Which instrument landing system categories define landing minimums?

Which instrument landing system categories define landing minimums?

• A. CAT II, CAT III, CAT IV
• B. CAT I, CAT II, CAT III
• C. CAT I, CAT II, CAT IV
• D. CAT I, CAT III, CAT IV

Answer: (B)

Landing minimums on an instrument approach come from the precision category of the ILS. Each category defines the minimum decision height and the minimum visibility you must have to continue the landing. As you move from Category I to Category II to Category III, the published minima get lower, enabling landings in progressively poorer weather conditions. Typically, Category I sets higher minima (around 200 feet DH with about 550 meters visibility), Category II allows lower minima (around 100 feet DH with about 300 meters visibility), and Category III allows even lower minima, down to very low visibilities or even no decision height for some subcategories. Because of this structure, Category I, Category II, and Category III collectively define landing minimums. CAT IV is not part of the standard ILS minimums, so it isn’t used to define typical landing minimums.

Landing minimums on an instrument approach come from the precision category of the ILS. Each category defines the minimum decision height and the minimum visibility you must have to continue the landing. As you move from Category I to Category II to Category III, the published minima get lower, enabling landings in progressively poorer weather conditions. Typically, Category I sets higher minima (around 200 feet DH with about 550 meters visibility), Category II allows lower minima (around 100 feet DH with about 300 meters visibility), and Category III allows even lower minima, down to very low visibilities or even no decision height for some subcategories. Because of this structure, Category I, Category II, and Category III collectively define landing minimums. CAT IV is not part of the standard ILS minimums, so it isn’t used to define typical landing minimums.