Alternates..

[Ajax 28]

Quick question.. I am trying to find in the CATS and CARS where it mentions if you use an alternate with an ILS approach, the weather (i think) must be above the non-precision approach minima, or something to that extent. I remember reading about it and wanna touch up on it, but now cant find it?

help appreciated!

[reptile]

The weather criteria for filing an airfield as alternate is:

Precision App Cat I: Non-precision Approach minima or if not available, Circling Approach minima

Non-Precision Approach: Non-precision Approach minima plus 200'(MDA) and +1000m RVR/VIS

Circling or Cloudbreak Procedure: Circling MDA

The above applies to ALL en-route and landing alternates. The weather criteria must be met for a period of 60 minutes before and after the airfields intended use

[Ajax 28]

Thanks alot! Just found it in the CATS as well now..

91.07.8 PLANNING MINIMA FOR IFR FLIGHTS

1. Planning minima for destination alternate aerodromes
(1) An owner or operator may only select the destination aerodrome or alternate
destination aerodrome when the appropriate weather reports or forecasts,
or any combination thereof, indicate that, during a period
commencing 1 hour before and ending 1 hour after the estimated time of
arrival at the aerodrome, the weather conditions will be at or above the
applicable planning minima as follows:
(a) Planning minima for the destination aerodrome
(i) RVR/visibility must be in accordance with that specified in CAR
91.07.5; and
(ii) for a non-precision approach or a circling approach, the ceiling
at or above MDH;
(b) Planning minima for destination alternate aerodrome must be in accordance
with Table 1.
Table 1: Planning minima – En route and destination alternates
Type of approach Planning minima
Cat II and III Cat I minima with RVR in accordance with TS 91.07.5
Cat I Non-precision minima and ceiling must be above the MDH
Non-precision Non-precision minima plus 200 ft added to MDH and 1 000 m added
to RVR/Visibility. Ceiling must be above the MDH + 200 ft.
Circling Circling

[supercow]

So according to table 1 for non precision approach planning you add 200ft to the MDH to get the new MDH say original was 1000ft then you add 200 ft to get 1200ft. The ceiling required is stated as MDH + 200ft. Is it 200ft on top of the new MDH or the original MDH in other words ceiling required is 1400ft or 1200ft?

[reptile]

You don't add 200ft to the MDA(H) to obtain a "new" MDA(H).

The forecast cloud ceiling must be at least 200ft above the published MDA(H) for an hour before and after your expected arrival at the facility.