Helicopter Question

Jay Honeck wrote:
As we were flying over to Newton, IA today, we started discussing icing and
snow -- something that we must constantly worry about in these parts for at
least the next 4 months.

As we were talking, we heard a "Flight for Life" 'copter on Unicom, which
got us to wondering how it is that these guys seem to fly in ANY weather.

Which got us to wondering further: How do helicopters handle ice? Are the
main rotor blades heated? Does the centrifugal force on those huge blades
prevent ice build up? What about the rest of the fuselage? How do they
de-ice themselves?

Thanks!

Jumping in here -

Having worked for a medevac operator where most of the helicopters were
VFR only, my guess is this - they don't fly in IMC, let alone IMC with
the possibility of icing.

I asked our helicopter pilots and mechanics about this time after time,
and their reply was always the same - "Flying in the clouds, running
into ice, and shooting approaches are dangerous. I can't believe you do
it in an airplane."

I'm sure there's more to it, but I never got a good answer.

Having worked for a medevac operator where most of the helicopters were
VFR only, my guess is this - they don't fly in IMC, let alone IMC with the
possibility of icing.

Of course, what's their definition of "IMC"?

Don't helicopters have a lower threshold for IMC than we fixed wing folks?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Don't helicopters have a lower threshold for IMC than we fixed wing folks?

It's a lower VFR ceiling and visibility limit, about half of
what the rest of us are held to. I guess we could call it an IMC
threshold. Helicopters can move forward slowly when the viz is bad, and
thereby avoid the cumulogranite.
But IMC and ice are two different hazards. I have heard of a
helicopter that runs hot bleed air through the rotors to deice them. I
don't know if that also applies to the tail rotor, or if it might be
electrically heated like a prop.

Dan

We can request "special VFR" that'll even allow for near "no vis" opt
IIRC.

"Flyingmonk" wrote in message
oups.com...
We can request "special VFR" that'll even allow for near "no vis" opt
IIRC.

Special VFR still requires a minimum of 1 mile visibility.

1 mile is close enough to none for me

Brian
CFIIG/ASEL

Yes, IIRC, "special VFR"

Yes, IIRC, "special VFR"

It's not SVFR. Note the (c) and (d) paragraphs in our Canadian
Law:

602.115 Minimum Visual Meteorological Conditions for VFR Flight in
Uncontrolled Airspace
602.115 No person shall operate an aircraft in VFR flight within
uncontrolled airspace unless
(a) the aircraft is operated with visual reference to the surface;
(b) where the aircraft is operated at or above 1,000 feet AGL
(i) during the day, flight visibility is not less than one mile,
(ii) during the night, flight visibility is not less than three
miles, and
(iii) in either case, the distance of the aircraft from cloud is not
less than 500 feet vertically and 2,000 feet horizontally;
(c) where the aircraft is not a helicopter and is operated at less than
1,000 feet AGL
(i) during the day, flight visibility is not less than two miles,
except if otherwise authorized in an air operator certificate or a
private operator certificate,
(ii) during the night, flight visibility is not less than three
miles, and
(iii) in either case, the aircraft is operated clear of cloud; and
(d) where the aircraft is a helicopter and is operated at less than
1,000 feet AGL
(i) during the day, flight visibility is not less than one mile,
except if otherwise authorized in an air operator certificate or a
flight training unit operator certificate - helicopter,
(ii) during the night, flight visibility is not less than three
miles, and
(iii) in either case, the aircraft is operated clear of cloud.

Dan

"Jay Honeck" wrote in message
news:XNvjf.611926$xm3.441724@attbi_s21...
Having worked for a medevac operator where most of the helicopters were
VFR only, my guess is this - they don't fly in IMC, let alone IMC with
the possibility of icing.

Of course, what's their definition of "IMC"?

Don't helicopters have a lower threshold for IMC than we fixed wing folks?

Yes. See FAR 91.155 and 91.157. For all practical purposes, helicopters
can fly in arbitrarily low visibility. 91.155 grants them this right in
Class G airspace, and 91.157 grants them this right elsewhere (with a
Special VFR clearance).

Since a pilot can get a Special VFR clearance pretty much anywhere that
there *isn't* Class G airspace near the surface (generally below 700 or 1200
feet, depending), this means that as long as the helicopter pilot can see
well enough to avoid obstacles, the visibility is defined as being
sufficient, no matter how low it actually is.

Pete

On Thu, 1 Dec 2005 11:15:30 -0800, "Peter Duniho"
wrote in
::


Since a pilot can get a Special VFR clearance pretty much anywhere that
there *isn't* Class G airspace near the surface (generally below 700 or 1200
feet, depending), this means that as long as the helicopter pilot can see
well enough to avoid obstacles, the visibility is defined as being
sufficient, no matter how low it actually is.

It was my understanding, that a Special VFR clearance was only issued
within the controlled airspace of the surface area of an airport:


§ 91.157 Special VFR weather minimums.

(a) Except as provided in appendix D, section 3, of this part,
special VFR operations may be conducted under the weather minimums
and requirements of this section, instead of those contained in
§91.155, below 10,000 feet MSL within the airspace contained by
the upward extension of the lateral boundaries of the controlled
airspace designated to the surface for an airport.

That doesn't seem to be what you are saying above. Did I miss
something?