Ask Captain Lim

Dear Captain Lim,

I stumbled upon your website while searching for information on the great 777 airliner and like many others, have found it to be quite informative.

One question that I have yet to find an answer to is the computer calls out for minimums. What does it mean to you as a pilot when you are coming in for a landing and the computer calls out "minimums!" between something like 200 and 100 feet? I've done Google searches for it and have yet to find a suitable answer.

Thank you for your time and happy flying.

Peace,

Corey A.

Hi Corey,

In aviation term, when the computer calls out "minimum!" it warns the pilot that he has reached the lowest safety altitude prior to landing. He must now make a decision whether to continue or abort the landing based on many criteria.

On the Boeing 777, the minimums can be 200 feet, 50 feet or 20 feet above the ground level. It depends on the type of approaches that the pilot and the plane are capable of performing. On top of that, the airfield's equipment must be able to provide that kind of precision landing service. A pilot without qualification for automatic landing can only fly up to 200 feet as compared to 20 feet for those who are trained and certified.

For instance, pilots of aircraft on instrument approaches are prohibited from continuing the final approach descent below the ?minimums? unless they can see the markings and lightings of the runway or threshold.

Procedurally, on a normal instrument approach (in bad weather) when the captain is flying the plane, if the computer fails to call out ?minimum?, the copilot will make the call. The captain will come back with one of the two responses:-

If he sees the runway, he will say "Landing!" or "Continue!" (depending on company procedure as to which term to use) and continues with the approach. If he sees nothing, he will say "Go around!" and abort the landing, attempts another approach or divert to another airport if he has reached his minimum diversion fuel.