The FAIRHAVEN Micro Alti 2 is a multifunction altimeter and vario designed for paraglider, paramotor, and hang-glider pilots. It is touted as the world's smallest, most sensitive, micro-power vario-altimeter, providing essential information to enhance the flying experience. Building on the success of the original Micro Alti, this redesigned version incorporates advanced sensors and electronics to deliver ultimate sensitivity and extended battery life within a wristwatch-sized package.

Function Description

The Micro Alti 2 serves as a comprehensive flight instrument, offering various functions accessible through its three buttons: TIMER (left), SET (middle), and ALTI (right).

Altimeter and Barometer Functions (ALTI button):

The ALTI button provides access to three types of altimeters and barometers. A quick press displays the altimeter or barometer name before showing the reading, and subsequent presses cycle through the options.

QNE: This mode indicates altitude relative to the standard pressure of 1013.25 mB, which corresponds to mean sea level as defined by the International Standard Atmosphere.
QNH: This can be set to the height of a hill or airfield, or used as a general pressure reference. To adjust QNH, hold the ALTI button to enter Height adjustment mode (H). Use the left and right buttons to set the desired height, then press SET to store it. You can also move to Pressure setting mode (P) and adjust it similarly, typically to the pressure provided by the local airfield.
ALTI 1, 2, and 3: These altimeters can be zeroed with a long press and are useful as take-off references. ALTI 1 offers high precision, measuring altitude in 10cm steps (or 4 inches) up to 1999.9, after which it reverts to 100cm steps.
BARO: This displays your local barometric pressure, which may differ from sea-level referenced weather reports. Altitude increases cause a decrease in pressure (approx. 1mB per 30 feet, decreasing at higher altitudes).
PRESSURE CHANGE: This function records changes in local air pressure over time, providing an indication of weather trends (e.g., approaching low-pressure systems). It's recommended to leave it on for an hour or overnight for accurate trend indication. In this mode, a segmented scale shows quarter millibar increments, with current pressure indicated by a flashing segment and previous excursions by other segments. It can be reset to current pressure with a long press on the ALTI button. This function is affected by changes in altitude and is intended as a guide for deciding whether to fly.

Time, Alarm, and Stopwatch Functions (TIMER button):

The TIMER button provides access to the time clock, alarm timer, and stopwatch.

Time Clock: An initial press shows the current time and automatically reverts to the previous mode. Pressing it again keeps the clock displayed with the vario. To set the clock, a long press allows adjustment of hours and minutes using the left and right keys, confirmed with the SET button.
Alarm Timer: A third press accesses the ALARM timer, useful for reminders or timing events. For paramotor pilots, it can serve as a fuel level prompt after familiarizing with fuel consumption. The alarm setting is permanently stored. To set the alarm, a long press on the TIMER button allows setting hours and minutes with the left/right buttons and SET button. Pressing SET again starts the countdown, and "ALARM ON" is displayed. To silence a sounding alarm, press the middle button. To cancel, return to ALARM mode and hold the left button ("ALARM OFF" will confirm). Switching off the device also cancels the alarm.
Stopwatch: This is the last option on the TIMER button.
- STOPWATCH AUTO START (flight timer): Initiated with a long press on the left button ("READY" is displayed). The stopwatch automatically starts when height changes by +/- 30 feet or 10 meters.
- The stopwatch can be started, paused, and restarted with further key presses. It can be zeroed with a long press on the TIMER button. Pressing any other key exits the stopwatch mode.

Vario and Utility Functions (SET button):

The middle SET button provides access to various functions and sub-menus.

Averager: The first item on the middle button is the averager, useful for determining overall climb rates in turbulent conditions. It displays "AV" followed by the averaging time (e.g., AV 20 for 20 seconds). It typically reverts to the current altimeter after a few seconds, but a further press keeps it in averager mode with the altimeter reading. The averager is shown as a black band of petals, with the normal vario rate indicated by a single flashing petal. Audio tones still respond quickly to lift or sink. The averaging period (1 to 60 seconds) can be adjusted with a long press on the middle button or in the right sub menu.
Vario: Displayed next (indicated by "V"), it provides a numerical readout of 0.1 meters per second and a resolution of up to 10mm per second on the petal display. The sensitivity of the petal display can be set with a long press or in the right settings menu.
Battery: Shows the actual battery voltage. Upper segments indicate charging, with a full charge (around 4 volts) shown by about 80% of segments. "BAtt" flashes when the battery drops to level "2," prompting recharge to prevent damage. A separate backup battery recharges with the main battery for the time clock.
G-Meter: Shows the strength of gravitational or centrifugal force, typically 1G at rest (displayed as G 1_00). Higher G-forces during turns or dives are displayed to two decimal places (e.g., G 2_15). The maximum G-force encountered during a flight is stored in the left sub menu and updated only if a higher value is registered. This reading can be reset with a long key press.
Temperature: Displays local air temperature in degrees Celsius (if not affected by sunlight or body heat). A long press switches to Fahrenheit.
Humidity %: Indicates saturation levels, useful when approaching cloud formations.
FM Radio: This feature allows listening to music, with vario tones blended into the audio. It's recommended to use a single 'over the ear' headphone for situational awareness. The radio is switched on with a long press on the FM RADIO option. Left and right buttons change stored stations (0-9). A further press on the middle button accesses volume control (left/right buttons), MONO/STEREO control, then EXIT and OFF. EXIT leaves the radio on, OFF switches it off. To store stations, a long press on the middle button in memory mode initiates scanning, stopping when a station is found. Press again to continue scanning or use left/right buttons to select a memory number, then SET to store. A long press on left or right exits scanning without storing. Vario tones are sent to the headphone socket, and radio volume should be adjusted for a suitable blend. "FM" on the display indicates the radio is on and consuming power.

Sub Menus:

The middle button also provides access to sub menus when "SUB" is displayed.

Left Sub Menu: Shows maximum and minimum readings for various parameters (altitude, humidity, G-force, temperature, lift, sink). All readings are permanently stored and can be individually reset with a long key press. Vario and G-Meter readings are visually represented on the petal display. "1-" indicates a vario reading exceeding 19. High and low readings are indicated by H and L. EXIT returns to clock or altimeter displays.
Right Sub Menu: Allows adjustment of regular user settings.
- PIZO: Controls the piezo bleeper. "n" turns it off, "Y" turns tones on, "A" enables automatic tone activation if barometric pressure changes by more than 1mB (silencing the vario until flying).
- AVERAGER SETTING: Sets the averaging display period from 1 to 60 seconds.
- SENSITIVITY: Adjusts the vario scale sensitivity. Petals reduce from the center as climb/descent rate increases. Settings range from 11 (5 mm/s petal sensitivity, 50 mm/s full scale, 0.1 m/s secondary scale) to 1 (5 m/s petal sensitivity, 50 m/s full scale, 100 m/s secondary scale). Specific settings include DEMO (10 mm/s petal, 0.1 m/s full scale, 0.2 m/s secondary), DEFS (Flying defaults: 0.2 m/s petal, 2 m/s full scale, 4 m/s secondary), Thermal flying (0.5 m/s petal, 5 m/s full scale, 10 m/s secondary), and General Aviation (1 m/s petal, 10 m/s full scale, 20 m/s secondary).
- VOLUME: Sets the bleeper volume in 20 steps (left/right buttons). Lower volumes slightly extend battery life. This does not affect headset volume.
- UP threshold (UP th): Sets the climb rate at which the vario begins to bleep, adjustable with left/right buttons to prevent excessive triggering.
- DOWN threshold (DN th): Sets the descent rate for a continuous tone, warning of rapid sink. Adjustable with left/right buttons.
- WEAK LIFT FINDER: Indicates rising air even if the glider isn't ascending. Typically set to the glider's sink rate; if rising air reduces sink, it chirps and speeds up as level flight is approached. Default is 1100 mm/second. Adjustable with left/right buttons. Can be switched off by setting to zero or "n" in the middle sub menu.
- VARIO DAMPING: Controls the responsiveness of vario audio and visual indications to height changes. A short response is quick but may react to wind buffeting; a slower response averages out small variations. The Micro Alti tends to silence until lift is detected during flight.
- PACE of tones: Sets the scale of vario tones. High settings make it more responsive to small altitude changes (e.g., ridge-soaring). Lower settings are useful for higher climb rates (e.g., thermalling), providing a more gradual tone variation over a larger range.
- Unit: Selects metric or imperial units: 1. Metric altimeter and vario in meters per second. 2. Altitude in feet and vario in feet (x100) per minute. 3. Altitude in feet and vario in meters per second.
- G-METER AUDIO: (Accessed with a right button press) Provides tones similar to the vario to indicate G-force, offering audible feedback for acrobatics and training. Selecting VARIO AUDIO reinstates the regular vario tone system.
- EXIT: Use left or right buttons to exit.
Middle Sub Menu (long press on SUB): Provides access to less-used settings, tests, and serial number. Short presses cycle options, left/right buttons change settings.
- DEMO: Sets the Micro Alti to be highly responsive for demonstration: Lift tone=30mm/second, Lift finder threshold=1.1m/s, sink threshold=800mm/s.
- DEFS: Loads typical flying defaults: Lift tone=100mm/second, Lift finder threshold=1.1m/s, sink threshold=2m/s.
- SHUT DOWN TIMER: Automatically shuts off the device after a period of inactivity (1 minute to 6 hours) to save battery. Button presses or pressure changes >1mB reset the timer. "SHUTTING DOWN" is displayed before shutdown. Can be disabled (set to OFF) or is disabled in PRESSURE CHANGE mode for long-term monitoring.
- WEAK LIFT FINDER: Switches the weak lift finder on or off.
- LED ON: Switches the blue Lift LED on or off (off prolongs battery life).
- USB ON/OFF: Enables/disables the USB port for communication.
- DATA FORMAT: Selects NMEA or hexadecimal USB data formats (right/left buttons).
- G th: Provides a threshold to prevent random triggering of the G-Meter tone system.
- CHG.H / CHG.L: Changes from high to low battery charging to extend battery lifetime.
- EXIT: Exits the menu.
- PIZO CHECK: Bleeps to check the piezo bleeper.
- LCD CHECK: Turns all LCD segments on.
- CONTRAST: Changes the LCD contrast.
- EXTENSION BLEEPER: Changes headphone jack output to drive a piezo extension bleeper.
- G CAL: Calibrates the G-Meter. To calibrate, press and hold SET until "Flat" appears, place the device on a flat, stationary surface, and press the left button. The G-Meter calibrates itself. Pressing the right button restores factory defaults.
- CLOCK ADJUST: Adjusts the clock if it's running fast or slow.
- QNE ADJUST: Adjusts the QNE reading to compensate for pressure sensor aging. Not recommended without a precision reference.
- BARO ADJUST: Adjusts barometric pressure reading to a known reference, considering height above sea level. Note that QNE and Barometric pressure change when adjusted; QNE is zero when barometric pressure equals 1013.25mB.
- FW VERSION: Displays the firmware version.
- SN (SERIAL NUMBER): Displays the device's unique serial number.

Usage Features

Getting Started: To switch on, press the middle button for about a second. To switch off, go to OFF on the middle button and press it for a second, or hold the middle button in any mode.
Menu Navigation: Press any button to move down its menu. Use EXIT to leave sub menus. A quick guide sheet provides an overview of menus.
Mounting: Can be mounted on the wrist, over a coat sleeve, on risers, or panel-mounted. A velcro strap (cuttable) and adhesive Velcro pads are supplied. A lanyard can be fastened through the strap retainer for extra security around the wrist or riser, ensuring it doesn't entangle with lines or controls. The strap retainer on the back can be fixed horizontally, vertically, or removed for flat surface mounting. When replacing the 4 screws, engage threads by turning slightly anti-clockwise before tightening; do not overtighten.
Audio Tones:
- Lift tone: A "bleep-bleep" that increases in rate and pitch with climb rate.
- Thermal finder tone: A short chirp that increases in frequency above the glider's sink rate.
- Sink tone: A continuous tone that starts high and reduces in frequency, indicating sinking air. Tone response can be customized in the Right Sub Menu.
Headphone/External Bleeper Socket: The device has an internal audio sounder ("bleeper") and a headphone socket. An external piezo bleeper can be connected and worn under a helmet or inside a headset cup, particularly useful for paramotor fliers. For open-ear helmets, the bleeper can be mounted near the ear in the padding. Stereo earbuds can also be used, or the Micro Alti can connect to an intercom (for tandem/sailplane gliding) or a paramotor headset auxiliary input. The device can be set for a headset or piezo bleeper in the middle sub menu. Headset vario tone volume is independent of internal bleeper volume. When using a piezo extension bleeper, use a stereo jack plug and leave the jack's ring unconnected.

Maintenance Features

Charging: Charge via the USB socket if the device doesn't function. The battery is a 100mA rechargeable lithium polymer type, automatically recharged when plugged into any USB 5-volt supply (computer, phone charger, sat-nav lead, solar charger). A car cigarette lighter charger is included.
Charging Indication: A red LED indicates charging. Approximately one hour of charge provides over 60 hours of autonomy (depending on use). If the FM radio is active, battery life is around 8 hours. The charger switches off, and the light extinguishes when fully charged. Even a short charge is sufficient for most flights.
Battery Replacement: New batteries can be supplied by Fairhaven and fitted by the user if required.
Firmware Updates: Fairhaven occasionally provides firmware updates to improve features and operation.
G-Meter Calibration: The G CAL function allows calibration of the G-Meter if it doesn't show approximately 1G at rest.
Clock Adjustment: The CLOCK ADJUST function allows fine-tuning if the clock runs fast or slow.
Pressure Sensor Adjustment: QNE ADJUST allows compensation for small changes in the altimeter's pressure sensor as it ages, though a precision reference is recommended for this. BARO ADJUST allows adjusting the barometric pressure reading to a known reference.

Important Note: This product is designed as an aid for amateur flying under visual flight rules and is not guaranteed for use in obstacle or aircraft avoidance. Specifications may change over time, and claims relate to the device at the time of manufacture.

Fairhaven Micro Alti 2 - User Notes Section; Personal Notes Area