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    Re: 3-Star Fix - "Canned Survival Problem"
    From: Mike Burkes
    Date: 2008 Jul 8, 16:46 -0700

    Hi GL that is pretty slick and I imagine the user would become
    accustomed to that type if that was his only exposure. It seems it is
    an advanced model i.e. I would assume the user has already visualized
    the wind triangle ala E6b and/or rough sketch and does not wish to
    fuss with pencil lines. Has anyone had experience with the Jepp Model
    CB-1(charles bravo dash one)? As always great stuff and thanks much!
    Mike Burkes
    
    On Jun 14, 10:11�pm, "Gary J. LaPook"  wrote:
    > Gary J. LaPook wrote:
    >
    > > Gary J. LaPook had written::
    >
    > > "The MB-2A is very similar to the MB-9 pictured here:
    >
    > >http://www.rekeninstrumenten.nl/pages%20and%20pictures/12071.jpg
    >
    > > except the true airspeed goes up to 1800 knots on the MB-9 while it
    > > only goes up to 1000 knots on the MB-2A. Since I don't fly planes that
    > > can exceed 1000 knots I prefer the MB-2A since its more limited speed
    > > range allows an expanded scale for the range it covers.
    >
    > > It is very similar to the Felesenthal PT computer pictured here:
    >
    > >http://www.rekeninstrumenten.nl/pages%20and%20pictures/12141.jpg
    >
    > > in that each of these computers solve the wind triangle with trig, no
    > > vector diagram is drawn."
    >
    > > Gary adds:
    >
    > > In case you were wondering how you can solve the wind triangle with
    > > trig on the MB-2A without a vector diagram �the answer is simple, the
    > > law of sines. TAS/sin RWA = WS/sin WCA = GS/sin (RWA +/- WCA). To do
    > > this on a digital calculator first figure the Relative Wind Angle (the
    > > angle the wind is coming from compared the true course, WD - TC. Next
    > > divide the True AirSpeed �by the sine of the RWA �and save that value
    > > in a memory as you will use this constant twice. �Next divide the Wind
    > > Speed by this constant, take the inverse sine and you have the Wind
    > > Correction Angle. Finally add or subtract the WCA from the RWA,
    > > subtract if the wind is a head wind and add if a tail wind, take the
    > > sine of this angle and multiply by the constant to give you Ground Speed.
    >
    > > The MB-2A does this computation for you. First place the TC arrow on
    > > the true course on the outermost RED scale and then read the RWA on
    > > the next inner RED scale lined up with the WD. �This first image shows
    > > this with the TC of 50, the WD of 100 giving a RWA of 50.
    >
    > > Next line up the TAS on the outermost BLACK "miles"scale with the RWA
    > > on the "wind scale" which is a sine scale. The next image shows 120
    > > knots lined up with 50 on the "wind scale."
    >
    > > The "constant" mentioned above is found uner the "1" index but you
    > > make no use of this and you don't even have to notice, the computer
    > > takes care of it for you.
    >
    > > Next look on the "miles" scale for the Wind Speed and take out the WCA
    > > on the "wind scale." The next image shows a 20 knot WS on the "miles"
    > > scale lined up with WCA of 7.3� on the "wind scale."
    >
    > > Subtracting this 7.3 WCA from the RWA of 50 we then set the cursor on
    > > 42.7 on the "wind scale" and read out the GS on the Miles scale, 106
    > > knots.
    >
    > > gl
    >
    > >>With the exception of the red numbers on the outside rings, your MB-2A
    > >>computer looks remarkably similar to the Jeppesen CR series (CR-3,
    > >>CR-6, etc.) - is it maybe a military version (or an earlier version)of
    > >>the Jepp one?
    >
    > >> Gary LaPook responds:
    >
    > >> The MB-2A is very similar to the MB-9 pictured here:
    >
    > >>http://www.rekeninstrumenten.nl/pages%20and%20pictures/12071.jpg
    >
    > >> except the true airspeed goes up to 1800 knots on the MB-9 while it
    > >> only goes up to 1000 knots on the MB-2A. Since I don't fly planes
    > >> that can exceed 1000 knots I prefer the MB-2A since its more limited
    > >> speed range allows an expanded scale for the range it covers.
    >
    > >> It is very similar to the Felesenthal PT computer pictured here:
    >
    > >>http://www.rekeninstrumenten.nl/pages%20and%20pictures/12141.jpg
    >
    > >> in that each of these computers solve the wind triangle with trig, no
    > >> vector diagram is drawn.
    >
    > >> The Jeppesen CR-3 pictured here:
    >
    > >>http://sliderule.mraiow.com/wiki/Jeppesen_CR-3
    >
    > >> uses a diagram on the back to determine wind factors so its method is
    > >> completely different than the previous computers. �All of these are
    > >> similar in that they have the standard time-speed-distance scales and
    > >> they allow for compressibility in computing true airspeed.
    >
    > >> The original E-6B pictured here:
    >
    > >>http://www.rekeninstrumenten.nl/pages%20and%20pictures/12081.jpg
    >
    > >> uses a wind vector diagram on the back and does not allow for
    > >> compressibility in TAS computations.
    >
    > >> gl
    >
    >
    >
    > �IMGP4734-1.JPG
    > 186KViewDownload
    >
    > �IMGP4735.JPG
    > 185KViewDownload
    >
    > �IMGP4736.JPG
    > 183KViewDownload
    >
    > �IMGP4737.JPG
    > 184KViewDownload- Hide quoted text -
    >
    > - Show quoted text -
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