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When landing, what exactly do the phrases "approaching minimums" and "minimums" mean in a commercial jet aircraft, when heard from the onboard cockpit voice.

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The "Approaching Minimums" callout is made by the Pilot Monitoring (or, in some cases equipment, the GPWS -- Ground Proximity Warning System) as the aircraft is descending on an instrument approach and has reached an altitude 100 feet above the minimums for that approach -- the Decision Altitude (DA -- typically used for a Cat I ILS, and set as XXX' MSL) or Decision Height (DH -- typically used for a Cat II or Cat III ILS and set as XXX' or XX' on the Radio Altimeter) or Minimum Descent Altitude (MDA -- typically used for a nonprecision approach and set as XXX' MSL). The response by the Pilot Flying is usually standardized and indicates he is looking outside in order to acquire the visual references he'll need to land.

The "Minimums" callout is made at the minimum altitude, and this is the point that the Pilot Flying has to make a decision -- continue or go around. His response at this point is again standardized so that the other pilot is entirely clear on the course of action. His response is usually something like "Landing" or "Continue", or else "Go Around." Often, the autopilot comes off at this point as well & you hear the horn indicating such on the CVR as well.

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    $\begingroup$ Why MSL in this case since airport can easily been above 200' MSL? $\endgroup$
    – vasin1987
    Sep 30 '15 at 9:56
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    $\begingroup$ For a Cat I ILS, you call minimums off the Baro altimeter, so for a runway at 605' MSL, you'd call "Minimums" at 805' MSL. That's a DA. For a Cat III ILS to the same runway, you'd call "Minimums" at 50' RA -- that's a DH. The DH would correspond to 655' MSL, but the Radio Altimeter is primary because of its accuracy. $\endgroup$
    – Ralph J
    Sep 30 '15 at 15:06
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    $\begingroup$ For U.S. operations an aircraft cannot descend below the MDA on a non-precision appch (unless granted special pre-authorization to do so) without the required vis environment in sight. Therefore, a missed appch must be initiated before the actual MDA so as not to dip below the MDA during the go around. On a precision appch requiring a missed appch (required vis environment not in sight) descent below the DA is authorized during the go around as long as it was initiated at or before the DA. This can affect exactly when the "approaching minimums" and "minimums" call out is made. $\endgroup$
    – 757toga
    Sep 20 at 20:43
  • $\begingroup$ @757toga Making those callouts off of the MDA itself would correspond with a "dive & drive" type of profile; for a constant angle descent approach toward a published MDA, the minimum altitude would have to be raised above the MDA for the reasons you discuss. My carrier refers to that MDA + 50' as the "Derived Decision Altitude" or DDA, which becomes your minimum for the approach. That's what's bugged on the altimeter, that's where the "Minimums" callout is made, and "Approaching Minimums" is made 100' above that. Since DDA isn't universal, I kept the answer to the more general cases. $\endgroup$
    – Ralph J
    Sep 20 at 21:33
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    $\begingroup$ Yours is a good answer and I agree with you. I was just adding a bit of detail. There are ops spec authorizations (I forget the details at this moment ) that allow a dip below the mda (same as a precision appch) avoiding the "derived DA" $\endgroup$
    – 757toga
    Sep 20 at 21:35
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"Approaching Minimums" you are about at your minimum descent altitude (MDA) or decision altitude (DA).

"Minimums" means you've arrived at that altitude.

Pilots use those phrases to alert the pilot flying when they're getting close to the ground. At minimums they will either have the runway environment in sight and decide to continue and land on the runway or they will not have the runway environment in sight and decide to go around.

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Approaching minimums is the decision making altitude or minimum altitude ( Generally 100 feet above the minimum altitude ). Captain callout ‘approaching minimums’ in order to decide that they will land on the runway or they will go around, that depends on the Captain. In their final approach if they are going for landing then the other pilot callout “ continue” or else the other pilot callout “Goaround” and then the landing was aborted....the Pilot pushes the thrust levers to its maximum position in order to get the maximum thrust generated by the engines and then the landing gear was retracted in order to goaround....

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    $\begingroup$ This seems to be contradictory with existing answers: Approaching minimums is not for decision making, but to warn that the decision to stop the descent has to be made soon, when reaching minimums (DH/MDA) $\endgroup$
    – mins
    Dec 16 '17 at 12:46

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