How do other airlines deal with SOP/callouts on Cat I

[A Squared]

First, if you are on a CAT I approach have any of the elements listed in 91.175 (b)(3) in sight (except (i), the approach lighting system) you *DO* have the required flight visibility. Minimum vis for a CAT one approach is 1/2 SM/2400 RVR. All the elements listed in 91.175 (b)(3) except (i) are at the runway threshold or beyond. If you are at 200 ft on the glideslope, you are slightly more than a half mile from the runway, so if you can see them, by definition, you have more than a half mile flight visibility. Even on a non-precision approach, if you are in compliance with 91.175 (b)(1), then you are more than 1/2 SM from the runway at MDA.

Now, it *is* theoretically possible to have the approach lightning system in sight at 200 ft, or the red terminating bars in sight at 100 ft, yet not have 1/2 mile flight visibility. I don't know of a reliable method to determine that you don't have 1/2 SM flight visibility in the 8 seconds that it takes to descend from 200 ft to 100 ft on the GS. If I get the approach lights in sight at 200 ft, and the threshold in sight at 100 ft, I'm willing to consider that close enough to the intent of the regulation, but that's probably not an answer you like. FWIW, I don't recall ever continuing below the DA on the approach lights without subsequently picking up the VASI/PAPI before 100 ft, which would be about 1/2 SM.


But, the whole continuing to 100 ft below the DA introduces a grey area, as is contradicts the rest of the regulation. If you get to 200 ft and you have the approach lights in sight, but you do not have the terminating bar or side row bars in sight, you have not determined that you have 1/2 SM visibility, so at that point, continuing below DA as per 91.175 (b) (3) (i) is inherently a violation of 91.175 (b)(2)

Given that those portions of the regulation are inherently contradictory, it seems reasonable to assume that the intent is that having have the specified visual references in sight is more important that the flight visibility, which is difficult to reliably determine.