Who can land in 'fog'

[[email protected]]

I read a report about a local airport with this statement:

"With existing Instrument Landing System (ILS) technology, inclement
weather, such as fog, is not a material obstacle to commercial service
operations."

I was under the impression that the FAA says fog is 1/4 mile
visibility. Can anyone legally land in fog?

[Mike Rapoport]

Most Cat II and Cat III approaches can land in fog.

Mike
MU-2


> wrote in message
oups.com...
>I read a report about a local airport with this statement:
>
> "With existing Instrument Landing System (ILS) technology, inclement
> weather, such as fog, is not a material obstacle to commercial service
> operations."
>
> I was under the impression that the FAA says fog is 1/4 mile
> visibility. Can anyone legally land in fog?
>

[[email protected]]

Is there somewhere I can find out if this airport (KORH) has an
appropriate Cat II or Cat III Approach?

I thought I heard it was a Cat I.

[Matt Whiting]

wrote:
> I read a report about a local airport with this statement:
>
> "With existing Instrument Landing System (ILS) technology, inclement
> weather, such as fog, is not a material obstacle to commercial service
> operations."
>
> I was under the impression that the FAA says fog is 1/4 mile
> visibility. Can anyone legally land in fog?
>

Cat III operations can and possibly Cat II as well.

Matt

[Peter Clark]

On 23 Nov 2005 13:12:22 -0800, wrote:

>Is there somewhere I can find out if this airport (KORH) has an
>appropriate Cat II or Cat III Approach?
>
>I thought I heard it was a Cat I.

11 and 29 at ORH are Cat 1's with minimum required 1/2 or 3/4 mile vis
respectively. I don't remember anything saying that the cause of the
low visibility changes the minimum required value (be it fog, snow,
rain, smoke, whatever) - as long as you have the required value you're
fine.

[Peter Clark]

On 23 Nov 2005 13:12:22 -0800, wrote:

>Is there somewhere I can find out if this airport (KORH) has an
>appropriate Cat II or Cat III Approach?
>
>I thought I heard it was a Cat I.

Sorry, not enough coffee today. ORH shouldn't (to my knowledge of the
regs) have anyone landing in 1/4 mi since 1/2 is the minimum for the
published approaches. They'd have to go to Bradley in CT, or Logan
for the nearest cat 2/3 approaches that I can think of/find off the
top of my head.

[Mike Rapoport]

ORH does not have a Cat II or III approach. Keep in mind that he visibility
that controls the approach is "flight visibility" not "ground visibility"
and when there is fog, flight visibility is usually greater than ground
visibility.

Most Cat II and III approaches are at major airports. One of the
requirements is that the runway must have centerline lighting which is
generally only found at the largest airports.

Mike
MU-2


> wrote in message
oups.com...
> Is there somewhere I can find out if this airport (KORH) has an
> appropriate Cat II or Cat III Approach?
>
> I thought I heard it was a Cat I.
>

[Peter Duniho]

> wrote in message
oups.com...
> Is there somewhere I can find out if this airport (KORH) has an
> appropriate Cat II or Cat III Approach?

Generally speaking, you can look at the A/FD information which is usually
up-to-date at www.airnav.com. If a Cat II or Cat III ILS approach is not
listed, then the airport isn't equipped for Cat II or Cat III approaches (I
think lighting and airport markings is the primary criteria).

Compare entries for major commercial airports, like KSEA, KLAX, or KLGA, to
see what an airport that does have Cat II and Cat III approaches looks like.

As far as your original question goes:

It is theoretically possible for an airplane to land using a Cat I approach
in fog. I don't know the exact cut-off to differentiate between "fog" and
"mist", but I doubt the article you're concerned about is actually using an
official definition. So, in the colloquial definition of "fog", visibility
could be anywhere from as much as a mile, maybe even more, to as low as 0
feet. A Cat I approach isn't sufficient for 0 visibility, but it's plenty
for 1 mile (and visibilities lower than that).

So...the answer to "can anyone legally land in fog" is "yes", even if the
airport has only a Cat I approach.

Pete

[The Visitor]

Lower may be approved, specific to the company. As are unpublished
approaches.

Peter Clark wrote:
> On 23 Nov 2005 13:12:22 -0800, wrote:
>
>
>>Is there somewhere I can find out if this airport (KORH) has an
>>appropriate Cat II or Cat III Approach?
>>
>>I thought I heard it was a Cat I.
>
>
> Sorry, not enough coffee today. ORH shouldn't (to my knowledge of the
> regs) have anyone landing in 1/4 mi since 1/2 is the minimum for the
> published approaches. They'd have to go to Bradley in CT, or Logan
> for the nearest cat 2/3 approaches that I can think of/find off the
> top of my head.

[Peter R.]

Mike Rapoport > wrote:

> Most Cat II and III approaches are at major airports. One of the
> requirements is that the runway must have centerline lighting which is
> generally only found at the largest airports.

Could the presence of a CAT II or III approach also be a function of a
greater occurrence of low visibility? My home airport, Syracuse (KSYR),
has a CAT II ILS, yet it is only a class C airport. During the winter we
experience heavy lake effect snow bands off Lake Ontario and I had
suspected that this was the reason for a CAT II ILS rather than its size.

--
Peter

[Robert M. Gary]

As someone who lives in fog and flys in it often, I say yes. Fog is
almost never uniform. The odds of the flight visibility being the same
as the tower reported vis is almost zero. Most of the time, I just
start to make out the runway lights nearing 100 feet AGL. Once at 100
AGL you can see A LOT more (probably because fog effect slant line
vis). Remember you can go down to 100 feet after seeing the rabbit. Its
kind of cool to look outside and see nothing but fog but a white
electric rabbit running back and forth!!

-Robert, Sacramento CA

[Tony]

Worth trying with a safety pilot while under the hood is to fly your
airplane all the way down a time or two. Full ILS to mins, keep the
localizer centered, maintain rate of decent. Sometime when everything
is stacked against you you may have to do something like that in real
life. It's a confidence builder knowing you can get down in near
zero/zero.

Mooneys with their low wings tell the pilot when they are a few feet
agl. I don't know how a Cessna would feel though.

[RK Henry]

On 23 Nov 2005 12:58:14 -0800, wrote:

>I read a report about a local airport with this statement:
>
>"With existing Instrument Landing System (ILS) technology, inclement
>weather, such as fog, is not a material obstacle to commercial service
>operations."
>
>I was under the impression that the FAA says fog is 1/4 mile
>visibility. Can anyone legally land in fog?

That raises another question: Who here has gotten the certification
for non-commercial Cat II? How difficult was the certification? Was it
worth the trouble? How difficult was it to maintain the currency? I've
thought it might be cool to be able to fly Cat II in a Cherokee, but I
doubt it's worth the trouble.

RK Henry

[Mike Rapoport]

It doesn't matter if the airspace around the airport is class C or B it only
matters if the requriements for the approach are met. Usually the hangup is
centerline lighting which is expensive to add. I'm sure that the airports
with frequent low weather are more likely to have the centerline lighting
although many airports in the PNW, including KBFI, do not have it.. I
suspect that there is an element of politics in who gets the money.

Mike
MU-2


"Peter R." > wrote in message
...
> Mike Rapoport > wrote:
>
>> Most Cat II and III approaches are at major airports. One of the
>> requirements is that the runway must have centerline lighting which is
>> generally only found at the largest airports.
>
> Could the presence of a CAT II or III approach also be a function of a
> greater occurrence of low visibility? My home airport, Syracuse (KSYR),
> has a CAT II ILS, yet it is only a class C airport. During the winter we
> experience heavy lake effect snow bands off Lake Ontario and I had
> suspected that this was the reason for a CAT II ILS rather than its size.
>
> --
> Peter

[Robert M. Gary]

If you are really landing 0/0 I would toss out the idea of trying to
flare. The glide slope is good down to 100 feet, after that it does
wacky. You would want to get the plane in a nose up attitude and a slow
decent rate and just wait for impact. Those of us that fly sea planes
were required to do that for our checkride. Berry Scheff wrote about
doing this during an ocean crossing flight.

-Robert (Mooney owner too)

[Robert M. Gary]

I"m not sure how you could know what the flight visibility was. I"ve
landed many times when tower is reporting 1/4 mile vis. There is no
requirement that you not land. The only FAA requirement is flight
visibility (which tower cannot measure). Since fog is almost never
uniform the odds that flight visibility are the same as tower
visibility is about as close to zero as you could get.

-Robert

[Bob Noel]

In article . com>,
"Robert M. Gary" > wrote:

> If you are really landing 0/0 I would toss out the idea of trying to
> flare. The glide slope is good down to 100 feet, after that it does
> wacky.

eh? For Cat III systems, the glide slope is good all the way to the runway.

--
Bob Noel
New NHL? what a joke

[Darrell S]

Robert M. Gary wrote:
> If you are really landing 0/0 I would toss out the idea of trying to
> flare. The glide slope is good down to 100 feet, after that it does
> wacky. You would want to get the plane in a nose up attitude and a
> slow decent rate and just wait for impact. Those of us that fly sea
> planes were required to do that for our checkride. Berry Scheff wrote
> about doing this during an ocean crossing flight.
>
> -Robert (Mooney owner too)

Naw. Autoland systems exchange crab to wing low at 150' AGL and at 50' AGL
the throttles come to idle and the aircraft enters Flare. At wheel spin up
it changes to "Roll Out" and continues to track the localizer centerline to
keep the aircraft on the runway. It makes beautiful landings.

--

Darrell R. Schmidt
B-58 Hustler History: http://members.cox.net/dschmidt1/
-

[Robert M. Gary]

Bob Noel wrote:
> In article . com>,
> "Robert M. Gary" > wrote:
>
> > If you are really landing 0/0 I would toss out the idea of trying to
> > flare. The glide slope is good down to 100 feet, after that it does
> > wacky.
>
> eh? For Cat III systems, the glide slope is good all the way to the runway.

I think you got lost in the thread. We've not talked about CAT III at
all in this part of the thread just flying an ILS down to the ground.
If you notice, some other trees from this thread moved off and talked
about cat III. You won't find any talk of CAT III going up the chain of
my post.

[Bob Noel]

In article . com>,
"Robert M. Gary" > wrote:

> > eh? For Cat III systems, the glide slope is good all the way to the runway.
>
> I think you got lost in the thread. We've not talked about CAT III at
> all in this part of the thread just flying an ILS down to the ground.
> If you notice, some other trees from this thread moved off and talked
> about cat III. You won't find any talk of CAT III going up the chain of
> my post.

ok.

But let me add that a Cat I glideslope could be ok down to runway, but usually
isn't. It just won't be flightchecked

--
Bob Noel
New NHL? what a joke

[Capt.Doug]

>"Robert M. Gary" wrote in message
>I"m not sure how you could know what the flight visibility was. I"ve
> landed many times when tower is reporting 1/4 mile vis. There is no
> requirement that you not land. The only FAA requirement is flight
> visibility (which tower cannot measure).

Air carriers are restricted to the 'reported' visibilty.

D.

[Capt.Doug]

>"Mike Rapoport" wrote in message
> It doesn't matter if the airspace around the airport is class C or B it
only
> matters if the requriements for the approach are met. Usually the hangup
is
> centerline lighting which is expensive to add. I'm sure that the airports
> with frequent low weather are more likely to have the centerline lighting
> although many airports in the PNW, including KBFI, do not have it.. I
> suspect that there is an element of politics in who gets the money.

The FAA's testing and evaluation center is located at ACY. They had a Cat II
installed but we couldn't use it because Cat II visibility requires SCMGS
and the taxiways didn't have centerline lighting. How's that for foresight?

D.

[Capt.Doug]

>"RK Henry" wrote in message
> That raises another question: Who here has gotten the certification
> for non-commercial Cat II? How difficult was the certification? Was it
> worth the trouble? How difficult was it to maintain the currency? I've
> thought it might be cool to be able to fly Cat II in a Cherokee, but I
> doubt it's worth the trouble.

Part 91 aircraft with an approach airspeed of less than 90 knots can be
approved for Cat II approaches. Print out AOPA's directions for this
certification before applying to the FAA because many inspectors won't know
what you are talking about. Staying current isn't much more work than
regular IFR currency.

D.

[Ron Rosenfeld]

On Thu, 24 Nov 2005 02:41:58 GMT, RK Henry >
wrote:

>On 23 Nov 2005 12:58:14 -0800, wrote:
>
>>I read a report about a local airport with this statement:
>>
>>"With existing Instrument Landing System (ILS) technology, inclement
>>weather, such as fog, is not a material obstacle to commercial service
>>operations."
>>
>>I was under the impression that the FAA says fog is 1/4 mile
>>visibility. Can anyone legally land in fog?
>
>That raises another question: Who here has gotten the certification
>for non-commercial Cat II? How difficult was the certification? Was it
>worth the trouble? How difficult was it to maintain the currency? I've
>thought it might be cool to be able to fly Cat II in a Cherokee, but I
>doubt it's worth the trouble.
>
>RK Henry

Paperwork took more time than the flight test.

Other than that, and the fact that I was the first to do it at my FSDO
(Portland, ME), it was not particularly difficult.

The recurrent flight checks (every 6 months with an FAA examiner) were
likewise easy to do.

I have not kept it up since I moved from KASH to KEPM.

In the three or four years that I maintained it, it was useful on one
occasion. And that was for obtaining an IFR clearance BGR-BOS at a time
when BOS was requiring that a/c headed there had to be able to land with an
RVR of 1200. (By the time we got to BOS, the visibility had improved to
1/2 mile).


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

[Al]

I had an waiver to go to 150' on a cat 1 approach for fog seeding. I had to
take a
check ride in the 182 with the FAA. It was an easy ride, and on one
appraoch, he kept me under the hood thru rollout. I regularly took off under
W0X0F conditions, (indefinite, 0 ceiling obscured, 0 visibility in fog.) We
could generally burn it out to 300 and a mile after 1 hour. (We poured a 1
pound coofee can full of ground up dry ice out of a hole in the belly,
during a 150' pass down the active.)

Al


"RK Henry" > wrote in message
...
> On 23 Nov 2005 12:58:14 -0800, wrote:
>
>>I read a report about a local airport with this statement:
>>
>>"With existing Instrument Landing System (ILS) technology, inclement
>>weather, such as fog, is not a material obstacle to commercial service
>>operations."
>>
>>I was under the impression that the FAA says fog is 1/4 mile
>>visibility. Can anyone legally land in fog?
>
> That raises another question: Who here has gotten the certification
> for non-commercial Cat II? How difficult was the certification? Was it
> worth the trouble? How difficult was it to maintain the currency? I've
> thought it might be cool to be able to fly Cat II in a Cherokee, but I
> doubt it's worth the trouble.
>
> RK Henry

[Morgans]

"Al" > wrote

> I had an waiver to go to 150' on a cat 1 approach for fog seeding.

> (We poured a 1 pound coofee can

Is that anything like a coffee can? <:-))

Really though, that sounds very interesting. What were the results of the
testing? Are tests still going on anywhere? Tell us more!
--
Jim in NC

[Al]

He he, you are right. It was very similar to a "Coffee" can, Folgers in
fact.

In Medford, Oregon, in the '70's and '80's, we flew fog seeding for
United Airlines. Equipment was a older C-182 with an inspection plate
removed in the center of the rear seat floor. We would grind up 15-20 lbs of
dry ice, and on repeated passes, pour 1 coffee can worth out the hole
through a dish pan, during a low approach. (The approaches were flown both
ways, front course to 150', climb to 800 agl, do a 90-270, and fly the
backcourse with no GS to 150' on the way back. Localizer flag indicated the
end of the runway).

If the conditions were right, we had great success. The fog had to be
between 33 and about 25 degrees for good results. We would seed for 20
minutes, wait for 20 minutes, and see results for about 20 minutes. (Later
known as the Bill Warren 20-20 rule of fog seeding) After 20 minutes of
seeding, (3-4 passes), it would snow on the ground for about 20 min. and the
visibility would improve. It was not uncommon to go from ceiling of 0 and an
RVR of less than 600 to 300 overcast and 1 mile. These results were very
local, just before you arrived at DH, you would bust into this "Clear
weather tube", the length of the runway.

This was "fascinating" flying. The first United flight in the morning was
due at 06:15, so one had to start seeding around 5:00. This, of course,
meant solid IFR at low altitude, at night, in a single engine airplane, in
icing conditions. With each pass, we would climb to VFR conditions, where
the temps were a lot higher, and burn off the Ice. I only did it for a year,
but there were pilots there like Bill, and George DiMartini that had done it
for years. Once on a training flight, I pulled an engine on George who
calmly shot a "No visibility" ILS to touchdown, deadstick.

I always felt more "lost" on the ground. After loading the aircraft, I would
start it, turn on the baggage light under the left wing, and put the left
main tire on the yellow taxi stripe. I would taxi out to the hold short
line, and shut it down for a minute while I climbed out and broke off the
3/4 inch of ice the prop had built up during taxi. Re-enter, re-start, and
taxi on a heading of 90 until the localizer for rwy32 centered, then a left
turn to 320, and depart.

Total pay was $15 per flight hour, so if you got 1 1/2 hours in the morning,
and the same in the evening(6:30pm departure), you could make almost $50 a
day before taxes. Instrument currency was never a problem, and you got
REALLY good at holding a heading.

Sometimes it almost seemed like a video game, or simulator. Once I had done
the twenty minutes of seeding, and the RVR was very slow coming up. United
was 30 North, so I decided to shorten my pattern, and drop a load right over
the RVR meter. After making a pass southbound, I started a left turn toward
the RVR meter and simply forgot to climb. Apparently there is a hill called
"Coker Butte" just east of the runway at Medford. It is about 100' high, and
passed under my left wing while I was in the turn. It has a white house with
a yellow bug light on the porch. There was a white 63-64 Chev Impala parked
in the driveway under the bug light, it had current Oregon plates.

Al






"Morgans" > wrote in message
...
>
> "Al" > wrote
>
>> I had an waiver to go to 150' on a cat 1 approach for fog seeding.
>
>> (We poured a 1 pound coofee can
>
> Is that anything like a coffee can? <:-))
>
> Really though, that sounds very interesting. What were the results of the
> testing? Are tests still going on anywhere? Tell us more!
> --
> Jim in NC
>

[Morgans]

"Al" > wrote

> Apparently there is a hill called
> "Coker Butte" just east of the runway at Medford. It is about 100' high,
and
> passed under my left wing while I was in the turn. It has a white house
with
> a yellow bug light on the porch. There was a white 63-64 Chev Impala
parked
> in the driveway under the bug light, it had current Oregon plates.

That story belongs in the big scare thread!

Is the procedure still widely used today?
--
Jim in NC

[David CL Francis]

On Fri, 25 Nov 2005 at 09:59:36 in message
<_hIhf.6632$Wu.5475@fed1read05>, Darrell S > wrote:

>Naw. Autoland systems exchange crab to wing low at 150' AGL and at 50' AGL
>the throttles come to idle and the aircraft enters Flare. At wheel spin up
>it changes to "Roll Out" and continues to track the localizer centerline to
>keep the aircraft on the runway. It makes beautiful landings.

I would have assumed that the flare depends mostly on the radar height
and not the glide slope. I don't see how glide slope alone can supply
the data on which to flare.

The change from crab to runway align according to information I have
regarding the 747-400, is that it takes place at 500 ft. The 50 ft
height for flare mode activation is confirmed in the same document.
--
David CL Francis