Flyer II is an entry-level vario in the new line of flight instrument by Digifly. Again, it is very orange but in comparison with the previous model VL100 Flyer the case is slightly smaller (slimmer). As before, the instrument is provided with a Velcro strap for leg-mounted application. The strap can be easily removed and the instrument can be mounted on a cockpit or a HG bracket. The whole technological concept is entirely new and Digifly backs it confidently by a 3 years warranty.
Using of the Instrument
If the old Flyer was a simple to use instrument where the instruction manual was more or less a formality, Flyer II goes one better. The easy to access menu contains a detailed description of each function and there is a little more one needs to know for a successful use of the instrument. Scrolling and selection of functions is, due to a smart design of gloves-friendly pushbuttons and their distinct marking entirely intuitive. A comprehensive instruction manual is possible to download from the Digifly website just in case.
Power Supply and Consumption
The power supply is provided by only one AA battery. The electronics works equally well with either alkaline battery or a rechargeable (NiMH or NiCd) cell. Inbuilt digital voltmeter displays the cell's voltage during the power-up and later, during a normal use is the remaining battery capacity displayed graphically by an icon at the bottom of the display. If using rechargeable cells, it is necessary to take in account their lower voltage; the icon will never display 100% full battery in this case. In an instrument with consumption as low as Flyer II has, using rechargeable batteries doesn't make much sense anyway. An alkaline battery lasts typically a whole season or longer.
During a normal use the power consumption is 29mA so a fully charged NiMH cell lasts almost 100 hours. A good alkaline battery lasts about twice as long. Flashing battery icon will signal if there is less than 20 hours left till "empty". This number is valid only for alkaline batteries, as in rechargeables the discharge curve is much steeper.
The manufacturer recommends performing battery change within 1 minute otherwise the clock will have to be reset. Our tests revealed the time has to be actually much shorter: about 10 seconds. But, nothing to worry about as resetting of the clock is a breeze anyway and even a keen user will not have to change the battery more than once a year.
Graphic altimeter is an interesting and innovative function. It displays the vertical projection of flight in real time showing the latest changes of altitude. The graph is not being recorded, but it is being continuously refreshed at a custom selected rate. The height difference the graph covers is also customisable.
Flyer II has 3 independent altimeters. The main Altimeter 1 is intended to show altitude and it is adjustable only from the menu. Remaining 2 altimeters can be adjusted either from the menu as well or zeroed from the main screen at the places of pilot's choice. Maximum displayed altitude is 9,999 meters and it can be presented in Feet as well.
Flyer II has two variometers. The analog one is in the shape of a bar at the left hand side of the display. The range of vertical speed is adjustable from +/- 1m/s to +/- 10m/s in 2m/s steps in accordance with conditions. This feature enables pilot to select the optimum range for any given situation. It is also possible to adjust the response time of the vario - a feature that can be compared to an adjustable automotive shock absorber.
The digital variometer displays vertical speed in large sized fonts in the range +/- 25m/s. This display can be averaged from 0 (immediate) to 60s time interval.
This feature in Flyer II is the most versatile I've seen in the 16 years of my testing of aviation instruments. I'm sure it is not only my subjective impression. As I can't demonstrate sounds on paper I'll try to explain how it works by words.
The volume is possible (the same as in the old Flyer) to adjust in 2 levels and also switch off completely from the main screen. The sound threshold is adjustable in the menu independently for lift and sink, in both cases starting from 0m/s. Very important for pilots who fly "by the ears" and want to know when they encounter the slightest movements of air in the "up" direction - even if the wing is still sinking.
The sound modulation is adjustable as well. There are 4 alternatives: low, medium, high and ultra. In light coastal conditions the ideal setting is "low" (fine distinction of low levels of lift), at a place like Owens Valley the "ultra" setting will do a better job. If you have a fine musical ear, you can also adjust the duration of individual tones and their pitch! At this point the standard sentence: "The instrument has this and that acoustics." is losing its meaning. Flyer II simply has the acoustics the pilot chooses. What more to say...
There was an error in the first firmware version preventing the above adjustments of acoustics. This was quickly rectified and the first owners of Flyer II had a nice demonstration how easy is to upgrade the firmware. A simple serial connection cable (old Flyer required a special programmer) is all what is needed and then you just download the free firmware from Digifly website.
Out of curiosity we cooled the instrument down to -30dg C. All 3 altimeter responded identically by reducing the displayed altitude by 21 meters, while the vario display reminded unaffected. This is a small step back from the virtually absolute temperature stability of the old Flyer.
Besides of a clock with a date display (day, moth and year) Flyer II has a chronograph as well. The chronograph can be operated either manually or automatically depending on option the owner selects as I explain later in the "Flights Recording" section.
A malicious attempt to enter a non-existent date (like 31st of April) Flyer II rejected, but surprisingly it didn't find anything strange about the 30th of February.
Flyer II features also a thermometer; one of the multi-function permanent display fields at the bottom part of the screen. It has a choice of units - either Celsius or Fahrenheit.
Scrolling thru the multi-function display you can also select barometric pressure in hPa (mB). The barometer can be calibrated in the menu section.
Total Energy Compensation
This feature eliminates vario responses to "non-thermic" ascends like a recovery from a steep dive etc. Sailplane pilots know this type of climb as a "stick thermal". An optional airspeed sensor is needed for the TEC function. The amount of compensation is adjustable according to the characteristics of the aircraft flown.
Flyer II stores peak values of the last 50 flights. The list of recorded values is well organized and comprehensive. It includes maximum and minimum altitude, maximum vertical speed in both directions, top airspeed (with AiS), accumulated climb, flight duration, date and time of takeoff.
Like in the previous model, the start of recording can be selected to be either manual or automatic. The automatic start is highly functional and reliable. The recording will start when Flyer II detects a certain change of altitude over a period of time. Both parameters are customisable.
The firmware of Flyer II enables the instrument to "talk" to the user in a few most widely used languages. Besides of the usual English this instrument has a good command of Spanish, French, German and Italian. Version 3.0 includes also Czech.
Traditionally Digifly designs their instruments as "upgradeable". The new range of instruments Flyer II is a part of can be upgraded even more easily than the previous models. A simple serial cable replaces the need for a special programmer. The possibility of upgrading firmware is a distinct advantage as the system is being continuously improved. With the latest hardware technology Flyer II can remain the "latest hit" thru firmware upgrades for many years to come.
Flyer II can be connected to PC by a serial cable (not supplied as standard). Similar instruments like Flytec 4005 or Brauniger Pilot don't offer this feature. The new cable is not compatible with the old Flyer. A new software for downloading flight data into an electronic logbook will be available from Digifly website for no extra cost soon. It was originally designed to be used with the more advanced instruments of this range like Cartesio II and Leonardo. You can lucidly compare characteristics of Digifly variometers in this table.
The above software may be unnecessary complicated for Flyer II as this instrument logs only the peak values (no 2D or 3D tracks) of each flight. For those who like things simple is being developed a third party software (a new version of Digifly Reader) by Luke Lemen. A demo version will be free as before. The full version allowing exporting data in TXT and XLS format will be downloadable from SkyFly shop for about Kc 400 ($20).
Digifly entered the aviation instrument market in 1989, but their products became truly popular on our market only in 2004 - 2005. Now, by the number of units sold Digifly instruments are by far the best selling varios in Czech Republic. From the perspective of functionality and the level of technology used, even the basic model Flyer II is so far ahead of the competition there is no real point of comparing this product with the basic models by other companies. It is hard to tell why other manufacturers slept in so hard.