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Old January 16th 13, 06:14 PM posted to rec.aviation.soaring
Eric Greenwell[_4_]
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Posts: 1,939
Default Glider EFIS anyone?

On 1/16/2013 1:45 AM, kirk.stant wrote:


Erik, once you have flown with a properly designed digital airspeed
indicator, you will hate going back to an analog one. We are trained
to think in terms of discrete, specific airspeed values, and while
yes you can glance at your airspeed indicator and (if you have flown
with it a lot) can get an idea of your speed ("3 o'clock is a safe
pattern speed, 2 o'clock is getting slow"), if you are aiming for a
specific speed you still have to compare the needle to the scale,
interpolate, and decide what speed it is indicating. With a big
number, it's just there. If I want 63 knots on final, I look at the
panel, see 61, and immediately know that I'm 2 knots slow. Ditto
when cruising - my nav computer says optimum Mc speed is 102 knots
(yeah, it's a good day out west ;^), I accelerate to what I think is
right judging by nose position on the horizon, then a glance see 106
and ease the nose up a bit.


The only time I use numbers when I'm thinking of or using airspeed is in
the pattern: I consider the wind and turbulence, then choose an amount
to add to my zero wind pattern speed. Once I have that, I fly to
maintain the needle at that position on the ASI - no more numbers.

All the flight before landing is done without numbers: follow the speed
director for speed to fly; thermal with the nose on the horizon; keep
the needle in the green (mostly); set flaps to the position indicated by
the needle.

Maybe if I had a digital readout for the ASI, I'd like it, but I don't
see how the actual number is useful for most of the flight. Next year,
I'll have glider with a glass panel, and then I'll have some experience
to better judge these choices.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)