Part 91 Instrument Approach Question

[A Squared]

I had this question as part of my practical. I was told better not land if RVR was below mins. Where would I look to support that? Well first I'd start with an approach would specify RVR, then I'd look 91.175(h)(1)...That specifies Ground visibility, not flight visibility be substituted for lack of rvr reported.

Then I'd go to ground visibility in part one and realise that I am not an accreddited observer or the U.S. National weather service or for that matter near the earths surface(although I guess that could be open for interpretation) and could not declare the visibility myself. I don't see anywhere I am allowed to convert RVR to flight visibility.

As Minitour pointed out, all 91.175(h) does is allow you to substitute Ground Vis for RVR if needed. It has nothing to do with whether you can descend below MDA/DA. that is governed by 91.175 (c) ...and that specifies flight visibility.

 

[gsrcrsx68]

You don't have to.

You don't need ground visibility to descend below MDA/DH and/or land.
-mini

Unless RVR is unavailable...then you need it To Land. True, 91.175 (c)(2) does allow you to operate under the DH, but operating under the DH does not mean you have met landing minimums...You can operate below the DH until 91.175(c)(1) is no longer possible.

The question morphed a bit from the original. The word "Land" got tossed in along the way. I still wont be landing if RVR is below landing minimums...Actually I wont even be flying then...

 

[paulsalem]

Unless RVR is unavailable...then you need it To Land. True, 91.175 (c)(2) does allow you to operate under the DH, but operating under the DH does not mean you have met landing minimums...You can operate below the DH until 91.175(c)(1) is no longer possible.

The question morphed a bit from the original. The word "Land" got tossed in along the way. I still wont be landing if RVR is below landing minimums...Actually I wont even be flying then...

(2) The flight visibility is not less than the visibility prescribed in the standard instrument approach being used; and

RVR is NOT FLIGHT VISIBILITY

 

[gsrcrsx68]

(2) The flight visibility is not less than the visibility prescribed in the standard instrument approach being used; and

RVR is NOT FLIGHT VISIBILITY

Nobody said RVR is Flight Visibilty. However you do find RVR under Visibility in the pilots glossary.

So are you saying you would be ok to land if a SIAP specified RVR and RVR was reported to be less than the minimum but you had the required flight visibility? I wouldn't do it.

Plus the allowed substitution for the landing minimums (where RVR is specified) is ground visibilty, not flight visibility.

The only thing I stated was I didn't believe you'd be ok to land...

 

[paulsalem]

Nobody said RVR is Flight Visibilty. However you do find RVR under Visibility in the pilots glossary.

So are you saying you would be ok to land if a SIAP specified RVR and RVR was reported to be less than the minimum but you had the required flight visibility? I wouldn't do it.

Plus the allowed substitution for the landing minimums is ground visibilty, not flight visibility.

The only thing I stated was I didn't believe you'd be ok to land...

By the letter of the law it would be legal.

 

[gsrcrsx68]

By the letter of the law it would be legal.

Really? At what point would you have met landing minimums specified in RVR?

 

[paulsalem]

If the fed came up to be and said you landed w/o the requried vis. I'd say "Sir, when I saw the runway environment, I had the flight visibility required for the published IAP. I am operating under FAR 91."

Don't misunderstand me, I'm not talking about lying about flight vis here. I'm simply saying that you COULD land if the RVR was below mins under part 91 IF you had the required flight visibility.

This is how I understand it.

 

[gsrcrsx68]

good enough...we gots a different view.

I spent too much time thinking this about this!

Thanks All.

 

[paulsalem]

I'm a little confused. Can you quote me a reg that states you must have RVR or Ground Visibility to land?

 

[gsrcrsx68]

Well RVR would be specified on the instrument appoach chart, making it the visibility portion of the landing minimum.

91.175(h)(2) specifies that if RVR is not reported then the RVR minimum shall be converted to ground visibility and that shall be the minimum the visibility minimum.

 

[paulsalem]

Well RVR would be specified on the instrument appoach chart, making it the visibility portion of the landing minimum.

91.175(h)(2) specifies that if RVR is not reported then the RVR minimum shall be converted to ground visibility and that shall be the minimum the visibility minimum.

Well i see where you are comming from. But 91.175(h)(2) only give you the ability to convert RVR into Ground Vis. This would only be useful IF ground vis/RVR was required for the approach (part 121, 135).

Below you'll read that for part 91 fight viibility is all thats required.

91.175

(d) Landing. No pilot operating an aircraft, except a military aircraft of the United States, may land that aircraft when—

(2) For all other part 91 operations and parts 121, 125, 129, and 135 operations, the flight visibility is less than the visibility prescribed in the standard instrument approach procedure being used.

No where does it say that the ground vis is required. If you belive otherwise can you quote it to me?

IF you still don't belive me, maybe ASquared will chime in, or someone else with more experience than us.

 

[gsrcrsx68]

Well i see where you are comming from. But 91.175(h)(2) only give you the ability to convert RVR into Ground Vis. This would only be useful IF ground vis/RVR was required for the approach (part 121, 135).

(2) For all other part 91 operations and parts 121, 125, 129, and 135 operations, the flight visibility is less than the visibility prescribed in the standard instrument approach procedure being used.

No where does it say that the ground vis is required. If you belive otherwise can you quote it to me?

I like your line of thought. That is good lawyering. If I ever get in a bind over this it will certainly be my defense. The word visibility(above) includes RVR and/or Ground Visibility prescribed by the procedure(pilots glossary). So in a way it almost adds an addtional burden of being sure that flight visibility is above the RVR prescribed on the chart. I have still not seen a reg that would allow me to operate in a way that is different from what is prescribed on a SIAP. Do you have a reg that states you may fly the procedure differently than what is printed on an approach chart?

(h)(2) tells you that if rvr is not reported then ground vis shall be(not may) used for an approach requiring RVR.

I would like to know if anyone has ever been violated on landing below the mins.

I still wouldn't do it...though I like your thinking.

 

[Doc Holiday]

paulsalem is correct. But I think where the confusion is coming from is the whole Part 91/135/121 thing. If you are at the DA/MDA on an approach, it does not matter what rules you are operating under (civilian), all you need is the required FLIGHT visibility to continue lower.

The difference between 91 and 135/121 happens way before you get to this point. Under Part 135/121 you may NOT start an approach if the airport is below minimums, and you may NOT pass the FAF if the weather is below minimuns for that particular approach. (minimums = RVR if reported or visibility)

gsrcrsx68, this is where the whole converting RVR to ground visibility and all that stuff you've be referencing comes into play - it is required for 135/121 to pass the FAF. After you're inside the FAF, the rules are the same. You just need the required FLIGHT visibilty.

 

[A Squared]

I would like to know if anyone has ever been violated on landing below the mins.

Probably. I couldn't find an NTSB decision that exactly addresses this but I did find one that is interesting in the larger context of the discussion.

http://www.ntsb.gov/o_n_o/docs/AVIATION/4338.PDF

Briefly the guy landed when reported vis was 1/16 SM and ran off the runway. He claimed that he had the runway lights in sight at 1500 ft. The FAA attelpted to violate him for a whole bunch of stuff, including a violation of 91.175(d). In his intital appeal, the ALJ accepted his statement that he had hte runway lights from 1500 ft, so the 91.175(d) chahrge was dismissed. This document linked is his appeal to the full board on the other charges, which was denied, but it does discuss how the 91.175(d) charge was dismissed in the previous appeal.

Two lessons:

1) Yes it is possible to beat a 91.175(d) violation if the judge beleives that you did have the flight visibilty, even though the reported vis is below minimums.

2) If you run of the runway and bend an airplane while landing when the reported vis is lower than the minimum , you're going to get violated for something, probably 91.13

 

[Donsa320]

Probably. I couldn't find an NTSB decision that exactly addresses this but I did find one that is interesting in the larger context of the discussion.

http://www.ntsb.gov/o_n_o/docs/AVIATION/4338.PDF

Briefly the guy landed when reported vis was 1/16 SM and ran off the runway. He claimed that he had the runway lights in sight at 1500 ft. The FAA attelpted to violate him for a whole bunch of stuff, including a violation of 91.175(d). In his intital appeal, the ALJ accepted his statement that he had hte runway lights from 1500 ft, so the 91.175(d) chahrge was dismissed. This document linked is his appeal to the full board on the other charges, which was denied, but it does discuss how the 91.175(d) charge was dismissed in the previous appeal.

Two lessons:

1) Yes it is possible to beat a 91.175(d) violation if the judge beleives that you did have the flight visibilty, even though the reported vis is below minimums.

2) If you run of the runway and bend an airplane while landing when the reported vis is lower than the minimum , you're going to get violated for something, probably 91.13

On the other hand if you land with the RVR or reported visibility at or better than required and you then run off the runway or have some other incident, you cannot claim that you could not see enough to make a safe landing. It is always the pilot's responsibility to see that the visibility is really at or above the required visibility minimum. IMHO

DC