The ClearNav Instruments vario system has been designed to provide glider pilots with the best possible climb and speed-to-fly guidance, as well as valuable secondary information, including wind speed and direction, air and ground speeds, and altitudes.
The system can also manage tasks using the high resolution display, includes a secure flight recorder and can use either probe or purely electronic Total Energy compensation. It fits into a single 57 MM hole and the “black box” (Air Data Computer or “ADC”) can mount either directly to the display module or separately for maximum flexibility.
The vario has been designed to be fully compatible with the “ClearNav” display and, through the use of the Cambridge Aero instruments Dataport, can also integrate with other moving map/glideslope devices. Go to CNv Vario Features for details.
Note that not all Club features are implemented, but as they become available they will be distributed to our customers at no charge.
Following very encouraging early sales and acceptance of the vario we are now hard at work on finishing the code. We expect to have almost all of the missing features working and fully tested by early 2013.
There will be two models which between them will cover the requirements of any glider pilot, from centering his or her first thermal to winning in competition. Both models share common hardware. Upgrades are straightforward, software only and can be done by the end user.
Models, Pricing and Schedule
The ClearNav Vario is available in two models: “Club” and “Cross Country”.
Both models offer state-of-the-art total energy variometry for climb and cruise. High performance pressure transducers and advanced digital filtering yield rapid, but well damped response.
Feedback from our customers confirms that the vario has an uncanny ability to respond to lift without the frequent false alarms which plague other fast varios.
A highly visible mechanical pointer responds rapidly and smoothly to glider vertical motions, and a high resolution digital display shows both a short-period average rate of climb, and the average since the climb began.
Audio tones allow for centering without reference to the display.
Both models provide netto and speed to fly information and both are extensively user-configurable to accommodate any sailplane and any pilot preference.
Speed to Fly information is presented by visual display, audio tones or both.
Other features common to both models are a unique “Get Home” screen which provides navigation and glideslope information to the point of takeoff, winds (headwind/tailwind and vector wind) and electronic Total Energy options.
A simple user interface and a profile editor make the products both easy to use and easy to configure.
The Cross Country model adds: a secure flight recorder, task management, and the widely used CAI Dataport which allows third-party devices to use GPS, airspeed, and altitude data generated by the vario, and to send task declarations to the Secure Flight Recorder.
CNv MAIN FEATURES
CNv ADDITIONAL FEATURES
Air Data Computer
The ADC is housed in a small aluminum enclosure which may be attached to the display/controller or separately mounted as required. In addition to four pressure transducers (Pitot, Static, Total Energy, and the cockpit static-referenced sensor mandated by the IGC for Secure Flight Recorders) the ADC has a three-axis accelerometer, a three-axis rate sensor (gyro), and a three axis magnetometer. The ADC provides connectivity via two CAN bus jacks, a serial jack and a USB jack. The USB jack can supply 950 mA to a connected device. A ten-position connector provides power and ground, and inputs for gear and spoiler alarms, a temperature probe and cruise/climb switching.
Display and Controller
The display/controller mounts in a 57 MM hole. A highly visible mechanical pointer driven with a micro-stepper motor displays Total Energy, Netto, or Relative Netto values. The high contrast, high resolution monochrome LCD can display a large range of in-flight data and is used in conjunction with two rotary encoders to control the instrument.
A telephone cable, terminated with modular plugs brings power and data from the ADC and carries data to the ADC. (A longer then stock cable can be used to position the ADC further away from the display/controller if required. The ADC UP/AFT orientation must be maintained in all installations.)
Many settings can be managed with the display/controller alone, others, such as polar selection, pilot name, audio behavior and the configuration of inputs on the ten-position connector, are managed with a PC-based editor. Multiple profiles may also be used to experiment with different instrument settings without having to make numerous changes in flight.
Simple User Interface
We have chosen a particularly simple UI which is easy to learn and hard to forget. There are two rotary knobs, one (at the top left) selects which screen is displayed (Cruise/Climb, MacCready, wind, etc). The other (at the bottom right) changes the value of a number on the selected screen (such as MC, altimeter setting, ballast, pointer time constants etc). For screens presenting multiple choices (such as flight logs, profiles etc) the knob highlights the active choice. Display screens are grouped to simplify their use: Flying Screens are used for items most commonly needed in flight, Settings Screens are typically used on the ground and are seldom used in flight, and Tools and Information screens are reserved for items which are not frequently used.
Almost all set values are “sticky” – once set they remain as set until set again. Generally the stickiness is indefinite. Some parameters, such as MC, bugs and ballast, are reset to default values when the vario is turned on the next day.
In general there is no “set/acknowledge” function – after a parameter is changed it remains at its new value on paging away to another screen.
If the vario is connected to a ClearNav display, MC, bugs, and ballast values are synchronized and tasks created using the ClearNav display may be copied to the vario. Copying a task to the vario gives the pilot a completely independent navigation and task management option as a backup.
Audio and pointer give fast Total Energy feedback to the pilot and the climb screen has two averagers for longer term assessment of climb:
|This and all screen images are simulations.
The “smart” 20 second digital averager (top right) is a filtered average climb rate. On the transition from cruise to climb this averager is reset. It initially shows the one second average, then the two second average etc until at twenty seconds and longer it shows the twenty second moving average.
A second averager (bottom right) shows the average climb for the current thermal from the start of the climb to now. This value is just the change in total energy divided by elapsed time since the start of the climb. Both averagers have associated timers (top left and bottom left).
Speed to Fly is displayed both in traditional push/pull format (left) and numerically as a smoothed Speed to Fly number (lower right). Audio tones allow accurate speed control without reference to the display.
The profile editor provides full control over the audio, including deadband width and optional suppression of sink tones. The time constant controlling the numeric Speed to Fly value is also controlled via the profile editor.
The winds screen
shows headwind/tailwind component (left) and vector wind (lower right). The arrow (top center) shows the direction of the wind relative to the nose of the aircraft.
Get Home Navigation
gives all the information needed to get home including distance, bearing and track, and an arrow which points to the home field, When the arrow is aligned with the nose of the glider it is flying direct to home. The arrival height is on the bottom of the screen. If this value is zero the glider will land just as it gets home (assuming sink and lift balance!).
Electronic Total Energy
“Electronic” Total Energy does not make use of a Total Energy probe but uses the pitot and static pressures instead. This allows the vario to be used in gliders not equipped with a Total Energy probe. The electronic Total Energy system may also be used in conjunction with a Total Energy probe to make adjustments to the probe response. This can be very useful for Total Energy probes with under-compensation behavior.
Secure Flight Recorder
Approved for all flights including World records.
Two levels of task management exist. The simplest allows a third party device to export a declaration (including the task and its control points) to the Secure Flight Recorder. Normally the task would be managed automatically so that after the start the active waypoint becomes the first task control point etc. We also provide a task screen which gives the pilot the ability to select the active waypoint using the lower right encoder.
It is also possible to export waypoint databases to the vario using the Profile Editor and a USB drive. If a waypoint database is present then there are additional options, including the ability to select landpoints ranked by distance:
Using the all-control-points option it is possible to manage any task quite independently. This provides a valuable backup in the event of a primary nav failure.
Many third-party applications can send and receive data over this open-source utility.
Netto and Relative Netto
The netto value at the top right of the cruise screen
is the average (with a time constant which can be set by the pilot) of the airmass vertical motion. This field can alternatively display relative netto (the climb rate that could be achieved if the glider were slowed to thermalling speed and put into a 45 degree bank).
A dedicated screen shows Indicated, True, and GPS ground speeds.
There are two altitude screens. One is conventional and shows msl altitude and the barometric pressure (“altimeter setting”), along with the GPS (WGS-84 ellipsoid) altitude:
The second altitude screen shows logger altitude, pressure altitude, and msl altitude using the barometer setting of the first screen.
Logger altitude is the one that determines penalties so it’s very useful to know. Because the static reference for the logger is the cockpit, not the system static, the logger altitude is often different from the system altitude.
Pressure altitude is useful if airspace is defined using flight levels.
The third line is the system msl altitude
Outside Air Temperature
An optional OAT sensor can be provided. It is wired to the ten-position connector. OAT corrections to TAS are minor but are done automatically when an OAT is present. Since a knowledge of the outside air temperature is often useful there is a screen to display this value.
The vario supply voltage is displayed on the same screen as the OAT.
Both the climb and the cruise screens show MC values but a separate screen
is used to set the MC value. This is the first screen which appears when the top right encoder is rotated clockwise. The Speed to Fly number is the neutral air value – it is the cruise speed in air with no vertical motion, taking into account the polar and the MC, ballast, and bugs settings.
By default the lower right encoder is the volume control.
The amount of ballast can be set on the top line:
The second and third lines show the total weight (dry weight plus ballast) and the wing loading.
The bugs screen allows for an estimated performance degradation. “100%” means 100% performance (not 100% bugs!). The computed best L/D value is a reminder of the performance degradation.
The time constants for the pointer and audio can be adjusted in flight. The digital averager time constant for netto may also be adjusted in flight.
Dry Weight Adjust
This facility is useful for two-seat gliders and for any glider where there might be large variations in pilot weight. The “base” weight (844 lbs in the example below) is set with the profile editor and can be adjusted with the LR knob.
Both UTC and local time are displayed. Both are derived from the GPS engine.
Polars for known gliders are provided in the CAI format in the Profile Editor. For two-span gliders we provide a facility which allows for switching between polars:
Under some conditions the display visibility can be enhanced through the use of the backlight.
All combinations of the following basic units of measure are supported:
Length: sm, nm, km, m, ft
Volume: US gal, l
Mass: lb, kg
Speed: mph, kt, km/h, m/s
Temperature: ºF, ºC
GPS data is available and includes position, time, altitude, EPE etc.
Flight logs with logging intervals of 1, 2, 4, 8, or 12 seconds can be downloaded to a USB drive.
A screen is provided to show the number of flights and total flight time for the day.
In the highly unlikely event that the pointer is not properly aligned to zero a means is provided to remove any offset.
User profiles, software updates and waypoint databases are copied to a USB drive. A simple interface allows the user to choose any or all of the options and upload them to the vario.
Switching can be automatic or manual. Three types of manual switching are supported: Flap, toggle, and momentary push-button. The toggle option allows pilots of non-flapped gliders to select cruise or climb using the kind of miniature toggle switch often mounted on the stick. The momentary switch option gives the pilot full control while maintaining the inherent advantages of an automatic system. This switch always puts the system into climb mode, and zeroes both averagers and both timers. Typically the pilot would use this switch when entering an exploratory turn in search of a thermal – if the pilot continues to circle the system remains in climb mode, if not it reverts to cruise mode. It will also be possible (using the Profile Editor) to make a conventional toggle switch behave like the push-button switch in that only a change, not the position of the switch matters.
The ten-position connector has inputs for gear and spoiler microswitches. A slow airspeed alarm is also provided.
ClearNav Vario Development Schedule
||NOV 23 2012
|COMPLETE BETA CODE
||JAN 31 2013
|TESTING AND CODE REFINEMENT
||FEB 01 2013 - MAR 31
|RELEASE CANDIDATE TESTING
||MAR 01 2013
||MAR 31 2013
Now shipping the Club Model with some features not yet released – these include wind information, electronic Total Energy, and get-home navigation.
Hardware configuration and production are now stable.
Complete Beta Code
By the end of January we expect to have completed code writing and to have all features working, including the flight recorder. At or about this time we will submit materials to the IGC, after which timing is out of our control although we expect to have the approval by or about May 01.
Testing and Refinement
As soon as we have useable code we will begin flight testing, mostly in the southern hemisphere but where possible in the USA also. Bench testing will parallel flight testing.
Release Candidate Testing
Multiple pilots will be flying with one or more release candidates at the US “Seniors” contest held at Seminole Gliderport in central Florida in the second week of March.
We will begin shipping hardware for new orders with the production release code and that code will be available for download and field-installation also.
ClearNav Vario Pricing
Refer to Pricing Page fo latest CNi pricing. (here)