Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!dogie!indri!aplcen!haven!rutgers!att!cbnews!cantrell@Alliant.COM
From: cantrell@Alliant.COM (Paul Cantrell)
Newsgroups: sci.military
Subject: Re: air defense wires
Message-ID: <5673@cbnews.ATT.COM>
Date: 15 Apr 89 04:19:03 GMT
References: <5546@cbnews.ATT.COM>
Sender: military@cbnews.ATT.COM
Organization: Alliant Computer Systems, Littleton, MA
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From: cantrell@Alliant.COM (Paul Cantrell)

In article <5546@cbnews.ATT.COM> henry@zoo.toronto.edu (Henry Spencer) writes:
>There is considerable work being done on equipping helicopters with some
>sort of short-range radar or lidar that can "see" wires, and a good many
>existing military helicopters are equipped with gadgets designed to cut
>any wires they strike, but the problem is by no means solved yet.

There are two current methods to deal with protecting helicopters from
wire strikes. Both were recently described in either Defense Helicopter World,
or possibly Rotor & Wing.

The first method is detection. This article cast some doubt on the viability
of the millimeter wave radar units for detecting wires, but did say that
a particular laser system was looking possible.

The second method is widely used today, in both civilian and military
helicopters. The WSPS (Wire Strike Protection System) consists of an upper
and lower wire cutter, and guides on the windshield and skids to deflect
the wire into the cutters. A typical installation costs in the neighborhood
of $35,000.

The article claimed that the majority of single wire strikes WITHOUT the
WSPS resulting in non-fatal crashes, while multiple wire strikes even WITH
the WSPS typically were fatal. Therefore, the major effect of having the
WSPS installed seemed to be to reduce the amount of damage to the helicopter,
and therefore the cost of the crash, but not the number of fatalities.

As someone who came within about 2 feet of a wire, and having a friend who
crashed a helicopter after a wire strike, I hope an effective technology
is found for this problem. For the helicopter I fly, it is the leading
cause of accident today.

					PC
					Comm/CFI Helicopter