The Best Altimeter for General Aviation, ever!!

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Every once in a while, I've had the opportunity to work on something that has turned out to be an industry game changer.  Giving a nod to my background in computer forensics, one recent game changer that I've been privileged to be a part of is the CRU / WiebeTech "Ditto" product, which sucks information from hard drives in a forensically sound manner.  In fact, it can do it from halfway around the planet.  It does other really cool stuff too, like support stealth mode, but I won't talk about that here.  :-O

My 30 year background in electronics, combined with my aviation passion, has allowed me to create a product which is simple to understand, and is very useful in multiple ways, and is affordable, and will be used by the owner, providing years of "why didn't someone do this before" moments as it provides valuable flight information.

It does many really cool things:

For instance, it displays Standard Indicated Altitude, which is received from a temperature compensated solid state pressure sensor circuit built inside the unit.  This is the altimeter function you've come to know and expect.  It works from 0 to 20K feet, no issues.  You set the local altimeter pressure, it gives you the altitude.

The screen looks like this:

Indicated Altitude on Altimeter from Belite Aircraft

There are two indicator lights on the left (only one is used in this model).  There are three switches in the unit.  In order to set the local pressure just touch the left or the right switch.  The pressure setting will move up and down.

If you touch the center switch, the unit will skip forward to the next mode, which is one of its coolest features:

*  DENSITY altitude.  The unit will supply the calculated density altitude, based on cockpit temperature.  This feature is alone worth its weight in gold.  I no longer guess or calculate the DA, I just touch a button and it reports it to me.  You don't have to input the local pressure setting for this to work correctly; in fact the local pressure setting is irrelevant to the Density Altitude calculation.  Density altitude looks like this:

Density Altitude calculation on Belite digital altimeter.

Density altitude, by convention, is always shown rounded to the nearest 100 feet.

By clicking the mode switch again (and again), you can move through several more display modes.  They include:

Current system voltage
Current absolute pressure in inches or in Pascals
Current system voltage alarm level
Current display system -- English or Metric
Temperature, in Fahrenheit or Celsius
VFR Cruising alarm enable

Displaying the current system voltage is straightforward.  I've got a screen shot showing an example:

Display the voltage

The unit shown was attached a nine volt battery.  It will work fine with anything between 8 and 14 volts, so attaching to any conventional 12/14v system is fine.

One of the screens lets you select a system voltage alarm level:

Display the voltage alarm

So for my 9 volt battery, I set this to 8.6 volts.  For a 12 volt system, I would probably set it to about 12.5 volts -- it would never go off unless the alternator failed.  It flashes a battery symbol in the lower left corner of the display when the voltage is low.

I like the temperature display, because I think the design of the display icon is kind of cute.  Here it is:

Belite digital altimeter showing temperature in fahrenheit.

As mentioned, there are several other screens which the unit will display.  While stepping through the screens, you can always switch back to indicated altitude by holding the center mode switch down for about 2 seconds.

And if you hold the same button down for about six seconds, the unit will turn off.  Touching any button brings it back to life.

While on the home (indicated altitude screen) if you push the mode button down, it will turn on a soft internal backlight.  The backlight may also be attached to an external dimmer, compatible with 0 to 12 volts.

Another really interesting function for the average General Aviation pilot is the VFR cruising alarm.  This alarm, when enabled, will flash the LED with a bright Red blink pattern when your altitude varies more than 100 feet from a VFR cruising altitude.  For instance, if you are flying at 5500 feet, and the alarm is enabled, and you stray downwards to 5399 feet, the alarm will alert you.

The unit is so sensitive and accurate, you may place it at your feet and read the altitude, then move it to over your head, and read the change in altitude.  There is a little single digit inaccuracy, but you will note a change in between 6 and 10 feet.  Also, the unit is very fast -- it updates information many times per second.

Here's some basic technical information.

1.  This unit weighs 50 grams, about 1.5 ounces.

2.  This unit consumes about 1 milliamp of power.  That is one-thousandth of an amp.  (Assuming the backlight is NOT turned on.)

3.  The external dimmer line is compatible with any voltage from 0 to 12V.  Must supply up to 40ma of power for the backlight.

4.  The unit will fit in any standard round 2.25" instrument hole.

5.  You may remove the metal faceplate and directly mount the unit in any flat panel (must drill appropriate holes and cutouts to accommodate.)

6.  Power supply must be between 8 and 14 volts.

7.  Indicated altitude is shown in increments of one foot.  Internal Analog to Digital converter has less resolution but is "dithered" to increase resolution.

8.  The unit is upgradeable via firmware downloads.

9.  It will display any altitude between 0 and 20,000 feet.

10.  The VFR cruising alarm margin is +/- 100 feet.

11.  As the unit is 'experimental', it may be used in any experimental airplane or ultralight airplane.  With manufacture support, it could be used in Light Sport Aircraft.

12.  When purchased in our enclosure version, it may be used in any aircraft.

You can order it from our online store, or from Aircraft Spruce, or from any of our international distributor partners.  Pricing is $249.95 (US), or $299.95 in an enclosure with battery.

Absolute Pressure in Pascals.

In summary, my competitive sales guide would read like this:

1)  Lightest industry weight -- 50 grams
2)  Smallest size -- very thin, fits standard panel 2.25" hole
3)  Lowest power consumption -- 1 milliamp
4)  Highest resolution -- 1 foot displayed
5)  Useful range -- 0 to 20,000 feet
6)  Safety paramount -- provides Density Altitude
7)  Cool additional features:  -- voltage alarm, VFR cruising alarm, more
8)  Great value -- $249.95
9)  Also available in an enclosure for use in any airplane