Today I awoke to find a cloud sitting on the ground bringing the vis down
to 1/16th of a mile. All the airlines here in KROC were forced to hold
from takeoff until it lifted a little. I know that the part 91 is 0/0
unless otherwise noted, what about part 131 or the airlines? Do they have
different takeoff mins? My next question is about the approach to
landing....if the wx during the landing was like this morning right, below
mins for sure (1/16th SM VV100), could a part 91 still attempt the approach
hopeing the was a hole in the scud and see the runway, but knowing its
below mins and will most likely go missed? What about the airlines and air
carriers, could they attempt the approach when the wx is below mins? I
guess what Im trying to ask is.....anyone allowed to attempt a approach
when the wx is below mins? What if the field is uncontrolled with an ILS
and does have AWOS reporting below mins. Does is matter if its controlled
or not? Im just wondering about this, dont get me wrong, I would NEVER
attempt a approach thats below mins. Just courious if its stated somewhere
in the FARS (I couldnt find it) about the approach to landing with below
mins WX.....thanks for the imput!

-Ben

jamin3508 wrote:
> Today I awoke to find a cloud sitting on the ground bringing the vis down
> to 1/16th of a mile. All the airlines here in KROC were forced to hold
> from takeoff until it lifted a little. I know that the part 91 is 0/0
> unless otherwise noted, what about part 131 or the airlines?

I couldn't find Part 131. If you mean parts 121 and 135, yes their rules are
different.

> Do they have
> different takeoff mins? My next question is about the approach to
> landing....if the wx during the landing was like this morning right, below
> mins for sure (1/16th SM VV100), could a part 91 still attempt the approach
> hopeing the was a hole in the scud and see the runway, but knowing its
> below mins and will most likely go missed?

Part 121/135 operators can't accept an approach clearance if the reported
weather is below minimums. "see the runway" is not sufficient for Part 91, either.

> What about the airlines and air
> carriers, could they attempt the approach when the wx is below mins?

No.

> I
> guess what Im trying to ask is.....anyone allowed to attempt a approach
> when the wx is below mins?

Part 91.

> What if the field is uncontrolled with an ILS
> and does have AWOS reporting below mins. Does is matter if its controlled
> or not?

No.

> Im just wondering about this, dont get me wrong, I would NEVER
> attempt a approach thats below mins.

Why wouldn't you? Are you operating under Part 121/135?

Just courious if its stated somewhere
> in the FARS (I couldnt find it) about the approach to landing with below
> mins WX.....thanks for the imput!

In article
utaviation.com>,
jamin3508 > wrote:

> Today I awoke to find a cloud sitting on the ground bringing the vis down
> to 1/16th of a mile. All the airlines here in KROC were forced to hold
> from takeoff until it lifted a little. I know that the part 91 is 0/0
> unless otherwise noted, what about part 131 or the airlines? Do they have
> different takeoff mins?

Part 121, I assume you mean, and yes, they have different takeoff mins.
At my company, we basically use the minimums on the Jeppesen charts.
It depends how the runway is equipped, but normally we need 1600RVR
(1/4mi) on a runway with standard takeoff minimums and adequate visual
references. In many places, we can take off with as low as 600 RVR,
but that requires multiple RVR sensors and a runway with centerline
lights. (Some operators can use 500RVR; 600 is as low as we can go.
It's in each specific airline's FAA ops specs.)

> My next question is about the approach to
> landing....if the wx during the landing was like this morning right, below
> mins for sure (1/16th SM VV100), could a part 91 still attempt the approach
> hopeing the was a hole in the scud and see the runway, but knowing its
> below mins and will most likely go missed?

Sticky area. You can definitely shoot the approach, but landing from
it could be problematic. The rules say "flight visibility," which you
can only really judge in-flight. Tower visibility really isn't a good
indicator of flight visibility, but RVR is a much more accurate view of
what you'll probably see from the cockpit.

I understand they *have* hung pilots out to dry for landing with RVR
below minimums. I don't have a specific cite for that, so it may be
urband legend. Perhaps someone can chime in on this one?

> What about the airlines and air
> carriers, could they attempt the approach when the wx is below mins?

No. If the visibility/RVR is below approach minimums, an air carrier
can't continue past the final approach point; he'd have to go missed at
that point if there wasn't a report of the visibility being at or above
the minimum. If touchdown zone RVR is available, it's the controlling
value that decides whether they can start the approach. If not, it's
visibility.

If they're already on the final approach segment and the visibility/RVR
goes down, they may continue the approach, but as far as landing goes,
we're back to "flight visibility." If the RVR is below minimums,
you're not likely to see the visual cues you need anyway. I'd continue
the approach and hope the reported RVR comes back up before DH, but a
missed approach is most likely at that point.

> I guess what Im trying to ask is.....anyone allowed to attempt a approach
> when the wx is below mins?

Yes, part 91 operators are completely free to attempt the approach, at
least down to DH.

> What if the field is uncontrolled with an ILS
> and does have AWOS reporting below mins. Does is matter if its controlled
> or not?

No, it doesn't matter. It's the only reported weather, which means if
it's reporting visibility below minimums, an air carrier can't fly the
approach. My company serves a couple of uncontrolled airports, and we
run into that from time to time. But a part 91 aircraft can start the
approach, definitely.

At an uncontrolled airport with an AWOS reporting below minimums, I'd
absolutely try the approach under part 91, because the visibility of an
AWOS is not often a good indicator of what you'll see. Flight
visibility may be just fine on the runway, often because it's on a
different part of the airport from the AWOS visibility measurement.
I've often seen a fog bank covering just half an airport, leaving most
of my landing runway completely clear.

> Im just wondering about this, dont get me wrong, I would NEVER
> attempt a approach thats below mins. Just courious if its stated somewhere
> in the FARS (I couldnt find it) about the approach to landing with below
> mins WX.....thanks for the imput!

The specific FAR is 91.175. It says an aircraft may not descent below
DH/MDA unless, among other things, "The flight visibility is not less
than the visibility prescribed in the standard instrument approach
being used." But it says nothing about *starting* the approach;
that's specific to air carrier operations. You're perfectly legal to
fly the approach; you just need to meet that reg in order to continue
past the bottom of the approach.

Hope that hhelps.

--
Garner R. Miller
ATP/CFII/MEI
Clifton Park, NY =USA=

I've shot approaches below minimums many times. I fly down to the fog
valley when vis is 0/0 and just shot approaches. Its good practice.

If you actually land and the approach calls for both a flight
visibility minimum AND lists an RVR minimum you could probably get in
trouble for landing when the RVR is reported below those mins.

-Robert

One addition to other posters comments on going below DH. You can go below
DH without having the runway in sight if you have the runway environment
(approach lighting system) is sight. You are authorized (91 and 135) to 100
feet. At 100 feet you must have the runway (which can mean only the end
lights of the runway) in sight.

Our FSDO operations inspector wants us to set 100 feet on the radar
altimeter because that is the absolute lowest you can go on a typical
approach. Many pilots prefer the DH AGL altitude set on the radalt.

Paul
"jamin3508" > wrote in message
lkaboutaviation.com...
> Today I awoke to find a cloud sitting on the ground bringing the vis down
> to 1/16th of a mile. All the airlines here in KROC were forced to hold
> from takeoff until it lifted a little. I know that the part 91 is 0/0
> unless otherwise noted, what about part 131 or the airlines? Do they have
> different takeoff mins? My next question is about the approach to
> landing....if the wx during the landing was like this morning right, below
> mins for sure (1/16th SM VV100), could a part 91 still attempt the
> approach
> hopeing the was a hole in the scud and see the runway, but knowing its
> below mins and will most likely go missed? What about the airlines and air
> carriers, could they attempt the approach when the wx is below mins? I
> guess what Im trying to ask is.....anyone allowed to attempt a approach
> when the wx is below mins? What if the field is uncontrolled with an ILS
> and does have AWOS reporting below mins. Does is matter if its controlled
> or not? Im just wondering about this, dont get me wrong, I would NEVER
> attempt a approach thats below mins. Just courious if its stated somewhere
> in the FARS (I couldnt find it) about the approach to landing with below
> mins WX.....thanks for the imput!
>
> -Ben
>

"jamin3508" > wrote in
lkaboutaviation.com:

> just wondering about this, dont get me wrong, I would NEVER attempt a
> approach thats below mins. Just courious if its stated somewhere in
> the FARS (I couldnt find it) about the approach to landing with below
> mins WX.....thanks for the imput!

Part 135 and Part 121 takeoff and landing minima are given in the
operations specifications of each certificate holder. Generally the
approach minima are whatever is published, but it can vary. Our ops
specs permit flying an ILS with 1/4 mile vis (in helicopters) and
takeoffs with 'adequate visibility reference' from a runway, meaning with
whatever visibility allows seeing the runway during the takeoff. It's
generally higher for airplanes. We can take off with 1/2 mile vis from
offshore platforms, and fly the approach with 3/4 mile vis. We also
cannot fly an approach to any airport that does not have official weather
reporting, regardless of the weather.

--
Regards,

Stan

"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety." B. Franklin

"Paul Lynch" > wrote

> One addition to other posters comments on going below DH. You can go
> below DH without having the runway in sight if you have the runway
> environment (approach lighting system) is sight. You are authorized
> (91 and 135) to 100 feet. At 100 feet you must have the runway (which
> can mean only the end lights of the runway) in sight.

I don't think that you fully understand 91.175....

(3) Except for a Category II or Category III approach where any
necessary visual reference requirements are specified by the
Administrator, at least one of the following visual references for the
intended runway is distinctly visible and identifiable to the pilot:

(i) The approach light system, except that the pilot may not descend
below 100 feet above the touchdown zone elevation using the approach
lights as a reference unless the red terminating bars or the red side
row bars are also distinctly visible and identifiable.

(ii) The threshold.

(iii) The threshold markings.

(iv) The threshold lights.

(v) The runway end identifier lights.

(vi) The visual approach slope indicator.

(vii) The touchdown zone or touchdown zone markings.

(viii) The touchdown zone lights.

(ix) The runway or runway markings.

(x) The runway lights.


It says that I can go below 100' on the approach lights only, if I
have either the red terminating bars or red side row bars visible.
The 100' limit is not applicable if I have any of the items (ii)
thru (x) in sight, ie, I can descend below DH with only the VASI
in sight or...the REILS for that matter.

Bob Moore
ATP CFI
PanAm (retired)

I guess I miss your point Bob. I don't think I said anything that conflicts
with 91.175. I am ready to be educated, for me that process is painfully
endless.

"Bob Moore" > wrote in message
. 122...
> "Paul Lynch" > wrote
>
>> One addition to other posters comments on going below DH. You can go
>> below DH without having the runway in sight if you have the runway
>> environment (approach lighting system) is sight. You are authorized
>> (91 and 135) to 100 feet. At 100 feet you must have the runway (which
>> can mean only the end lights of the runway) in sight.
>
> I don't think that you fully understand 91.175....
>
> (3) Except for a Category II or Category III approach where any
> necessary visual reference requirements are specified by the
> Administrator, at least one of the following visual references for the
> intended runway is distinctly visible and identifiable to the pilot:
>
> (i) The approach light system, except that the pilot may not descend
> below 100 feet above the touchdown zone elevation using the approach
> lights as a reference unless the red terminating bars or the red side
> row bars are also distinctly visible and identifiable.
>
> (ii) The threshold.
>
> (iii) The threshold markings.
>
> (iv) The threshold lights.
>
> (v) The runway end identifier lights.
>
> (vi) The visual approach slope indicator.
>
> (vii) The touchdown zone or touchdown zone markings.
>
> (viii) The touchdown zone lights.
>
> (ix) The runway or runway markings.
>
> (x) The runway lights.
>
>
> It says that I can go below 100' on the approach lights only, if I
> have either the red terminating bars or red side row bars visible.
> The 100' limit is not applicable if I have any of the items (ii)
> thru (x) in sight, ie, I can descend below DH with only the VASI
> in sight or...the REILS for that matter.
>
> Bob Moore
> ATP CFI
> PanAm (retired)

"Paul Lynch" > wrote

> I guess I miss your point Bob. I don't think I said anything that
> conflicts with 91.175. I am ready to be educated, for me that process
> is painfully endless.

Well....you said:
" At 100 feet you must have the runway (which can mean only the end
lights of the runway) in sight."

I mearly pointed out that you do not have to have the runway (nor the
end lights of the runway) in sight. The Touchdown Zone Markings will do
quite well as will the VASI and obviously... the Runway Markings.

Bob Moore

On Fri, 09 Sep 2005 20:40:16 GMT, Bob Moore >
wrote:

>"Paul Lynch" > wrote
>
>> One addition to other posters comments on going below DH. You can go
>> below DH without having the runway in sight if you have the runway
>> environment (approach lighting system) is sight. You are authorized
>> (91 and 135) to 100 feet. At 100 feet you must have the runway (which
>> can mean only the end lights of the runway) in sight.
>
>I don't think that you fully understand 91.175....
>
>(3) Except for a Category II or Category III approach where any
>necessary visual reference requirements are specified by the
>Administrator, at least one of the following visual references for the
>intended runway is distinctly visible and identifiable to the pilot:
>
>(i) The approach light system, except that the pilot may not descend
>below 100 feet above the touchdown zone elevation using the approach
>lights as a reference unless the red terminating bars or the red side
>row bars are also distinctly visible and identifiable.
>
>(ii) The threshold.
>
>(iii) The threshold markings.
>
>(iv) The threshold lights.
>
>(v) The runway end identifier lights.
>
>(vi) The visual approach slope indicator.
>
>(vii) The touchdown zone or touchdown zone markings.
>
>(viii) The touchdown zone lights.
>
>(ix) The runway or runway markings.
>
>(x) The runway lights.
>
>
>It says that I can go below 100' on the approach lights only, if I
>have either the red terminating bars or red side row bars visible.
>The 100' limit is not applicable if I have any of the items (ii)
>thru (x) in sight, ie, I can descend below DH with only the VASI
>in sight or...the REILS for that matter.
>
>Bob Moore
>ATP CFI
>PanAm (retired)

And don't forget 91.175(c)(2) which says that in order to operate below DH,
you ALSO need to have "the visibility prescribed in the standard instrument
approach being used".


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

>>It says that I can go below 100' on the approach lights only, if I
>>have either the red terminating bars or red side row bars visible.
>>The 100' limit is not applicable if I have any of the items (ii)
>>thru (x) in sight, ie, I can descend below DH with only the VASI
>>in sight or...the REILS for that matter.
>>
>>Bob Moore
>>ATP CFI
>>PanAm (retired)
>
>
> And don't forget 91.175(c)(2) which says that in order to operate below DH,
> you ALSO need to have "the visibility prescribed in the standard instrument
> approach being used".
>
>
> Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

The approach light aspect of the rule presumes you will acquire at least
one other of the runway visual cues prior to crossing the threshold
because you will be unable to see the ALS by that point (unless you have
a rear view mirror ;-)

On Sat, 10 Sep 2005 12:59:19 GMT, Tim > wrote:

>
>>>It says that I can go below 100' on the approach lights only, if I
>>>have either the red terminating bars or red side row bars visible.
>>>The 100' limit is not applicable if I have any of the items (ii)
>>>thru (x) in sight, ie, I can descend below DH with only the VASI
>>>in sight or...the REILS for that matter.
>>>
>>>Bob Moore
>>>ATP CFI
>>>PanAm (retired)
>>
>>
>> And don't forget 91.175(c)(2) which says that in order to operate below DH,
>> you ALSO need to have "the visibility prescribed in the standard instrument
>> approach being used".
>>
>>
>> Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)
>
>The approach light aspect of the rule presumes you will acquire at least
>one other of the runway visual cues prior to crossing the threshold
>because you will be unable to see the ALS by that point (unless you have
> a rear view mirror ;-)

You still need the flight visibility specified in the approach, if you are
below DH/MDA, don't you?

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

Ron Rosenfeld wrote:

>
> You still need the flight visibility specified in the approach, if you are
> below DH/MDA, don't you?
>
>
Absolutely, and continuously until touching down.

In article >,
Tim > wrote:

> Ron Rosenfeld wrote:
>
> >
> > You still need the flight visibility specified in the approach, if you are
> > below DH/MDA, don't you?
> >
> >
> Absolutely, and continuously until touching down.

Let's say the required vis is 2 miles. Reported weather is 3 miles, and
sure enough, you spot the field 3 miles away. By the time you're on 1/2
mile final, it starts to rain and the visibility goes down to 1 mile, but
you can still see the runway clearly. Are you really required to go missed
at that point?

On Sat, 10 Sep 2005 18:41:28 -0400, Roy Smith > wrote:

>In article >,
> Tim > wrote:
>
>> Ron Rosenfeld wrote:
>>
>> >
>> > You still need the flight visibility specified in the approach, if you are
>> > below DH/MDA, don't you?
>> >
>> >
>> Absolutely, and continuously until touching down.
>
>Let's say the required vis is 2 miles. Reported weather is 3 miles, and
>sure enough, you spot the field 3 miles away. By the time you're on 1/2
>mile final, it starts to rain and the visibility goes down to 1 mile, but
>you can still see the runway clearly. Are you really required to go missed
>at that point?

Yes, but *MY* flight visibility was 2 miles at that point. *I* could see
past the far end of the runway. (That's my story and I'm sticking to it).




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

Roy Smith wrote:
> In article >,
> Tim > wrote:
>
>
>>Ron Rosenfeld wrote:
>>
>>
>>>You still need the flight visibility specified in the approach, if you are
>>>below DH/MDA, don't you?
>>>
>>>
>>
>>Absolutely, and continuously until touching down.
>
>
> Let's say the required vis is 2 miles. Reported weather is 3 miles, and
> sure enough, you spot the field 3 miles away. By the time you're on 1/2
> mile final, it starts to rain and the visibility goes down to 1 mile, but
> you can still see the runway clearly. Are you really required to go missed
> at that point?

Legally, yes. But, with high minimums like those you cite, most pilots
would land. The regulation is written with the typical minimums in
mind; i.e. 3/4 or 1 mile (and lower with ALS).

Paul Lynch wrote:
> One addition to other posters comments on going below DH. You can go below
> DH without having the runway in sight if you have the runway environment
> (approach lighting system) is sight. You are authorized (91 and 135) to 100
> feet. At 100 feet you must have the runway (which can mean only the end
> lights of the runway) in sight.
>
> Our FSDO operations inspector wants us to set 100 feet on the radar
> altimeter because that is the absolute lowest you can go on a typical
> approach. Many pilots prefer the DH AGL altitude set on the radalt.
>
Alas, so many FSDO inspectors do not really understand the regulations
and they refuse to use FAA headquarters resources that are there to
"assist."

If your inspector went to AFS-410 (All-weather ops branch) and told them
what he is recommending, they would tell him that he is, in effect,
creating a second DA, which is contrary to the minimums in the SIAP.

Paul Lynch wrote:

> I guess I miss your point Bob. I don't think I said anything that conflicts
> with 91.175. I am ready to be educated, for me that process is painfully
> endless.

Bob is making a distinction that has no practical effect. If you're on
G/S and much below 100 feet you can't see any part of the ALS system
because it is directly below you rapidly passing behind you. Thus, you
will have to see one of the other runway cues or begin the miss approach.

Not really. The minimums don't change. He is suggesting a radalt
technique, one which I do not concur with. His suggestion does comply with
the regs, but adds complexity to an already complex situation (ceiling right
at decision height and actual viz right at mins, possibly lower).

Despite all the yelling about landing below the measured mins, if the pilot
sees the lights he can continue below the DH, and below 100'AGL with the
necessary visual cues. Those visual cues might not be there in the daytime,
but may be there at night because of a bigl approach light system.

The FAA would have a hard time busting a pilot who says he saw the required
items no matter what the RVR machine was saying. The pilot's inflight
visibility should be controlling (not that the Feds haven't tried to make
their power known in this case).


"Tim" > wrote in message
nk.net...
> Paul Lynch wrote:
>> One addition to other posters comments on going below DH. You can go
>> below DH without having the runway in sight if you have the runway
>> environment (approach lighting system) is sight. You are authorized (91
>> and 135) to 100 feet. At 100 feet you must have the runway (which can
>> mean only the end lights of the runway) in sight.
>>
>> Our FSDO operations inspector wants us to set 100 feet on the radar
>> altimeter because that is the absolute lowest you can go on a typical
>> approach. Many pilots prefer the DH AGL altitude set on the radalt.
>>
> Alas, so many FSDO inspectors do not really understand the regulations and
> they refuse to use FAA headquarters resources that are there to "assist."
>
> If your inspector went to AFS-410 (All-weather ops branch) and told them
> what he is recommending, they would tell him that he is, in effect,
> creating a second DA, which is contrary to the minimums in the SIAP.

Paul Lynch wrote:
> Not really. The minimums don't change. He is suggesting a radalt
> technique, one which I do not concur with. His suggestion does comply with
> the regs, but adds complexity to an already complex situation (ceiling right
> at decision height and actual viz right at mins, possibly lower).

"Not really" is the operative phrase. Does it or does it not modify
minimums. It can be argued both ways. And, the use of a radar
altitmeter at such a critically low height without an "RA" survey
further muddies the waters.

First, I am not defending the technique, only trying to explain the POI's
position.

Second, the minumums don't change. No need to get lawerly on me.

Third, the FAA muddies the waters by creating a situation where you can go
below DH to 100' above the touchdown zone without actually having the runway
insight. How you manage that is clearly technique, and not something I
would even think of attempting in a single pilot aircraft. Even with two
pilots, the technique must be briefed and coordinated or it is likely to be
more dangerous than just going missed.


> wrote in message
ink.net...
> Paul Lynch wrote:
>> Not really. The minimums don't change. He is suggesting a radalt
>> technique, one which I do not concur with. His suggestion does comply
>> with the regs, but adds complexity to an already complex situation
>> (ceiling right at decision height and actual viz right at mins, possibly
>> lower).
>
> "Not really" is the operative phrase. Does it or does it not modify
> minimums. It can be argued both ways. And, the use of a radar altitmeter
> at such a critically low height without an "RA" survey further muddies the
> waters.

Paul Lynch wrote:
> First, I am not defending the technique, only trying to explain the POI's
> position.
>
> Second, the minumums don't change. No need to get lawerly on me.

Well, this issue was raised and put to bed on my airline quite a few
years ago. So, you see it one way at your carrier, my carrier saw it
differently. ALPA's All-Weather Flying Committee viewed it at the time
as a second DA, and FAA Washington agreed at the time.
>
> Third, the FAA muddies the waters by creating a situation where you can go
> below DH to 100' above the touchdown zone without actually having the runway
> insight. How you manage that is clearly technique, and not something I
> would even think of attempting in a single pilot aircraft. Even with two
> pilots, the technique must be briefed and coordinated or it is likely to be
> more dangerous than just going missed.

I wouldn't even know how to apply it on a Cat I ILS or NPA.
>

And that is why we are politely ignoring the POI. He has other crazy ideas
at times too.


> wrote in message
k.net...
> Paul Lynch wrote:
>> First, I am not defending the technique, only trying to explain the POI's
>> position.
>>
>> Second, the minumums don't change. No need to get lawerly on me.
>
> Well, this issue was raised and put to bed on my airline quite a few years
> ago. So, you see it one way at your carrier, my carrier saw it
> differently. ALPA's All-Weather Flying Committee viewed it at the time as
> a second DA, and FAA Washington agreed at the time.
>>
>> Third, the FAA muddies the waters by creating a situation where you can
>> go below DH to 100' above the touchdown zone without actually having the
>> runway insight. How you manage that is clearly technique, and not
>> something I would even think of attempting in a single pilot aircraft.
>> Even with two pilots, the technique must be briefed and coordinated or it
>> is likely to be more dangerous than just going missed.
>
> I wouldn't even know how to apply it on a Cat I ILS or NPA.
>>