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I pulled the current 14 CFR § 91.175 — Takeoff and landing under IFR directly from the eCFR. The page is current through October 1, 2026. ([eCFR][1])

14 CFR § 91.175 — eCFR

§ 91.175 — Headings

([eCFR][1])

Brief IFR Study Guide

1. Instrument approach requirement — (a)

For a civil airport, when an instrument approach is necessary, use a standard instrument approach procedure prescribed under Part 97, unless FAA-authorized otherwise.

Think:

Civil airport + IFR approach → Part 97 procedure. ([eCFR][1])

2. Which DA/DH or MDA applies? — (b)

The authorized DA/DH or MDA is the highest of:

1. The approach procedure's DA/DH or MDA
2. The PIC's prescribed DA/DH or MDA
3. The DA/DH or MDA appropriate for the aircraft equipment being used

Memory aid: Procedure + Pilot + Equipment → highest value. ([eCFR][1])

3. Can you descend below DA/DH or MDA? — (c)

This is one of the most important oral-exam sections.

You need all three:

① Position

• Continuously in a position to make a landing on the intended runway
• Using a normal rate of descent
• Using normal maneuvers

② Visibility

• Flight visibility must be at least the approach's prescribed visibility

③ Visual reference

• At least one qualifying portion of the runway environment must be distinctly visible and identifiable.

Qualifying references include:

• Approach light system
• Threshold
• Threshold markings
• Threshold lights
• REIL
• VASI/PAPI or other visual glideslope indicator
• Touchdown zone / markings
• Touchdown zone lights
• Runway / runway markings
• Runway lights

Important: Using the approach lights alone limits descent to 100 feet above TDZE, unless the required red terminating bars or red side-row bars are visible. ([eCFR][1])

Oral-exam shorthand:

Position + Visibility + Visual Reference = below minimums

4. Landing — (d)

Don't confuse being allowed to descend below DA/MDA with being allowed to land.

For most operations covered here, you may not land if flight visibility is below the visibility prescribed by the approach procedure.

So:

Below DA/MDA: requires the §91.175(c) conditions.

Landing: also requires the applicable visibility requirement. ([eCFR][1])

5. When is the missed approach required? — (e)

Immediately execute the appropriate missed approach when the §91.175(c) requirements aren't met:

• Below MDA, or
• At the MAP, including a DA/DH when applicable, and at any time afterward until touchdown

There is also a circling-specific requirement: if an identifiable part of the airport is no longer distinctly visible during circling, a missed approach is required unless the loss of visibility results only from a normal bank during the circling approach. ([eCFR][1])

Key distinction:

DA/MAP reached without required references → missed approach.

6. IFR takeoff minimums — (f)

This paragraph applies specifically to operations under Parts 121, 125, 129, and 135. ([eCFR][1])

If no Part 97 takeoff minimum is published:

Also remember the ODP requirement:

If an ODP is published for the runway, the pilot must use it or an alternative procedure/route assigned by ATC, subject to the additional performance requirements in §91.175(f)(4). ([eCFR][1])

7. Military airports — (g)

For civil aircraft operating IFR into or out of a military airport:

Follow the instrument procedures and takeoff/landing minimums prescribed by the military authority having jurisdiction.

([eCFR][1])

8. RVR ↔ visibility — (h)

If an approach specifies RVR but RVR isn't reported for the runway, convert RVR to ground visibility using the table.

Key values worth memorizing:

This conversion does not apply to Category II/III minimums. ([eCFR][1])

9. Radar vectors / unpublished routes — (i)

When radar vectors are being used:

Maintain the last assigned altitude after receiving an approach clearance until established on a published route segment or instrument approach segment, unless ATC assigns another altitude.

Once established:

Published altitudes apply.

This is an excellent oral-exam question because pilots sometimes incorrectly assume they can immediately descend when receiving an approach clearance. ([eCFR][1])

10. Procedure turns — (j)

You may not make a procedure turn when:

• Being radar vectored to the final approach course/fix
• Conducting a timed approach from a holding fix
• The procedure specifies "No PT"

Unless ATC specifically clears you to do so. ([eCFR][1])

11. ILS components — (k)

Basic ILS components:

Localizer + Glideslope + Outer Marker

For CAT II/III:

+ Inner Marker, when installed for that purpose.

The regulation also identifies acceptable substitutes for the outer marker, including:

• Compass locator
• PAR/ASR
• DME/VOR/NDB fixes authorized by the procedure
• Suitable RNAV system used with an appropriate fix

([eCFR][1])

§91.175 — Test-Day Mental Model

I'd reduce the entire regulation to this sequence:

APPROACH → MINIMUMS → BELOW MINIMUMS → LAND → MISSED APPROACH

APPROACH

91.175(a)

Use the prescribed Part 97 procedure.

MINIMUMS

91.175(b)

Use the highest applicable DA/DH or MDA.

BELOW MINIMUMS

91.175(c)

Need:

Position + Visibility + Visual Reference

LAND

91.175(d)

Visibility requirement must still be satisfied.

MISSED APPROACH

91.175(e)

If required conditions aren't met at/below the applicable decision point, go missed.

Then remember the supporting sections:

F = Takeoff minimums

G = Military airports

H = RVR conversion

I = Radar/unpublished routes

J = Procedure turns

K = ILS components

This makes §91.175(a)–(k) a particularly useful framework for an Instrument Rating/CFII oral exam because it follows the actual progression of an IFR flight from approach clearance through landing or missed approach. ([eCFR][1])

[1]: https://www.ecfr.gov/current/title-14/section-91.175 "eCFR :: 14 CFR 91.175 -- Takeoff and landing under IFR. (FAR 91.175)"