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The future for our CVD pilots: GD Review Panel’s findings, in black and white

"...much evidence was presented to support the view that most CVD in pilots is not likely to be of aeromedical significance"

“…much evidence was presented to support the view that most CVD in pilots is not likely to be of aeromedical significance”

The full report of the Colour Vision Deficiency General Direction Review Panel runs to 87 pages. In the interests of brevity, we have condensed it to three A4 pages. Fifty-nine written submissions were received in response to the consultation process. Of these, 15 were from aviation groups and the remaining 44 from individuals.

The Principal Medical Officer, Dr Dougal Watson, also provided the panel with a PowerPoint presentation. In answer to a question regarding the reasoning behind the proposed flight restrictions for a pilot who is CVD, he said that the “restrictions are historical”. This was a key issue for the panel, particularly in relation to the risk posed by a pilot with CVD, the different operational environments pilots operate in and who should be determining restrictions under which a pilot is to operate.

The PMO also said that he thought practical flight tests are unreliable.

But in the panel’s now-released opinion, a flight examination has the same status as a medical examination in ensuring that a pilot is not a threat to the public and renewing their privileges to fly. Here are the key points in the panel’s report:

Part 6 – Conclusions

  1. The colour vision status of those holding a medical certificate issued under CAR Part 67 needs to be known, just as other aspects of the physical status of pilots is known; e.g. other aspects of vision, hearing and mental health status. If routine screening or non-routine examination (including a practical test) acceptable to the Director can be passed, then the CVD is not of aeromedical significance.
  2. The promulgation of a GD for colour vision is appropriate to provide certainty, clarity and consistency.
  3. CVD is a potential safety threat although there is difficulty in establishing exactly what the threat is. In this respect, the guidance provided by ICAO is not helpful. The ICAO Manual of Civil Aviation Medicine admits that there is very little information which shows the real, practical implications of colour vision defects on aviation safety. ICAO standards for colour vision pre-date many advances in aviation technology and flight safety, which raises doubt over the validity of many of the traditional reasons for imposing restrictions on a CVD pilot and calls into question what is and is not of aeromedical significance. The situation is compounded by inconsistent standards being applied by different states and by the same state over time.
  4. Advances in aviation, technology and training mean greater emphasis can be placed on interpreting information rather than simply the recognition of colours if this is not essential to the operation. These advances, and the additional safety they bring to aviation in general, are such that relaxing CVD requirements will likely not impact on safety. No evidence or compelling argument was presented to the panel that related perceived aeromedical significance of CVD to known or proven threats to flight safety. On the contrary, much evidence was presented to support the view that most CVD in pilots is not likely to be of aeromedical significance. Similarly, the accumulated hours flown by pilots around the world, especially in Australia, suggests CVD pilots are likely to pose no greater safety risk than a non-CVD pilot.
  5. There is a lack of evidence to support the proposed medical certificate restrictions, and the proposed restrictions do not reflect risks posed by CVD in the context of modern aviation.
  6. Any restrictions imposed on a pilot with a CVD condition must be applied on the basis of an identifiable threat to safety or risk. The question as to whether or not a condition is of aeromedical significance, and hence the level of risk, is dependent on the operational context; the type and nature of the operation; type of aircraft; and crew composition. What may be significant for one situation may not be for another. The variability is too great to be dealt with by generalised restrictions as proposed in the GD.
  7. There is no strong link between the office-based examination of CVD and real world realities. Under the proposed GD, the assessment of interferes with or likely to interfere with is ascertained from office-based assessments only. This assessment cannot be made from office-based tests only and can only be determined by an in-flight practical test. While aviation medicine and flight operations specialists will need to be involved in the development of protocols for in-flight testing, only a flight examiner or flight instructor will be in a position to assess the ability of a pilot with a CVD condition to operate an aircraft safely. Thus the effect that a CVD condition will have on the ability of a pilot to safely exercise the privileges of a licence is a flight operations issue, not a medical issue.
  8. The CAD test appears to be the best office-based occupational test available and it is appropriate that it is added to the list of acceptable non-routine examinations. Overall though, the GD appears to be too limited in acceptable non-routine tests and while the GD suggests other tests may be acceptable to the Director, AC67-1 does not reflect this.
  9. Consistency in standards and restrictions with other states, particularly Australia, is desirable; however it is more appropriate to direct any initiatives in this respect to ICAO to progress.
  10. A three-tier testing regime which includes an in-flight test is a more appropriate method than the proposed GD to assess colour vision and to determine the ability of a candidate to safely exercise the privileges or the safe performance of the duties to which the relevant medical certificate relates. Such a regime would maintain New Zealand’s compliance with ICAO requirements in this respect and will identify the operational risks of CVD. The three tiers are:
  • Stage 1 – Initial Routine Screening. The current screening proposed by the GD using the Ishihara test using the pass criteria as proposed in the GD.
  • Stage 2 – Non-routine office-based examination. Should an applicant not pass routine screening, non-routine office-based examinations are conducted to establish the nature and severity of the condition. If any test is passed, then the condition can be deemed as not of aeromedical significance.
  • Stage 3 – Practical test. Should it be necessary, a specifically tailored flight assessment or simulator exercise is conducted to determine the ability of the candidate to safely operate an aircraft.
  1. It is appropriate that Stage 2 and 3 testing is conducted through the AMC process, including the ability for a candidate to forego non-routine examinations and accept restrictions based on the initial screening results.
  2. Any restrictions placed on a candidate’s certificate must be based on the context of the individual’s circumstances; the nature and severity of the condition, and the intended operation

Part 7 – Recommendations

  1. The CVD GD Review Panel recommends that the Director proceed with the General Direction – Impaired Colour Vision with the following changes:
  2. Review the GD with respect to acceptable non-routine office based examinations to ensure other tests currently in use by other ICAO regulatory authorities are included as acceptable tests.
  3. Introduce the CAD test as proposed.
  4. Include a practical flight test to the examination procedure as a third stage following initial screening and non-routine examination so that a candidate may demonstrate their ability to operate an aircraft safely.
  5. Ensure that certificate endorsements, including the need for any ongoing tests should a CVD condition be deemed to be of aeromedical significance, are based on input from both medical and operational staff and are related to the individual’s particular situation with respect to condition and operational context, and noting that only an in-flight test can assess the ability of a pilot with a CVD condition to operate an aircraft safely.
  6. Develop appropriate protocols, procedures and guidance to ensure the practical test is appropriate to the nature and severity of an applicant’s CVD condition and the context of the candidate’s intended operation and the identifiable risk that the candidate poses.
  7. The Review Panel further recommends that the Director conducts further evaluation into the colour perception needs of air traffic controllers.

The bottom line.

This report does not reflect CAA policy and simply provides guidance to the Director. We will need to wait until the PMO provides his report to the Director. A final decision on what process the CAA will adopt is not expected until November.


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