Part 91 Approach

cimepilot

Well-Known Member
I know a Part 91 pilot can start an approach when visibility is below minimums for the approach. But, what about this scenario:

The prescibed visibility on the approach is 1 mile. The reported vis. is 1/4 mile, but over the final fix the pilot sees the runway lights. When he gets lower, he determines the flight vis. on the runway is only about 1/4 to 1/2 mile. Can he legally land? Does he only have to have the runway in sight or does he have to determine the flight vis. is at least what is published for the approach?
 

drumminpilot

Well-Known Member
Well, here's what I found....

91.175c- ...no pilot may operate an aircraft...at any airport below the authorized MDA or continue an approach below the authorized DH unless:
1)The aircraft is...in a position from which a descent to a landing...can be made at a normal rate of descent...
2)The flight visibility is not less than the visibility prescribed in the SIAP being used; and
3) blah, blah, blah about seeing stuff....

91.175d-Landing. No pilot...may land an aircraft when the flight visibility is less than the visibility prescribed in the SIAP being used.


Glad you asked..... I needed that little refresher.....
 

pavelump

Well-Known Member
If you've been cleared for the approach and the visibility drops below minimus AFTER you have reached the FAF or FAP, you can legally give it a shot. If you can see the runway environment/lights, you can land. Otherwise you have to go missed. If the vis. drops below minimums BEFORE you get to the FAP/FAF, you can't attempt the approach.

Of course, if you have crossed the FAF/FAP and you get down to the MDA/DA you don't see sh#t.... Common sense I guess, unless you have a CATIII ILS!

Dave
 

Jason

Well-Known Member
That only applies to part 121/135. Under part 91 even if the airport is "zero/zero" you can fly approaches all day long but as mentioned above you must have the prescribed elements in sight to continue the approaches past mins/DA. Flight vis is controllng - ground vis is not.

Jason
 

cimepilot

Well-Known Member
Is the pilot the only person who can determine flight vis.? Or can the FAA inspector on the ground bust you because the reported vis. was less than the minimums?
 

mikek123

Well-Known Member
[ QUOTE ]
Is the pilot the only person who can determine flight vis.? Or can the FAA inspector on the ground bust you because the reported vis. was less than the minimums?

[/ QUOTE ]

The visibility required is flight visibility so as long as the distance you can see is greater than the required visiblity than you are good to land. The ATIS could be reporting 1/4 mile vis. but if you see 2 miles than you are good.
 

E_Dawg

Moderator
From a legal standpoint it's all about what you determine the visibility to be prior to landing. I suppose that if you can see the runway environment yet simultaneously determine the visibility is less than minimums, you are required to go around.

With that said, from a safety standpoint, if you have the runway environment in sight at or prior to the DH/MAP, and determine that a normal descent to a landing can be made, go ahead.

But think about it for a minute... to make a normal descent to a landing on most nonprecision approaches you'd have to have the runway environment in sight way before you get to the MAP, and if that happens you know the visibility is more than the perscribed minimums. Also, on precision approaches the minimums are usually such that if you have the runway environment in sight at the DH (you can see distinct things, not just a few lights) then vis is fine. It's all about what YOU can see, what YOU determine the flight visibility to be, and no one else is able to do that (no one will be at your exact spot at the exact time).
 

mikek123

Well-Known Member
Just make sure that if you decide to go ahead and land when the visibility is below minimums that you aren't the only one that has landed in the last hour. If everyone else is going missed and you decide to land, you better hope there isn't an FAA guy sitting around the airport. He might have a few questions for you.
 

E_Dawg

Moderator
And the other issue is why would you want to shoot an approach to a below minimums airport. You are setting yourself up for a venture below the MDA/DH to 'see what's there' (not directing this at you cimepilot; just posing the question).
 

mikek123

Well-Known Member
[ QUOTE ]
And the other issue is why would you want to shoot an approach to a below minimums airport.

[/ QUOTE ]

Just because the ATIS or METAR is reporting below minimums doesn't mean it is. Those reports can be up to an hour old so I don't really see the problem shooting an approach if it is below minimums as long as you are prepared to go missed especially if the weather is borderline.
 

Antonio

New Member
You can shoot the approach all day but the regs states two parts: Approach requirements and Landing requirements. The landing requirements states that you must have the required flight visibility to land the aircraft. Ironically, the visibility you get off the ATIS is based on ground visibility. If you use Jeppesen charts, you have an added benefit. It gives info on the runway markings. Each white stripe is 120' long and the space between them is 80' long. Thus with 9 stripes seen you have 1800' visibility.

Don't land without the prescribed visibility, it is only a way to lose you ticket you worked so hard to get.


Sec. 91.175 Takeoff and landing under IFR.

APPROACHES (a) Instrument approaches to civil airports.
Unless otherwise authorized by the Administrator, when an instrument
letdown to a civil airport is necessary, each person operating an aircraft,
except a military aircraft of the United States, shall use a standard
instrument approach procedure prescribed for the airport in part 97 of this
chapter.
(b) Authorized DH or MDA. For the purpose of this section, when the
approach procedure being used provides for and requires the use of a DH or
MDA, the authorized DH or MDA is the highest of the following:
(1) The DH or MDA prescribed by the approach procedure.
(2) The DH or MDA prescribed for the pilot in command.
(3) The DH or MDA for which the aircraft is equipped.
(c) Operation below DH or MDA. Where a DH or MDA is applicable, no pilot
may operate an aircraft, except a military aircraft of the United States, at
any airport below the authorized MDA or continue an approach below the
authorized DH unless--
<font color="red"> </font> <font color="black"> </font> (i) The approach light system, except that the pilot may not descend below
100 feet above the touchdown zone elevation using the approach lights as a
reference unless the red terminating bars or the red side row bars are also
distinctly visible and identifiable.
(ii) The threshold.
(iii) The threshold markings.
(iv) The threshold lights.
(v) The runway end identifier lights.
(vi) The visual approach slope indicator.
(vii) The touchdown zone or touchdown zone markings.
(viii) The touchdown zone lights.
(ix) The runway or runway markings.
(x) The runway lights.


(d) LANDING. No pilot operating an aircraft, except a military aircraft of
the United States, may land that aircraft when the flight visibility is less
than the visibility prescribed in the standard instrument approach procedure
being used.
 
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