FAQ
Find answers to our most frequently asked questions below. Before contacting us through our support service, please check here to see if you can find a solution to your problem.
Applies to: All Flybox products equipped with a CAN bus interface.
Communication failures on a CAN bus network are almost always caused by installation or wiring issues rather than by the connected instruments. Before troubleshooting the equipment, verify that the CAN network has been installed correctly.
Verify CAN-H and CAN-L Connections
Ensure that the CAN-H and CAN-L conductors have not been reversed.
Swapping these two signals prevents communication between all devices connected to the network.
Verify CAN Bus Termination
A CAN bus must always be terminated with two 120 Ω resistors, one installed at each end of the network.
With the aircraft electrical system switched OFF, measure the resistance between CAN-H and CAN-L using a digital ohmmeter.
The measured value should be approximately 60 Ω.
If the measured resistance differs significantly from this value:
verify that both termination resistors are installed;
verify that each resistor is rated at 120 Ω;
verify that the resistors are installed only at the two physical ends of the CAN bus.
Incorrect or missing termination is one of the most common causes of unreliable CAN communication.
Dual CAN Networks on ECU-Controlled Engines
Rotax iS engines and many other electronically controlled engines are equipped with two independent CAN networks.
When connecting these engines to an EFIS that provides only one CAN interface, installers sometimes connect the two CAN networks together.
Although each network may already be correctly terminated, connecting them in parallel reduces the overall termination resistance to approximately 30 Ω, preventing reliable communication.
For this reason, Flybox strongly recommends measuring the total CAN bus resistance after the complete installation has been wired and before powering the system.
For additional installation recommendations, refer to the Flybox CAN Bus Installation Guide.
Click the button on the right to view a brief guide.
Communication failures on a CAN bus network are almost always caused by installation or wiring issues rather than by the connected instruments. Before troubleshooting the equipment, verify that the CAN network has been installed correctly.
Verify CAN-H and CAN-L Connections
Ensure that the CAN-H and CAN-L conductors have not been reversed.
Swapping these two signals prevents communication between all devices connected to the network.
Verify CAN Bus Termination
A CAN bus must always be terminated with two 120 Ω resistors, one installed at each end of the network.
With the aircraft electrical system switched OFF, measure the resistance between CAN-H and CAN-L using a digital ohmmeter.
The measured value should be approximately 60 Ω.
If the measured resistance differs significantly from this value:
verify that both termination resistors are installed;
verify that each resistor is rated at 120 Ω;
verify that the resistors are installed only at the two physical ends of the CAN bus.
Incorrect or missing termination is one of the most common causes of unreliable CAN communication.
Dual CAN Networks on ECU-Controlled Engines
Rotax iS engines and many other electronically controlled engines are equipped with two independent CAN networks.
When connecting these engines to an EFIS that provides only one CAN interface, installers sometimes connect the two CAN networks together.
Although each network may already be correctly terminated, connecting them in parallel reduces the overall termination resistance to approximately 30 Ω, preventing reliable communication.
For this reason, Flybox strongly recommends measuring the total CAN bus resistance after the complete installation has been wired and before powering the system.
For additional installation recommendations, refer to the Flybox CAN Bus Installation Guide.
Click the button on the right to view a brief guide.
Applies to: All Flybox instruments featuring fuel level indication (excluding Fuel Computer functions).
If the fuel level indication appears inaccurate after calibration, the instrument may still be operating correctly.
During the calibration procedure, the instrument continuously monitors the electrical output of the fuel level sender.
If the voltage variation generated by the added fuel is too small to be measured reliably, the following message is displayed:
Small variation in mV
When this message appears, the quantity of fuel that has just been added is not included in the calibration curve.
For example, if 5 litres of fuel are added three consecutive times and the message is displayed after each addition, the calibration process will ignore a total of 15 litres.
This behaviour is normal.
It simply indicates that, at that specific float position, the fuel sender does not provide sufficient resolution for the instrument to detect such a small change in fuel level.
Recommendations
For best calibration accuracy:
follow the calibration procedure described in the instrument manual;
add sufficient fuel at each calibration step to produce a measurable sensor output variation;
verify that the installed fuel sender is compatible with the instrument specifications.
If the fuel level indication appears inaccurate after calibration, the instrument may still be operating correctly.
During the calibration procedure, the instrument continuously monitors the electrical output of the fuel level sender.
If the voltage variation generated by the added fuel is too small to be measured reliably, the following message is displayed:
Small variation in mV
When this message appears, the quantity of fuel that has just been added is not included in the calibration curve.
For example, if 5 litres of fuel are added three consecutive times and the message is displayed after each addition, the calibration process will ignore a total of 15 litres.
This behaviour is normal.
It simply indicates that, at that specific float position, the fuel sender does not provide sufficient resolution for the instrument to detect such a small change in fuel level.
Recommendations
For best calibration accuracy:
follow the calibration procedure described in the instrument manual;
add sufficient fuel at each calibration step to produce a measurable sensor output variation;
verify that the installed fuel sender is compatible with the instrument specifications.
Applies to: Flybox instruments that measure CHT, coolant temperature or oil temperature using direct analogue sensor inputs (for example Rotax 912 and Rotax 914 engines).
Unlike CAN bus-equipped engines, these engines provide temperature information through dedicated analogue sensors.
Most of these sensors are grounded through their metal body and use a single signal wire connected to the instrument. As a result, all temperature measurements are referenced to the engine ground.
If incorrect or unstable temperature indications are observed, inspect the wiring carefully.
Differential Inputs
Some Flybox instruments use differential temperature inputs, which can be identified by the presence of two terminals for each sensor input.
In this configuration:
one terminal is connected to the sensor signal;
the second terminal must be connected to the same engine ground or to the instrument GND, exactly as shown in the installation manual.
Failure to provide the correct reference ground may result in inaccurate or unstable temperature readings.
Always follow the wiring diagram supplied with the specific instrument model.
Unlike CAN bus-equipped engines, these engines provide temperature information through dedicated analogue sensors.
Most of these sensors are grounded through their metal body and use a single signal wire connected to the instrument. As a result, all temperature measurements are referenced to the engine ground.
If incorrect or unstable temperature indications are observed, inspect the wiring carefully.
Differential Inputs
Some Flybox instruments use differential temperature inputs, which can be identified by the presence of two terminals for each sensor input.
In this configuration:
one terminal is connected to the sensor signal;
the second terminal must be connected to the same engine ground or to the instrument GND, exactly as shown in the installation manual.
Failure to provide the correct reference ground may result in inaccurate or unstable temperature readings.
Always follow the wiring diagram supplied with the specific instrument model.
Applies to: EFC-P, EFC-Plus and Air-EFCF Flap Controllers.
If the automatic flap positions cannot be programmed successfully, verify the following conditions before repeating the calibration procedure.
Initial Flap Position
Before entering programming mode, the flaps must not be resting against either limit switch.
Move the flaps to an intermediate position using MANUAL mode before starting the programming procedure.
If the flaps remain at either mechanical limit, the controller will not enter programming mode.
Programming Was Not Completed Successfully
If the flaps operate correctly in MANUAL mode but automatic positioning is unavailable, the programming procedure may not have been completed successfully.
Repeat the complete programming sequence exactly as described in the instrument manual.
LED Diagnostic Codes
Whenever the controller detects a fault during programming or operation, the status LEDs display a specific flashing pattern identifying the detected condition.
Refer to the instrument manual for a complete description of the available diagnostic codes and the corresponding corrective actions.
If the automatic flap positions cannot be programmed successfully, verify the following conditions before repeating the calibration procedure.
Initial Flap Position
Before entering programming mode, the flaps must not be resting against either limit switch.
Move the flaps to an intermediate position using MANUAL mode before starting the programming procedure.
If the flaps remain at either mechanical limit, the controller will not enter programming mode.
Programming Was Not Completed Successfully
If the flaps operate correctly in MANUAL mode but automatic positioning is unavailable, the programming procedure may not have been completed successfully.
Repeat the complete programming sequence exactly as described in the instrument manual.
LED Diagnostic Codes
Whenever the controller detects a fault during programming or operation, the status LEDs display a specific flashing pattern identifying the detected condition.
Refer to the instrument manual for a complete description of the available diagnostic codes and the corresponding corrective actions.
Applies to: All Flybox instruments equipped with an integrated magnetometer.
Flybox instruments equipped with an integrated magnetometer incorporate a high-sensitivity electronic compass. To ensure accurate heading information, careful attention must be paid to the installation environment.
Keep the Instrument Away from Ferrous Materials
Steel components, including mounting brackets, structural members, firewall hinges and standard steel fasteners, may retain residual magnetism capable of distorting the local magnetic field.
For best performance:
Install the instrument at least 15–20 cm (6–8 in) away from ferrous structures whenever possible.
Maintain the same minimum distance from avionics containing speakers, transformers, magnets or high-current coils.
Important
Secure the instrument using non-magnetic hardware, such as brass or AISI 316 stainless steel fasteners.
Even a single magnetic screw located close to the magnetometer may introduce significant heading errors.
Minimize Electromagnetic Interference
Electrical current flowing through a conductor generates a magnetic field. High-current cables supplying landing lights, electric fuel pumps, alternators and similar equipment are among the most common sources of interference.
To minimize installation-induced magnetic disturbances:
maintain a minimum clearance of 20–30 cm (8–12 in) from high-current wiring;
avoid routing power cables directly behind the instrument;
whenever possible, twist positive and negative conductors together to reduce the emitted magnetic field.
Verify the Installation Location
Before drilling the instrument panel, verify that the selected mounting position is free from significant magnetic interference.
A simple practical test is recommended.
Place a conventional magnetic compass, or a smartphone compass application, at the intended installation location.
Switch the aircraft master power ON.
Turn electrical equipment such as radios, lights and electric fuel pumps ON and OFF.
Observe whether the compass heading changes.
If the compass indication changes noticeably while electrical equipment is operated, choose a different mounting location.
Perform Compass Calibration
Once the installation has been completed, perform the compass calibration procedure described in the applicable instrument manual.
This procedure (commonly referred to as a Compass Swing) allows the instrument to compensate for the aircraft's permanent magnetic deviation.
Calibration is mandatory after installation.
Note
Calibration compensates only for small, stable magnetic deviations. It cannot eliminate errors caused by installing the instrument too close to strong magnetic or electromagnetic sources.
Flybox instruments equipped with an integrated magnetometer incorporate a high-sensitivity electronic compass. To ensure accurate heading information, careful attention must be paid to the installation environment.
Keep the Instrument Away from Ferrous Materials
Steel components, including mounting brackets, structural members, firewall hinges and standard steel fasteners, may retain residual magnetism capable of distorting the local magnetic field.
For best performance:
Install the instrument at least 15–20 cm (6–8 in) away from ferrous structures whenever possible.
Maintain the same minimum distance from avionics containing speakers, transformers, magnets or high-current coils.
Important
Secure the instrument using non-magnetic hardware, such as brass or AISI 316 stainless steel fasteners.
Even a single magnetic screw located close to the magnetometer may introduce significant heading errors.
Minimize Electromagnetic Interference
Electrical current flowing through a conductor generates a magnetic field. High-current cables supplying landing lights, electric fuel pumps, alternators and similar equipment are among the most common sources of interference.
To minimize installation-induced magnetic disturbances:
maintain a minimum clearance of 20–30 cm (8–12 in) from high-current wiring;
avoid routing power cables directly behind the instrument;
whenever possible, twist positive and negative conductors together to reduce the emitted magnetic field.
Verify the Installation Location
Before drilling the instrument panel, verify that the selected mounting position is free from significant magnetic interference.
A simple practical test is recommended.
Place a conventional magnetic compass, or a smartphone compass application, at the intended installation location.
Switch the aircraft master power ON.
Turn electrical equipment such as radios, lights and electric fuel pumps ON and OFF.
Observe whether the compass heading changes.
If the compass indication changes noticeably while electrical equipment is operated, choose a different mounting location.
Perform Compass Calibration
Once the installation has been completed, perform the compass calibration procedure described in the applicable instrument manual.
This procedure (commonly referred to as a Compass Swing) allows the instrument to compensate for the aircraft's permanent magnetic deviation.
Calibration is mandatory after installation.
Note
Calibration compensates only for small, stable magnetic deviations. It cannot eliminate errors caused by installing the instrument too close to strong magnetic or electromagnetic sources.
Applies to: All Flybox instruments equipped with an altimeter function.
Every Flybox barometric sensor is individually calibrated during manufacturing and normally requires no further adjustment throughout its service life.
If a difference is observed when comparing the instrument with a known, properly calibrated reference altimeter, the barometric offset can be adjusted.
User-Adjustable Instruments
The following instruments allow the altitude offset to be adjusted directly from the Setup Menu:
Omnia Alti-Vario
Eclipse NG
SkySense
Refer to the Adjust Offset or mBar Offset section of the applicable User Manual.
Password-Protected Calibration
For the following products:
Oblò
Oblò2
Eclipse
offset adjustment is protected by a service password available from Flybox Technical Support.
Recommendation
Do not perform offset calibration unless a genuine discrepancy has been confirmed using a reliable reference instrument.
Unnecessary recalibration may reduce measurement accuracy rather than improve it.
Every Flybox barometric sensor is individually calibrated during manufacturing and normally requires no further adjustment throughout its service life.
If a difference is observed when comparing the instrument with a known, properly calibrated reference altimeter, the barometric offset can be adjusted.
User-Adjustable Instruments
The following instruments allow the altitude offset to be adjusted directly from the Setup Menu:
Omnia Alti-Vario
Eclipse NG
SkySense
Refer to the Adjust Offset or mBar Offset section of the applicable User Manual.
Password-Protected Calibration
For the following products:
Oblò
Oblò2
Eclipse
offset adjustment is protected by a service password available from Flybox Technical Support.
Recommendation
Do not perform offset calibration unless a genuine discrepancy has been confirmed using a reliable reference instrument.
Unnecessary recalibration may reduce measurement accuracy rather than improve it.
Applies to: All Flybox instruments equipped with a USB interface for firmware updates, configuration backup and restore, data logging or maintenance operations.
If the instrument fails to recognize a USB flash drive, verify the following items.
Verify USB Flash Drive Compatibility
For maximum compatibility, Flybox recommends using a USB flash drive with the following characteristics:
maximum capacity: 2 GB;
file system: FAT32;
no unnecessary files or folders.
USB devices that do not meet these requirements may not be detected correctly.
Verify File Location
Firmware files, configuration files and all other Flybox files must be copied directly into the root directory of the USB flash drive.
Files stored inside folders or subdirectories will not be detected.
Verify USB Wiring
If the USB extension cable has been manufactured or wired during aircraft installation, verify that the D+ and D− data lines are connected correctly.
Reversing these signals prevents communication with the storage device.
Use a Dedicated Maintenance USB Drive
Flybox recommends using a dedicated USB flash drive reserved exclusively for instrument maintenance.
Avoid storing unrelated files on the device.
For maximum reliability, Flybox supplies USB flash drives that have been fully tested and verified for compatibility with all supported products.
If the instrument fails to recognize a USB flash drive, verify the following items.
Verify USB Flash Drive Compatibility
For maximum compatibility, Flybox recommends using a USB flash drive with the following characteristics:
maximum capacity: 2 GB;
file system: FAT32;
no unnecessary files or folders.
USB devices that do not meet these requirements may not be detected correctly.
Verify File Location
Firmware files, configuration files and all other Flybox files must be copied directly into the root directory of the USB flash drive.
Files stored inside folders or subdirectories will not be detected.
Verify USB Wiring
If the USB extension cable has been manufactured or wired during aircraft installation, verify that the D+ and D− data lines are connected correctly.
Reversing these signals prevents communication with the storage device.
Use a Dedicated Maintenance USB Drive
Flybox recommends using a dedicated USB flash drive reserved exclusively for instrument maintenance.
Avoid storing unrelated files on the device.
For maximum reliability, Flybox supplies USB flash drives that have been fully tested and verified for compatibility with all supported products.
Applies to: All Flybox instruments equipped with analogue sensor inputs.
Connecting a single analogue sensor to more than one instrument is generally not recommended.
Many analogue sensors are designed to drive only one measurement circuit. When multiple instruments are connected in parallel, each instrument influences the electrical load seen by the sensor, potentially causing inaccurate readings on every connected device.
Sensors Most Commonly Affected
The following sensor types are particularly sensitive to parallel connections:
4–20 mA pressure transmitters (such as the Rotax oil pressure sensor);
Type J and Type K thermocouples;
resistive fuel level senders;
resistive oil temperature sensors;
low-power analogue voltage-output sensors.
Recommendation
Not all sensor technologies behave identically.
If multiple instruments must share the same sensor, consult Flybox Technical Support before installation to verify compatibility and avoid inaccurate measurements or possible damage to the connected equipment.
Connecting a single analogue sensor to more than one instrument is generally not recommended.
Many analogue sensors are designed to drive only one measurement circuit. When multiple instruments are connected in parallel, each instrument influences the electrical load seen by the sensor, potentially causing inaccurate readings on every connected device.
Sensors Most Commonly Affected
The following sensor types are particularly sensitive to parallel connections:
4–20 mA pressure transmitters (such as the Rotax oil pressure sensor);
Type J and Type K thermocouples;
resistive fuel level senders;
resistive oil temperature sensors;
low-power analogue voltage-output sensors.
Recommendation
Not all sensor technologies behave identically.
If multiple instruments must share the same sensor, consult Flybox Technical Support before installation to verify compatibility and avoid inaccurate measurements or possible damage to the connected equipment.
Applies to: PR1-P Propeller Controller.
If the controller operates correctly in MANUAL mode but fails to enter CONSTANT SPEED mode, verify that the internal MOSFET output stage is functioning correctly.
Perform the following procedure with the aircraft safely on the ground and the engine stopped.
Select MANUAL mode.
Hold the RPM DEC switch until the propeller reaches maximum pitch.
Move the selector to CONSTANT SPEED mode.
The controller should automatically drive the propeller towards the minimum pitch position.
If no movement occurs, the MOSFET output stage has most likely failed.
The controller must be returned to Flybox for inspection and repair.
If the controller operates correctly in MANUAL mode but fails to enter CONSTANT SPEED mode, verify that the internal MOSFET output stage is functioning correctly.
Perform the following procedure with the aircraft safely on the ground and the engine stopped.
Select MANUAL mode.
Hold the RPM DEC switch until the propeller reaches maximum pitch.
Move the selector to CONSTANT SPEED mode.
The controller should automatically drive the propeller towards the minimum pitch position.
If no movement occurs, the MOSFET output stage has most likely failed.
The controller must be returned to Flybox for inspection and repair.
Applies to: PR1-P Propeller Controller.
The troubleshooting procedure depends on the propeller system installed.
Electric Propellers with Slip Rings
Inspect the following components:
slip ring brushes;
brush spring tension;
cleanliness of the slip rings;
oxidation or contamination of the contact surfaces.
Poor electrical contact may prevent sufficient current from reaching the propeller actuator.
Some propeller gear motors rotate together with the propeller hub. At high rotational speeds, centrifugal force may reduce brush contact pressure, interrupting motor operation.
If this condition is suspected, consult the propeller manufacturer.
Verify Actuator Speed
Measure the time required for the propeller to move from minimum pitch to maximum pitch.
If this movement requires more than approximately 3–4 seconds, rapid throttle application may temporarily allow engine RPM to exceed the selected value before blade pitch can respond.
This behaviour is a limitation of the propeller actuation system and does not indicate a malfunction of the PR1-P controller.
Electro-Hydraulic Propellers
For propellers using an electro-hydraulic actuation system, inspect the hydraulic circuit for trapped air.
Air bubbles are compressible and introduce a delay between controller output and blade movement.
This delay may cause unstable regulation or continuous RPM oscillations.
Bleed the hydraulic circuit thoroughly before performing additional troubleshooting.
Verify RPM Signal
Regardless of propeller type, always confirm that the controller is receiving a valid RPM signal.
The PR1-P continuously displays the measured engine RPM in the upper-right corner of the display.
If this value differs from the aircraft's primary tachometer, inspect the RPM pickup wiring and verify that the controller is receiving a valid input signal.
The troubleshooting procedure depends on the propeller system installed.
Electric Propellers with Slip Rings
Inspect the following components:
slip ring brushes;
brush spring tension;
cleanliness of the slip rings;
oxidation or contamination of the contact surfaces.
Poor electrical contact may prevent sufficient current from reaching the propeller actuator.
Some propeller gear motors rotate together with the propeller hub. At high rotational speeds, centrifugal force may reduce brush contact pressure, interrupting motor operation.
If this condition is suspected, consult the propeller manufacturer.
Verify Actuator Speed
Measure the time required for the propeller to move from minimum pitch to maximum pitch.
If this movement requires more than approximately 3–4 seconds, rapid throttle application may temporarily allow engine RPM to exceed the selected value before blade pitch can respond.
This behaviour is a limitation of the propeller actuation system and does not indicate a malfunction of the PR1-P controller.
Electro-Hydraulic Propellers
For propellers using an electro-hydraulic actuation system, inspect the hydraulic circuit for trapped air.
Air bubbles are compressible and introduce a delay between controller output and blade movement.
This delay may cause unstable regulation or continuous RPM oscillations.
Bleed the hydraulic circuit thoroughly before performing additional troubleshooting.
Verify RPM Signal
Regardless of propeller type, always confirm that the controller is receiving a valid RPM signal.
The PR1-P continuously displays the measured engine RPM in the upper-right corner of the display.
If this value differs from the aircraft's primary tachometer, inspect the RPM pickup wiring and verify that the controller is receiving a valid input signal.
Applies to: All Flybox instruments equipped with a fuel pressure indication function.
If the indicated fuel pressure drops below the normal operating range during takeoff, climb or other high-power operating conditions, the indication should never be dismissed as an instrument malfunction.
Flybox instruments display the pressure measured by the installed sensor and are not influenced by engine operating conditions or power settings. A low fuel pressure indication generally reflects an actual reduction in fuel system pressure.
Recommended Checks
Verify the actual fuel pressure using approved maintenance procedures.
Inspect the fuel pumps, filters, hoses and fittings.
Check for restrictions, leaks or partial obstructions within the fuel system.
Confirm that the installed pressure sender is operating correctly.
Important
Treat every low fuel pressure indication as a potential engine-related issue until the cause has been positively identified.
If the indicated fuel pressure drops below the normal operating range during takeoff, climb or other high-power operating conditions, the indication should never be dismissed as an instrument malfunction.
Flybox instruments display the pressure measured by the installed sensor and are not influenced by engine operating conditions or power settings. A low fuel pressure indication generally reflects an actual reduction in fuel system pressure.
Recommended Checks
Verify the actual fuel pressure using approved maintenance procedures.
Inspect the fuel pumps, filters, hoses and fittings.
Check for restrictions, leaks or partial obstructions within the fuel system.
Confirm that the installed pressure sender is operating correctly.
Important
Treat every low fuel pressure indication as a potential engine-related issue until the cause has been positively identified.
Applies to: All Flybox instruments equipped with Exhaust Gas Temperature (EGT) monitoring.
Flybox EGT systems are designed for use with Type K thermocouples.
A correctly functioning Type K thermocouple generates the same electrical signal regardless of manufacturer. Therefore, measurement accuracy depends primarily on the quality of the installation.
Verify Thermocouple Polarity
Type K thermocouples are polarized devices.
Incorrect polarity at any point in the installation will produce incorrect temperature readings.
Verify the polarity of:
the thermocouple;
extension cables;
compensated connectors;
instrument input terminals.
Use the Correct Extension Cable
If the thermocouple leads require extension, only Type K compensated extension cable shall be used.
Using standard copper conductors introduces additional thermoelectric junctions that generate measurement errors.
Verify Connector Compatibility
All intermediate connectors must also be suitable for Type K thermocouples.
Because colour coding varies between international standards, always identify polarity using the manufacturer's documentation rather than wire colour alone.
Flybox EGT systems are designed for use with Type K thermocouples.
A correctly functioning Type K thermocouple generates the same electrical signal regardless of manufacturer. Therefore, measurement accuracy depends primarily on the quality of the installation.
Verify Thermocouple Polarity
Type K thermocouples are polarized devices.
Incorrect polarity at any point in the installation will produce incorrect temperature readings.
Verify the polarity of:
the thermocouple;
extension cables;
compensated connectors;
instrument input terminals.
Use the Correct Extension Cable
If the thermocouple leads require extension, only Type K compensated extension cable shall be used.
Using standard copper conductors introduces additional thermoelectric junctions that generate measurement errors.
Verify Connector Compatibility
All intermediate connectors must also be suitable for Type K thermocouples.
Because colour coding varies between international standards, always identify polarity using the manufacturer's documentation rather than wire colour alone.
Applies to: All Flybox instruments equipped with an RPM indication function.
The recommended troubleshooting procedure depends on the engine installation.
Rotax 912 / 912 ULS / 914 Engines
These engines provide the RPM signal through an inductive pickup.
The pickup has two wires:
one wire connects to the Flybox RPM input;
the second wire must be connected to aircraft ground (GND).
Failure to connect the reference ground correctly may prevent accurate RPM detection.
Rotax 914 TCU Connection
When obtaining the RPM signal from the Rotax 914 TCU:
Connect TCU Pin 13 to the RPM input.
Connect TCU Pin 26 to aircraft ground (GND).
RPM Threshold Adjustment
For Vigilus and EngiMaster, the RPM detection threshold can be adjusted through the Setup Menu.
If unstable RPM readings are observed, verify that the threshold has been configured correctly for the installed pickup.
CAN Bus Equipped Engines
When engine data is received through the CAN bus, incorrect RPM indication may result from:
incorrect CAN wiring;
incorrect CAN termination;
incorrect engine configuration within the instrument.
Refer to CAN Bus Communication Issues FAQ for additional troubleshooting information.
The recommended troubleshooting procedure depends on the engine installation.
Rotax 912 / 912 ULS / 914 Engines
These engines provide the RPM signal through an inductive pickup.
The pickup has two wires:
one wire connects to the Flybox RPM input;
the second wire must be connected to aircraft ground (GND).
Failure to connect the reference ground correctly may prevent accurate RPM detection.
Rotax 914 TCU Connection
When obtaining the RPM signal from the Rotax 914 TCU:
Connect TCU Pin 13 to the RPM input.
Connect TCU Pin 26 to aircraft ground (GND).
RPM Threshold Adjustment
For Vigilus and EngiMaster, the RPM detection threshold can be adjusted through the Setup Menu.
If unstable RPM readings are observed, verify that the threshold has been configured correctly for the installed pickup.
CAN Bus Equipped Engines
When engine data is received through the CAN bus, incorrect RPM indication may result from:
incorrect CAN wiring;
incorrect CAN termination;
incorrect engine configuration within the instrument.
Refer to CAN Bus Communication Issues FAQ for additional troubleshooting information.
Applies to: Flybox instruments connected to an external GPS receiver.
If no GPS data is received, verify the following points.
Verify Communication Speed
The GPS receiver and the Flybox instrument must use the same serial communication speed.
Flybox GPS receivers are factory configured for 9600 baud.
Verify NMEA Sentences
Third-party GPS receivers must transmit the NMEA sentences required by the connected Flybox instrument.
Refer to the Installation Manual for the minimum supported NMEA message set.
Allow Time for Initial Satellite Acquisition
The first GPS fix may require several minutes under unfavourable conditions.
Acquisition time may increase if:
the aircraft is inside a hangar;
the antenna has a limited view of the sky;
nearby structures obstruct satellite visibility.
Verify Ground Reference
Both devices must share the same electrical ground.
A missing common ground may prevent reliable serial communication.
Verify Incoming GPS Data
Most Flybox instruments provide a diagnostic page that displays incoming GPS information.
Use this page to confirm that valid NMEA data is being received before investigating additional causes.
If no GPS data is received, verify the following points.
Verify Communication Speed
The GPS receiver and the Flybox instrument must use the same serial communication speed.
Flybox GPS receivers are factory configured for 9600 baud.
Verify NMEA Sentences
Third-party GPS receivers must transmit the NMEA sentences required by the connected Flybox instrument.
Refer to the Installation Manual for the minimum supported NMEA message set.
Allow Time for Initial Satellite Acquisition
The first GPS fix may require several minutes under unfavourable conditions.
Acquisition time may increase if:
the aircraft is inside a hangar;
the antenna has a limited view of the sky;
nearby structures obstruct satellite visibility.
Verify Ground Reference
Both devices must share the same electrical ground.
A missing common ground may prevent reliable serial communication.
Verify Incoming GPS Data
Most Flybox instruments provide a diagnostic page that displays incoming GPS information.
Use this page to confirm that valid NMEA data is being received before investigating additional causes.
Applies to: All Flybox instruments equipped with serial GPS inputs.
The serial output of a GPS receiver (typically labelled GPS TX) can generally be connected to multiple Flybox instruments simultaneously.
Unlike analogue sensors, a GPS output transmits digital NMEA data that can be received by more than one device without affecting signal quality. Under normal installation conditions, a single GPS TX output can reliably drive up to three Flybox instruments connected in parallel.
Installations involving a greater number of instruments may also operate correctly, but compatibility depends on the characteristics of the GPS source and should be verified experimentally.
Wiring Recommendations
When connecting one GPS receiver to multiple instruments:
connect the GPS TX line to the GPS input of each instrument;
ensure that all devices share the same electrical ground (GND);
verify that all connected instruments are configured with the same baud rate as the GPS receiver.
Note
This recommendation applies only to digital serial GPS outputs carrying NMEA data. It does not apply to analogue sensors or other signal types, which may not operate correctly when connected to multiple instruments in parallel.
The serial output of a GPS receiver (typically labelled GPS TX) can generally be connected to multiple Flybox instruments simultaneously.
Unlike analogue sensors, a GPS output transmits digital NMEA data that can be received by more than one device without affecting signal quality. Under normal installation conditions, a single GPS TX output can reliably drive up to three Flybox instruments connected in parallel.
Installations involving a greater number of instruments may also operate correctly, but compatibility depends on the characteristics of the GPS source and should be verified experimentally.
Wiring Recommendations
When connecting one GPS receiver to multiple instruments:
connect the GPS TX line to the GPS input of each instrument;
ensure that all devices share the same electrical ground (GND);
verify that all connected instruments are configured with the same baud rate as the GPS receiver.
Note
This recommendation applies only to digital serial GPS outputs carrying NMEA data. It does not apply to analogue sensors or other signal types, which may not operate correctly when connected to multiple instruments in parallel.
Applies to: Flybox instruments supporting firmware updates via USB.
Most firmware update failures are caused by incompatible USB flash drives rather than by the instrument itself.
For maximum compatibility, Flybox recommends using a USB flash drive with the following characteristics:
maximum capacity: 2 GB;
FAT32 file system;
no unnecessary files or folders.
Modern high-capacity USB storage devices are not always compatible with embedded systems that do not use a conventional operating system.
Flybox supplies USB flash drives that have been fully tested for firmware updates, configuration backup and data logging.
Some firmware or configuration files provided by Flybox or downloaded from the Flybox website may be supplied as .zip archives.
Before copying them to the USB flash drive, extract (unzip) the archive. Only the extracted files should be placed in the root directory of the USB flash drive. Do not copy the .zip file itself, as Flybox instruments cannot read compressed archives.
In case you need it, here you can find help to unzip files: Click Here
Most firmware update failures are caused by incompatible USB flash drives rather than by the instrument itself.
For maximum compatibility, Flybox recommends using a USB flash drive with the following characteristics:
maximum capacity: 2 GB;
FAT32 file system;
no unnecessary files or folders.
Modern high-capacity USB storage devices are not always compatible with embedded systems that do not use a conventional operating system.
Flybox supplies USB flash drives that have been fully tested for firmware updates, configuration backup and data logging.
Some firmware or configuration files provided by Flybox or downloaded from the Flybox website may be supplied as .zip archives.
Before copying them to the USB flash drive, extract (unzip) the archive. Only the extracted files should be placed in the root directory of the USB flash drive. Do not copy the .zip file itself, as Flybox instruments cannot read compressed archives.
In case you need it, here you can find help to unzip files: Click Here
Applies to: All Flybox Fuel Computer systems.
The Fuel Computer is a valuable flight management aid, but it should never be considered the primary reference for determining the amount of fuel remaining on board.
Fuel planning, pre-flight visual inspection and compliance with the Aircraft Flight Manual remain the pilot's responsibility.
Several physical factors influence measurement accuracy.
Fuel Density
The flow transducer measures fuel volume, not fuel mass.
Because fuel density changes with temperature, the same measured volume corresponds to slightly different fuel masses under different environmental conditions.
A small measurement uncertainty is therefore unavoidable.
Flowmeter Linearity
The turbine flow sensor is optimized for normal cruise fuel flow.
Accuracy may decrease during:
idle;
taxi;
descent;
takeoff;
maximum climb.
This behaviour is an inherent characteristic of volumetric flow measurement.
Fuel Pulsations and Air Bubbles
The flowmeter measures everything that rotates the turbine.
Pressure pulsations, cavitation and entrained air may therefore produce temporary indications that do not correspond to actual engine fuel consumption.
Installation Quality
Installation quality has a direct effect on measurement accuracy.
Sharp bends, restrictions, nearby pumps or excessive heat may disturb fuel flow before it reaches the transducer.
Follow the installation recommendations provided in the applicable manual.
Important
Always determine the required fuel reserve using standard flight planning methods and verify fuel quantity visually before every flight.
The Fuel Computer is a valuable flight management aid, but it should never be considered the primary reference for determining the amount of fuel remaining on board.
Fuel planning, pre-flight visual inspection and compliance with the Aircraft Flight Manual remain the pilot's responsibility.
Several physical factors influence measurement accuracy.
Fuel Density
The flow transducer measures fuel volume, not fuel mass.
Because fuel density changes with temperature, the same measured volume corresponds to slightly different fuel masses under different environmental conditions.
A small measurement uncertainty is therefore unavoidable.
Flowmeter Linearity
The turbine flow sensor is optimized for normal cruise fuel flow.
Accuracy may decrease during:
idle;
taxi;
descent;
takeoff;
maximum climb.
This behaviour is an inherent characteristic of volumetric flow measurement.
Fuel Pulsations and Air Bubbles
The flowmeter measures everything that rotates the turbine.
Pressure pulsations, cavitation and entrained air may therefore produce temporary indications that do not correspond to actual engine fuel consumption.
Installation Quality
Installation quality has a direct effect on measurement accuracy.
Sharp bends, restrictions, nearby pumps or excessive heat may disturb fuel flow before it reaches the transducer.
Follow the installation recommendations provided in the applicable manual.
Important
Always determine the required fuel reserve using standard flight planning methods and verify fuel quantity visually before every flight.
Applies to: FX75 Autopilot Servo.
Whenever an FX75 servo disengages, the connected instrument immediately displays an alarm identifying the reason for the disengagement.
Before contacting Flybox Technical Support:
read the alarm message;
note the exact text displayed;
include this information in the support request.
Providing the alarm information significantly reduces troubleshooting time.
Refer to the Autopilot Alarm section of the applicable User Manual for a complete description of all alarm conditions.
Whenever an FX75 servo disengages, the connected instrument immediately displays an alarm identifying the reason for the disengagement.
Before contacting Flybox Technical Support:
read the alarm message;
note the exact text displayed;
include this information in the support request.
Providing the alarm information significantly reduces troubleshooting time.
Refer to the Autopilot Alarm section of the applicable User Manual for a complete description of all alarm conditions.
Applies to: Flybox Wi-Fi Interface.
If the FLYBOX_WIFI_XXXXXXXX network cannot be accessed, verify the following:
the correct password has been entered;
the green status LED is illuminated;
the correct wireless network has been selected.
A flashing green LED indicates normal communication activity.
If the FLYBOX_WIFI_XXXXXXXX network cannot be accessed, verify the following:
the correct password has been entered;
the green status LED is illuminated;
the correct wireless network has been selected.
A flashing green LED indicates normal communication activity.
The first thing to check is whether the electronic MOSFET bridge output is operational.
If it does not move, it means that the output is burnt out and the Controller needs to be sent for repair.
If it does not move, it means that the output is burnt out and the Controller needs to be sent for repair.
Applies to: All Flybox instruments equipped with an oil pressure indication function.
Verify that the installed pressure sender is one of the models supported by the instrument.
Then confirm that the correct sender type has been selected in the instrument configuration menu.
An unsupported sender or incorrect configuration will result in inaccurate pressure indications.
Verify that the installed pressure sender is one of the models supported by the instrument.
Then confirm that the correct sender type has been selected in the instrument configuration menu.
An unsupported sender or incorrect configuration will result in inaccurate pressure indications.
Applies to: Flybox Current Sensor – Part Number 601060.
If charging current is displayed with reversed polarity, interchange terminals A+ and A−.
No additional configuration is required.
If charging current is displayed with reversed polarity, interchange terminals A+ and A−.
No additional configuration is required.
Applies to: Flybox Rotor RPM Instruments.
Rotor speed is typically measured using inductive or Hall-effect sensors.
If rotor RPM is incorrect or unavailable:
verify sensor polarity;
verify signal voltage compatibility;
verify that the sensor type is supported by the instrument.
The Flybox Rotor RPM Sensor P/N 105896 (PNP output) requires an external pull-down resistor.
When using third-party sensors, verify that the appropriate pull-down resistor has been installed.
Finally, confirm that the correct Pulses per Revolution value has been configured.
Rotor speed is typically measured using inductive or Hall-effect sensors.
If rotor RPM is incorrect or unavailable:
verify sensor polarity;
verify signal voltage compatibility;
verify that the sensor type is supported by the instrument.
The Flybox Rotor RPM Sensor P/N 105896 (PNP output) requires an external pull-down resistor.
When using third-party sensors, verify that the appropriate pull-down resistor has been installed.
Finally, confirm that the correct Pulses per Revolution value has been configured.
Applies to: All Flybox display-equipped instruments.
Some polarized sunglasses may significantly reduce the visibility of LCD displays.
The orientation of the polarization filter varies between eyewear manufacturers, and no industry standard exists regarding its alignment.
Flybox displays use a horizontally oriented polarizing filter. If the sunglasses employ a different polarization angle, the display may appear dark or completely unreadable unless the pilot tilts his or her head.
This behaviour is a characteristic of polarized optics and does not indicate a display malfunction.
The FAA advises against the routine use of polarized sunglasses in the cockpit because they may reduce or eliminate the visibility of electronic flight instruments fitted with anti-glare filters.
Some polarized sunglasses may significantly reduce the visibility of LCD displays.
The orientation of the polarization filter varies between eyewear manufacturers, and no industry standard exists regarding its alignment.
Flybox displays use a horizontally oriented polarizing filter. If the sunglasses employ a different polarization angle, the display may appear dark or completely unreadable unless the pilot tilts his or her head.
This behaviour is a characteristic of polarized optics and does not indicate a display malfunction.
The FAA advises against the routine use of polarized sunglasses in the cockpit because they may reduce or eliminate the visibility of electronic flight instruments fitted with anti-glare filters.
Applies to: APR1, all models.
APR1 can generate two different file types when a USB flash drive is used. Although both files are saved to the same USB device, they serve completely different purposes.
Understanding the difference between them helps ensure that the correct file is provided when requesting technical support.
Parameter File (.PAR)
The .PAR file contains the complete APR1 configuration, including all user settings and calibration parameters.
This file is intended for:
restoring the configuration after replacing an instrument;
backing up the current setup;
loading an updated parameter set supplied by Flybox Technical Support.
When an APR1 is replaced, it is generally not necessary to send the .PAR file to Flybox. The parameter file can normally be generated by our Technical Support team and loaded into the replacement unit. Likewise, if a change in system behaviour is required, Flybox will provide an updated .PAR file ready to be loaded into the instrument.
Flight Log File
The Log file contains the data recorded during flight, including operating parameters and system events.
This file is required whenever Flybox Technical Support requests flight data to investigate a reported problem or analyse system behaviour.
Unlike the .PAR file, the Log file records what actually happened during operation and is therefore the only file that can be used for troubleshooting.
Which File Should I Send?
If Flybox requests your instrument configuration, send the .PAR file.
If Flybox requests data from a flight, send the Log file.
If you are unsure, contact Flybox Technical Support before sending the files.
Sending the correct file allows the issue to be analysed more quickly and helps avoid unnecessary delays.
Also consult the FAQ "The Instrument Does Not Recognize the USB Flash Drive" for more information on using data saving on USB.
APR1 can generate two different file types when a USB flash drive is used. Although both files are saved to the same USB device, they serve completely different purposes.
Understanding the difference between them helps ensure that the correct file is provided when requesting technical support.
Parameter File (.PAR)
The .PAR file contains the complete APR1 configuration, including all user settings and calibration parameters.
This file is intended for:
restoring the configuration after replacing an instrument;
backing up the current setup;
loading an updated parameter set supplied by Flybox Technical Support.
When an APR1 is replaced, it is generally not necessary to send the .PAR file to Flybox. The parameter file can normally be generated by our Technical Support team and loaded into the replacement unit. Likewise, if a change in system behaviour is required, Flybox will provide an updated .PAR file ready to be loaded into the instrument.
Flight Log File
The Log file contains the data recorded during flight, including operating parameters and system events.
This file is required whenever Flybox Technical Support requests flight data to investigate a reported problem or analyse system behaviour.
Unlike the .PAR file, the Log file records what actually happened during operation and is therefore the only file that can be used for troubleshooting.
Which File Should I Send?
If Flybox requests your instrument configuration, send the .PAR file.
If Flybox requests data from a flight, send the Log file.
If you are unsure, contact Flybox Technical Support before sending the files.
Sending the correct file allows the issue to be analysed more quickly and helps avoid unnecessary delays.
Also consult the FAQ "The Instrument Does Not Recognize the USB Flash Drive" for more information on using data saving on USB.