FAR 135.225 Weather Minimums Explained for Pilots

What FAR 135.225 Actually Says

FAR 135.225 governs when a Part 135 pilot may begin or continue an instrument approach. At its core, the regulation establishes a gate: before you start the approach, the latest weather report or forecast for that airport must show conditions at or above the authorized minimums for the approach you intend to fly.

In practical terms, this means you need to check the most recent METAR, ATIS, or ASOS report before initiating the approach. If the reported ceiling is below the published Minimum Descent Altitude (or Decision Altitude) or the visibility is below the published minimum, you cannot begin the approach under Part 135.

The regulation applies to the moment you begin the approach. Once you have started and the weather drops below minimums, you may continue to the missed approach point and look for the required flight visibility and visual references. But you cannot begin the approach if the weather was already below minimums before you started.

The Key Gotcha

The part that trips up pilots in interviews is the dual requirement. Both ceiling and visibility must be at or above minimums. A ceiling of 300 feet with 3 miles visibility does not satisfy an approach that requires 200-foot ceilings and one-half mile visibility if the ceiling portion is fine but you are checking the wrong approach plate. Conversely, perfect ceilings with visibility below minimums also fails.

Now change the visibility to 1/4 mile. Even though the ceiling is well above minimums, the visibility is below the required 1/2 mile. Under 135.225, you cannot begin that approach.

How It Differs from Part 121

This is one of the most common follow-up questions in interviews, especially at regional airlines that operate under both Part 121 and Part 135 certificates, or when a candidate is transitioning from 135 to 121.

The critical difference is that Part 121 allows you to shoot the approach even when the weather is reporting below minimums. Part 135 does not. This is a fundamental distinction and an easy interview question to get wrong if you conflate the two.

For more on how Part 121 and 135 differ in interviews, see our Part 121 vs Part 135 interview guide.

Why Interviewers Ask About 135.225

This regulation is a favorite interview topic for several reasons:

• It tests regulatory knowledge at a practical level, not just rote memorization.
• It reveals decision-making discipline. A pilot who understands the gate concept demonstrates that they respect hard limits rather than bending rules when the pressure is on.
• It differentiates candidates. Many pilots coming from Part 91 backgrounds have never operated under this restriction and default to Part 121 thinking. Knowing the distinction shows you have done your homework.
• It sets up follow-on scenario questions about weather deteriorating mid-approach, missed approach procedures, and diversion planning.

If you are interviewing at a Part 135 operator or a regional carrier, expect a question on this regulation or a scenario that tests your understanding of it. Practice with our Instrument checkride prep questions and operator-specific question banks.

How to Study This Effectively

• Read the actual regulation. FAR 135.225 is only a few paragraphs. Read it once in full, then restate it in your own words.
• Build scenario flashcards. Create 5-6 scenarios with different ceiling/visibility combinations and practice quickly determining whether the approach is authorized.
• Know the exceptions. There are provisions for Category II and III approaches, and for operations with approved weather reporting limitations. Know they exist even if you do not need the details.
• Connect it to ADM. In your interview answer, tie the regulation back to aeronautical decision-making. The rule exists because approaching in below-minimum weather without the appropriate equipment and crew qualifications is an unacceptable risk.