Flying through known or forecast icing

"Bob Gardner" wrote in message
. ..
As George said, in Adminstrator vs Bowen, in 1974, the Administrative Law
Judge said, more or less, "known does not mean a near-certainty of icing
conditions, only that icing conditions are being reported or forecast."

But that 1974 decision is at odds with the current AIM, which defines
various icing conditions in section 7-1-23
(http://www.faa.gov/atpubs/aim/Chap7/aim0701.html#7-1-23):

"Forecast Icing Conditions--Environmental conditions expected by a National
Weather Service or an FAA-approved weather provider to be conducive to the
formation of in-flight icing on aircraft."

"Known Icing Conditions--Atmospheric conditions in which the formation of
ice is observed or detected in flight."

So according to the AIM, forecast icing is not tantamount to known icing.
Rather, only a PIREP of icing (or a pilot's own observation in flight)
constitutes known icing.

Although the AIM isn't regulatory, it does purport to furnish information
that is relevant to a pilot's understanding of FAA regulations. So when the
latest AIM defines a term that the FARs use but don't define, it would
violate due process to expect pilots to know and use some other definition
instead. (Does anyone know if the current AIM definitions were present back
when the previous rulings on known vs. forecast icing conditions were
issued?)

--Gary

What if anything happens to the whole "known versus forecast" issue if there
is a pirep for "negative icing in clouds".
"Matt Whiting" wrote in message
...
John Doe wrote:
Ok, I know this is one of those "it depends" answers, but I'm curious as
to what folks are willing to do in the winter time.

Assumptions:

Single engine piston aircraft with NO de-icing equipment.

Situation:

It's wintertime. You want to fly XC and there are midlevel clouds in the
forecast with the potential for icing to occur.

It looks like the band is thin enough to climb through and cruise in the
clear above the weather.

SO:

1) If the cloud layer is forecast to potentially have icing, can you
legally and would you climb through the layer to get up high for your
trip? how thick a layer, type of forecast, time spent in the layer, etc.
What would you be willing to risk transition through possible icing?

I believe the recent interpretations is that this would be illegal as the
cloud layer at below freezing temps would constitute an area of "known"
icing and thus penetrating it would not be legal. As to what I would do
personally ... well, I won't answer that here! :-)


2) Would that change any if those same conditions were now reported icing
from a recent PIREP?

It would change my personal view of the situation, but I don't think it
changes the legality.


3) If it's reported, can you transit the cloud layer legally?

I don't believe you can do so legally.


4) Let's say yoru trip starts off VFR but by the time you get to your
destination, a cloud layer has formed that has reported icing in it. Can
or or would you be willing to transit this layer to land at this
destionation or would you turn around or divert to land someplace to stay
out of the clouds?

Again it depends, but if I had sufficient fuel, I'd probably divert. If I
was low on fuel, I'd descend through the layer.

Matt

Gary Drescher wrote:

So according to the AIM, forecast icing is not tantamount to known icing.
Rather, only a PIREP of icing (or a pilot's own observation in flight)
constitutes known icing.

Here's the punch line from one of Yodice's columns in AOPA Pilot. Emphasis added.

"The NTSB precedents are clear. Relevant pireps *and forecasts* constitute
'known icing conditions' into which a flight is prohibited unless the aircraft
is specifically certificated by the FAA for flight into known icing conditions."

AOPA members can view the entire article here
http://www.aopa.org/members/files/pi...05/pc0508.html

George Patterson
Coffee is only a way of stealing time that should by rights belong to
your slightly older self.

Under current FAA/NTSB rules, nothing, the forecast stands
until officially amended.

The old joke, summer time forecast...
Chance of severe thunderstorms and tornadoes along and 1,000
miles either side of a line from 150 miles south of
Washington, DC to 300 miles north of San Francisco, CA. Tops
to FL600.

Winter forecast, same line from an unknown location to an
unknown location, with this...
Blizzard and whiteout conditions over the continent and
coastal waters, chance of moderate to severe icing from the
surface to FL240.

The forecast calls "wolf" so many times that pilots and
ground pounders became complacent. At least here in Kansas,
the new standard for issuing a "severe thunderstorm warning"
was changed for the 2005 season. They increased the size of
the hailstones and the winds that trigger a warning so there
would be fewer warnings.

Since Kansas can have steady winds of 25 to 40 knots and
higher gusts, without being associated with any storm, the
severe T storm warning of gusts to 60 mph didn't really
alert most locals.


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

"pgbnh" wrote in message
. ..
| What if anything happens to the whole "known versus
forecast" issue if there
| is a pirep for "negative icing in clouds".
| "Matt Whiting" wrote in message
| ...
| John Doe wrote:
| Ok, I know this is one of those "it depends" answers,
but I'm curious as
| to what folks are willing to do in the winter time.
|
| Assumptions:
|
| Single engine piston aircraft with NO de-icing
equipment.
|
| Situation:
|
| It's wintertime. You want to fly XC and there are
midlevel clouds in the
| forecast with the potential for icing to occur.
|
| It looks like the band is thin enough to climb through
and cruise in the
| clear above the weather.
|
| SO:
|
| 1) If the cloud layer is forecast to potentially have
icing, can you
| legally and would you climb through the layer to get up
high for your
| trip? how thick a layer, type of forecast, time spent
in the layer, etc.
| What would you be willing to risk transition through
possible icing?
|
| I believe the recent interpretations is that this would
be illegal as the
| cloud layer at below freezing temps would constitute an
area of "known"
| icing and thus penetrating it would not be legal. As to
what I would do
| personally ... well, I won't answer that here! :-)
|
|
| 2) Would that change any if those same conditions were
now reported icing
| from a recent PIREP?
|
| It would change my personal view of the situation, but I
don't think it
| changes the legality.
|
|
| 3) If it's reported, can you transit the cloud layer
legally?
|
| I don't believe you can do so legally.
|
|
| 4) Let's say yoru trip starts off VFR but by the time
you get to your
| destination, a cloud layer has formed that has reported
icing in it. Can
| or or would you be willing to transit this layer to
land at this
| destionation or would you turn around or divert to land
someplace to stay
| out of the clouds?
|
| Again it depends, but if I had sufficient fuel, I'd
probably divert. If I
| was low on fuel, I'd descend through the layer.
|
| Matt
|
|

"George Patterson" wrote in message
news:GJhof.1362$Jr1.200@trnddc01...
Gary Drescher wrote:

So according to the AIM, forecast icing is not tantamount to known icing.
Rather, only a PIREP of icing (or a pilot's own observation in flight)
constitutes known icing.

Here's the punch line from one of Yodice's columns in AOPA Pilot. Emphasis
added.

"The NTSB precedents are clear. Relevant pireps *and forecasts* constitute
'known icing conditions' into which a flight is prohibited unless the
aircraft is specifically certificated by the FAA for flight into known
icing conditions."

Right, but the NTSB precedents cited are not recent (some are more than
thirty years old), whereas the FAA's current definition of "known icing
conditions"--which I quoted from the latest AIM--explicitly contradicts
those precedents.

--Gary

Gary, the most recent case was in 2005. That's what George was linking to.

Bob Gardner

"Gary Drescher" wrote in message
...
"George Patterson" wrote in message
news:GJhof.1362$Jr1.200@trnddc01...
Gary Drescher wrote:

So according to the AIM, forecast icing is not tantamount to known
icing. Rather, only a PIREP of icing (or a pilot's own observation in
flight) constitutes known icing.

Here's the punch line from one of Yodice's columns in AOPA Pilot.
Emphasis added.

"The NTSB precedents are clear. Relevant pireps *and forecasts*
constitute 'known icing conditions' into which a flight is prohibited
unless the aircraft is specifically certificated by the FAA for flight
into known icing conditions."

Right, but the NTSB precedents cited are not recent (some are more than
thirty years old), whereas the FAA's current definition of "known icing
conditions"--which I quoted from the latest AIM--explicitly contradicts
those precedents.

--Gary

"Bob Gardner" wrote in message
...
"Gary Drescher" wrote in message
...
"George Patterson" wrote in message
news:GJhof.1362$Jr1.200@trnddc01...
"The NTSB precedents are clear. Relevant pireps *and forecasts*
constitute 'known icing conditions' into which a flight is prohibited
unless the aircraft is specifically certificated by the FAA for flight
into known icing conditions."

Right, but the NTSB precedents cited are not recent (some are more than
thirty years old), whereas the FAA's current definition of "known icing
conditions"--which I quoted from the latest AIM--explicitly contradicts
those precedents.

Gary, the most recent case was in 2005. That's what George was linking to.

No, the AOPA article he linked to says explicitly that the issue of known
vs. forecast icing conditions was *not* addressed in the most recent case
that the article discusses. The article goes on to say, "The board addressed
this issue most recently more than a dozen years ago, and in 1974 and 1976
before that. All are old cases."

Also, the article begins by saying that "the FAA offers very little guidance
to pilots operating 'non-commerically'" regarding what is meant by "known
icing conditions". In fact, though, the current AIM defines the term clearly
(and clearly distinguishes it from "forecast icing conditions"); the article
makes no mention of the AIM's definition.

Therefore, either the AIM definition first appeared after the article was
written, or else the article's author was unaware of the FAA's
already-published definition. Either way, the article does not provide sound
legal guidance in light of the FAA's current definition.

(George's link again:
http://www.aopa.org/members/files/pi...05/pc0508.html.)

--Gary

Gary
If you wait just a little, the legal definition will change again and
the hapless pilot will still be shafted and left bankrupt trying to
defend against the FAA steamroller legal section.
While I am pleased to see some really good input from the practical
standpoints, I'd hate to see it change into a legal discussion and
forget the original intent was ice and how to cope with it.
I've written at least a half dozen published articles on ice in general
aviation and so far they have withstood the test of time. As anyone
knows though, longevity lends credence to nearly any stated position if
its restated enough!?
Best Regards and Merry Christmas/Happy New Year
Ol Shy & Bashful

wrote in message
oups.com...
If you wait just a little, the legal definition will change again and
the hapless pilot will still be shafted

That seems unlikely for the foreseeable future. But if the definition does
change, someone here is likely to call attention to it.

While I am pleased to see some really good input from the practical
standpoints, I'd hate to see it change into a legal discussion and
forget the original intent was ice and how to cope with it.

Yup, legality and safety are not synonymous. Still, I think it would be safe
to fly IFR through a thin cloud layer (with plenty of room above and below)
even if there's a forecast for occasional moderate icing in clouds. And
according to the AIM's current definition of "known icing conditions", that
would be legal (for Part 91), as long as there are no PIREPs that confirm
the forecast.

Best Regards and Merry Christmas/Happy New Year

A cheerful solstice to you too!

--Gary

"Gary Drescher" wrote

Yup, legality and safety are not synonymous. Still, I think it would be
safe
to fly IFR through a thin cloud layer (with plenty of room above and
below)
even if there's a forecast for occasional moderate icing in clouds. And
according to the AIM's current definition of "known icing conditions",
that
would be legal (for Part 91), as long as there are no PIREPs that confirm
the forecast.

Section 91.527: Operating in icing conditions.

(b) Except for an airplane that has ice protection provisions that meet the
requirements in section 34 of Special Federal Aviation Regulation No. 23, or
those for transport category airplane type certification, no pilot may fly—

(1) Under IFR into known or forecast moderate icing conditions; or

(2) Under VFR into known light or moderate icing conditions unless the
aircraft has functioning de-icing or anti-icing equipment protecting each
propeller, windshield, wing, stabilizing or control surface, and each
airspeed, altimeter, rate of climb, or flight attitude instrument system.

(c) Except for an airplane that has ice protection provisions that meet the
requirements in section 34 of Special Federal Aviation Regulation No. 23, or
those for transport category airplane type certification, no pilot may fly
an airplane into known or forecast severe icing conditions.

(d) If current weather reports and briefing information relied upon by the
pilot in command indicate that the forecast icing conditions that would
otherwise prohibit the flight will not be encountered during the flight
because of changed weather conditions since the forecast, the restrictions
in paragraphs (b) and (c) of this section based on forecast conditions do
not apply.

It appears that for purposes of an IFR flight the rules do not rely on any
definition of "known" versus "forecast" - they're both covered right in the
reg. Paragraph (d) appears to allow a pirep of no icing to supercede the
forcast.