IFR minimums ?

P

piperpilot12w

Well-Known Member
What is the controlling factor for minimums on an approach - Ceiling, Visibility or both? I think it's visibility, but want to make sure.

How would you apply this to when you are preparing to do the approach. Does ceiling and visibility have to be above minimums to start the approach, or just visibility.
 
So if there was an approach that called for an MDA of 500 and 1/2 mi vis, and actual conditions were 400 ovc and 1 mi vis

I could attempt to do the approach because visibility is controlling, and in this case 1 mi is above the min, although when I get to the MDA of 500 I will probably be in the clouds and wont see anything.

Is that correct. I'm preparing for an interview
 
If you are part 91 you can do an approach even if it is reported at 0/0. you have to have flight conditions as determined by the pilot that is at or greater than what is required by the approach. That being said, shooting an approach when it is below minimums is probably only going to burn gas and time.

135, and 121 is another story.
 
No tricks here.
Just trying to get a complete understanding of this in case I was asked a similar question in a 121 interview.
 
piperpilot12w said:
No tricks here.
Just trying to get a complete understanding of this in case I was asked a similar question in a 121 interview.
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For 121, if it is below weather mins, you cannot start the approach. If you are past the FAF and the weather drops below mins, you may continue the approach.
 
piperpilot12w said:
What is the controlling factor for minimums on an approach - Ceiling, Visibility or both? I think it's visibility, but want to make sure.

How would you apply this to when you are preparing to do the approach. Does ceiling and visibility have to be above minimums to start the approach, or just visibility.
Click to expand...

It's both. You can attempt the approach but once when you get to MAP and don't see the runway environment you got to go play somewhere else or try a different approach with lower minimums.
 
mojo6911 said:
For 121, if it is below weather mins, you cannot start the approach. If you are past the FAF and the weather drops below mins, you may continue the approach.
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Say the minimums on the plate are 500 ft/1 mile.

I THINK his question is 'is the weather below minimums if the ceiling is reported below 500 feet, or if the visibility is reported below 1 mile, or either?'

btw, the answer is 'if the visibility is reported below 1 mile.'
 
ppilot said:
Say the minimums on the plate are 500 ft/1 mile.

I THINK his question is 'is the weather below minimums if the ceiling is reported below 500 feet, or if the visibility is reported below 1 mile, or either?'

btw, the answer is 'if the visibility is reported below 1 mile.'
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Is it? So you're heading into, say Aspen, where the minimums are about 2000 AGL and 3 miles (http://naco.faa.gov/d-tpp/0804/05889LDE.PDF) . You are saying that if ASE is reporting, say a 500' ceiling and 20 miles visibility (not that unlikely), under 135 or 121, you would be allowed to begin the approach?

Do you have a source for that? I'm really just asking. I haven't had the need to look into that myself (despite reports to the contrary, FAA publications are =not= my bedside reading material of choice).
 
MidlifeFlyer said:
Is it? So you're heading into, say Aspen, where the minimums are about 2000 AGL and 3 miles (http://naco.faa.gov/d-tpp/0804/05889LDE.PDF) . You are saying that if ASE is reporting, say a 500' ceiling and 20 miles visibility (not that unlikely), under 135 or 121, you would be allowed to begin the approach?

Do you have a source for that? I'm really just asking. I haven't had the need to look into that myself (despite reports to the contrary, FAA publications are =not= my bedside reading material of choice).
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Absolutely!

Under part 135 the reg is 135.225(a)(2).

The only time a ceiling comes into play when discussing minimums is when deciding if an alternate is needed or selecting an alternate.
 
Ian J said:
Absolutely!

Under part 135 the reg is 135.225(a)(2).

The only time a ceiling comes into play when discussing minimums is when deciding if an alternate is needed or selecting an alternate.
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This isn't the same for 121 too is it?
 
Ian J said:
Absolutely!

Under part 135 the reg is 135.225(a)(2).
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Wait, Ian. All 135.225(a)(2) says is

==============================
The latest weather report issued by that weather reporting facility indicates that weather conditions are at or above the authorized IFR landing minimums for that airport.
==============================

I know that reg. What I'm asking for is the source of the statement that "authorized IFR landing minimums" refers only to the visibility and not the ceiling.

Now, in 121 it's a bit different. 121.651(b) specifically talks about visibility:
==============================
Except as provided in paragraph (d) of this section, no pilot may continue an approach past the final approach fix, or where a final approach fix is not used, begin the final approach segment of an instrument approach procedure -
(1) At any airport, unless the U.S. National Weather Service, a source approved by that Service, or a source approved by the Administrator, issues a weather report for that airport; and
(2) At airports within the United States and its territories or at U.S. military airports, unless the latest weather report for that airport issued by the U.S. National Weather Service, a source approved by that Service, or a source approved by the Administrator, reports the visibility to be equal to or more than the visibility minimums prescribed for that procedure.
==============================

For 121, I can see that visibility controls. But where is it for 135?
 
MidlifeFlyer said:
Wait, Ian. All 135.225(a)(2) says is

==============================
The latest weather report issued by that weather reporting facility indicates that weather conditions are at or above the authorized IFR landing minimums for that airport.
==============================

I know that reg. What I'm asking for is the source of the statement that "authorized IFR landing minimums" refers only to the visibility and not the ceiling.

Now, in 121 it's a bit different. 121.651(b) specifically talks about visibility:
==============================
Except as provided in paragraph (d) of this section, no pilot may continue an approach past the final approach fix, or where a final approach fix is not used, begin the final approach segment of an instrument approach procedure -
(1) At any airport, unless the U.S. National Weather Service, a source approved by that Service, or a source approved by the Administrator, issues a weather report for that airport; and
(2) At airports within the United States and its territories or at U.S. military airports, unless the latest weather report for that airport issued by the U.S. National Weather Service, a source approved by that Service, or a source approved by the Administrator, reports the visibility to be equal to or more than the visibility minimums prescribed for that procedure.
==============================

For 121, I can see that visibility controls. But where is it for 135?
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It's in 91. I don't have the rules in front of me right now, but I think it's in 91.175.
 
ppilot said:
It's in 91. I don't have the rules in front of me right now, but I think it's in 91.175.
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91.175(c) talks needing the required flight visibility in order to descend from the MDA or DA. But, that's not specific to 135 and, as mojo aptly put it
Yup. If you are in the clouds at MDA ... your visibility is going to be 0.
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, so ceiling is pretty irrelevant at that point (that's why I asked why it was a trick question).

OTOH, there are specific rules on when you can start or continue an approach based on reported minimums for 135 and 121 ops (135.225 and 121.651 for example) that don't apply to Part 91 ops (where you can start down even if 0/0 is being reported), which is what I thought was being discussed

Two different questions.
 
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