Approach Categories

TopperHarley · Post by **TopperHarley** » Thu Oct 26, 2006 6:38 pm

I was always under the impression that the speeds for category A-E were all indicated airspeeds; however, I was reviewing an online website recently and it said the speeds were all groundspeeds.

There doesnt seem to be any confirmation in the AIM or CAP Gen. Does anyone have a reference? Opinions?

complexintentions · Post by **complexintentions** » Thu Oct 26, 2006 7:17 pm

Groundspeed. The same aircraft can be in one category one day and another the next, based on the winds.

Those categories give you protection (terrain clearance) at a certain altitude to a certain distance. If you cover that ground a lot faster or a lot slower it will obviously affect your ability to maneuver and stay within that protected space.

I believe 55+ used to design approaches I'm sure he could give you a much more precise answer?

helpCX · Post by **helpCX** » Thu Oct 26, 2006 7:44 pm

It depends on what country the chart you were looking at was published in. Some use IAS,TAS,G/S

helpCX · Post by **helpCX** » Thu Oct 26, 2006 7:48 pm

I forgot to add we use IAS in Canada. Its on the approach chart legend in the CAP GEN (page 29) as well as the IPM and in the CARS but I dont remember where.

Clodhopper · Post by **Clodhopper** » Thu Oct 26, 2006 7:58 pm

CAP GEN (Effective 0901Z August 3rd, 2006) wrote:
Page 29

"The appropriate aircraft category and resultant approach minima are determined by the airspeed at which the aircraft is to be manouevred"

Cheers