Needles vs. numbers

[zoynyne]

I seem to prefer gauges with a needle on a circle (or any "scale" for that matter) over numerical displays. It seems much easier to get a good picture of what's happening at a glance that way.

High performance motorcycles today have retained old style tachometers for this reason, while adopting a digital speedometer to save weight. The ability to instantly see RPM during a very quick glance is deemed more important than the weight savings - and weight savings is a major priority there...

Is there a similar preference among pilots?

I should add, I'm not talking analog versus digital here (in terms of the actual working method), but purely of the information display method.

Isn't there a point of diminishing returns when a large number of information displays are condensed to a small area via the usage of numbers instead of needles on circles?

It would seem to me the only way to really make up for the loss of a needle on a "scale" would be to incorporate color changes into the displays - "bugs" if you will...

[lnuss]

Generally speaking, I agree with you that analog displays are easier to read/interpret than digital displays, especially when they are color-coded or banded. And the more quickly you need the information, the more difference there is between the two types.

A good example is the 12 hour clock face, vs. a numerical readout. I can tell the time on a 12 hour face from a lot further away than I can read the numbers. And "digital" watches often have the information so small that I must put on reading glasses to find out what time it is, but on a small 12 hour watch (even a ladies watch) a glance suffices.

Add to that the fact that you can get a "feel" (and the trend, for that matter) for the analog position of a dial/gauge/watch/etc. that is unavailable at any distance or size from the "digital" display.

To a degree the "tape" format gives the best (or sometimes the worst) of both "analog" and "digital," since it combines a sort-of analog with a numerical readout.

Because of all that, for most things I prefer the old "steam" gauges in aircraft over the CRT/LCD/etc. MFD type displays for the "sacred six," but I welcome the moving maps and other things that have been added on the MFDs.

And I don't think the color changes are going to replace more than a tiny amount of the information you get from analog, moving needle/dial displays.

[TornadoWilkes]

Now, as a simmer, I had immense difficulty trying not to look at gauges. After a long intense period of being smacked with a book each time I looked down, I know have feeling of dread each time I see a needle through peripheral vision.

Throwing a coat over the panel was my only respite and provided me with some real fantastic IFR skills.

I now tell heading by straining to see the sun through the clouds. Having no natural horizon is no problem either for a true professional, I simply have to check which direction the rain is falling to know where down is, although that fine rain that soaks you through doesn't work quite as well.

Seat of the pants feel is particularly important I believe, how moist they are determines how close I may or may not be to a mountain and a wet thumb in the airstream can give an airspeed calculation accurate to I don't know, around 40kts either way. If your wet thumb forms icicles, then there's a good chance that you're high up.

So are you climbing or descending? Have your ears popped? Heh who needs instruments? Its certainly simpler when you learn to fly "au naturel."

[flyinggriffin]

I read somewhere the other day on one of the aviation forums that studies have shown that the new displays are not as easy to read as the newer PFDs that you see in the airliners. We humans being very adaptive can make just about any sort system work.

The nice thing about needles vs the numbers is that a needle can show you a trend that a string of numbers going by can't. Take the simple ADF. Lets face it, no matter how much pilots bellyache about the difficulties of an ADF one simple fact remains, when all else fails point the needle at the nose of the plane, keep it there and unless the winds are exceptionally strong you will get there. Simple. Flying a holding pattern and want to see if you are too wide, or too close, just look at the needle. VORs and ILSs are the same. The needle swings back and forth.

Lets look at an altimeter analog vs digital. Once I am at cruise, a quick glance at the dial lets me know not only how much I am deviating, but the rate as well. It is amazing how the simple angle between two needles can tell you so much so fast.

Now, if you have ever used a HSI in real life, you would love to use it all the time. It makes flying an instrument approach or airway simple. Make it into a picture on an LCD screen is one thing, but don't change the form.