Determining flight visibility.

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150man

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150man
Let's say one is tootling along at 5,500 in class E airspace. According to the regs, one must have 3 mi. visibility at mimimum and be separated from clouds by 500 ft. below, 1,000 ft. above or 2,000 ft. horizontal. Question is how do you know what your flight visiblilty is? Are we just supposed to estimate it?
 
You mean you don't carry a laser rangefinder in your flight bag?? For shame!!!:goofy:


My instructor gave me a good tip that works well in helping me judge separation.

In my training environment, the "home" runway is 6,000 ft long. Having done a few patterns around it, I've developed a good sense of estimating 6,000 ft.

So for 500 feet, I picture threshhold to half the distance to the 1000-ft touchdown marker, for 2000-feet, I picture threshhold to the 2nd taxiway.
 
In the midwest, you just count section lines.
 
As I've said in my Checkride Advice, when the examiner asks how far away a cloud is or what the vis is, s/he's testing your knowledge, not your eyes.
 
EdFred said:
In the midwest, you just count section lines.
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I've always thought this rule refered to the visibility at your altitude, not on the ground below you. Say you're over some fog. The vis on the ground might be 1/4 mile but a couple thousand feet up it could be unlimited. Which do you go by?
 
150man said:
I've always thought this rule refered to the visibility at your altitude, not on the ground below you. Say you're over some fog. The vis on the ground might be 1/4 mile but a couple thousand feet up it could be unlimited. Which do you go by?
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Unlimited. But I'd hope my engine didn't skip a beat, too.
 
150man said:
I've always thought this rule refered to the visibility at your altitude, not on the ground below you. Say you're over some fog. The vis on the ground might be 1/4 mile but a couple thousand feet up it could be unlimited. Which do you go by?
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That's true but if you're scud running at 1000 AGL under the clouds you can often expect that the slant visibility to the ground ahead is similar to the flight visibility along your altitude. And unless there's a tall tower at 12 O'clock reaching your altitude there's really no way to estimate visibility if you can't see the ground at all.
 
The only time you'll be asked to defend this estimate is after you've screwed up, so don't screw up.
 
airguy said:
The only time you'll be asked to defend this estimate is after you've screwed up, so don't screw up.
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...because if you screw up just this much you'll be flying a cargo plane full of rubber dog **** out of Hong Kong!
 
...And don't, under any circumstances, call the local approach control and say "We're about 600 above this broken layer, any idea where there's a hole we can duck down through?"
 
Ron Levy said:
...and if you did screw up, the FAA will find a way to hose you even if you can show the flight vis was legal. See Administrator v. Pisarek. So like airguy said, "don't screw up."
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Wow at first I read this as "didn't" screw up, so I clicked the link. I start going down the facts of the case, and I'm thinking to myself how did the FAA know that he didn't have that 1500 foot visibility? Especially since they were talking about 91.175 and how he was on an instrument approach.

Ahh, but then we get to this point:

Code: 
As a result, the plane was
dragged even farther to the left and came to rest off the paved
runway. The aircraft, owned by respondent's corporate client,
sustained damage to its landing gear and propellers.

Yep, guess he screwed up.

This sounds more like appeals court didn't want to go out and call the pilot a liar.

I'm curious about all the "passenger-carrying" language. As far as the regs are concerned it doesn't matter (other than the 3 in 3 requirements not at question in this case) if you are carrying a passenger or not. Does that "up" the ante in regards to 91.13 - careless and reckless? It's OK to be reckless solo, but not with a passenger? Or can one not be careless if it's your own hide? Somehow I think if he had been by himself the decision would have read the same without all the "passenger-carrying" language.

I always thought that 91.13(a) is a lot like Article 1 Section 8.3. The catch-all to allow the feds to do whatever they want.
 
JeffDG said:
...And don't, under any circumstances, call the local approach control and say "We're about 600 above this broken layer, any idea where there's a hole we can duck down through?"
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What about if you're on an IFR clearance, and say... no gyro? :wink2:

While I'm legal to be there, I may not want to do a full approach at the moment. Especially if there is some block of VFR that would allow me to descend.

I don't want to cancel though! I mayend up having to do that no-gyro approach. Now where is that instrument cover, this thing wobbling all too and frow sure is distracting.... I think it's under the seat here....:wink2:
 
bdlarkin said:
I'm curious about all the "passenger-carrying" language. As far as the regs are concerned it doesn't matter (other than the 3 in 3 requirements not at question in this case) if you are carrying a passenger or not. Does that "up" the ante in regards to 91.13 - careless and reckless? It's OK to be reckless solo, but not with a passenger? Or can one not be careless if it's your own hide? Somehow I think if he had been by himself the decision would have read the same without all the "passenger-carrying" language.
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I've seen nothing in the regs or the case law to suggest the FAA considers the mere presence of passengers in deciding if a pilot was careless/reckless, although I have seen cases in which the carriage of paying passengers was cited as requiring additional care.
I always thought that 91.13(a) is a lot like Article 1 Section 8.3. The catch-all to allow the feds to do whatever they want.
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That's more or less true, but there are limits. Essentially, what the NTSB said on that point was something to the effect of "It is neither possible nor required for the Administrator to anticipate all possible unsafe conduct and write specific regulations to prohibit such conduct."
 
During the Great War and WWII, most pilots were either commissioned or non commissioned officers. It was assumed that they were also gentlemen and men of their word.

Even though we have numerous methods in place where others can check on us electronically, not every little thing can always be monitored. The powers that be, expect us to fly honorably, and follow the rules.

With that in mind, if a pilot claims he was maintaining weather and cloud clearance minimums, and there is no one that can dispute that claim, then that pilot was indeed observing the correct minimums.

In other words, give it your best estimate.

John
 
I don't see any need to sweat this stuff unless you see an aircraft alongside you that says "FAA" on it. :wink2:
You have to know the gospel, of course, when you are tested by agents of the FAA, and it is wise to cancel when reported conditions do not meet the legal minimums, but anybody who's flown for a while has had that moment at least once: "am I legal right now? I dunno, but I am OK flying in this."

And if you're a bit conservative like me, you've probably had the converse moment: "I can't believe I'm legal right now; this is scary".

There being no reliable way to know precisely how far you are from any given cloud, or how far towards that obscured horizon you can fly before you can't see the ground or anything beyond your wingtips, what's really important for VFR flight is whether or not you, the PIC, finds the visibility adequate at any given time. That's the spirit of the regs, particularly 91.13, which effectively covers the obvious inability of the FAA to know what sort of conditions you are dealing with at any given moment.

At one time, before IFR plans with radar coverage, even before gyros were commonplace, it was legal to continue as long as you could see the ground ("ground contact" or "contact" flying).

Nowadays, that's forbidden in most VFR situations, but it's perfectly legal to fly VFR over a solid cloud deck or fog, as long as you meet the clearance requirements for the airspace.

Given today's congestion, the early practice would seem unwise, even if you are confident you could recover from a disorientation-related upset as long as you could see the ground. And bailing out when low on fuel on top or unable to maintain control without gyros doesn't work too well today... the plane is more likely to hurt persons or property when it comes down.

But an emergency descent through clouds, or worse yet, into ground-hugging fog, seems even more foolhardy. Yet it is perfectly legal to set yourself up for such a scenario these days... unless it doesn't work out, in which case you might get clobbered with 91.13 (and rightly so, IMHO).

I'm not condoning busting VFR minimums; I'm "just sayin'". The regs don't keep you safe; your judgment keeps you safe.
 
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bdlarkin said:
What about if you're on an IFR clearance, and say... no gyro? :wink2:

While I'm legal to be there, I may not want to do a full approach at the moment. Especially if there is some block of VFR that would allow me to descend.

I don't want to cancel though! I mayend up having to do that no-gyro approach. Now where is that instrument cover, this thing wobbling all too and frow sure is distracting.... I think it's under the seat here....:wink2:
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Well...ATC wanted to put VFR flight following in for him and he didn't know that his Columbia 400 was "/G" "Sorry, I don't know what slant-G means"
 
rottydaddy said:
At one time, before IFR plans with radar coverage, even before gyros were commonplace, it was legal to continue as long as you could see the ground ("ground contact" or "contact" flying).

Nowadays, that's forbidden in most VFR situations, but it's perfectly legal to fly VFR over a solid cloud deck or fog, as long as you meet the clearance requirements for the airspace.
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Good post! Just a minor quibble: depending on your altitude, it's quite possible to be legal VFR with no clouds below and still be unable to see the ground well enough to navigate visually. Usually lights from the ground penetrate the murk better than ground features do during the day (as do aircraft lights!), so your effective visibility can actually be better at night. But in remote areas with few ground lights, and at say 7000 feet, it's very easy to find yourself in what are effectively instrument conditions as it starts to get dark, even with decent visibility, say 5-7 miles.
 
150man said:
Let's say one is tootling along at 5,500 in class E airspace. According to the regs, one must have 3 mi. visibility at mimimum and be separated from clouds by 500 ft. below, 1,000 ft. above or 2,000 ft. horizontal. Question is how do you know what your flight visiblilty is? Are we just supposed to estimate it?
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The better questions are related to how do you determine when you're pushing the minimums you should be flying in. If you're sitting there wondering the question you asked for very long I would assert that is an indicator that you're getting close to doing something you shouldn't be doing, regardless of what the FARs say on the subject. It's my experience as a somewhat veteran IFR flyer and scud runner (I have a VFR only aircraft now) that the actual FAR mins are a scary place to be in all but the most simple flights.
 
rottydaddy said:
At one time, before IFR plans with radar coverage, even before gyros were commonplace, it was legal to continue as long as you could see the ground ("ground contact" or "contact" flying).
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Actually, it was legal to continue even if you couldn't see the ground. The Air Commerce Regulations of June 1, 1928, contain no requirement to see the ground. Of course, as there were no electronic NAVAIDS at that time flight without reference to the ground wasn't very practical.

It wasn't called Contact Flight at that time either. As there was no other kind of flying there was nothing to differentiate.

Nowadays, that's forbidden in most VFR situations, but it's perfectly legal to fly VFR over a solid cloud deck or fog, as long as you meet the clearance requirements for the airspace.
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The Civil Air Regulations of 1943 required a minimum distance for Contact Flight of 500' above or below clouds or 2000' horizontally.
 
I recall an instance in central Wisconsin where I pulled the plug. I said to myself, "no way is this safe or legal". I hit the nearest button, headed toward the nearest airport. On the way there I passed a quartet of cubs flying in formation and a couple other aircraft. I asked the guys there a what point they expected the weather to improve, and they said, "oh, around October". It was July.
 
azure said:
Good post! Just a minor quibble: depending on your altitude, it's quite possible to be legal VFR with no clouds below and still be unable to see the ground well enough to navigate visually. Usually lights from the ground penetrate the murk better than ground features do during the day (as do aircraft lights!), so your effective visibility can actually be better at night. But in remote areas with few ground lights, and at say 7000 feet, it's very easy to find yourself in what are effectively instrument conditions as it starts to get dark, even with decent visibility, say 5-7 miles.
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Good point- I was thinking day VFR; night flight is a whole 'nother kettle of fish. Even harder to tell if you're legal when you can't even see the clouds... :D
 
roncachamp said:
Actually, it was legal to continue even if you couldn't see the ground. The Air Commerce Regulations of June 1, 1928, contain no requirement to see the ground. Of course, as there were no electronic NAVAIDS at that time flight without reference to the ground wasn't very practical.

It wasn't called Contact Flight at that time either. As there was no other kind of flying there was nothing to differentiate.



The Civil Air Regulations of 1943 required a minimum distance for Contact Flight of 500' above or below clouds or 2000' horizontally.
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I see... I guess I had my time periods mixed up.
At any rate, what made any such flight safe back then was the quality of the pilot's decision-making, with a little luck added in.... no different today, really.
 
150man said:
Let's say one is tootling along at 5,500 in class E airspace. According to the regs, one must have 3 mi. visibility at mimimum and be separated from clouds by 500 ft. below, 1,000 ft. above or 2,000 ft. horizontal. Question is how do you know what your flight visiblilty is? Are we just supposed to estimate it?
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I'm gonna say your flight visibility is at least 3mi.


Isn't it?:ihih:





(Don't be stupid. 3mi is nothing. If you're VFR with 3mi vis and you aren't a 20,000hr bush pilot you have no business being up there. Go where vis is better or land. Stat.)

IMHO. YMMV.
 
Let me amend that -- if you're close enough to 3mi vis to be wondering about it, assume it's 3 mi and make decisions accordingly.
 
rottydaddy said:
Good point- I was thinking day VFR; night flight is a whole 'nother kettle of fish. Even harder to tell if you're legal when you can't even see the clouds... :D
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Yeah, coming back the other night, Leslie and I had an encounter with what looked like from a distance an area of mist. We could see through it, but it was hazy on the far side. When we got closer, it started interacting with the strobes! On the far side, visibility was suddenly P6. Since we could literally see through it, I would be hard pressed to call it a cloud, but from a distance, we had no idea that it was a localized area of reduced visibility.
 
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