An ILS is sub-divided into categories depending on it's accuracy. Factors affecting the category are aircraft equipment, airport equipment and crew training.
The higher the category the less restrictive are the landing minimums so the higher the chance of a successful approach.
- CAT I - DH not lower than 200ft and RVR not less than 550m
- CAT II - DH not lower than 100ft and RVR not less than 300m
- CAT IIIA - DH lower than 100ft/no DH and RVR not less than 200m
- CAT IIIB - DH lower than 50ft/no DH and RVR not less than 75m
- CAT IIIC - No DH/RVR limitations (Not actually in use)
DH: Decision Height (height above aerodrome level at which a go around must be initiated if not visual)
RVR - Runway Visual Range
ASW currently operate to CAT II standards. The Q200 will have various equipment installed to make it CAT III enabled such as twin FMS and a HUD
