Helicopter Question

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!
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Ice on helicopters is a problem and they need to be deiced.
The issues are different in detail but not in principle.
The rotor flexes a lot and that can shed ice on some areas,
but rotors have nodes that don't flex. Also inlets,
instruments and such can all ice. Most helicopters are not
certified for icing conditions. Those used by the North Sea
oil companies and the military transports usually are. Each
copter is different.

I had a friend who flew Santa from one town to another for
the mall, they got into ice in a Jet Ranger and made a dozen
stops in fields along the 30 mile route, to stop and knock
the iced off. It probably was not a legal flight, but I
wasn't the pilot or on the bird.


--
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



"Jay Honeck" wrote in message
news:a5qjf.582408$x96.381721@attbi_s72...
| 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!
| --
| Jay Honeck
| Iowa City, IA
| Pathfinder N56993
| www.AlexisParkInn.com
| "Your Aviation Destination"
|
|

Well, I can tell you that helis are not free from ice worry. I know
Apaches have heaters in their blades allowing them to de-ice. Sadly,
they can not use them because it causes problems with blade
delamination. Which really means the cure is worse than ice. Hehe.
Go figure. For $24Mil per Longbow, surely you didn't really expect an
all weather bird!

Long story short, if they fly in icing weather, I imagine are they have
some form of heating in their blades.

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.

Don't know about ice on rotors, but experienced engine out due to carb
icing once.

Helicopters face the same challenges of other aircraft. However, there
are some differences. The rotor blades are very flexible ... more than
one would think. This serves to remove the formation of large amounts
of ice. Small films are probably able to form, but large heavy films
probably do not in most circumstances. Additonally, helicoptors are
fairly well insulated capsules with large engines piggy-backed right
behind the cabin. This helps since these two capsules can preserve the
generated heat, pretty well. Yes, other external parts can ice up, but
the whole cabin is pretty much the helicopter. The rest, is a lot of
smaller surface area. Personally, I think the tail section and rear
rotor would be the trouble area under such circumstances.
Flyingmonk wrote:
Don't know about ice on rotors, but experienced engine out due to carb
icing once.

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"

Just fly very, very low. I had a friend who flew Huey's. He said if the
detected ANY ice, they would land in whatever field they could. They
once camped out for 1/2 day. At CAP we were sent to look for a National
Guard Helo about a month ago. Turns out it landed in a field to wait
out icing weather and just couldn't get to a phone.

-Robert

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

Yes, IIRC, "special VFR"