REFLECTOR: Anti-Ice

Wed Aug 23 09:42:58 CDT 2006

I think we can all agree that flying intentionally into known Ice is a
bad retirement plan in any small plane.
On the other hand, if you fly IFR, you will likely encounter icing at
some point and although your first action should be to get out of the
icing condition, an effective method to shed the ice would be an asset.

That having been said, the "PETD" method below seems suitable, but not
yet available. The other websites I listed below use a thermal tape
which requires about 60 amps (I think). This is intermittent.

I guess no one on the reflector has tried any of these strategies.
Any other ideas?

LJE

-----Original Message-----
From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of Chuck Harbert
Sent: Wednesday, August 23, 2006 10:31 AM
To: reflector at tvbf.org
Subject: Re: REFLECTOR: Anti-Ice

Larry, I thot I posted some comments about flying with ice about a month

ago. I didn't keep a copy, so I'll say it again. A V test pilot (lots of
V 
hours) told me that he had collected a fair amount of ice (over 1/2") on
the 
canard and it not only slowed the plane, but also the plane began a
pitch 
buck oscillation which he felt was caused by the canard stalling. He was

very concerned about loss of control and now avoids any potential for
icing. 
He talked with the factory about it a couple years ago.

I went to the website for Ice Engineering (watched the wing video) and
then 
went to an article at the Dartmouth Engr website 
http://engineering.dartmouth.edu/thayer/research/ice-engg.html (copy
below) 
which talks about the technology and the Goodrich tests. This looks very

promising for light planes, and particularly for V's conditions. It'll 
probably be expensive now that Goodrich has the rights, but might be
worth 
it if you plan to fly in possible icing conditions. Hopefully, it will
be 
available in a couple years.

------------------------------

Petrenko's PETD uses a thin, electrically-conductive film applied to the

surface of, for example, an airplane or a windshield or almost any other

object in need of ice protection. The film is then heated with a 
milliseconds-long pulse of electricity. The beauty of this method is
that 
only a micrometer-thin layer of ice directly at the ice-material
interface 
is heated without having to heat the bulk of the object to which the ice
is 
stuck. Even in extreme cold, PETD achieves nearly perfect efficiency
because 
neither the object nor the air is heated-the heat simply does not have
time 
to propagate into the environment. Just one single pulse of electricity 
melts the interfacial ice and instantly releases any additional
build-up, 
which then easily slides off. Regular electric pulsing can keep surfaces

consistently ice-free while maintaining low overall power consumption.

      > Aerofoil de-icing (1.5MB)
      > Panel de-icing (1.5MB)
      > Power line de-icing (1.3MB)
      > Windshield de-icing (1.1MB)

      > Download QuickTime Player

The de-icing film can consist of either a transparent conductor (such as

indium tin oxide) for window or lens applications, or of a more durable 
coating (such as titanium) when extra wear-resistance is needed. For 
protection of large surfaces, thin metal foil or carbon-fiber composites
are 
most effective.

Almost no heat energy is lost or wasted in this process and this optimal

energy-efficiency in melting ice from surfaces is what makes PETD 
energetically feasible for aerospace applications and automobile 
windshields. Resistive heaters, such as the heated wires on rear windows
of 
cars, cannot melt ice from windshields or wings because strong
convective 
heat loss prevents the wires from reaching ice-melting temperatures
without 
unrealistically high power usage. Heat loss to the earth and air is the 
reason traditional heaters are impractical for de-icing roads, bridges, 
walkways, and roofs. But Petrenko's super-efficient PETD has
demonstrated 
immediate effectiveness and saves up to 99% of electric energy compared
to 
conventional heaters. Goodrich Aerospace has completed the first
in-flight 
testing of PETD on a small prop-plane. The results were "outstanding,"
and 
the next phase of field testing will involve a jet aircraft.

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