Canadian Approach Categories

[hawk37]

Canadian AIM

RAC Rules of the air

Arrival

9.21 AIRCRAFT CATEGORIES Aircraft performance differences have an effect on the airspace and visibility needed to perform certain manoeuvres. In order that the appropriate obstacle clearance areas and landing and departure minima can be established, five different aircraft categories have been identified. Aircraft that are manoeuvred within these category speed ranges are to use the appropriate instrument approach minima for that category. For example, an aircraft that is flown on a straight-in approach at 135 KIAS is to use the Category C approach minima. However, if that same aircraft is required to manoeuvre on a circling approach at 143 KIAS, then the Category D circling minima applies. The category speed groupings are: Table 9.14—Aircraft Categories CATEGORY A B C D E SPEEDS up to 90 KIAS (includes all rotorcraft) 91 to 120 KIAS 121 to 140 KIAS 141 to 165 KIAS above 165 KIAS

So…Canada no longer uses a category based on maximum allowable landing weight?

And if one is light enough, and thus at a slower VRef, one can change from cat C to Cat B, and the pilot can use Cat B minimums instead?

References appreciated

Hawk

[+TSRA]

So…Canada no longer uses a category based on maximum allowable landing weight?

Well, yes and no. The categories may be based on speed, but then speed is based on aircraft performance, itself a function of aircraft weight and configuration.

I'll use the Q400 as an example because I can at least talk somewhat intelligently about it. Depending on weight and flap configuration, a Q400 could be anywhere from Category B to E. It normally sits nicely in Category C, but I've been Flaps 35 with a reference speed of 114 KIAS quite recently. If I was fully configured and actually had to do a circling approach, I'd normally maneuver 5 to 10 knots faster than VREF if I was really tight for space (Penticton's runway 34 when approaching from the north is a great example of where you may have to do this)

Using 5 knots on a non-gusty day, I get 119 KIAS to maneuver with, and thus I can stay within Category B minimums. On the same aircraft on a gusty day, I'm using a 10-knot correction and now I'm at 124 KIAS and within Category C minimums. But this is almost theoretical. If I actually had to circle in a medium or large aircraft, I wouldn't be using such tight tolerances.

Now, take that same aircraft again but at a slightly higher weight with a flaps issue on a hot day in Calgary and my reference and maneuvering speeds are much more likely to be the higher end of Category D or even into Category E.

So again, while the categories are displayed on speed, it ultimately still boils down to what my landing weight and configuration permit me to fly at.

As for references, these are going right back to basics: CAR 602.01 and CAR 602.07. Not allowed to do anything that jeopardizes people on the ground and not allowed to do anything outside the aircraft flight manual. Going slower than the AFM violates both of those, so if the AFM says that at a certain weight I fly a certain minimum speed, that's what I do.

Finally, remember that VREF is not a maneuvering speed. It's the speed you're going to cross 50' above the runway threshold. You're not going to maneuver the aircraft during a circling approach at VREF, you're going to do that VAPP (or whatever V-speed designation is in the AFM). A VREF 115 knots may be Category B, if you fly the maneuver at 130 knots, then you use the higher category minimums as with circling approaches we're concerned about the radius of the arc that will be flown during the circle-to-land maneuver, and that's based on the speed we fly that arc at, not the speed that will be used when that maneuver is complete.

[hawk37]

Thanks for your reply +TSRA. I'm still not clear whether Canada uses a category based on VRef at MAXIMUM allowable landing weight (as opposed to actual weight). Of course, manouevering at a higher airspeed can put you in a higher category, I understand that.

In the US and under ICAO rules, one cannot drop drown a category ever. Under these rules, if you happen to be at lower weight and hence a slower speed (eg now below 120 kts where Cat B is now the category) one CANNOT legally use the lower category minimums.

[Mostly Harmless]

Thanks for your reply +TSRA. I'm still not clear whether Canada uses a category based on VRef at MAXIMUM allowable landing weight (as opposed to actual weight). Of course, manouevering at a higher airspeed can put you in a higher category, I understand that.

In the US and under ICAO rules, one cannot drop drown a category ever. Under these rules, if you happen to be at lower weight and hence a slower speed (eg now below 120 kts where Cat B is now the category) one CANNOT legally use the lower category minimums.

Same rules in Canada. You can go up a category due to weight or configuration (IE: Flapless landing, emergency, weight, etc) but you can not go down a category because you are light that day. The aircraft is certified in a category and it's that level or higher.

[hawk37]

Mr. Harmless, that's what I thought. However the Canadian AIP , quote above, does not go into that detail. See my post 1 for the full quote. Specifically it says

"an aircraft that is flown on a straight-in approach at 135 KIAS is to use the Category C". Now, at max landing weight that might be 141 kts, which would be a cat D aircraft under US and ICAO rules, and perhaps higher minimums for Cat D versus Cat C.

"Flown" is the word in the AIP, I take that to be (normally) VRef. No mention of Max landing weight, no mention of not changing categories to a lower one, no mention of being in one category only unless faster, no mention of being certified to one category only (Canadians, that is, the US and ICAO do say differently). Only that the category is determined based on speed "flown".

As I said, the US and ICAO are quite specific about the one category only.

Do you have additional information on this for flights in Canada?

[Mostly Harmless]

I didn't have time to do a deep dive but, https://tc.canada.ca/en/aviation/reference-centre/advisory-circulars/advisory-circular-ac-no-302-019

Section 2.3 - 1 (a)
Aircraft Approach Speed Category. A grouping of aircraft based on a reference landing speed (VREF), if specified, or if VREF is not specified, 1.3 times stall speed (VSO) at the maximum certificated landing weight. VREF, VSO, and the maximum certificated landing weight are those values as established for the aircraft by the certification authority of the country of registry.

I think that's the part you are looking for... or at least I hope that is what you are looking for.

[hawk37]

Capt Harmless, that is exactly the information I thought should be available for those piloting aircraft in Canada. And it is in line with directives to pilots in other countries.

Only problem is, in para 1.2 it does NOT include PILOTS that it applies to.

It applies to all "Canadian airport operators, manufacturers, suppliers, Transport Canada Civil Aviation (TCCA) Headquarters and regional personnel, and the aviation industry involved with the planning, design, and maintenance activities at Canadian aerodromes"

No mention of applying to pilots at all!!!! And it is advisory only.

But thanks for your time, no need to spend further time. Appreciate your efforts. Maybe we should put this issue to bed. Hawk.