FAR Ninety-One Point One Seventy-Five, the Approach Ban, and the One Thing That Legally Lets You Leave Minimums and Land Off an Instrument Approach

Under FAR 91.175, paragraph (c), you may descend below the decision altitude (DA) or minimum descent altitude (MDA) and land only when all three of these conditions are met at once: you’re in a position for a normal descent to landing, the flight visibility meets the minimum on the approach plate, and at least one required visual reference for the runway is distinctly visible. Miss any one of them and you are legally required to go missed.

This is the regulation that governs the bottom of every instrument approach you’ll ever fly. It’s also one of the most misunderstood - so let’s break it down the way you’ll actually use it in the cockpit.

What Is Decision Altitude, and Why Does It Matter?

On a precision approach, decision altitude is the moment of truth. At that exact altitude, you either see what you need to see, or you execute the missed approach. There’s no leveling off and no lingering. You make a decision - which is exactly why it’s called decision altitude.

The question is: what, precisely, do you need to see? That’s where FAR 91.175(c) spells it out in plain language.

What Are the Three Conditions in FAR 91.175?

There are three conditions, and every one of them must be true before you leave minimums to land. Not one, not two - all three.

Condition 1 - Position for a normal landing. You must be in a position from which a normal descent to the runway can be made using normal maneuvers. For a Part 91 operator flying a straight-in approach, that descent must allow touchdown within the touchdown zone.

If you break out high, or off to the side, and reaching the runway would require a diving, slipping, banking, brakes-on arrival, you have not met condition one. This is the stabilized approach concept written directly into regulation: if you can’t fly it down like a normal, stable landing, you’re not allowed to land.

Condition 2 - Flight visibility. The flight visibility must be at or above the visibility prescribed for the approach you’re flying. The critical word is flight visibility - not the reported visibility from ATIS or the tower.

Condition 3 - One required visual reference. At the DA or MDA, at least one item from a specific list of visual references for the intended runway must be distinctly visible and identifiable to you.

Flight Visibility vs. Reported Visibility: What’s the Difference?

This distinction trips up more instrument students than anything else in the reg, so slow down here.

Reported visibility is a ground measurement - what a sensor or an observer sees from a fixed point on the airport. The number printed on your approach plate as a minimum, however, is flight visibility: what you, the pilot, can see forward from the cockpit in flight.

Here’s the part that surprises people: under Part 91, the reported ground visibility does not legally prohibit you from flying the approach. There is no approach ban in Part 91 the way there is for airlines operating under Part 121. If ATIS reports a quarter mile and your approach calls for half a mile, a Part 91 pilot is legally allowed to fly the approach and take a look.

The catch that keeps this from being a loophole: when you reach minimums, the flight visibility you actually observe out the window must still meet the number on the plate in order to land. So you can fly down and look - but if you can’t see far enough at the DA, you have not met condition two, and going missed is mandatory, not optional.

Put simply: reported visibility tells you whether it’s smart to try; flight visibility tells you whether you can land. The regulation puts that honest judgment squarely on you.

What Visual References Let You Descend Below Minimums?

For condition three, at least one of the following must be distinctly visible and identifiable for the intended runway:

• The approach light system (ALS)
• The threshold
• The threshold markings
• The threshold lights
• The runway end identifier lights (REIL)
• The visual approach slope indicator (VASI or PAPI)
• The touchdown zone or touchdown zone markings
• The touchdown zone lights
• The runway or runway markings
• The runway lights

You only need one of these - distinctly visible and identifiable. See one item, meet the other two conditions, and you are legally cleared to leave minimums and land.

The Approach Light Sub-Rule: The 100-Foot Floor

There’s one important exception to memorize. If the only visual reference you have is the approach lights, you may descend to 100 feet above the touchdown zone elevation - but no lower - unless you can also see the red terminating bars or the red side row bars.

In other words, the approach lights alone get you down to 100 feet. To go lower, you need something more: the red bars, the runway, the threshold, the touchdown zone, or another item from the list. If you can’t see it by 100 feet, you go missed from 100 feet. Brief this before you ever start down.

How Do You Apply 91.175 in the Cockpit?

Picture it. You’re coming down an ILS to decision altitude. You look up and, floating in the murk, you make out the sequenced flashing lights - the “rabbit,” the approach light system. That’s item one on the list: condition three satisfied. You’re positioned for a normal descent to the touchdown zone: condition one satisfied. You judge your forward flight visibility meets the half mile the approach requires: condition two satisfied. All three - you land.

But remember the sub-rule. If all you have is those approach lights, you keep descending only to 100 feet above touchdown zone elevation. If by then you still can’t see the red terminating bars, the runway, the threshold, or the touchdown zone, you go missed from 100 feet. That’s a live possibility on a real approach.

Turn the regulation into a rhythm you can run in the two or three seconds you have at minimums: Position. Visibility. One item from the list. Say it out loud in the airplane. When you break out low and fast with the runway rushing up, you won’t have time to dig through the regs - it needs to be already loaded.

Why This Regulation Exists

Be honest about the temptation at minimums. You’ve flown the whole approach, you’re tired, you want to be down, and the runway is tantalizingly close. Every instinct wants to stretch it - to tell yourself I think I can see enough. This regulation exists precisely for that moment. It exists to protect you from yourself.

The discipline to go missed when you haven’t genuinely met all three conditions is the mark of a real instrument pilot. Anyone can fly the approach when the weather is good. The rating is about what you do when it isn’t.

What Your Examiner Wants to Hear

On the checkride, your examiner won’t be satisfied with just the visibility number. They want to hear the three conditions, the list of visual references, and the approach light sub-rule - the 100-foot floor. That single detail separates the applicant who memorized a number from the one who actually understands the bottom of an approach.

Today’s material comes straight from the Federal Aviation Regulations, 91.175, the visual reference list in paragraph (c), and the Instrument Flying Handbook.

Key Takeaways

• All three conditions in FAR 91.175(c) must be met to descend below DA/MDA and land: normal position for landing, flight visibility at or above the prescribed minimum, and one required visual reference in sight.
• Flight visibility - not reported visibility - controls the landing under Part 91. There is no Part 91 approach ban, so you may fly the approach and look, but you must genuinely see the required visibility to land.
• You need only one item from the list of visual references distinctly visible and identifiable.
• If the approach lights are your only reference, you may descend only to 100 feet above TDZE unless you also see the red terminating bars or red side row bars.
• The regulation is a real-time cockpit checklist: Position, Visibility, One item from the list.