Yes, I do. I don't know of a legal definition, but physically, the only difference between a cloud bank and a fog bank is altitude above ground level.
When is a field really IFR?
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Yes, I do. I don't know of a legal definition, but physically, the only difference between a cloud bank and a fog bank is altitude above ground level.
Here's what the Pilot/Controller Glossary has to say on the subject:
Considering clouds and fog to be different entities for legal purposes would be impractical, because in mountainous areas, it's common for a there to be cloud layers that come in contact with the ground where the terrain rises to the height of the clouds. So legally, where would you say that it stopped being a cloud and started being fog? Where the cloud contacts the mountain? One foot away from the mountain? One mile from the mountain? Coming up with a legal distinction between them that made any sense would be an impossible problem.
"CLOUD- A cloud is a visible accumulation of minute water droplets and/or ice particles in the atmosphere above the Earth's surface. Cloud differs from ground fog, fog, or ice fog only in that the latter are, by definition, in contact with the Earth's surface."
Considering clouds and fog to be different entities for legal purposes would be impractical, because in mountainous areas, it's common for a there to be cloud layers that come in contact with the ground where the terrain rises to the height of the clouds. So legally, where would you say that it stopped being a cloud and started being fog? Where the cloud contacts the mountain? One foot away from the mountain? One mile from the mountain? Coming up with a legal distinction between them that made any sense would be an impossible problem.
EdFred
Taxi to Parking
I would say if there is clear are directly below the phenomena, then it is a cloud. If not, it's fog. Yes, the same mass can be both a cloud and fog.
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Velocity173
What's the confusion here? If its less than 5/8s visibility it's reported as fog. Anything above that is BR.
nosehair
Cleared for Takeoff
The purpose of the cloud clearance requirements in 91.155 is to provide separation of ifr traffic from ifr traffic.
No traffic separation is provided in uncontrolled airspace except the 1 mi vis for vfr traffic.
So if you want to call the ground fog a cloud , you still only remain clear of fog.
Another point. If you depart class g with an 800' ceiling with class e beginning at 700, and you level at 600, you are clear of clouds in class g, but only 200 below the cloud at 800.
Still legal.
No traffic separation is provided in uncontrolled airspace except the 1 mi vis for vfr traffic.
So if you want to call the ground fog a cloud , you still only remain clear of fog.
Another point. If you depart class g with an 800' ceiling with class e beginning at 700, and you level at 600, you are clear of clouds in class g, but only 200 below the cloud at 800.
Still legal.
ChrisK
En-Route
And scary as hell without radar.
nosehair
Cleared for Takeoff
That totally depends on experience, equipment, overall wx, airport and terrain environment which is not considered in this discussion.
poadeleted20
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No, it's not. The FAA has pressed plenty of cases where the only charge was 91.13. The only way they'll not bother you about IFR in Class G is in those big brown areas out in Utah and the like.
poadeleted20
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Is that fog bank thick enough (horizontal vis) to be called a cloud layer? If yes, I wouldn't try it. If no, it should not be a problem. The question is what the FAA will call it based on the reported weather at the time, and that's kind of a crap shoot when the conditions are deteriorating like that.
RotorAndWing
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If an Inspector is going to try to get an EIR through the office and through the Regional Attorney and his only charge is 91.13 he better have an EIR file about 2 inches thick. Even then it is very difficult to accomplish as there has to be a lot of supporting evidence.
poadeleted20
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Out of 386 cases charging 91.13 which reached the NTSB since 1992, 24 had only a 91.13 charge. That's a rate of just over 6%. Sounds to me like it's rare, but not extraordinary.
RotorAndWing
Final Approach
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Again, it takes an EIR with lots of supporting evidence to try to get a solitary charge of 91.13. One would need several IOP's to support this, let alone get it through the EDP before proceeding with the EIR. Regional Attorneys typically aren't willing to take on a case if they can't win it.
From FAA Order 2150.3B Compliance and Enforcement
Appendix E. Examples
1. Elements of Regulations. A frequently-cited regulation is 14 C.F.R. § 91.13, Careless or
Reckless Operation. This seemingly simple regulation has numerous elements. The actual
wording is:
CARELESS OR RECKLESS OPERATION
(a) Aircraft operations for the purpose of air navigation. No person may operate an
aircraft in a careless or reckless manner so as to endanger the life or property of another.
(b) Aircraft operations other than for the purpose of air navigation. No person may
operate an aircraft, other than for the purpose of air navigation, on any part of the surface of an
airport used by aircraft for air commerce (including areas used by those aircraft for receiving or
discharging persons or cargo), in a careless or reckless manner so as to endanger the life or
property of another.
a. Subparagraphs of 14 C.F.R. § 91.13. The regulation has two subparagraphs.
Subparagraph (a) covers "Aircraft operations for the purpose of air navigation". Subparagraph
(b) covers "Aircraft operations other than for the purpose of air navigation". Because the two
subparagraphs cover two different conditions, i.e., for the purpose of air navigation vs. other than
for the purpose of air navigation, there must be an item of proof (IOP) that provides evidence to
identify one or the other as appropriate. If evidence shows that an aircraft was being taxied from
the hanger to the line, subparagraph (b) would be appropriate. But if evidence shows an aircraft
to have been on a take-off roll, then subparagraph (a) would be appropriate. There must be
evidence to support the choice. Assume, for example, that the operation was for the purpose of
air navigation and sub-paragraph (a) applies. The elements that must be included as an IOP are:
(1)A person.
(2)Operate (for purpose of air navigation).
(3)An aircraft.
(4)Careless or reckless.
(5)Endangerment.
(6)Life or property of another.
b. First Element. The first element is identifying the person, putting them in the aircraft,
and proving that this person was an operator of the aircraft. Identifying the person and showing
his or her operation of the aircraft may be done through witness statements, a response to the
letter of investigation, documents such as logbooks, or training records, or Air Traffic reports.
The form of the evidence can vary, but who the person is must be documented. For certificated
airman, such as pilots and mechanics, ISIS data on qualifications will be an additional IOP.
c. Second Element. The second element to prove is that the aircraft was being operated for
purposes of air navigation. For an aircraft that is airborne, or taxiing in from a flight, this is easy. For an aircraft that is on the ramp, or a taxiway, you will need some evidence to establish
whether subparagraph (a) or (b) is the appropriate choice.
d. Third Element. The third element to prove is that an aircraft was involved. A
definition of aircraft is found in 14 C.F.R. § 1.1, General Definitions. Aircraft means a device
that is used or intended to be used for flight in the air. The specific form of the evidence can
vary, but a specific aircraft must be identified through IOPs. A supporting IOP will be a copy of
aircraft registration data from the Integrated Safety Information System (ISIS). [Note:
Ultralights are not aircraft, they are vehicles, with their own definition under 14 CFR part 103.]
e. Fourth Element. The fourth element is selecting between careless or reckless and
providing evidence to support the decision. Careless indicates a lack of care, an act a reasonably
prudent person would not commit if mindful of the potential consequences. Reckless can be
alleged when there is evidence that a person intended to do what they did. It is not necessary to
prove, or even allege, that they knew that their action was a violation of any regulation. For
either choice, the careless/reckless element must be supported by evidence in one or more IOPs.
(1) Example of reckless IOP. For example, during the investigation of a gear-up landing
incident, the evidence may include a statement from the aircraft owner who had personally
advised the pilot the gear system was inoperative or a statement from a passenger who was told
by the pilot that the normal gear system was inoperative. This evidence may indicate that a
charge of reckless is appropriate.
(2) Example of careless IOP. On the other hand, the evidence may include a picture of
the aircraft on the runway with the gear-handle up, a statement from a mechanic saying the gear
operated normally when tested, or a statement from the pilot saying he was preoccupied with
other traffic. This evidence may indicate that a charge of careless is appropriate.
(3) Evidence indicating no violation. If the evidence included a mechanic’s statement
and repair order stating that the gear malfunctioned because of a broken part, then there may be
no violation of 14 C.F.R. § 91.13.
f. Fifth Element. The fifth element in this regulation is endanger. An IOP in a gear-up
landing might consist of evidence documenting the aircraft damage that endangered the property
of another. It is not necessary to show actual endangerment, evidence of potential endangerment
is sufficient. Appropriate evidence in a low flying case might include pictures of a school
playground that was flown over, statements from teachers describing children in the playground
at the time, and the altitude of the aircraft relative to terrain features. Potential endangerment can
often be best explained in the section B analysis.
g. Sixth Element. The sixth and final element in this example requires evidence that the
endangerment was to the life or property of another. If the above gear-up landing example is in
a rented aircraft, the evidence to prove this element could be an ISIS report showing that the
owner is another. Evidence of a passenger in the aircraft would also support this element, as the
passenger is another. If an aircraft flown solo was entirely owned by the violator, and if there is
no nearby property or persons to be endangered, there very well may be no violation.
2. Summary. To summarize, all enforceable regulations include some number of elements and
evidence to support each of the elements must be included in an EIR to support a violation.
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We were discussing whether you're legal to enter class E airspace at 700 AGL when there's a fog bank on the other end of the airport. Below 10,000 MSL, you have to be either 1,000 feet above any clouds, or 2,000 feet away from them horizontally. That's why we were discussing whether a fog bank is legally considered a cloud.
It may not matter from a practical point of view, but legally, I don't see a clear distinction between a cloud and a fog bank, especially when you consider that the same cloud can touch the ground at some points and not others.
roncachamp
Final Approach
Nonsense. IFR traffic does not have to remain clear of clouds or adhere to 91.155.
No traffic separation is provided in uncontrolled airspace at all. The cloud clearance requirements in uncontrolled airspace above 1200' AGL are the same in Class G airspace as they are in Class E airspace.
There is no physical difference between cloud and fog.
Correct.
skidoo
Line Up and Wait
And this is a great point with some practical value. I had wondered about the value of class G until I experienced a 600ft ceiling with 40+ mile visibility underneath and the direction of flight desired had CAVU just 15 miles out, all over lake water. So, one could take off over the water, level off at 500 ft (or less if desired) and fly towards the sunshine.
poadeleted20
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Exactly. If you look at a fog bank from above, it looks just like a cloud bank from above, i.e., you can't see the planes in it until they pop up through the top, and when you're in it, you can't see the planes above it until you pop up through the top. Hence, the FAA's insistence that VFR aircraft in controlled airspace stay well above the tops so they and IFR aircraft coming out of the cloud/fog don't surprise each other.
poadeleted20
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As far as 91.155 is concerned, yes, but you still have to worry about 91.119 regarding minimum altitudes other than as needed for takeoff and landing. It doesn't take much to be a "congested area," and 600 AGL isn't enough to meet 91.119 in that situation.
poadeleted20
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500 AGL over open water is legal, but don't try this over significantly populated areas -- 91.119 applies.
roncachamp
Final Approach
That same insistence applies in uncontrolled airspace above 1200' AGL, and below that altitude at night.
ChrisK
En-Route
This is all very helpful. The foggy night I am thinking of had wisps of fog that were still write easy to see completely through. I'm guessing that it would have been legal to depart in that case.
In addition to whatever official reports may be available, I figure that if there's a portion of it that I can't see through, then that portion is a cloud and not mist.
poadeleted20
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Just remember that if it's less than 1sm, it's IFR even in Class G, and you need to be IFR equipped, rated, and current to launch even if it's not technically a "cloud".
ChrisK
En-Route
So greater than 1 mile in class G and you can go, and you PROBABLY won't get into trouble once you hit controlled airspace (unless there is a low cloud that isn't causing lower visibility to be reported on the field). The safety or propriety of this operation, of course, depends on other factors.
poadeleted20
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Pretty much so. Just remember that when you enter the overlying controlled airspace, much greater 91.155 VMC cloud clearance and visibility requirements come into effect, and there can be a "no man's land" where VFR isn't legal between the base of controlled airspace and the higher point where you begin to meet those 91.155 controlled airspace cloud clearance/vis requirements even if you were legal to be VFR in the G-space below the base of controlled airspace.
Amen -- what is legal isn't always safe/smart.