not enough visibility?

Ron Levy said:
Technically, 2 miles flight vis is the minimum to descend and operate below the MDA, not a "landing minimum." On this approach, you can continue past the MAP at or above MDA as long as you have the required vis and the ground in sight so you can navigate visually until you acquire the runway environment, at which point you can leave MDA if the other 91.175 requirements are met. Of course, there's nothing wrong with going missed at the MAP if you do not have the runway environment in sight, but it will result in missing on occasions where you could still legally (and probably safely) have completed the approach.
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You can descend below the MDA at the MAP as long as you have the required flight visibility. There is no requirement to remain at the MDA after the MAP on the "fly visual". 91.175 doesn't apply for the "fly visual".
 
alfadog said:
I think a couple folk in the thread had it right and what you say was certainly where the thread ended up.
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I re-read and did not find the part dealing with when you could start your descent. There is no requirement to remain at the MDA.
 
Captain said:
So again. Are we saying we are going to level at MDA, fly past the MAP without the field, runway, or lights in sight and just continue because we can see the ground and determine that we do have 2 miles of Vis?

That's the way I read it. It does seem strange because we now have 5 miles to fly and if that Vis goes from 2 to 1 to 0 we are in a real spot as the MAP is on the wrong side of us and the restricted area is going to get popped.
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And you can descend from the MDA if you have the flight visibility, no need to wait until you see the runway.
 
One reason that pilot's assume that with a "fly visual", that they have to remain at the MDA or treat the DA as a MDA until they have the runway in sight is the way it is depicted on the AeroNav charts. I think it would be clearer if they did not chart a level segment as that is not what is intended.
 
John Collins said:
You should be very confident that you can complete the approach, because once you are past the MAP at the MDA or below the MDA, you are on your own if you need to miss the approach. This is similar to the problem of missing an approach after circling has commenced, only worse. Often the reason for the "fly visual to the airport" has to do with the climb criteria of 200 feet per NM required if you start the miss at the MAP and at the MDA. You should examine the DP or ODP and have a plan in mind as to how you would execute a miss once you are pat the MAP or below the MDA. This planning should be done before you leave the ground on departure.
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Thank's John, most excellent. So yeah, the FAA has approach that says 'man up' because you can f- yourself here'. :lol:
 
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John Collins said:
You can descend below the MDA at the MAP as long as you have the required flight visibility. There is no requirement to remain at the MDA after the MAP on the "fly visual". 91.175 doesn't apply for the "fly visual".
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Nonetheless it is wise to remain at MDA until fairly close in because then obstacle clearance is assured. In fact, there is no penalty for remaining at MDA until overhead the airport, check the wind, then enter traffic for the favored runway. There is lots of room on the west side before the mountains start rising. (see attach)

What I think is misleading, though, is the circle-to-land maneuvering area to goes into the resticted area. The boundary is not very far away.

This airport seldom has bad weather. But, when it does it is a hard driving rain, which would almost certainly make the "Z" IAP available because nothing is going on then at China Lake.
 

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So I'm thinking my IAP to a contact approach analyogy wasn't too far off the mark.
 
Ron Levy said:
The visibility min shown on an approach chart is flight vis, not ground vis, so for Part 91 ops, it's up to you as the pilot to determine from the cockpit in flight whether you have it or not, regardless of the reported ground vis.
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How does the pilot determine the visibility from the cockpit in flight?
 
Not if you know the area. If you don't, yes. An easy educated guess.

Telephone poles are typically a standard distance apart. Roads are typically a standard size. Buildings. Etc etc etc.

Ron's estimate isn't as inaccurate as it may sound if any standard sized objects are in sight.

There do be dragons here with optical illusions, however. ;)
 
Captain said:
Okay, you get to the MAP, have 3 miles flight Vis, DR you 017 hdg and never see the runway. How long do you DR? Til you guess the airport is behind you?
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Since you used an IFR GPS to get to the MAP, won't the GPS be counting up the distance from the MAP? If so, I would say that when it gets to 5 without the airport coming into view, time to execute plan B.

If I hadn't previously flown into this airport in VFR conditions, then depending on what I saw out the window, I might do the same as you and start a missed at the MAP if the visibility were less than five miles.
 
Captain said:
So I'm thinking my IAP to a contact approach analogy wasn't too far off the mark.
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Sure sounds like it; seems it takes it even one step further since a controller can't recommend the procedure and here it's written.
 
roncachamp said:
That's called guessing.
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Welcome to the world of equipment operating. It's called referencing to a known mental and/or otherwise visible standard to scale against (like section lines or city blocks); you are correct in thinking the information would be highly suspect to be incorrect. When I ask guys to tell me how far off a bridge they are without referencing the radar they do not do particularly well at it lol. You end up with an upside down 'W' for a Bell Curve though and most people can come close enough. The people in the center dip have usually over 10 years in the trade. Thing is they leave it up to PIC, remember, the MINIMUM in flight visibility is 2 miles, you can choose to bail out at MAP with greater if you're not comfortable.
 
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Henning said:
Welcome to the world of equipment operating. It's called referencing to a known mental and/or otherwise visible standard to scale against (like section lines or city blocks); you are correct in thinking the information would be highly suspect to be incorrect. When I ask guys to tell me how far off a bridge they are without referencing the radar they do not do particularly well at it lol. You end up with an upside down 'W' for a Bell Curve though and most people can come close enough. The people in the center dip have usually over 10 years in the trade. Thing is they leave it up to PIC, remember, the MINIMUM in flight visibility is 2 miles, you can choose to bail out at MAP with greater if you're not comfortable.
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And you can continue with less than the minimum required visibility, as long as your guess on the visibility is at least the minimum.
 
roncachamp said:
And you can continue with less than the minimum required visibility, as long as your guess on the visibility is at least the minimum.
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Exactly. The number represents a comfort scale to the pilot. 3 miles is minimum for VFR and 1 mile is minimum to need instruments, so the pilots comfort level should be above that required for when they switch to instruments and less than what they would have navigating pilotage. That level of comfort is what the pilot should use to make the determination.
 
Ron Levy said:
One looks out the windshield and estimates the distance to the farthest object on the ground s/he can see.
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Here is a method I saw somewhere and actually did on a club 172m.

With a friend sitting in the cockpit, measure the distance from asphalt to his eye level. Let us say it is 6 feet. Have him look directly down over the nose. Measure from beneath him to the closest point he can see on the asphalt. Let us say it is 49 feet.

Calculate the rough ratio. 49/6 = 12 (close enough). Remember 12. Flying along at 1000 feet, if you can see the ground directly over the nose, you have at least 2 nm vis; 1,000 x 12 = 12,000'.

One caveat. For best accuracy, you have check that the airplane on the ramp has the same sight picture to the horizon as cruise.

edit: Actually you should be the one sitting in the pilot's seat. My friend was the same height as me so I let him have the easy job :) You could even do this yourself at a bit more effort.
 
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Another good one over flat terrain & water is horizon is 3 miles for every 6' height of eye and you judge by a percentage of their distance to the horizon.
 
Henning said:
Exactly. The number represents a comfort scale to the pilot. 3 miles is minimum for VFR and 1 mile is minimum to need instruments, so the pilots comfort level should be above that required for when they switch to instruments and less than what they would have navigating pilotage. That level of comfort is what the pilot should use to make the determination.
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And if the pilot's level of comfort is 1 1/2 miles he's okay to continue on the approach?
 
roncachamp said:
And you can continue with less than the minimum required visibility, as long as your guess on the visibility is at least the minimum.
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Not true. Since the visibility required is "flight visibility" (not ground visibility as reported by a ground observer or ground-based device) and by definition flight visibility is measured from the cockpit, if you see that far, you do have the required minimum visibility per 91.175. This has been tested before the NTSB, and they agreed on this point -- see Administrator v. Pisarek.
http://www.ntsb.gov/legal/o_n_o/docs/Aviation/4338.pdf
Of course, if the ground vis is 1/16 sm and you continue based on your own determination of 2 sm flight vis, and it ends badly, you may still, like Pisarek, be cooked for 91.13 careless/reckless, but that's a different issue.
 
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Henning said:
Exactly. The number represents a comfort scale to the pilot. 3 miles is minimum for VFR and 1 mile is minimum to need instruments, so the pilots comfort level should be above that required for when they switch to instruments and less than what they would have navigating pilotage. That level of comfort is what the pilot should use to make the determination.
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I'm not sure how the FAA would like that as a way to determine whether or not you have 2 sm flight vis. I think they'd rather hear that you could see an object on the ground two miles ahead. How you determine that it is 2 sm is a bit more difficult, but I think alfadog's method is supportable.
 
alfadog said:
Yes, but my question is, if I know that I am flying there tomorrow and IFR is forecast, can I find out then if the restricted area will be active the next day?
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I believe I recall that The giant TRACON (Joshua) that controls that vast area established a special telephone number a long time ago for pilots to call an ask about the status of the many restricted areas out there. Another option is to ask the first Joshua controller on hand off.
 
Ron Levy said:
Not true. Since the visibility required is "flight visibility" (not ground visibility as reported by a ground observer or ground-based device) and by definition flight visibility is measured from the cockpit, if you see that far, you do have the required minimum visibility per 91.175. This has been tested before the NTSB, and they agreed on this point -- see Administrator v. Pisarek.
http://www.ntsb.gov/legal/o_n_o/docs/Aviation/4338.pdf
Of course, if the ground vis is 1/16 sm and you continue based on your own determination of 2 sm flight vis, and it ends badly, you may still, like Pisarek, be cooked for 91.13 careless/reckless, but that's a different issue.
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Flying for hire you need both flight and ground visibility.
 
aterpster said:
Flying for hire you need both flight and ground visibility.
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If you mean 135, 121, etc, yes, but there is for-hire flying (such as a corporate pilot) that doesn't fall under that rule. In any event, I thought we were looking at the basic Part 91 situation. Throw in those other Parts and the discussion changes.
 
Ron Levy said:
If you mean 135, 121, etc, yes, but there is for-hire flying (such as a corporate pilot) that doesn't fall under that rule. In any event, I thought we were looking at the basic Part 91 situation. Throw in those other Parts and the discussion changes.
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I don't think so. "Captain" was taking it to his training department early in the thread. The concept of "Fly visual to airport" applies the same to commercial and non-commercial operators.

As an aside these two IAPs were established to meet the requirements of a commuter carrier that served the airport at the time.

Edit: When the commuter operated there they had their own weather observer. The G/A guy is on his own at this airport, which is not insignificant when it is socked in with out of those unusual (but not rare) winter rainstorms.
 
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roncachamp said:
And if the pilot's level of comfort is 1 1/2 miles he's okay to continue on the approach?
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The pilot calls it 2 miles and continues, that's the way it's set up still. Remember, the spirit of IFR lies with people named Doolittle and Jeppesen, not lawyers and bureaucrats. It's what the 'command' in pilot in command is about.
 
aterpster said:
I don't think so. "Captain" was taking it to his training department early in the thread. The concept of "Fly visual to airport" applies the same to commercial and non-commercial operators.
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Except it doesn't. Commercial operators must have both the requisite flight visibility and the ground visibility reported and above mins; the rest of us need only the requisite flight vis which we can determine for ourselves.
 
Ron Levy said:
Except it doesn't. Commercial operators must have both the requisite flight visibility and the ground visibility reported and above mins; the rest of us need only the requisite flight vis which we can determine for ourselves.
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Don't they also have to have the approach approved for use on their certificate? I remember way less tricky/risky approaches having pilot minimum attached to them at Express 1.
 
Ron Levy said:
Except it doesn't. Commercial operators must have both the requisite flight visibility and the ground visibility reported and above mins; the rest of us need only the requisite flight vis which we can determine for ourselves.
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Oh, Ron, please, the concept is identical for all operators.
 
Ron Levy said:
Fine, but the context of that part of the discussion was Steven's questions about visibility minimums, and that part is different.

Thread creep -- bleah.:vomit:
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It crept early on. :lol:
 
Henning said:
Don't they also have to have the approach approved for use on their certificate? I remember way less tricky/risky approaches having pilot minimum attached to them at Express 1.
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For a Part 121 operator no doubt about it. They also would have to have an approved weather reporting source, typically a station agent at a place like this.

The interesting question: Does the on-demand 135 operator need some sort of FSDO approval to fly into this airport? The airport is important to the town of Ridgecrest. In fact, I am surprised it doesn't have automated weather by this time.
 
aterpster said:
The interesting question: Does the on-demand 135 operator need some sort of FSDO approval to fly into this airport? The airport is important to the town of Ridgecrest. In fact, I am surprised it doesn't have automated weather by this time.
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There is no general regulatory requirement for by-location approval for on-demand 135 operations. Any such requirement would be in their individual ops specs, although I've never heard of such.
 
aterpster said:
The interesting question: Does the on-demand 135 operator need some sort of FSDO approval to fly into this airport? The airport is important to the town of Ridgecrest. In fact, I am surprised it doesn't have automated weather by this time.
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As far as I know, OpSpec approval for authorized airports is only required for commuter part 135 under OpSpec C070. Our OpSpecs authorizes us to dispatch to an airport under IFR that does not have weather reporting as long as an alternate airport is available with approved weather reporting that is forecast to be at or above IFR landing minimums.
 
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