not enough visibility?

[iHenning]

Originally Posted by roncachamp

And you can continue with less than the minimum required visibility, as long as your guess on the visibility is at least the minimum.

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.

[alfadog]

Originally Posted by Ron Levy

One looks out the windshield and estimates the distance to the farthest object on the ground s/he can see.

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.

[iHenning]

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.

[Steven P McNicoll]

Originally Posted by Henning

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.

And if the pilot's level of comfort is 1 1/2 miles he's okay to continue on the approach?

[Cap'n Ron]

Originally Posted by roncachamp

And you can continue with less than the minimum required visibility, as long as your guess on the visibility is at least the minimum.

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.

[Cap'n Ron]

Originally Posted by roncachamp

And if the pilot's level of comfort is 1 1/2 miles he's okay to continue on the approach?

Sure -- if the pilot has the required flight vis, which in this case is 2 statute miles. The pilot's level of comfort is not a legal issue.

[Cap'n Ron]

Originally Posted by Henning

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.

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.

[aterpster]

Originally Posted by alfadog

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?

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.

[aterpster]

Originally Posted by Ron Levy

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.

Flying for hire you need both flight and ground visibility.

[Cap'n Ron]

Originally Posted by aterpster

Flying for hire you need both flight and ground visibility.

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.

[aterpster]

Originally Posted by Ron Levy

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.

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.

[iHenning]

Originally Posted by roncachamp

And if the pilot's level of comfort is 1 1/2 miles he's okay to continue on the approach?

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.

[Cap'n Ron]

Originally Posted by aterpster

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.

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.

[iHenning]

Originally Posted by Ron Levy

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.

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.

[aterpster]

Originally Posted by Ron Levy

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.

Oh, Ron, please, the concept is identical for all operators.

[Cap'n Ron]

Originally Posted by aterpster

Oh, Ron, please, the concept is identical for all operators.

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.

[aterpster]

Originally Posted by Ron Levy

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.

It crept early on.

[aterpster]

Originally Posted by Henning

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.

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.

[Cap'n Ron]

Originally Posted by aterpster

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.

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.

[Jason]

Originally Posted by aterpster

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.

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.

[iHenning]

Originally Posted by aterpster

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.

We were in Jetsteams under a 135 certificate at the time still. Don't know if it would be different unscheduled.

[aterpster]

Originally Posted by Ron Levy

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.

Interesting that a weather report comes up for the airport in Foreflight.

[Captain]

OpSpecs give areas of operations. Like "authorized to operate in North America excluding the magnetic anoylomy zone in Canada"

I've never seen specific airport authorized but I suppose some could be excluded. Plus requirement like paved runway, or IAP served could be attached. Each OpSpec has a section of "Approved Operations" and "Not Approved Operations" also. That's where it list types of approaches authorized and not authorized.

[Cap'n Ron]

Originally Posted by aterpster

Interesting that a weather report comes up for the airport in Foreflight.

Well, then -- I guess the on-demand 135 folks are good to go there.

[Cap'n Ron]

Originally Posted by Captain

OpSpecs give areas of operations. Like "authorized to operate in North America excluding the magnetic anoylomy zone in Canada"

I've never seen specific airport authorized but I suppose some could be excluded. Plus requirement like paved runway, or IAP served could be attached. Each OpSpec has a section of "Approved Operations" and "Not Approved Operations" also. That's where it list types of approaches authorized and not authorized.

I think that's typical of on-demand 135 operators. The scheduled carriers (121 or 135 commuter ops) get controlled more tightly.