Correct Scottish.CPL, the CAD is NOT approved by EASA and the situation could be more serious than you think.
EU Regulation 1178/2011 Annex IV Part MED states:
MED.B.075 Colour vision
(a) Applicants shall be required to demonstrate the ability to perceive readily the colours that are necessary for the safe performance of duties.
(b) Examination
(1) Applicants shall pass the Ishihara test for the initial issue of a medical certificate.
(2) Applicants who fail to pass in the Ishihara test shall undergo further colour perception testing to establish whether they are colour safe.
(c) In the case of Class 1 medical certificates, applicants shall have normal perception of colours or be colour safe. Applicants who fail further colour perception testing shall be assessed as unfit. Applicants for a Class 1 medical certificate shall be referred to the licensing authority.
(d) In the case of Class 2 medical certificates, when the applicant does not have satisfactory perception of colours, his/her flying privileges shall be limited to daytime only.
This is complemented by the Acceptable Means of Compliance, which then states:
AMC1 MED B.075 Colour vision
(a) At revalidation, colour vision should be tested on clinical indication.
(b) The Ishihara test (24 plate version) is considered passed if the first 15 plates, presented in a random order, are identified without error.
(c) Those failing the Ishihara test should be examined either by:
(1) anomaloscopy (Nagel or equivalent). This test is considered passed if the colour match is trichromatic and the matching range is 4 scale units or less; or by
(2) lantern testing with a Spectrolux, Beynes or Holmes-Wright lantern. This test is considered passed if the applicant passes without error a test with accepted lanterns.
The question arises whether the AMC is an "APPROVED CODE OF PRACTICE" and if so, it has the same status as a legal Statutory Instrument, e.g. the Highway Code is an ACOP to the Road Traffic Act and as such, whilst charges for alleged offences would be brought under the RTA the authoritative document for determination of knowledge of the rules would be the Highway Code, i.e. the man on the Clapham omnibus is not expected to know the ins and outs of the RTA but is expected to know the Highway Code.
Myself, as there are two levels of sub-regulatory document I believe the AMC has the status of an ACOP, with Guidance Material forming a less regulatory Code of Practice, which normally contains information such as best industry practice, to be used, as the name suggests, as guidance.
This being the case, the CAA must use the tests prescribed by law and any medical issued by the CAA using the CAD Test as its means of determining colour vision is not compliant with EASA Part-MED and as such (using the word very carefully) illegal, rendering the Part-FCL licence unlawful and the operation of aircraft by any person holding such a licence unlawful and uninsured.
This could be disastrous for any persons holding such a licence involved in any accident which resulted in damage to property or injury to persons, regardless of whether the cause of the incident had anything to do with eyesight. Any decent insurance investigator would look closely at the holder's licence and if he came to the same conclusion the insurer could refuse to pay out.
As the CAA prosecutes breaches of aviation legislation in the criminal Courts it stands to reason that this is covered by criminal and not civil law.
The CAA also states unequivocally that it is unable to make any exceptions to EASA driven EU Regulations and that it is the responsibility of the licence holder to ensure compliance with the appropriate legislation. How can the licence holder comply with the law if it is the regulator that is breaking the law in the first place.
This needs clarification and I think it's about time AOPA stepped up to the mark here with the CAA Legal Department and get them to state, in writing, why these medicals ARE lawful and why the CAA Medical Department is permitted to breach EU Regulation 1178/2011 and the AMC.