Many of us who use Infinite Flight are familiar with Instrument Approach Procedures and maybe even the associated charts. The addition of a terminal procedure database that came in the 20.1 update certainly made learning about instrument procedures more accessible to users across the community. Now, anyone can easily load any published SID, STAR, IAP or even oceanic track directly into their flight plan, whereas before the update users had to manually reference the procedures themselves before inputting it into the app.
When we load a procedure in Infinite Flight, it also grabs the associated altitude restrictions and adds them to our flight plan as well (with varying degrees of success). This is certainly a convenient feature, but it does leave out one important piece of information when it comes to IAPs- minimums, which are not added to your flight plan, or provided as information to reference.
Every approach procedure in use today has some form of published minimums. They can come in the form of a Decision Altitude (DA, DH), Minimum Descent Altitude (MDA, MDH), or even just weather minimums for a visual approach. When minimums are depicted as an altitude value (DA, MDA), they provide a minimum altitude that informs the pilot of the lowest height they can descend to on the approach before a few criteria are met. Are minimums important in IF? Well, it depends how serious you are about being realistic.
FAR 91.175 (c) tells us exactly what we need to descend below the published minimums of an approach to be able to land.
Here’s what the regulation says:
(c) Operation below DA/DH or MDA. Except as provided in § 91.176 of this chapter, where a DA/DH or MDA is applicable, no pilot may operate an aircraft, except a military aircraft of the United States, below the authorized MDA or continue an approach below the authorized DA/DH unless –
(1) The aircraft is continuously in a position from which a descent to a landing on the intended runway can be made at a normal rate of descent using normal maneuvers, and for operations conducted under part 121 or part 135 unless that descent rate will allow touchdown to occur within the touchdown zone of the runway of intended landing;
(2) The flight visibility is not less than the visibility prescribed in the standard instrument approach being used; and
(3) Except for a Category II or Category III approach where any necessary visual reference requirements are specified by the Administrator, at least one of the following visual references for the intended runway is distinctly visible and identifiable to the pilot:
(i) The approach light system, except that the pilot may not descend below 100 feet above the touchdown zone elevation using the approach lights as a reference unless the red terminating bars or the red side row bars are also distinctly visible and identifiable.
(ii) The threshold.
(iii) The threshold markings.
(iv) The threshold lights.
(v) The runway end identifier lights.
(vi) The visual glideslope indicator.
(vii) The touchdown zone or touchdown zone markings.
(viii) The touchdown zone lights.
(ix) The runway or runway markings.
(x) The runway lights.
What does this mean in less formal English? It means you can’t descend below minimums unless these three criteria are all met:
A. You can proceed normally to landing without having to do a ridiculous rate of descent or a 90 degree bank, for example.
B. The visibility that you are observing from the cockpit is at or better than the one in your approach.
C. You can see one of the 10 runway elements listed above.
If these three are met, you can proceed lower to land.