Canada/US descent below minima

I was discussing this approach with some U.S. pilots before I revised the numbers up — at the time, I remembered not seeing the runway until below 100 feet, though now I’m fairly certain I saw it at 130 feet.

I was taken aback when one of the U.S. pilots asked me if this was a confession. It turns out that the U.S. regulations for descending below DH or MDA are different from the Canadian regulations — in Canada, once we’ve seen the required visual reference (such as approach lights, or the PAPI), we’re OK to land — legally, if not safely — even if we don’t actually see the runway until the wheels touch it. See RAC 9.19.3 Landing Minima in the Canadian AIM for details.

The American regulations in FAR 91.175 have similar required visual references, but there is an important addition of a step-down altitude when you spot the approach lights first:

(3) Except for a Category II or Category III approach where any necessary visual reference requirements are specified by the Administrator, at least one of the following visual references for the intended runway is distinctly visible and identifiable to the pilot:
(i) The approach light system, except that the pilot may not descend below 100 feet above the touchdown zone elevation using the approach lights as a reference unless the red terminating bars or the red side row bars are also distinctly visible and identifiable.
[…]

That extra 100 foot restriction isn’t in the Canadian regulations. In fact, AN (SSALR) approach lighting doesn’t even have red side row bars, and the terminating bar is green.

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About David Megginson

Scholar, tech guy, Canuck, open-source/data/information zealot, urban pedestrian, language geek, tea drinker, pater familias, red tory, amateur musician, private pilot.
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