121 wx to shoot approach prior to final fix

[Eric]

I have been told one thing and heard another. I read 121.651, and I still have questions.

Any help on the following scenarios will be appreciated. Assume this flying is done under part 121

1. Prior to final approach fix, you get atis and it reports 3/4 mile vis, ceiling 100 feet. You are going to fly an ILS. The approach requires 1/2 mile vis and has a 200' dh. Can you start the approach.

2. How about same scenario above, but the reported wx is 1/4 mile vis, ceiling 300 feet?

3. How about a non-precision approach. Plate calls for 1 mile and 500' mda. Wx reports 2 miles vis and a 300 foot ceiling?

4. Same non precision with wx reported as 1/2 mile, 700' ceiling.


I think answers to these questions will help clear up my 'visiblity is controlling' conundrum. Do you start the approach based on visibility, ceiling, or both.

Thanks

 

[vclean]

Yes, no, yes, no.

Approach visibility determines if you may continue past the FAF.

 

[falcon20driver]

Yep, visibility is the only minimum required.

 

[ThomasR]

I have been told one thing and heard another. I read 121.651, and I still have questions.

Any help on the following scenarios will be appreciated. Assume this flying is done under part 121

1. Prior to final approach fix, you get atis and it reports 3/4 mile vis, ceiling 100 feet. You are going to fly an ILS. The approach requires 1/2 mile vis and has a 200' dh. Can you start the approach.

2. How about same scenario above, but the reported wx is 1/4 mile vis, ceiling 300 feet?

3. How about a non-precision approach. Plate calls for 1 mile and 500' mda. Wx reports 2 miles vis and a 300 foot ceiling?

4. Same non precision with wx reported as 1/2 mile, 700' ceiling.

I think answers to these questions will help clear up my 'visiblity is controlling' conundrum. Do you start the approach based on visibility, ceiling, or both.

Thanks

Hope I am not confusing this too much:

1) No
2) Yes
3) No
4) No

You can bust Vis only on precision to MDA

 

[falcon20driver]

Hope I am not confusing this too much:

1) No
2) Yes
3) No
4) No

You can bust Vis only on precision to MDA

I think you got a couple of those answers bassackwards ThomasR.

#1 is Yes

#2 in No

#3 is Yes I believe, I've only flown 135 and I'm pretty sure visibility is all that is required to begin any approach, I'm going to check that one.

#4 is NO

 

[bafanguy]

Falcon20 is correct. Viz is all that controls and RVR controls ( rather than prev.viz) if that is what is reported. It gets a bit more complicated re circling approaches and receiving below mins viz report AFTER entering the final approach segment. A lot fo this stuff is spelled out in Ops Specs and FAR 121, as you mentioned.

 

[Zulu]

Here's the applicable portion (bold added):

121.651.......

(b) 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—............

(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.

Notice that it says nothing about ceiling, precision vs. nonprecision, straight-in vs. circling, etc. As far as FAR 121 is concerned, ceiling in irrelevant and visibility rules for beginning an approach. Note that the company ops specs can (and probably will) be more restrictive.

So, by 121 only, my answers would be:
(1) Yes (meets visibility minimums)
(2) No (doesn't meet visibility minimums)
(3) Yes (meets visibility minimums)
(4) No (doesn't meet visibility minimums)

 

[bafanguy]

Part 121 doesn't mention a ceiling, but our Ops Specs have ceiling requirement for circling. We require "ceiling- 1000 feet or the published CatD/highest speed HAA, whichever is higher". This undoubtedly varies with companies. It can get a bit complicated when you start talking approach legalities. It's a pretty interesting subject, though.

 

[typhoonpilot]

Just as an aside, some Non-Precision approaches say " ceiling required " on them. Somebody got an example ?

TP

 

[COEX-FO]

Number 2 is No if CAT I and YES if CAT II.

COEX is now CAT II and 100/RVR1200 you are good to go!

It's fun, did it a few times to mins!

 

[Lindy]

Sometimes ceiling is controlling as well as visibility -- pursuant to OPS SPECS and a High Mins Captain.


However, I believe your question was presuming that the Captain had the requisite 100 Hours in make/model.

 

[bafanguy]

COEX-FO,


One has to be careful about these approach legalities. If I'm reading the question correctly,the original question said the approach "required" 1/2 viz. This means it's a CAT 1 ILS. So 1/4 mile reported viz is no-go. CAT 2 is a separate animal legality-wise and there are a bunch more hoops to jump to be legal...CAT 3 is even more so. It's a fun subject to kick around.

 

[Eric]

Thanks guys. I was told a couple of things. I'm glad to see that I interpreted the regulation correctly. I was told by someone that on an ILS all you needed was vis but on a non-precision you needed both ceiling and vis to start the approach.

 

[Singlecoil]

All you need is vis period. On a non-precision you know you may not break out, but there are plenty of times when the ceiling is broken or the clouds are right over the AWOS, but not the runway where you will see enough to land.

 

[bafanguy]

Typhoonpilot's Question....

TP,

Good question about a ceiling requirement for a non-presision approach. All I found was the statement in the Jeps Intro, " In some parts of the world..." but nothing more than that. Couldn't find any reason why so I looked in TERPS, but couldn't find an answer cuz I was immediately overtaken by uncontrollable drowziness and couldn't go on.

My guess is that "...some parts of the world..." have antiquated criteria, or there are cases of obstacle clearance problems in the final segment that can't be worked around any other way and still have a doable approach. The latter is most likely.

I looked in my old Jeps but couldn't find an example but then if you just go back and forth to BNA, you don't run into such problems !! Some sharpshooter on here will have the scientific answer...

 

[profile]

Other parts of the world have different procedures, some include ceiling requirements at some airfields. They are hardly "antiquated", in fact, in many respects, it is the U.S. that needs to catch up in both facilities and procedures.

 

[bafanguy]

Well, Profile, you're right..."antiquated" is not the right word. The US did, at one time, require ceilings if I remember correctly but changed to the visibility criterion so long ago I'd have to dig for the date. You caught me in an unconscious display Amerocentrism ( just made that up, pretty good, huh ? ).


As for going back to ceiling requirements in the US, don't know...I think our current system gives the crew more say-so. For example, if the required viz for the approach is OK, but you know the ceiling is so low there's no chance ( or in your judgement as PIC there's no chance ) of seeing enough to land, you just don't make the approach. If, though, due to irregular cloud bases, transient precip, fill in your own reasons, you think that even though the ceiling is lower than MDA/DA you feel there's a reasonable chance of making a safe approach and seeing something anyway, you have the legal option of trying the approach ( how's that for a runon sentence ? ). Being stuck with a ceiling requirement removes the exercise of your judgement and experience as PIC.

Just a thought.

 

[SkyWestCRJPilot]

I agree with everything said here. Visibility is the only limiting factor. But regarding the ceiling on nonprecision approaches, every time I've gone missed approach was when the visibility was met but the ceiling was below the MDA. I tried to get in but couldn't. In the future I will still continue to try to get in when the visibility allows but from my experience when the ceiling is below the MDA I have never gotten in. Something to consider.

 

[bafanguy]

Skywest,

I'm not surprised at your experience with ceilings below MDA, but at least you had the option to shoot/not shoot the approaches. Your "front line" feel/judgement for a situation is probably better than some FAA lawyer who writes FAR's.

 

[profile]

I would say that the "vis only" requirement was pushed more by the operators than the pilots. I doubt it was ALPA that pushed for that, I would guess it was ATA driven, with the associated implications. It might be true that it gives the PIC more options, but also means that the Capt is put in a position of explaining his/her actions if he/she decides not to fly the approach when all the weather is ok except the ceiling.