flying in snow

[Teacherjh]

In a typical spam can (say an archer), which has no deice at all (save pitot
heat), is it safe to fly in snow? More generally, of course the snow will
bounce off and not stick to the wings (right?) but what about the clouds that
are producing snow - will they also produce airframe ice? If it's above
freezing on the ground, and the clouds are very high, and it's snowing, then as
I climb I'll (yes?) climb above the freezing level - is there danger in that
transition when it's snowing? (I presume there's no freezing rain or sleet,
else I'd see it on the ground, no?)

Jose


--
(for Email, make the obvious changes in my address)

[Peter Duniho]

"Teacherjh" > wrote in message
...
> In a typical spam can (say an archer), which has no deice at all (save
pitot
> heat), is it safe to fly in snow?

It can be, yes. However, all of the usual caveats about flying in visible
moisture with freezing conditions apply.

Typically, in a cloud or not, you'll just get a light accumulation of snow
on forward surfaces of the airplane: leading edge of the wing, front of
tires (for fixed-gear airplanes), temperature probe, etc.

However, a heavy wet snow could result in significant rime ice accumulation,
and any kind of snow has the potential for blocking the air filter. It's
important to have all of the usual precautions that you'd have in any sort
of freezing/precip conditions, including a well-thought-out escape plan.

I can't think of any situation where precipitation that's freezing rain
aloft would show up as snow on the ground, but I think it would be unwise to
rule that possibility out. Weather does funny things some times.

Generally speaking though, when you see snow, things are cold enough that
all you'll get is plain old snow, and it will be too cold for it to produce
any significant accumulation.

Pete

[Mike Rapoport]

The snow itself will not stick but you will find ice in the snow producing
clouds, particularly if the snow falling out of them is the "little
styrofoam balls" type. Sometimes there are no clouds when it is snowing the
flake type. The flake type is formed by moisture going directly from vapor
to crystal whereas the ball type is a collection of supercooled cloud
droplets frozen together.

So the bottom line is that you will not get airframe ice if you can see
where you are going.

Mike
MU-2


"Teacherjh" > wrote in message
...
> In a typical spam can (say an archer), which has no deice at all (save
pitot
> heat), is it safe to fly in snow? More generally, of course the snow will
> bounce off and not stick to the wings (right?) but what about the clouds
that
> are producing snow - will they also produce airframe ice? If it's above
> freezing on the ground, and the clouds are very high, and it's snowing,
then as
> I climb I'll (yes?) climb above the freezing level - is there danger in
that
> transition when it's snowing? (I presume there's no freezing rain or
sleet,
> else I'd see it on the ground, no?)
>
> Jose
>
>
> --
> (for Email, make the obvious changes in my address)

[Brad Z]

Oh good Mike, you're alive!


(see related thread on R.A.S)

"Mike Rapoport" > wrote in message
hlink.net...
> The snow itself will not stick but you will find ice in the snow producing
> clouds, particularly if the snow falling out of them is the "little
> styrofoam balls" type. Sometimes there are no clouds when it is snowing
the
> flake type. The flake type is formed by moisture going directly from
vapor
> to crystal whereas the ball type is a collection of supercooled cloud
> droplets frozen together.
>
> So the bottom line is that you will not get airframe ice if you can see
> where you are going.
>
> Mike
> MU-2
>
>
> "Teacherjh" > wrote in message
> ...
> > In a typical spam can (say an archer), which has no deice at all (save
> pitot
> > heat), is it safe to fly in snow? More generally, of course the snow
will
> > bounce off and not stick to the wings (right?) but what about the clouds
> that
> > are producing snow - will they also produce airframe ice? If it's above
> > freezing on the ground, and the clouds are very high, and it's snowing,
> then as
> > I climb I'll (yes?) climb above the freezing level - is there danger in
> that
> > transition when it's snowing? (I presume there's no freezing rain or
> sleet,
> > else I'd see it on the ground, no?)
> >
> > Jose
> >
> >
> > --
> > (for Email, make the obvious changes in my address)
>
>

[BTIZ]

a major concern.. especially if snow is heavy.. is blocking the air filter
intake and forcing use of an alternate air source.. does your "carb heat"
just apply heated air to the regular air intake to the carb or manifold? or
is it an "alternate air source"

BT

"Teacherjh" > wrote in message
...
> In a typical spam can (say an archer), which has no deice at all (save
pitot
> heat), is it safe to fly in snow? More generally, of course the snow will
> bounce off and not stick to the wings (right?) but what about the clouds
that
> are producing snow - will they also produce airframe ice? If it's above
> freezing on the ground, and the clouds are very high, and it's snowing,
then as
> I climb I'll (yes?) climb above the freezing level - is there danger in
that
> transition when it's snowing? (I presume there's no freezing rain or
sleet,
> else I'd see it on the ground, no?)
>
> Jose
>
>
> --
> (for Email, make the obvious changes in my address)

[Larry Dighera]

On Thu, 18 Mar 2004 11:27:18 -0800, "Peter Duniho"
> wrote in Message-Id:
>:

>any kind of snow has the potential for blocking the air filter.

I only see that as an issue if you are downwind of an active volcano,
and the ambient atmosphere is dust laden. It's my understanding that
most aircraft induction systems have a spring-loaded door that admits
air in the event of an interruption of flow through the filter
element.

[Mike Rapoport]

And it feels good!...

966MA was owned by a doctor who I met a couple of times. He and his wife
were nice people.

Mike
MU-2

"Brad Z" > wrote in message
news:plp6c.36349$1p.545565@attbi_s54...
> Oh good Mike, you're alive!
>
>
> (see related thread on R.A.S)
>
> "Mike Rapoport" > wrote in message
> hlink.net...
> > The snow itself will not stick but you will find ice in the snow
producing
> > clouds, particularly if the snow falling out of them is the "little
> > styrofoam balls" type. Sometimes there are no clouds when it is snowing
> the
> > flake type. The flake type is formed by moisture going directly from
> vapor
> > to crystal whereas the ball type is a collection of supercooled cloud
> > droplets frozen together.
> >
> > So the bottom line is that you will not get airframe ice if you can see
> > where you are going.
> >
> > Mike
> > MU-2
> >
> >
> > "Teacherjh" > wrote in message
> > ...
> > > In a typical spam can (say an archer), which has no deice at all
(save
> > pitot
> > > heat), is it safe to fly in snow? More generally, of course the snow
> will
> > > bounce off and not stick to the wings (right?) but what about the
clouds
> > that
> > > are producing snow - will they also produce airframe ice? If it's
above
> > > freezing on the ground, and the clouds are very high, and it's
snowing,
> > then as
> > > I climb I'll (yes?) climb above the freezing level - is there danger
in
> > that
> > > transition when it's snowing? (I presume there's no freezing rain or
> > sleet,
> > > else I'd see it on the ground, no?)
> > >
> > > Jose
> > >
> > >
> > > --
> > > (for Email, make the obvious changes in my address)
> >
> >
>
>

[Peter Duniho]

"Larry Dighera" > wrote in message
...
> I only see that as an issue if you are downwind of an active volcano,
> and the ambient atmosphere is dust laden. It's my understanding that
> most aircraft induction systems have a spring-loaded door that admits
> air in the event of an interruption of flow through the filter
> element.

Huh? Many do not. All aircraft that I've flown DO have an alternate air
system; most of the C172-class planes I know of use carb heat as their
alternate air, not a spring-loaded door. My own airplane has a
spring-loaded door, but that's most likely because it's also fuel-injected,
so there's no carb heat installed.

But regardless of how the alternate air system works, it's still an issue to
be aware of. And in all cases I know of, the alternate air system means
unfiltered air. In cruise flight, not necessarily a problem, but if it also
means turning on the carb heat, it means a) you need to be aware of the
potential for the need to use carb heat, and b) you'll want to remind
yourself of the various implications of operating with the carb heat turned
on (like, need to readjust the mixture, fuel efficiency changes, maximum
power changes, that sort of thing).

You don't need to be downwind of an active volcano to care about the air
filter getting clogged.

Pete

[Teacherjh]

>>
does your "carb heat"
just apply heated air to the regular air intake to the carb or manifold? or
is it an "alternate air source"
<<

The former, I believe, though I'll check it out. It's an archer (we also have
a dakota, which should be similar). There is an "alternate air" lever, but
that's an alternate static source.

Jose

--
(for Email, make the obvious changes in my address)

[Rick Durden]

Jose,

Lot of bad information and old wives' tales on this thread. sigh

Outside of clouds, when you are flying in snow it will not stick to
the airframe. Even heavy wet snow will not stick, so airframe icing
is not a problem. The concerns to be aware of when flying in snow are
the very serious restriction to visibility that often occurs. When
flying IFR you may be able to see the ground during the approach, but
not pick out the runway until you are over it. You've got 500 feet of
vertical visibility, and about that horizontally, but you see the
runway from above and try to circle for it. Lots of dead pilots
because of that error. Once you start the turn you lose sight of the
runway and have no visual reference horizontally, so you are trying to
do a circle to land without the requisite vis requirements. It's best
to miss the approach immediately. If you are VFR and fly into snow
the problem is that vis can change very fast and can put you into IMC
in seconds. Otherwise, the concerns about flying in snow are P
static, if your airplane doesn't have good static wicks. If you start
to lose your radios you can try holding your hand, fingers spread
wide, about a half inch from the windshield and move it back and
forth. Sometimes you'll feel the static discharge you get after
walking across a rug and touching metal, as the airplane discharges,
and you get the radios back for a few minutes. It doesn't always
work, but it works often enough it's worth a try. The other concern
is with wet snow in that it can pack the air filter on the engine air
intake and either reduce the air flow or block it. At that point you
just switch to carb heat or alternate air as appropriate for your
aircraft.

You will only get rime ice when in clouds, you will not get it in
snow. Clear ice comes from freezing rain and is another matter
entirely.

Suggest you check out back issues of IFR Magazine for more information
on flying in snow. They've dealt with it at length. Here in Michigan
we fly in snow all the time, it's just no big deal. With frequent
lake effect snow you learn to chose an altitude to stay out of the
clouds because that's where the ice is. If it's snowing, you're fine
(if you are IFR, you may be screwed if VFR because of vis). Runway
operations are a different matter, and getting around the airport may
range from merely exciting to impossible. You may also find that
after stopping your brakes have melted snow which then refroze as ice
and locked one or both wheels. On landing you tend not to try for
greasers as you may have a locked wheel, and it takes a while for
enough friction on the tire to build up to apply enough rotational
force to break the ice. In the meantime you listen to a tire squeal
and you have little rolling control from that tire, so if you touch
down a bit firmly the wheels will get a good rotational jolt from the
runway and break the ice fairly quickly. Just be ready to steer the
airplane with aerodyanmic controls after landing as the runway may be
very slippery and a tire or two may not be turning.

All the best,
Rick

(Teacherjh) wrote in message >...
> In a typical spam can (say an archer), which has no deice at all (save pitot
> heat), is it safe to fly in snow? More generally, of course the snow will
> bounce off and not stick to the wings (right?) but what about the clouds that
> are producing snow - will they also produce airframe ice? If it's above
> freezing on the ground, and the clouds are very high, and it's snowing, then as
> I climb I'll (yes?) climb above the freezing level - is there danger in that
> transition when it's snowing? (I presume there's no freezing rain or sleet,
> else I'd see it on the ground, no?)
>
> Jose

[John Galban]

(Teacherjh) wrote in message >...
> >>
> does your "carb heat"
> just apply heated air to the regular air intake to the carb or manifold? or
> is it an "alternate air source"
> <<
>
> The former, I believe, though I'll check it out. It's an archer (we also have
> a dakota, which should be similar). There is an "alternate air" lever, but
> that's an alternate static source.
>

Technically it's both. When you use carb heat in an Archer, it
bypasses the regular intake path / air filter and sends unfiltered
warm air to the intake manifold (that would make it an "alternate air"
source). This is quite useful when your intake is blocked. I've had
to use it twice for that reason. Once because of snow buildup on the
filter and another time when I somehow sucked up a plastic supermarket
bag (commonly seen floating around in thermals here in the southwest).

John Galban=====>N4BQ (PA28-180)

[Peter Duniho]

"Rick Durden" > wrote in message
m...
> Lot of bad information and old wives' tales on this thread. sigh

Unfortunately, Rick is adding to that bad information.

> Outside of clouds, when you are flying in snow it will not stick to
> the airframe. Even heavy wet snow will not stick, so airframe icing
> is not a problem.

Do NOT believe this. I have flown outside of clouds in snow and seen it
stick. As I mentioned, typically only a very light amount winds up on the
forward surfaces of the airplane, but it is absolutely false that snow
outside of clouds will not stick to the airframe.

The rest of his post (except where he revisits this point) is informative,
and does introduce a couple of points not already mentioned.

Pete

[Rick Durden]

Jose,

The carburetor heat provides air from a source inside the cowling and
bypasses the air filter. It is an alternate air source for the engine
and is heated.

All the best,
Rick

(Teacherjh) wrote in message >...
> >>
> does your "carb heat"
> just apply heated air to the regular air intake to the carb or manifold? or
> is it an "alternate air source"
> <<
>
> The former, I believe, though I'll check it out. It's an archer (we also have
> a dakota, which should be similar). There is an "alternate air" lever, but
> that's an alternate static source.
>
> Jose

[Larry Dighera]

On Thu, 18 Mar 2004 19:01:54 -0800, "Peter Duniho"
> wrote in Message-Id:
>:

>"Larry Dighera" > wrote in message
...
>> I only see that as an issue if you are downwind of an active volcano,
>> and the ambient atmosphere is dust laden. It's my understanding that
>> most aircraft induction systems have a spring-loaded door that admits
>> air in the event of an interruption of flow through the filter
>> element.
>
>Huh? Many do not.

Of the 5 POHs I checked, only the Rockwell International 112A
mentioned using carb-heat as an alternate air source. Neither the
1974 Cessna Centurion, nor 1973 Cessna Cardinal RG, nor 1974 Cessna
Stationair, nor Piper Archer II, nor Bellanca Super Viking POH/Owner's
Manuals mention alternate air. Or, at least I couldn't find it.

>All aircraft that I've flown DO have an alternate air
>system; most of the C172-class planes I know of use carb heat as their
>alternate air, not a spring-loaded door.

In the C-172S there is no carb-heat (it's injected).

>My own airplane has a
>spring-loaded door, but that's most likely because it's also fuel-injected,
>so there's no carb heat installed.
>
>But regardless of how the alternate air system works, it's still an issue to
>be aware of. And in all cases I know of, the alternate air system means
>unfiltered air. In cruise flight, not necessarily a problem, but if it also
>means turning on the carb heat, it means a) you need to be aware of the
>potential for the need to use carb heat, and b) you'll want to remind
>yourself of the various implications of operating with the carb heat turned
>on (like, need to readjust the mixture, fuel efficiency changes, maximum
>power changes, that sort of thing).
>
>You don't need to be downwind of an active volcano to care about the air
>filter getting clogged.

Right. What I was attempting to imply was that at cruise altitude the
air is generally free of impurities normally filtered unless there is
a source of such impurities upwind spewing to significant heights.

[G.R. Patterson III]

Larry Dighera wrote:
>
> Of the 5 POHs I checked, only the Rockwell International 112A
> mentioned using carb-heat as an alternate air source.

My understanding from the old Jeppesen-Sandersen PP manual was that this is
standard; IOW, if your plane has carb heat, that's the alternate air source.
I would assume that most POHs would not mention something that they feel to be
obvious.

George Patterson
Battle, n; A method of untying with the teeth a political knot that would
not yield to the tongue.

[Peter Duniho]

"Larry Dighera" > wrote in message
...
> Of the 5 POHs I checked, only the Rockwell International 112A
> mentioned using carb-heat as an alternate air source.

See George's post. If there's carb heat, there's usually alternate air,
even if the manual doesn't say so.

> >All aircraft that I've flown DO have an alternate air
> >system; most of the C172-class planes I know of use carb heat as their
> >alternate air, not a spring-loaded door.
>
> In the C-172S there is no carb-heat (it's injected).

So? What's your point? Are you claiming the 172S has no alternate air
source?

> Right. What I was attempting to imply was that at cruise altitude the
> air is generally free of impurities normally filtered unless there is
> a source of such impurities upwind spewing to significant heights.

I understand what you were trying to imply. But the point here is that
filtration is not the only concern with many alternate air systems, since
they combine two completely different functions (carb heat and alternate
air).

Pete

[Malcolm Teas]

"Peter Duniho" > wrote in message >...
> "Rick Durden" > wrote in message
> m...
> > Lot of bad information and old wives' tales on this thread. sigh
>
> Unfortunately, Rick is adding to that bad information.
>
> > Outside of clouds, when you are flying in snow it will not stick to
> > the airframe. Even heavy wet snow will not stick, so airframe icing
> > is not a problem.
>
> Do NOT believe this. I have flown outside of clouds in snow and seen it
> stick. As I mentioned, typically only a very light amount winds up on the
> forward surfaces of the airplane, but it is absolutely false that snow
> outside of clouds will not stick to the airframe.
>
> The rest of his post (except where he revisits this point) is informative,
> and does introduce a couple of points not already mentioned.

Rick has got a lot of experience. Personally, I'm not so sure I would
dismiss it easily. I'm sure you to though, and If I'd seen
differently I might look for other reasons: local temperature
differences perhaps? I'm no snow expert, but have lived in snowy
climates so I know that when snow's near the freezing point it's
wetter and sticks more readily.

-Malcolm Teas

[Peter Duniho]

"Malcolm Teas" > wrote in message
om...
> Rick has got a lot of experience.

And as I said, his post did include some useful information.

However...

> Personally, I'm not so sure I would dismiss it easily.

I hope that if you had seen with your own eyes the facts that contradict his
statement, you would.

> I'm sure you to though, and If I'd seen
> differently I might look for other reasons: local temperature
> differences perhaps?

I never said snow ALWAYS sticks to the airframe. I simply said that it can.

Rick has this problem, maybe rooted in all that experience he's supposed to
have, that he thinks he can make a single statement that applies 100% of the
time. Witness his comments about aircraft insurance as well.

I don't care how much experience a person has, it's foolish to make wild
generalizations without having the facts to back them up. Especially when
someone has already said that they have personal experience to the contrary.

Pete