Altimeter Regions

Altimeter Regions


Domestic Airspace		Altimeter Regions		Controlled Airspace		Uncontrolled Airspace		Airspace Classification		RVSM

Introduction

Canadian airspace is divided, for the purpose of altimetry, into two regions described below.

Altimeter Setting Region

he Altimeter Pressure Region includes that area of southern Canada depicted in the image above up to but not including 18 000ft, only.

Aircraft operating within the Altimeter setting region must adjust their altimeters to the reported current altimeter setting of the nearest station.
An altimeter setting (QNH) is the setting made to an altimeter so it will indicate altitude ASL (bove sea level). Canadian altimeter settings are reported in inches of mercury ( " Hg )

Standard Pressure Region

The Standard Pressure Region includes that area of northern Canada depicted in the image above, and also all airspace above 18'000ft (FL180) everywhere in Canada.

In the standard pressure region the altimeter is set to standard pressure (29.92" Hg). For take-off and climb from an airport in this region altimeter should be set to the current altimeter setting of the departure airport, and reset to 29.92" once terrain clearance is assured. For descent and landing the current altimeter setting of the destination airport should be used once final descent has been initiated.

Altimeters must be reset after entering, and before leaving the Standard Pressure Region, unless otherwise instructed by ATC.
A transition level exists between the Altimeter Setting Region and the Standard Pressure Region. This is FL180.
When climbing (immediately after passing FL180) set your altimeter to 29.92" Hg.
When descending (immediately before passing FL180) set your altimeter to the local altimeter setting.

FL180 is only used for cruising if the pressure along the entire route is greater than 29.93" Hg.

Cruising Altitudes

Canada applies the east-west semi-circular altitude system as depicted below.

West track (180°-359°) Even Altitudes		East track (000°- 179°) Odd Altitudes
4,000 ft 6,000 ft 8,000 ft 10,000 ft 12,000 ft 14,000 ft 16,000 ft FL 180 FL 200 FL 220 FL 240 FL 260 FL 280 FL 300 FL 320 FL 340 FL 360 FL 380 FL 400 FL 430 FL 470 FL 510 ...		5,000 ft 7,000 ft 9,000 ft 11,000 ft 13,000 ft 15,000 ft 17,000 ft FL 190 FL 210 FL 230 FL 250 FL 270 FL 290 FL 310 FL 330 FL 350 FL 370 FL 390 FL 410 FL 450 FL 490 FL 530 ...