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Details About the
Tangent Flight Computer
Features and Specifications

A Description of the Tangent
Tangent Flight Computer Specifications

Arai Design announces the Tangent Flight Computer.

The Tangent Flight Computer is a radical departure from the standard field of hang gliding and paragliding instruments in that it offers sailplane flight computer capabilities at hang gliding variometer prices. It has proven it's capabilities: Gold Medal, '96 Women's Worlds; Silver Medal, '93 Worlds; '94 & '95 US National Title; '95 British National Title; First and second, '95 & '96 East Coast and '95 Hobbs meets. The Tangent is the choice of 6 out of 7 US Team pilots. It works, and it works well. Chris Arai designed the TFC from the ground up with XC performance in mind: It is doubtful any other instrument designer is as familiar with requirements of XC flying.

The Tangent includes all the regular variometer features such as airspeed, altitude, rate of climb, and total energy, but it's specialty is in implementing the speed-to-fly (S2F) theory so that it is accessible to all pilots. Rather than having to "chase the needle" as with MacCready speed rings, the Tangent tells the pilot to speed up or slow down with audio tones, so that the pilot is free to look ahead and make decisions rather than stare at a speed ring. The Tangent has two audio modes: The climb mode is the usual variometer interrupted tone proportional to rate of climb. The second is the S2F or glide mode. In this mode there are two tones that are distinct from the climb tones. One tone indicates that the pilot needs to speed up, the other tells the pilot to slow down. When the pilot is flying the optimum speed, the vario becomes silent. Also unique to the TFC is the Auto Switching feature. The TFC will automatically detect when the pilot is flying in lift or sink and switch the audio between glide mode and climb mode. The TFC can also be manually switched between the two modes.

What most pilots don't realize is how much performance they are losing by not flying S2F, nor how much variation of their speed is required in order to fly S2F. Any pilot who has flown with a speed ring may have discovered that they were not flying at the optimum speeds. They may also have noticed improved gliding performance, but they would also know how much you have to stare at the vario to fly correctly. Most pilots don't use speed rings because it's too much hassle to set up or too complicated to understand and use. The Tangent takes care of all that.

The Tangent Flight Computer implements the full S2F theory, going far beyond the simple MacCready Ring. It calculates the S2F based on head/tail wind, expected next climb rate and the glider's polar. The polar is adjusted for pilot weight and ballast, as well as for changes due to altitude. The airspeed is also compensated for altitude, since true airspeed is required for accurate S2F. Up to 10 different polars may be stored. The pilot needs only know the basic concepts of the S2F theory and none of the math.

Another feature is the final glide calculator. Input distance to goal (manually or via GPS interface) and the wind, the Tangent will tell you when to leave in order to make goal in the least amount of time using either your current average climb or your speed ring setting. This allows you to monitor your progress while on final glide.

Now available is the GPS interface. Connected via cable to popular GPS units such as the Garmin 38/40/45/90 series, the Tangent can calculate the component of head wind and make final glide a snap.

The Tangent has a very clean and easy to use interface, making it both the most sophisticated instrument and the simplest to use. The display is organized into multiple pages which show in-flight data, set up parameters, polar information, and final glide information. All the parameters are clearly labeled in each display, making adjustments easy even without constant reference to the manual. Pilots who can't remember how to program their radio can easily operate the TFC. Even if your VCR forever flashes "12:00" you will have no problems with the Tangent.

Not only are the features different, but so is the technology. It is based upon a microprocessor powerful enough to implement S2F, final glide, and a Total Energy system that we believe is the best in the industry. The display is not a fixed image LCD which offers limited information, but an alphanumeric display so that it can display unlimited amounts of information. This not only expands the Tangent's usefulness and accessibility, but also protects the pilot's investment since new features can be easily added via firmware upgrades. Another new feature is an airspeed indicator without moving parts. No more dust in the bearings of that little propeller. The circuit board is 4 layer surface mount which is well shielded from EMI/RFI. The case has a aluminum back plate that has proven extremely sturdy in many hard landings.

The Tangent Flight Computer is targeted at recreational and competition cross country pilots. The price is competitive with top of the line hang/para gliding variometers. There is no other variometer on the market that has the capabilities of the Tangent Flight Computer. The Tangent is available now with a one week delivery. All inquiries are welcome.



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