Skydiving is an inherently risky activity that can lead to injury or death. All skydiving equipment is subject to failure. Failure to follow instructions, warnings, and operating procedures could imperil you and others. Audible altimeters use extremely high sound pressure levels in order to cut through noise, and can cause hearing damage; Freefall Data Systems LLC recommends using earplugs when using any type of audible altimeter. It is important to understand that altimeters should only be used as a secondary indication of altitude—second to a visual ascertainment—as they are subject to error and malfunction. Many factors can compromise the accuracy of a barometric altimeter reading, including but not limited to: body position, position relative to other skydivers or objects, altimeter placement, and malfunction. In the end, each skydiver is and must be responsible for his or her own altitude awareness and safety. Loss of one's own altitude awareness can in certain cases lead to endangering others on the ground as well as in the sky. SonoAlti 2 was designed for military skydivers or trained skydivers licensed by a national parachute organization, and is not intended for student use. For convenience, this altimeter contains no security features; this also means that if Bluetooth mode is on and has not yet timed out (two minutes), anyone with the FDS Altis app within range (approximately ten feet from the altimeter) could change the settings of your altimeter. SonoAlti 2 will not function as an altimeter during a skydive if Bluetooth mode is on. Although it is possible to set the altimeter using Bluetooth mode on ascent in an aircraft, it is better practice to create presets beforehand and select them using the preset button on the altimeter before a jump or during ascent. Many distractions can occur on a skydive; just because you are wearing an altimeter, it does not mean that you will necessarily register the information it is intended to convey. Additionally, just because two altimeters (e.g. a wrist mounted one and an audio-visual altimeter) are in sync during ascent, this does not necessarily mean that they will be in sync during freefall or under canopy as well, as barometric altimeters are more greatly affected by wakes (burbles) at high speeds than at low speeds. This altimeter contains a lithium polymer battery; do not use it if the case is damaged in any way.
This product was manufactured for skydiving only. By using this product, you accept full responsibility for its use and agree that Freefall Data Systems LLC will not be legally held responsible for any malfunction whatsoever that this product may have, whether good or defective.
SonoAlti 2 is an audible altimeter and data logger with a rugged anodized aluminum case. It utilizes a piezoelectric loudspeaker to provide audible alarms at altitudes of a user's choosing during the three phases of a skydive: ascent, freefall, and canopy. There are 32 different sounds a user can choose from, 18 of which were conceived for freefall and 14 of which were conceived for canopy and ascent. The altimeter stores five presets with unlimited alarms and can be set using the FDS Altis app using Android or iOS via Bluetooth® wireless technology. Bluetooth mode is initiated via a button press-and-hold and times out automatically. Presets can be selected on the fly using another button on the altimeter, eliminating the need to carry a mobile device for this purpose. The app can also be used to synchronize jump data (altitude, vertical descent speed, temperature) to Freefall Data System's cloud-based FDS Logbook. Approximately 1,000 jumps can be stored in the altimeter before synchronization is required, but it is recommended to synchronize data often to avoid logging errors. SonoAlti 2 also enables users to set a custom freefall threshold (default is 80 mph), which can be useful for wingsuiters as well as swoopers. Additionally, it allows one to disable all freefall alarms below a certain altitude, so that only canopy alarms are heard below that altitude. SonoAlti 2 automatically adjusts to local elevation, allows for landing zone elevation adjustments in each preset, and is always on until the battery is discharged. No data or settings are lost when the battery has discharged. SonoAlti 2 has a rechargeable lithium polymer battery with a life of approximately 250 jumps or 2 months. The battery takes approximately 4 hours to charge fully. One can check the battery status by pressing and holding both buttons at once (more details below). A low battery warning (an audible alarm at 1,000 feet ) is given if the altimeter has a low battery and does not have much life remaining. Battery life depends on how the altimeter is used and transported. The longest battery life is obtained when storing the altimeter in one location. The altimeter also features a travel mode, which ensures no data is logged and can also be used as a battery-saving mode. SonoAlti 2 can be used with full accuracy as high as 30,000 feet MSL.
SonoAlti 2 fits in the audible pocket of most skydiving helmets. The speaker should face the jumper's ear as described in the instructional video above.
The iOS or Android app used to set SonoAlti 2 is called FDS Altis. It can be downloaded on Google Play or Apple's App Store. First download the app onto your device from the App Store or Google Play. Open the app and first carefully read and agree to the Terms of Service. At this point you can log in if you have a Wi-Fi signal and an FDS Logbook account, or simply press "Cancel" or "Login as Guest" if you are not using the logbook or out of range of Wi-Fi. After this, press and hold the Bluetooth button (the lower button) on SonoAlti 2 until you hear a sound indicating that Bluetooth mode has been turned on . After this, select SonoAlti 2 and then "CONNECT & SYNC." Your SonoAlti 2 should appear with its serial number (e.g. FDS SA2 23R6A, where the last five digits are the serial number). Select your device and the altimeter will begin to send data to the device. A blue light on the altimeter indicates an active connection. It generally takes approximately five seconds to transfer the data. To set up the altimeter for its first use, click on "Settings" and you will see another menu in which you can set up to five "Presets" as well as "Main" settings at the top that apply to all presets. To download data from the altimeter or upload jumps to the cloud, click on "Data Syncing" (this will be greyed out and not available if you do not have an FDS Logbook account or a Wi-Fi signal). If you click on "Info," you can check the serial number, battery status, the number of jumps since the internal memory was last reformatted, and the current device firmware version. When finished using the app, you can either disconnect on the app and manually power off Bluetooth mode by pressing and holding the Bluetooth button until you hear a sound indicating that Bluetooth mode is off . You can also simply let Bluetooth mode automatically time out after two minutes of inactivity. The time-out prevents one from accidentally leaving Bluetooth mode on, which drains the battery more quickly and does not register altitude.
Under "Main" settings, one can adjust the center frequency of all audible alarms. Changing this can be useful if you are having trouble hearing the audible alarms or those who find the default center of 4.0 kHz a bit too piercing. This will depend on the user's own hearing and preferences, and can also depend on the user's helmet set-up. Below this, one can choose whether or not the altimeter logs jumps; this could be useful when loaning the altimeter to another jumper. Next, one can activate or deactivate metric mode, which makes it so that the FDS Altis app displays in kilometers per hour and meters. SonoAlti 2 also features a travel mode in which it is ensured that the altimeter is not activated in any way; this is also useful as a general battery saving mode. The altimeter does not function on a skydive when in travel mode. Finally, you can set your next jump number here; this is useful when you first set up your altimeter, or in case you did not use the altimeter on a jump and need to manually adjust the next jump number.
When one clicks on a preset, you will see a menu with two options, the top of which is "General" settings. At the top, one can set a landing zone offset for that particular preset; enter a positive number if your landing zone is higher than your take-off altitude, a negative number of it is lower. A custom freefall threshold can be entered below this, which can be useful for wingsuiters and swoopers (e.g. wingsuiters might use something like 30 mph and swoopers 100 mph). Below this, one can disable all freefall alarms and alarms below a certain altitude; this is also useful for wingsuiters and swoopers who want to be absolutely sure to hear their canopy alarms below a certain altitude. At the bottom, you can set audible alarm volumes for the three different phases of the skydive. There are five possible volume levels.
Under "Alarms," one can set alarms to sound during the three phases of a skydive: ascent, freefall, and canopy. Ascent alarms are simply entered as a single altitude, and all alarms on ascent will sound for four seconds. Enter a number and press "Insert" with the desired alarm selected. You can hear the alarms by selecting them, or listen to them all online here. To delete an alarm, hold down on it (Android) or swipe left (iOS). Depending on the speed of the aircraft utilized, the lowest alarm that should be used is approximately 1,000 feet for fast aircraft, although altitudes in the hundreds will also work for slower aircraft. Freefall and canopy alarms—in contrast to ascent alarms—are set to sound in altitude ranges; we find this to be the most beneficial design for altitude awareness (versus sounding for a number of seconds) because it imparts the user with additional information of when they have exited an altitude window as well as entered it. For canopy alarms, we recommend a range of at least 50 feet (e.g. 1,000 to 950 feet); for freefall, at least 500 feet is recommended. One should consider one's descent rate when deciding on ranges, keeping in mind, for example, that in normal belly-to-earth freefall we cover 100 feet in only about 1/2 second—a blip. We recommend at least two alarms on ascent to verify the altimeter is working and to cross-check with other altimeters for accuracy. The number of alarms that can be set for ascent, freefall, and canopy is unlimited.
Once you have set up your altimeter with the app, you can now select between your various presets on the device itself. To select a preset, hold the top button of your altimeter down until you hear a series of beeps; make certain that your altimeter is not in Bluetooth mode when doing this. The number of beeps you hear indicates the current preset (e.g. Preset 5 ). If you press and hold again, or keep holding, the altimeter will cycle through the various presets.
Freefall Data Systems recommends users come up with their own presets, but for convenience, SonoAlti 2 comes with a single preset stored in Preset 1. The settings are as follows: two ascent alarms at 1,500 and 12,000 feet ; three freefall alarms at 6,000-5,500 , 4,500-4,000 , and 3,000-2,500 feet ; three canopy alarms at 1,000-950 , 600-550 , and 300-250 feet .
Although SonoAlti 2 can log hundreds of jumps before the memory is full—at which point logging is automatically disabled—Freefall Data Systems recommends syncing data often in order to reduce the occurence of logging errors. In order to use "Data Syncing", you must have a Wi-Fi connection, and a set-up subscription to FDS Logbook. Once you have set up your logbook, in "Logbook Settings" you will see dropzones, aircraft, and equipment located on the first tab: these are the "Current Settings" in your logbook, which can be changed in FDS Logbook as well. When syncing jumps in the Data Syncing tab, the jumps will be uploaded according to the current settings in the logbook. The number of data files on the altimeter is shown at the top. Press "Go" next to "Download Files from Altimeter" to begin downloading data. The files will download one after another, and will only be erased from your altimeter when they are successfully downloaded to your mobile device. You can cancel the downloading at any time in order to stop transferring data. Below this, you can see the number of files on your mobile device waiting for upload to the cloud. You can "Upload All Files" by pressing "Go" or upload them individually in the list below; this can be useful if you know that certain jumps were made at different locations. Then one can change the Logbook (aka "Current") Settings. To delete a file from the mobile device (if one wishes to discard data), press and hold on that file (Android) or swipe left (iOS). Deleting a jump file from a mobile device is permanent and cannot be undone.
SonoAlti 2's battery typically lasts approximately 250 jumps or 2 months. Digital altimeters that are subject to long car rides through hilly or mountainous terrain will naturally discharge the battery faster. The longest battery life is obtained by leaving the altimeter in one location. Simply driving with the altimeter to work in normal circumstances, however, will not significantly reduce the battery life of SonoAlti 2.
SonoAlti 2 has a lithium polymer battery that is rechargeable with the included USB cord. It takes approximately four hours to fully charge the battery when it is completely empty. A red LED indicates that the battery is charging, and this LED will go off to indicate the altimeter is done charging. It should only be necessary to recharge the altimeter periodically, as it was designed to have a long battery life. During long periods of storage (e.g. winter months), the altimeter should be charged once every two months in order to preserve battery life. It is best to store the altimeter in a cool, dry place.
In addition to being able to check SonoAlti 2's battery status on the app under "Info," one can also hold down both buttons (provided one is not in Bluetooth mode). Then the number of beeps indicates the status of the battery. 10 beeps indicates 100%, 9 beeps indicates 90%, 8 beeps 80%, etc. (e.g. battery at 40% ).
Refer to the Instructional Video to carry out a firmware update.
If the altimeter fails to function on a skydive, first make sure the altimeter is charged. Next, if the altimeter is charged, see if you can select a preset on the unit on the ground to see if it is responding as expected (press and hold the top button). Perhaps the wrong preset was selected. If the altimeter does not respond to any type of button presses, take a small paper clip and insert it into the small hole adjacent the Bluetooth button and depress the manual reset button (you should feel the button slightly give way). This will reset the unit, which takes several seconds. If necessary, it will also reformat the flash memory in the altimeter in the case that it has been corrupted. This unfortunately means that you have lost your data and settings. Now try to connect your altimeter via the app. Certain Android devices may be required to bind the device via Bluetooth settings before the altimeter is visible. It also may be necessary to restart certain Android devices before being able to connect. If this fails to solve your problem, visit the FDS Forum or contact Freefall Data Systems LLC for assistance.