. The ability to pass a color vision MFT as described below:
· Must read and correctly interpret in a timely manner aviation instruments or displays, particularly those with colored limitation marks, and colored instrument panel lights, especially marker beacon lights, warning or caution lights, weather displays, etc.
· Must recognize terrain and obstructions in a timely manner; have the applicant select several emergency landing fields, preferably under marginal conditions, and describe the surface (for example, sod, stubble, plowed field, presence of terrain roll or pitch, if any), and also describe how the conclusions were determined. Further, ask the applicant to identify obstructions such as ditches, fences, terraces, low spots, rocks, stumps, and, in particular, any gray, tan, or brown objects in green fields.
3. Must visually identify in a timely manner the location, color and significance of aeronautical lights. To minimize the effect of an applicant memorizing the color of a light associated with a particular light system, the ASI should make every effort to not use the light system name during the flight, but rather to ask the applicant to identify a light color and the significance of as many of the following lights as possible:
· Colored lights of other aircraft in the vicinity.
· Runway approach lights, both the Approach Light System (ALS) and Visual Glideslope Indicators.
· Runway edge light system.
· Runway End Identifier Lights.
· In‑runway lighting (runway centerline (CL) lights, touchdown zone (TDZ) lights, taxiway lead‑off lights, land and hold short lights.
· Airport boundary lights.
· Taxiway lights (edge lights, CL lights, clearance bar lights, runway guard lights, and stop bar lights.
· Red warning lights on television towers, high buildings, stacks, etc.
· Airport beacon lights.
b) An applicant for a third‑class airman medical certificate who has defective color vision must demonstrate the ability to pass the OCVT (see 6)a)1) above).
5-1527 PROCEDURES FOR THE SLT ONLY.
A. PTRS. Open PTRS file.
B. Schedule Appointment. Schedule the appointment, during daylight conditions or as specified in the LOA. Instruct the applicant to bring the LOA and medical certificate to the appointment.
C. Test Coordination. The ability to identify aviation red, green, and white is verified using the SLT. This test may be accomplished at the FSDO or the nearest air traffic control (ATC) tower which has a tower signal light or hand‑gun signal light. The operator of the equipment must ensure it is properly maintained and in good working order prior to initiating the test. In addition, every effort should be made to provide an environment that does not hamper the applicant's ability to successfully complete the test, i.e., mist, fog, dirty ATC Tower windows, Tower Cab shades drawn, overcast, etc. The signal light operator must not have the sun to their back. The ASI shall not indicate the accuracy of the readings during the test. If the applicant does not call each color correctly within the time period that the light is shown, the applicant fails; the test, however, is continued until completion.
D. Conduct SLT.
1) The signal light operator should shine the light steadily for a period of five seconds twice randomly as directed by the ASI for each color, green, red, and white.
2) The ASI must pre‑arrange the sequence of 12 lights to be shown to the applicant. Each color must be shown at least one time at 3 minute intervals for 5 seconds. Inform the light operator of the signal that will be used (hand signal, radio, etc.) to indicate when to shine the light.
3) The ASI must accompany the applicant to an area approximately 1,000 feet from the light operator and ask the applicant to respond to each of six lights by stating the light color shown. Instruct the applicant to respond within the 5 seconds after the light is shown.
4) Signal the light operator to begin the procedure.
a) Using the job aid in Figure 5‑164, record the color displayed and applicant's response.
b) After a 3‑minute interval, repeat the procedure until all six lights are shown.
5) Accompany the applicant to an area approximately 1,500 feet from the light operator, and repeat the procedures outlined above. Be sure that all six lights have been displayed before completing the test.
6) Applicants who pass the OCVT and the color vision Medical Flight Test (see paragraph 5‑1523G of this chapter) will be given a letter of evidence valid for all classes of medical certificates and will have no limitation or comment made on the certificate regarding color vision as they meet the standard for all classes. Applicants who only pass the OCVT will be given a letter of evidence valid for third‑class medical certificate. Certificates for third‑class will have a comment put in the limitation area of the certificate that reads: 3rd class letter of evidence. This comment is necessary to avoid an upgrade in class without further testing.
7) An applicant who fails the SLT portion of the OCVT during daylight hours may repeat the test at night. Should the airman pass the SLT at night, the restriction "NOT VALID FOR FLIGHT DURING DAYLIGHT HOURS BY COLOR SIGNAL CONTROL" must be placed on both the replacement medical certificate and the new SODA by the issuing medical office or the Aerospace Medical Certification Division, AAM‑300. The airman must have taken the daylight hours test first and failed prior to taking the night test. The day test documentation must be combined with the night test documentation and sent to the issuing medical office or to AAM‑300.
8) Should the applicant fail the SLT portion of the OCVT during daylight hours and at night, the restriction "NOT VALID FOR NIGHT FLYING OR BY COLOR SIGNAL CONTROL" must be placed on the medical certificate. If needed, contact the Regional Medical Office or the Aerospace Medical Certification Division, AAM‑300, to specify the correct wording on the certificate. Applicants who fail the daylight SLT are not eligible for a first‑ or second‑class medical certificate, and may not be given a letter of evidence or have the limitation removed or modified.
NOTE: Airmen with this limitation should be advised that to minimize the effect of loss of radio communications, they should as a safety practice carry an extra radio, and in the event of ATC radio communication outage to consider in planning their flight the possibility to divert to another airport or to an uncontrolled airport.
