Does anyone consider it somewhat dangerous that at your alternate
airport, the weather can be forecast to be as low as your alternate
minimums? Seems the potential for problems.

For example, using Carlsad California CRQ as the planned alternate,
where the VOR-A is the approach you plan to fly if necessary (assume
the ils is out). For a cat C aircraft, the alternate minimums are
1000 and 3. The approach minimums are 972 feet height above airfield,
and 3 miles without dme.

So is this all ok?

Stan

> wrote:
> Does anyone consider it somewhat dangerous that at your alternate
> airport, the weather can be forecast to be as low as your alternate
> minimums? Seems the potential for problems.

There are lots of stupidities in the alternate rules. For example,
there's no requirement that your alternate "make sense".

Around here, BDR and HVN are about 10 miles apart, both right on the
edge of the water. What's happening at one weather-wise is pretty
much guaranteed to be happening at the other. Yet, it's perfectly
legal for me to file IFR to one and use the other as my alternate.
Legal, but pointless.

When I'm picking an alternate, my goal is to find someplace that I'm
damned sure I can get into if my destination goes down. That implies
a much more conservative approach than just meeting the letter of the
law.

On Wed, 06 Apr 2005 15:33:21 GMT, wrote:

>Does anyone consider it somewhat dangerous that at your alternate
>airport, the weather can be forecast to be as low as your alternate
>minimums? Seems the potential for problems.
>
>For example, using Carlsad California CRQ as the planned alternate,
>where the VOR-A is the approach you plan to fly if necessary (assume
>the ils is out). For a cat C aircraft, the alternate minimums are
>1000 and 3. The approach minimums are 972 feet height above airfield,
>and 3 miles without dme.
>
>So is this all ok?
>
>Stan
>
>


How about this approach:

(a) Plan your flight to get to your destination, and then to some
other airport where you are very comfortable that you can get in,
without regard to whether it's a "legal" alternate or not. Calculate
the fuel requirement plus one hour (or maybe 2, whatever makes you
comfortable)

(b) Plan another flight using a legal alternate. Calculate the fuel
requirement plus 45 minutes.

If you cannot carry enough fuel to meet the greater of (a) or (b),
don't go.

In Canada, the alternate weather minimums are the same 600/2 and 800/2
as the US, but also 300 ft and 1 mile above the mda/dh and vis.
Whichever is greater. Your point about 2 places with the same weather
phenomena is well taken.
Stan

On 6 Apr 2005 11:49:53 -0400, (Roy Smith) wrote:

>
>There are lots of stupidities in the alternate rules. For example,
>there's no requirement that your alternate "make sense".
>

You are not required to go to your filed alternate if you cannot get into
your destination; ATC has no idea of what you filed as an alternate. What is
the problem??

Bob Gardner

> wrote in message
...
> Does anyone consider it somewhat dangerous that at your alternate
> airport, the weather can be forecast to be as low as your alternate
> minimums? Seems the potential for problems.
>
> For example, using Carlsad California CRQ as the planned alternate,
> where the VOR-A is the approach you plan to fly if necessary (assume
> the ils is out). For a cat C aircraft, the alternate minimums are
> 1000 and 3. The approach minimums are 972 feet height above airfield,
> and 3 miles without dme.
>
> So is this all ok?
>
> Stan
>
>
>
>

wrote in news:kru751l8bu0ve04b4j7gnfdqh2rk39hjlh@
4ax.com:

> Does anyone consider it somewhat dangerous that at your alternate
> airport, the weather can be forecast to be as low as your alternate
> minimums? Seems the potential for problems.

But that's the definition of alternate minimums - the weather must be
forecast to be at least as good as the alternate minimums.

> For example, using Carlsad California CRQ as the planned alternate,
> where the VOR-A is the approach you plan to fly if necessary (assume
> the ils is out). For a cat C aircraft, the alternate minimums are
> 1000 and 3. The approach minimums are 972 feet height above airfield,
> and 3 miles without dme.

Why assume the ILS is out? If it's out, the alternate minimums should be
higher. If the permitted approach minimums are 972/3, then that's why
the alternate minimums are 1000/3, obviously.

> So is this all ok?

Why wouldn't it be? Maybe I'm misunderstanding your question, but I
don't see a problem with any of this, just from your post, no other
information available.

--
Regards,

Stan

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

> Around here, BDR and HVN are about 10 miles apart, both right on the
> edge of the water. What's happening at one weather-wise is pretty
> much guaranteed to be happening at the other. Yet, it's perfectly
> legal for me to file IFR to one and use the other as my alternate.
> Legal, but pointless.
>
> When I'm picking an alternate, my goal is to find someplace that I'm
> damned sure I can get into if my destination goes down. That implies
> a much more conservative approach than just meeting the letter of the
> law.

Sometimes I encounter the opposite problem - there's no real danger of being
left without a safe place to go, but it's hard to find a legal alternate
within range. This can happen in the summer when there's a slight chance of
thunderstorms over a large area. All the forecasts include something like
"TEMPO ceiling 500, visibility 1 in heavy rain showers," making them
unavailable as alternates, but since the storms are only scattered, there's
very little chance that all the airports will be unusable at the same time.

Stan, here in Canada, the forecast weather at your alternate must be
at least 300 feet and 1 mile above the approach minimums (or 600/2 or
800/2, whichever is higher). Supposedly to help ensure you can make
it in at your alternate. A kind of buffer.
I was just surprised to see that in the US, there are no such
additives.
And so, the alternate weather limits in the US can be the same as the
approach limits, in a very **FEW** cases.
CRQ was an example I found.
As an explanation to why it is only in a "few" cases, I notice in the
US that alternate weather limits must be at or above circling approach
limits too. And so, **normally** you find straight in approach limits
are less that alternate weather limits.
Canada does not have that circling minimums requirement as part of
alternate weather requirements.

On 07 Apr 2005 04:26:10 GMT, Stan Gosnell > wrote:

wrote in news:kru751l8bu0ve04b4j7gnfdqh2rk39hjlh@
>4ax.com:
>
>> Does anyone consider it somewhat dangerous that at your alternate
>> airport, the weather can be forecast to be as low as your alternate
>> minimums? Seems the potential for problems.
>
>But that's the definition of alternate minimums - the weather must be
>forecast to be at least as good as the alternate minimums.
>
>> For example, using Carlsad California CRQ as the planned alternate,
>> where the VOR-A is the approach you plan to fly if necessary (assume
>> the ils is out). For a cat C aircraft, the alternate minimums are
>> 1000 and 3. The approach minimums are 972 feet height above airfield,
>> and 3 miles without dme.
>
>Why assume the ILS is out? If it's out, the alternate minimums should be
>higher. If the permitted approach minimums are 972/3, then that's why
>the alternate minimums are 1000/3, obviously.
>
>> So is this all ok?
>
>Why wouldn't it be? Maybe I'm misunderstanding your question, but I
>don't see a problem with any of this, just from your post, no other
>information available.

I think it's better to require the forecast weather to protect the
highest minimums published (for the procedure) than to add an arbitrary
300' buffer. It's better for the pilot to determine what kind of buffer
he would like to add, if any, than to have the government decide what
your buffer should be. Some pilots would be comfortable with no buffer,
while others may want a much higher buffer than 300 ft.
Right now the alternate minimums in the USA are determined by using a
standard value based on the type of approach being flown, or a ceiling
and visibility exceeding the highest circling minima for that
procedure/category, whichever is higher.
You can always add 300 ft to that value if you prefer, but why force it
on all other pilots?
The only time it would be dangerous is if both the primary and alternate
airports had drastic weather changes that made the field below minimums.
That could happen whether you had the USA alternate minimums, or
Canadian minimums (extra 300').
Another alternative is to pick an airport for an alternate that allows
straight in procedures for the equipment you have, that would give you
extra ceiling/vis to play with.

JPH


wrote:
> Stan, here in Canada, the forecast weather at your alternate must be
> at least 300 feet and 1 mile above the approach minimums (or 600/2 or
> 800/2, whichever is higher). Supposedly to help ensure you can make
> it in at your alternate. A kind of buffer.
> I was just surprised to see that in the US, there are no such
> additives.
> And so, the alternate weather limits in the US can be the same as the
> approach limits, in a very **FEW** cases.
> CRQ was an example I found.
> As an explanation to why it is only in a "few" cases, I notice in the
> US that alternate weather limits must be at or above circling approach
> limits too. And so, **normally** you find straight in approach limits
> are less that alternate weather limits.
> Canada does not have that circling minimums requirement as part of
> alternate weather requirements.
>
> On 07 Apr 2005 04:26:10 GMT, Stan Gosnell > wrote:
>
>
wrote in news:kru751l8bu0ve04b4j7gnfdqh2rk39hjlh@
>>4ax.com:
>>
>>
>>>Does anyone consider it somewhat dangerous that at your alternate
>>>airport, the weather can be forecast to be as low as your alternate
>>>minimums? Seems the potential for problems.
>>
>>But that's the definition of alternate minimums - the weather must be
>>forecast to be at least as good as the alternate minimums.
>>
>>
>>>For example, using Carlsad California CRQ as the planned alternate,
>>>where the VOR-A is the approach you plan to fly if necessary (assume
>>>the ils is out). For a cat C aircraft, the alternate minimums are
>>>1000 and 3. The approach minimums are 972 feet height above airfield,
>>>and 3 miles without dme.
>>
>>Why assume the ILS is out? If it's out, the alternate minimums should be
>>higher. If the permitted approach minimums are 972/3, then that's why
>>the alternate minimums are 1000/3, obviously.
>>
>>
>>>So is this all ok?
>>
>>Why wouldn't it be? Maybe I'm misunderstanding your question, but I
>>don't see a problem with any of this, just from your post, no other
>>information available.
>
>

wrote in
:

> Stan, here in Canada, the forecast weather at your alternate must be
> at least 300 feet and 1 mile above the approach minimums (or 600/2 or
> 800/2, whichever is higher). Supposedly to help ensure you can make
> it in at your alternate. A kind of buffer.
> I was just surprised to see that in the US, there are no such
> additives.
> And so, the alternate weather limits in the US can be the same as the
> approach limits, in a very **FEW** cases.
> CRQ was an example I found.
> As an explanation to why it is only in a "few" cases, I notice in the
> US that alternate weather limits must be at or above circling approach
> limits too. And so, **normally** you find straight in approach limits
> are less that alternate weather limits.
> Canada does not have that circling minimums requirement as part of
> alternate weather requirements.

In general, airports use standard alternate minimums, and the required
alternate minimums are listed on the back of the airport diagram. I must
confess that I really haven't read or worried about Part 91 alternate
minimums in a very long time, because I don't use them. My alternate
minimums are in my ops manual and ops specs. We add 200' to the
published approach minimum altitude for the approach we intend to use,
and use either 1 mile vis or published, whichever is higher, and only are
required to have 30 minutes reserve at the alternate. So for most
airports with an ILS, the alternate minimums are 400/1. As you can see,
there isn't a huge margin for error here. Fortunately, a diversion to
the alternate is rare, since we can cut the published visibility in half,
and since it's legal to descend to 100' above the TDZE with the approach
lights in sight, a miss off the ILS is seldom required, especially at
night, and I have never done one except on checkrides.

Flying a spam can for pleasure rather than profit is a very different
thing, though.

--
Regards,

Stan

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

Bob Gardner wrote:
> You are not required to go to your filed alternate if you cannot get into
> your destination; ATC has no idea of what you filed as an alternate. What is
> the problem??
>
The role of an alternate is to determine your minimum fuel requirements more
than any other practical use.

> So is this all ok?
>
> Stan

Usually yes. Keep in mind, your FILED alternate does not have to be the
actual field you divert to. You simply have to have "ON PAPER" a field
that is within your capabilities (fuel) and specified weather conditions.

There may be DOZENS of other fields nearby/in range that are safe and
useable, but are unable to be listed as legal alternates.

I say usually. A big part of this decision is what the weather is across
the region. Is the entire region socked in low/hard or is there a
localized weather phenom that will move on/clear up/etc?

From a legal standpoint, its good to go. From a safety standpoint, its
all relative. If it doesnt worsen, its just as safe as any other IFR
flight to near minimums. If the whole region is blanketed by low clouds
you may shut yourself out.

With regards to your example (assuming ILS our at Carlsbad), as a
general rule, I would want to have an alternate that had a working ILS
with good precision minimums available to me, so that there is a large
margin between the higher "alternate" minimums and the actual minimums
that I will fly the approach to.

Dave

I always like to have a very good VFR alternate I can find
with nothing more than a working compass and clock. I
probably would not go to a filed alternate unless I had a
total radio/electrical failure. Often the airport at my
destination with the lowest minimums isn't the airport where
the cars are parked. Also, often in the foggy season, the
entire plains and Mississippi Valley are at a steady and
stable 400 feet and 1-2 miles in fog and stratus. The
nearest airport with alternate minimums (600-2 or 800-2) may
be several hundred miles away, which means that a big
turbo-prop or jet is needed just to fly from Wichita to
Kansas City, since the alternate is beyond fuel range.


--
James H. Macklin
ATP,CFI,A&P

--
The people think the Constitution protects their rights;
But government sees it as an obstacle to be overcome.
some support
http://www.usdoj.gov/olc/secondamendment2.htm
See http://www.fija.org/ more about your rights and duties.


"Dave S" > wrote in message
et...
|
| > So is this all ok?
| >
| > Stan
|
| Usually yes. Keep in mind, your FILED alternate does not
have to be the
| actual field you divert to. You simply have to have "ON
PAPER" a field
| that is within your capabilities (fuel) and specified
weather conditions.
|
| There may be DOZENS of other fields nearby/in range that
are safe and
| useable, but are unable to be listed as legal alternates.
|
| I say usually. A big part of this decision is what the
weather is across
| the region. Is the entire region socked in low/hard or is
there a
| localized weather phenom that will move on/clear up/etc?
|
| From a legal standpoint, its good to go. From a safety
standpoint, its
| all relative. If it doesnt worsen, its just as safe as any
other IFR
| flight to near minimums. If the whole region is blanketed
by low clouds
| you may shut yourself out.
|
| With regards to your example (assuming ILS our at
Carlsbad), as a
| general rule, I would want to have an alternate that had a
working ILS
| with good precision minimums available to me, so that
there is a large
| margin between the higher "alternate" minimums and the
actual minimums
| that I will fly the approach to.
|
| Dave

File what you have to, fly what you need to. Let's not try to solve
decision making issues with regulation.

-Robert

This issue is raised in AIM 5.1.9(b) anyway:

b. The FAA has identified three possible situations where the failure
to plan for an alternate airport when flying IFR to such a destination
airport could result in a critical situation if the weather is less
than forecast and sufficient fuel is not available to proceed to a
suitable airport.
1. An IFR flight to an airport where the Minimum Descent Altitudes
(MDAs) or landing visibility minimums for all instrument approaches are
higher than the forecast weather minimums specified in 14 CFR Section
91.167(b). For example, there are 3 high altitude airports in the U.S.
with approved instrument approach procedures where all of the MDAs are
greater than 2,000 feet and/or the landing visibility minimums are
greater than 3 miles (Bishop, California; South Lake Tahoe, California;
and Aspen-Pitkin Co./Sardy Field, Colorado). In the case of these
airports, it is possible for a pilot to elect, on the basis of
forecasts, not to carry sufficient fuel to get to an alternate when the
ceiling and/or visibility is actually lower than that necessary to
complete the approach.
2. A small number of other airports in mountainous terrain have MDAs
which are slightly (100 to 300 feet) below 2,000 feet AGL. In
situations where there is an option as to whether to plan for an
alternate, pilots should bear in mind that just a slight worsening of
the weather conditions from those forecast could place the airport
below the published IFR landing minimums.
3. An IFR flight to an airport which requires special equipment; i.e.,
DME, glide slope, etc., in order to make the available approaches to
the lowest minimums. Pilots should be aware that all other minimums on
the approach charts may require weather conditions better than those
specified in 14 CFR Section 91.167(b). An inflight equipment
malfunction could result in the inability to comply with the published
approach procedures or, again, in the position of having the airport
below the published IFR landing minimums for all remaining instrument
approach alternatives.

I would not like to see the FAA change the rules to handle
these exceptions, but a good pilot will note the conditions
and always plan for the worst. Even in perfectly clear
skies, Aspen is still just ONE runway. If there is a gear
up landing, you will go to an alternate.
If the weather is IFR at 800-2 and you're in the soup when
the airport equipment fails, you'll go to an alternate.

Whether that alternate is 10 miles away or 800 depends on
where you are flying and how much fuel you can carry.


--
James H. Macklin
ATP,CFI,A&P

--
The people think the Constitution protects their rights;
But government sees it as an obstacle to be overcome.
some support
http://www.usdoj.gov/olc/secondamendment2.htm
See http://www.fija.org/ more about your rights and duties.


> wrote in message
oups.com...
| This issue is raised in AIM 5.1.9(b) anyway:
|
| b. The FAA has identified three possible situations where
the failure
| to plan for an alternate airport when flying IFR to such a
destination
| airport could result in a critical situation if the
weather is less
| than forecast and sufficient fuel is not available to
proceed to a
| suitable airport.
| 1. An IFR flight to an airport where the Minimum Descent
Altitudes
| (MDAs) or landing visibility minimums for all instrument
approaches are
| higher than the forecast weather minimums specified in 14
CFR Section
| 91.167(b). For example, there are 3 high altitude airports
in the U.S.
| with approved instrument approach procedures where all of
the MDAs are
| greater than 2,000 feet and/or the landing visibility
minimums are
| greater than 3 miles (Bishop, California; South Lake
Tahoe, California;
| and Aspen-Pitkin Co./Sardy Field, Colorado). In the case
of these
| airports, it is possible for a pilot to elect, on the
basis of
| forecasts, not to carry sufficient fuel to get to an
alternate when the
| ceiling and/or visibility is actually lower than that
necessary to
| complete the approach.
| 2. A small number of other airports in mountainous terrain
have MDAs
| which are slightly (100 to 300 feet) below 2,000 feet AGL.
In
| situations where there is an option as to whether to plan
for an
| alternate, pilots should bear in mind that just a slight
worsening of
| the weather conditions from those forecast could place the
airport
| below the published IFR landing minimums.
| 3. An IFR flight to an airport which requires special
equipment; i.e.,
| DME, glide slope, etc., in order to make the available
approaches to
| the lowest minimums. Pilots should be aware that all other
minimums on
| the approach charts may require weather conditions better
than those
| specified in 14 CFR Section 91.167(b). An inflight
equipment
| malfunction could result in the inability to comply with
the published
| approach procedures or, again, in the position of having
the airport
| below the published IFR landing minimums for all remaining
instrument
| approach alternatives.
|

800-2 at Aspen? Not for me!
If KASE flirts with 2000-3, I'm going to my alternate.
Not much different for Eagle County, either.
I've diverted to Grand Junction and Montrose several times.

"Jim Macklin" > wrote in message news:UWLKf.102996$4l5.42576@dukeread05...
>
> .... Even in perfectly clear
> skies, Aspen is still just ONE runway. If there is a gear
> up landing, you will go to an alternate.
> If the weather is IFR at 800-2 and you're in the soup when
> the airport equipment fails, you'll go to an alternate.
> --
> James H. Macklin
> ATP,CFI,A&P
>

Did not mean Aspen at 800-2, 800-2 is a flat land
non-precision alternate airport for filing minimum. Note
the term, minimum, you can always select more, higher.
Personally, I would not do Aspen unless the weather in the
area was 2,000 feet above the peaks, the only times I've
been in there, it was either clear or high cirrus, beautiful
place under those conditions.

Each of the conditions listed was intended to be independent
of the other, sorry if I confused you.

Just to refresh the pilots out there;
ALL IFR flight plans require an alternate and the fuel
required to get there, unless
the weather one hour before and after ETA, is forecast to be
2,000 and 3. Any airport listed as an alternate must be
forecast at the time of arrival to be 600-2 with glide slope
and 800-2 without. [or very good weather if no approach].
If the destination does not have an approved approach an
alternate is always required.

The penalty for having to file an alternate is you have to
have the fuel [weight] and the penalty for not having an
alternate, filed or not and the fuel to get there is
possibly death.


--
James H. Macklin
ATP,CFI,A&P

--
The people think the Constitution protects their rights;
But government sees it as an obstacle to be overcome.
some support
http://www.usdoj.gov/olc/secondamendment2.htm
See http://www.fija.org/ more about your rights and duties.


"John R. Copeland" > wrote in
message
...
800-2 at Aspen? Not for me!
If KASE flirts with 2000-3, I'm going to my alternate.
Not much different for Eagle County, either.
I've diverted to Grand Junction and Montrose several times.

"Jim Macklin" > wrote
in message news:UWLKf.102996$4l5.42576@dukeread05...
>
> .... Even in perfectly clear
> skies, Aspen is still just ONE runway. If there is a gear
> up landing, you will go to an alternate.
> If the weather is IFR at 800-2 and you're in the soup when
> the airport equipment fails, you'll go to an alternate.
> --
> James H. Macklin
> ATP,CFI,A&P
>