Do you fly in mountainous regions?

If you’re training to obtain your Instrument Rating, you may have come across the part in the CAP GEN that explains minimum altitudes for Designated Mountainous Regions.

The following video is a short excerpt from Hangaaar’s Commercial Pilot online ground school as well as our Instrument Rating online ground school course where Conrad lays this out pretty clearly…

Hangaaar’s Pilot Tip – Minimum IFR Altitudes in Designated Mountainous Region

[00:00:00] One of the guiding principles of enroute IFR is we’re never going to be lower than a thousand feet above ground level. That’s the absolute lowest we’re going to be. And that’s only outside of Designated Mountainous Regions. So we’ll talk about Designated Mountainous Regions in a minute, but the lowest wherever going to be is a thousand feet above the ground.

[00:00:25] And we have to apply a temperature correction. And when we talk about being a thousand feet above the ground, we’re expecting to do that with a five nautical mile radius around the airplane. Think of the width of a control zone, right? Five nautical mile radius normally is what it is. So you’re not supposed to be operating really low to the ground in cloud, without some idea of how high the terrain is around you.

[00:00:53] The temperature correction must be applied, of course, because the colder it gets, the less accurate and the more dangerous [00:01:00] our altitude situation becomes. More about that in a minute. 

[00:01:04] A practical question is how do we know if we’re in a Designated Mountainous Region? You may be flying in a Designated Mountainous Region now and not even know it.

[00:01:13] The answer is  the CAP GEN and the AIM have a map showing the Designated Mountainous Regions. Depending on which mountainous region you’re in, you may have to fly at either 2000 or 1500 feet AGL as a minimum. This is because mountains get in the way of airplanes. 

[00:01:31] But the other thing is mountains create unique problems with altimeters and, you know, altimeters can get fooled in certain conditions in mountainous regions.

[00:01:41] So we never want the airplane impacting the terrain at a high speed in a high rate. 

[00:01:48] So here’s the answer to that question. This is the actual map from the CAP GEN, the text on the top right explains how to use the map. You can find this in the CAP GEN. [00:02:00] The current page of this is 15 as this is written, but remember the page numbers of the CAP GEN change all the time.

[00:02:09] Here’s that same diagram blown up and summarized. 

[00:02:14] So areas one and five, so British Columbia and the Yukon and parts of Alberta, the Rocky mountain areas, require 2000 feet. Also Baffin Island and Ellesmere Island. 

[00:02:28] Now some of you may not fly up there regularly, but if you fly long enough, you will. And those are the two areas in Canada that require 2000 feet.

[00:02:38] The other areas, two, three, and four require 1500 feet. Again in broad strokes, the Eastern part of Quebec, just North of the St. Lawrence Valley and Labrador and the Island of Newfoundland and also parts of new Brunswick require 1500 feet, and again, Southern new [00:03:00] Brunswick, you’re not in that Designated Mountainous Region.  Northern new Brunswick, you are. All of the Island of Newfoundland is a Designated Mountainous Region, but it only requires 1500 feet. 

[00:03:12] There’s a whole caution thing that you should read on here, basically talks about the effects of temperature and mountain waves, they throw your altimeter off by as much as 3000 feet.

[00:03:23] So in other words, it may tell you that you’re 3000 feet higher. Then you really are. You could see how that would be a problem.