USER MANUAL

REVISION A | 07.24.2015
REVISION HISTORY

ALTA USER MANUAL

PART NUMBER: 770-00042

REVISION DATE DESCRIPTION

A July 2015 Initial Release
| USER MANUAL 3

CONTENTS

2 Revision History

3 Contents

5 ALTA OVERVIEW 

6 Disclaimer and Warning

7 LIMITATION OF LIABILITY

8 Introduction

9 Symbols, Abbreviations and Terminology

12 Dimensions

14 Included Items

15 Specifications

19 Limitations

20 System Diagrams

24 ALTA Mobile App

24 Additional Required Components (not included)

25 SETTING UP ALTA 

26 Unfolding ALTA

30 Radio Installation

35 Radio Mapping

40 Configuring Top or Bottom Mount

42 Isolator Cartridges

43 Battery Installation

47 Compass Calibration

49 Propellers

51 First Person View (FPV)

54 FPV On Screen Display Setup

58 Tuning ALTA

61 ALTA Flight Parameters

64 OPERATING ALTA 

65 Flight Controller Modes

67 Home Switch
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67 Arm Enable Switch

68 Status Light

70 Orientation Lights

71 ALTA App Monitor

72 NORMAL PROCEDURES 

73 Unpacking and Setup

74 Before Starting

76 Before Takeoff

78 After Every Flight

79 After Last Flight

80 EMERGENCY PROCEDURES 

81 Emergency Guidance

82 Pilot Disorientation

83 Unexpected Flight Controller Behavior

84 Battery Exhaustion

85 Status Light Warning Indicator Illuminates

86 Loss of Radio Control Signal

87 Loss of FPV Signal

89 Data Logging

89 Performance

89 Weight / Endurance Performance Data

90 MAINTAINING ALTA 

91 General Information and Techniques

92 Maintenance Items

95 Replacement of Parts

96 Firmware Update Process

97 TROUBLESHOOTING 

100 APPENDIX 

101 Appendix A. Default Tuning Values

102 Appendix B. Data Logging Fields
| USER MANUAL 5

ALTA OVERVIEW 
| USER MANUAL 6

DISCLAIMER AND WARNING

IMPORTANT - Please read this disclaimer and warning carefully and review 

the ALTA User Manual prior to flight. If you have any questions, please contact 

support@freeflysystems.com prior to using the ALTA. You can review the most 

current version of this User Manual at www.freeflysystems.com/software-manuals/. 

By using the ALTA, you acknowledge that you have read, understand and agree to 

this disclaimer. You agree that you are solely responsible for your conduct while 

using the ALTA, and for any direct or indirect consequences that may result from its 

use. You agree to only use the ALTA for proper purposes that are in accordance with 

local and airspace rules and regulations. 

» ALTA is not a toy and should be operated with extreme care, as improper 

operation can cause damage to property, serious personal injury or death. 

» As with any multi-rotor helicopter, the ALTA is a complex and technical 

machine. Novice pilots should invest sufficient time on a flight simulator 

and seek training from an experienced pilot prior to operation. The ALTA 

User Manual and a flight simulator are no substitute for training with an 

experienced pilot, particularly when it comes to learning how to safely 

operate the ALTA. Novice pilots should never fly without the supervision of 

an experienced pilot.

» Always check the ALTA and its components prior to operation.

» Always maintain a safe distance from the ALTA when in use.

» Never attempt to touch the ALTA when the propellers are moving.

» Never fly the ALTA over or around people, power lines or other aircraft.

» Never fly with any propellers that have visible imperfections or damage. 

» Always keep children and animals a safe distance away from the ALTA 

when in use and when changing configurations.

» Always remove the propellers or power ALTA using a low power source 

when making a change to the configuration of the ALTA to prevent propeller 

strikes in the event of unintentional motor starts.

» Always remove the configuration jumper when making changes to the 

configuration of the ALTA. 

» Always test the ALTA with the propellers removed to make sure that the 

motors are spinning in the correct direction and that the motor assignment 

is correct with respect to the SYNAPSE flight controller. If you have either 

of these wrong, the ALTA will be uncontrollable and dangerous.

» It is your responsibility to perform a full system check of the ALTA prior to 

every flight. 

» It is your responsibility to learn how to safely operate the ALTA and to adhere to all applicable rules and regulations.

» Fly at your own risk.
| USER MANUAL 7

LIMITATION OF LIABILITY

IN NO EVENT SHALL FREEFLY BE LIABLE TO BUYER FOR ANY INDIRECT, 

CONSEQUENTIAL, PUNITIVE, INCIDENTAL, OR SPECIAL DAMAGES, OR ANY 

DAMAGES WHATSOEVER RESULTING FROM THE USE OF THE ALTA OR FROM LOSS 

OF USE, DATA OR PROFITS (HOWEVER CAUSED AND UNDER ANY THEORY OF 

LIABILITY), EVEN IF FREEFLY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH 

DAMAGES. IN NO EVENT SHALL FREEFLY’S LIABILITY FOR A PRODUCT (WHETHER 

ASSERTED AS A TORT CLAIM, A CONTRACT CLAIM OR OTHERWISE) EXCEED THE 

AMOUNTS PAID TO FREEFLY FOR SUCH PRODUCT. NOTWITHSTANDING ANYTHING 

HEREIN, IN NO EVENT SHALL FREEFLY’S LIABILITY FOR ALL CLAIMS ARISING OUT 

OF OR RELATING TO THIS AGREEMENT EXCEED THE AMOUNTS PAID BY BUYER TO 

FREEFLY FOR PRODUCT IN THE LAST TWELVE (12) MONTHS. IN NO EVENT WILL 

FREEFLY BE LIABLE FOR COSTS OF PROCUREMENT OR SUBSTITUTE GOODS BY 

BUYER. THE LIMITATIONS SET FORTH HEREIN SHALL APPLY TO ALL LIABILITIES 

THAT MAY ARISE OUT OF THIRD-PARTY CLAIMS AGAINST BUYER. THESE 

LIMITATIONS SHALL APPLY NOTWITHSTANDING ANY FAILURE OF ESSENTIAL 

PURPOSE OF ANY LIMITED REMEDY. 

Freefly shall not be liable for damages or injuries incurred directly or indirectly from 

the use of the ALTA including, but not limited to, the following situations:

» Failure of operator to follow proper instructions and safety warnings found 

at www.freeflysystems.com.

» Failure of the operator to follow onboard safety warnings while using the 

ALTA.

» Failure of the operator to follow and comply with local rules and regulations.

» Failure of the operator to inspect the ALTA and its components prior to 

operation.

» Failure of the operator to properly maintain and/or service the ALTA 

through an authorized Freefly Service Center with genuine ALTA parts.

» Use of third-party products on the ALTA.

» Use of the ALTA in a physically or mentally impaired capacity.

» Use of the ALTA without sufficient training.

» Use of the ALTA in unsafe conditions, including but not limited to, bad or 

severe weather, such as rain, wind, snow, lightning, dust storms, etc., or in 

areas of magnetic or radio interference, such as power stations, broadcasting and cell phone towers, government prohibited airspace, etc.

» Improper operation, misjudgment or risky behavior while using the ALTA.

» Infringement of third party data, audio or video rights recorded when using 

the ALTA.
| USER MANUAL 8

INTRODUCTION

ALTA is a professional multi-rotor aircraft designed for demanding 

cinematic, television, and photographic applications. Within five 

minutes, ALTA can unfold from its carrying case to flying some of 

the most capable cinema cameras on either the top or bottom of the 

aircraft. The SYNAPSE flight controller is purpose-built for cinema 

use, yielding precise, yet smooth control.

This User Manual has been prepared to describe the complete 

operation of airframe and flight control systems, and the normal 

maintenance of those items. Do not operate ALTA without reading and 

understanding this manual.

This manual is not a substitute for adequate flight training. Training 

requirements can vary when operating in different countries or under 

different flight conditions. Always consult local regulations before 

flying ALTA. In areas where there are no flight training requirements, 

it is the sole determination of the pilot-in-command as to whether he 

or she has the appropriate level of training or experience for a given 

flight. Always set and adhere to personal minimums and fly within 

your own capabilities.
| USER MANUAL 9

SYMBOLS, ABBREVIATIONS AND TERMINOLOGY

WARNINGS, CAUTIONS AND NOTES

Throughout the manual, warnings, cautions and notes are used to highlight various 

important procedures. These are defined as follows:

WARNING

Warnings are used to highlight procedures which, if not strictly observed, 

may result in personal injury or loss 

of life.

CAUTION

Cautions are used to highlight procedures which, if not strictly observed, 

may cause damage to equipment.

NOTE

Notes are used to highlight specific 

operating conditions or steps of a 

procedure.

SPEED TERMINOLOGY

GS Ground Speed is the speed of an 

aircraft relative to the ground

TAS True Airspeed is the airspeed of an 

aircraft relative to undisturbed air

METEOROLOGICAL TERMINOLOGY

ISA International Standard Atmosphere in which:

The air is a dry, perfect gas;

The temperature at sea level is 15° 

Celsius (59° Fahrenheit);

The pressure at sea level is 1013.2 

mbar (29.92 inches Hg);

The temperature gradient from sea level 

to the altitude at which the temperature is 

-56.5°C (-69.7°F) is -0.00198°C (-0.003564°F) 

per foot and zero above that altitude
| USER MANUAL 10

MSL Mean Sea Level is the average height above 

the surface of the sea for all stages of tide

AGL Above Ground Level is the height of 

the aircraft above the ground

OAT Outside Air Temperature is the free air static 

temperature surrounding the aircraft

Pressure Altitude Altitude measured from standard sea level pressure 

(29.92 in. Hhg) by a pressure or barometric altimeter

It is the indicated pressure altitude corrected for 

position and instrument error. In this Manual, 

altimeter instrument errors are assumed to be zero

POWER TERMINOLOGY

Maximum Continuous 

Power Output

The maximum typical power output of a 

motor averaged over the entire flight

Maximum Instantaneous 

Peak Power Output

The maximum power output of a motor during 

any phase of flight, such as when maneuvering

FLIGHT AND POWERPLANT CONTROL

Throttle Stick The radio controller stick responsible for 

throttle control. For Mode 2 controllers, this 

is the vertical movement of the left control 

stick. For Mode 1 controllers, this is the 

vertical movement of the right control stick

Yaw Stick The radio controller stick responsible 

for yaw (also called pan) control 

For Mode 2 and Mode 1 controllers, this is the 

lateral movement of the left control stick

Pitch Stick The radio controller stick responsible for 

pitch control. For Mode 2 controllers, this is 

the vertical movement of the right stick 

For Mode 1 controllers, this is the 

vertical movement of the left stick

Roll Stick The radio controller stick responsible for roll 

control. For Mode 2 and Mode 1 controllers, this is 

the lateral movement of the right control stick

Pitch/Roll Stick 

or Cyclic Stick

The radio control stick responsible 

for both pitch and roll control

For Mode 2 controllers, this is the right stick
| USER MANUAL 11

WEIGHT AND BALANCE

Maximum Takeoff 

Weight (MTOW)

Maximum allowable weight at liftoff

Standard Empty Weight Weight of a standard aircraft

Basic Empty Weight Standard empty weight plus optional equipment

Useful Load Difference between take off weight 

and basic empty weight

Payload Useful load less battery weight

GENERAL TERMINOLOGY

sUAS Small Unmanned Aircraft System includes all 

components of the system required for the flight of 

an unmanned aircraft, including the radio controller, 

data link and other related support equipment
| USER MANUAL 12

DIMENSIONS

457 

(18.0)

1064 

(41.9)

178

(7.0)

220

(8.7)

1126 

(44.3)

1533

(60.4)

180

(7.1)

318 

(12.5)

1

2

3

4

5

6

UNFOLDED PLAN VIEW WITH BOOM NUMBERING SCHEME MM (INCH)

457 

(18.0)

178

(7.0)

220

(8.7)

1126 

(44.3)

180

(7.1)

318 

(12.5)

1

2

3

4

5

6

UNFOLDED SIDE VIEW WITH LANDING GEAR MM (INCH)

457 

(18.0)

1064 

(41.9)

178

(7.0)

220

(8.7)

1126 

(44.3)

1533

(60.4)

1

2

3

4

5

6

UNFOLDED FRONT VIEW WITHOUT LANDING GEAR MM (INCH)
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220 

(8.7)

FOLDED SIDE VIEW MM (INCH)

550 

(21.7)

515 

(20.3)

515 

(20.3)

180 

(7.1)

205 

(8.1)

220 

FOLDED PLAN VIEW MM (INCH)

550 

(21.7)

515 

(20.3)

515 

(20.3)

180 

(7.1)

205 

(8.1)

FOLDED FRONT VIEW MM (INCH)
| USER MANUAL 14

INCLUDED ITEMS

1. Case

2. ALTA

3. Case Lid Foam

4. Isolator Cartridges

a. (6) Teal (Installed)

b. (6) Black

c. (6) Red

5. Documentation

6. USB-Futaba Power Cable

7. Inverted Landing Gear

8. Antenna Tubes

9. FPV Cables

a. Skyzone/BOSCAM

b. ImmersionRC/Fat Shark

c. Ready Made RC

10. Fasteners

a. (4) M3 × 8 Socket Head for 

Toad In The Hole Male Adapter

b. (2) M3 × 8 Flat Head for Accessory 

Mount

11. Toad In The Hole Male Adapter

12. 5.5mm Wrench

13. Hex Drivers (1.5mm, 2.0mm, 2.5mm)

14. Accessory Mount

15. Double-Sided Tape
| USER MANUAL 15

SPECIFICATIONS

DIMENSIONS

DIAMETER (DOES NOT INCLUDE PROPS)

Unfolded Diameter 1126 mm

Folded Diameter 515 mm

Height to base of Toad In The Hole (TITH) 220 mm

POWERPLANT

Number of Motors 6

Motor Type Direct Drive 3-Phase PMAC Outrunner

Motor Model F45

Motor Max Continuous Power Output 350 W

Motor Max Instantaneous 

Peak Power Output

950 W

Maximum RPM (flat rated) 6300 RPM

Equivalent Kv 384

Electronic Speed Controller Freefly Silent-Drive Sine Wave ESC

PROPELLERS

Material Carbon fiber with balsa core

Propeller Orientation (3) CW and (3) CCW Props

Propeller Type 18 × 6 Folding

BATTERY

Nominal Battery Voltage 6S / 22.2V

Maximum Battery Size 240 × 180 × 80 mm

Maximum Battery Quantity 2 Battery Packs (Parallel)

Battery Connectors 2× EC5 (Parallel)

Required Minimum Battery 

Discharge Rating

Dual Pack: 200A / 400A Peak

Single Pack: 300A / 600A Peak
| USER MANUAL 16

WEIGHTS

Maximum Gross for Takeoff1 13.6 kg (30.0 lbs)

Maximum Useful Load2 9.1 kg (20.0 lbs)

Maximum Payload3 6.8 kg (15.0 lbs)

Typical Standard Empty Weight: 4.5 kg (10.0 lbs)

SPECIFIC LOADINGS

Typical Specific Power4 145 W/kg

Thrust Ratio at MTOW1 1.85 : 1

1 At sea level, ISA.

2

 Top and bottom mount. Includes batteries.

3

 Payload weight top or bottom mount.

Battery weight not included and mounted 

on opposite side from payload.

4

 At MTOW, sea level, ISA.
| USER MANUAL 17

FLIGHT CONTROLLER

Model Name Freefly SYNAPSE flight controller

Flight Modes Manual, Height Mode, Position 

Mode, Return-To-Home, Autoland

Supported Inputs: DSMX, DSM2, S.Bus, 

S.Bus2, PPM, FPV SD

Supported Radios Futaba S.Bus & S.Bus2, DSMX, 

DSM2 (Spektrum/JR), PPM, 

PPM Invert, PPM Graupner

Supported Radio Controller 

Telemetry Systems

Futaba w/ built-in voltage sense port

Minimum Radio Controller 

Channels Required

5

Supported GNSS GPS, GLONASS, Galileo

Supported SBAS QZSS, WAAS, EGNOS, MSAS

First-Person View System 

Video Formats

NTSC, PAL

Supported First-Person 

View Transmitters

Skyzone, BOSCAM, 

ImmersionRC, Fat Shark

Supported First-Person View Cameras Ready Made RC

First-Person View OSD Telemetry User Configurable

Installed Transceivers Wi-Fi

Data Logging Rate 25 Hz

LIGHTING AND INDICATION

Status Light 1 Watt Red, 1 Watt White

Orientation Lights 3-Watt RGB LED

Orientation Light Color Options Red, Yellow, Blue, Green, White

Accessory Lighting Port 12 VDC

Accessory Lighting Port Location Outboard on Boom Ends

ISOLATION SYSTEM

Vibration Isolation System Silicone O-Rings

Option 1: Soft / Light Payloads Red O-Rings

Option 2: Medium / Medium Payloads Teal O-Rings

Option 3: Stiff / Heavy Payloads Black O-Rings
| USER MANUAL 18

PAYLOAD MOUNTING

Mounting Locations Bottom and Top Mount

Mounting System Freefly Toad In The Hole 

(TITH) Quick Release

FPV Camera Mount Forward, underneath chassis

FPV Transmitter Mount Boom #5
| USER MANUAL 19

LIMITATIONS

 NOTE

These limitations are advisory in nature and do not extend or 

restrict limitations provided by local aircraft operational regulation.

POWERPLANT LIMITATIONS

Maximum RPM 6300 RPM

Maximum Battery Voltage 25.2 Volts

Minimum Average Battery Voltage 19.2 Volts

ENVIRONMENTAL LIMITATIONS

Do not fly ALTA in temperatures exceeding 45oC (113oF) or below -20oC(-4oF).5

WEIGHT LIMITS

Maximum Takeoff Weight 13.6 kg (30.0 lbs)

Maximum Useful Load 6.8 kg (15.0 lbs)

FLIGHT CONTROLLER LIMITS

Maximum Pitch/Roll Angle 45°

Maximum Yaw Rate 150° / second

5 Must additionally observe battery temperature ratings.
| USER MANUAL 20

SYSTEM DIAGRAMS

sUAS HIGH LEVEL

ALTA App

FPV Rx,

Preview Monitor

Radio Controller

GPS Satellite

2.4GHz MōVI Controller

HD Video Link,

Preview Monitor
| USER MANUAL 21

FLIGHT CONTROL

CAN

PWM

Status

Light

ESC

SYNAPSE

Flight

Controller

SC ESC

SC ESC

B. Futaba Receiver or Generic Receiver

 S.BUS, S.BUS 2 or PPM

A. Spektrum Receiver

DSMX, DSM 2

A.

B.

6 Position Lights
| USER MANUAL 22

POWER SYSTEM

SYNAPSE

Flight

Controller

EC5 Connector

Motor

 Lights*

REGULATORS

FUSE

Flight

Battery

Flight

Battery

Motor

 Lights*

Motor

 Lights*

FPV Tx

FPV CAM

Motor

 Lights*

Motor

 Lights*

Motor

 Lights*

R E C E I V E R

R E C E I V E R

12v 5v 5v

Futba Tel.

FUSE

* for orientation

‡ only one USB 

 cable provided

‡

‡
| USER MANUAL 23

FPV EQUIPMENT

SYNAPSE

Flight

Controller

FPV Camera Lead

Pre-installed

FPV Tx Lead

Pre-installed

FPV Tx Cable

Boscam/Skyzone or Fat Shark/ImmersionRC

FPV Tx

(not included)

FPV Camera

(not included)

FPV Camera Cable
| USER MANUAL 24

ALTA MOBILE APP

The ALTA App is used to configure ALTA parameters and to monitor ALTA’s status 

during flight. To download the ALTA App, search for “Freefly ALTA” in the App Store 

or on Google PlayTM.

Parameters may only be adjusted while ALTA is on the ground and disarmed. In 

addition, radio mapping parameters can only be adjusted when the Configuration 

Jumper is removed. For more information on radio mapping, see the Radio Mapping 

section of this manual.

When making configuration changes with the ALTA App, wait three seconds for the 

app to automatically save changes to ALTA before shutting off the app or the mobile 

device.

The ALTA App will be actively maintained, and additional functionality may be added 

over time. For information on individual app updates, refer to the App release notes.

ADDITIONAL REQUIRED COMPONENTS (NOT INCLUDED)

RADIO CONTROLLER

ALTA supports a variety of radio controllers as outlined in the Flight Controller 

Specifications. A minimum of five (5) channels are required, with four (4) used for 

flight control, and the remaining one (1) used for mode selection.

However, a radio controller with at least 9 channels is highly recommended to make 

use of Velocity and Climb Rate Clamps, Return-To-Home, and Arm Enable functions. 

It is recommended to use a radio controller with a three way switch for the Mode, 

Home and Arm Enable functions, and a knob or slider input for both the Velocity and 

Climb Rate Clamp functions.

FLIGHT BATTERY

ALTA can accommodate a variety of Lithium Polymer (LiPo) flight battery packs. 

Battery packs must be 6S, having a nominal voltage of 22.2 V. When running two 

packs, each pack must have a continuous discharge rating of 200 amps or greater, 

and a peak discharge rating of 400 amps or greater. When running a single pack, the 

pack must have a continuous discharge rating of 300 amps or greater, and a peak 

discharge rating of 600 amps or greater. For additional information on expected 

flight durations, refer to the Performance Section of the manual.
| USER MANUAL 25

SETTING UP ALTA 
| USER MANUAL 26

UNFOLDING ALTA

ALTA features swan-neck booms that fold into a compact size for 

travel. They are secured in an open position for flight using overcenter latches.

TO UNFOLD ALTA

1. Remove ALTA from case

2. Fold down all six boom retention clips

3. Open ALTA booms
| USER MANUAL 27

4. Snap shut all six boom latches until they “click” 

5. Visually confirm all latches are seated properly

6. Remove prop protectors
| USER MANUAL 28

TO FOLD ALTA

1. Secure props with prop protectors

2. Unlatch all six booms

3. Close ALTA booms
| USER MANUAL 29

4. Fold up all six boom retention clips to secure booms
| USER MANUAL 30

RADIO INSTALLATION

RADIO CONTROLLER RECEIVER

ALTA requires the installation of a radio control system. S.Bus, S.Bus2, DSM2, 

DSMX, and PPM (including inverted PPM and Graupner) receiver types are 

supported.

Additionally, ALTA supports radio receiver diversity using S.Bus, S.Bus2, DSM2 and 

DSMX receivers. This means two receivers may be installed, and the SYNAPSE flight 

controller will automatically use the receiver with the best signal quality. Using two 

receivers requires the radio controller to be bound to both receivers.

Refer to the instructions provided with your radio controller to complete the binding 

process. For Spektrum/JR radios, a receiver is required to bind the satellites to a 

radio controller.

1. Locate the noted closeout panels used for receiver 

installation (between booms 1 & 2 and 5 & 6)

2. Remove side closeout panel with radio wires using a 1.5mm hex driver
| USER MANUAL 31

3. Identify required wire

S.BUS/S.BUS2 DSM2/DSMX

PPM

4. Feed wire through grommet

5. Replace side closeout panel

6. Plug in receiver/satellite to wire per the radio 

manufacturer’s installation instructions
| USER MANUAL 32

7. Attach receiver/satellite to exterior using the provided double sided tape

a. Futaba & PPM

b. Spektrum/JR

8. For Futaba receivers, feed antenna wires into antenna 

tubes and zip tie to noted mounting location

9. Repeat 1-7 on opposite side for dual receivers (only 

applies to Futaba and Spektrum/JR)
| USER MANUAL 33

RECOMMENDED RECEIVER PLACEMENT

FUTABA

Mount Futaba receivers 15mm from the wiring grommet for easy S.Bus wire 

installation and removal (See Radio Controller Receiver step 7a).

SPEKTRUM/JR SATELLITES

Mount satellites so antennae are blocked by the airframe as little as possible. If 

using two receivers, place them at a 90° angle to each other. (See Radio Controller 

Receiver 7b)

VOLTAGE TELEMETRY

ALTA supports battery voltage telemetry on Futaba radios using a receiver that 

supports an external voltage sensor, such as the R7008SB. To set up ALTA with 

voltage telemetry for Futaba radios:

1. Locate the radio receiver wire bundle behind the 

closeout panel between booms 1 and 2.

2. Identify the voltage sense wire and connector in the bundle. It is the small, 

2-pin white connector attached to a black and red twisted wire pair.

 NOTE

This wire is already connected to an in-line fuse. 

Soldering a fuse into this wire is not required.
| USER MANUAL 34

3. Feed the voltage sense wires through the grommet on the closeout panel.

4. Connect the white connector to the external voltage 

sense port on the Futaba receiver.
| USER MANUAL 35

RADIO MAPPING

ALTA can be used with a variety of radio controllers. Different radio controllers can 

map functions to different channels, so properly mapping controller channels to 

ALTA functions is an important step before flying. Radio mapping is performed using 

the ALTA App.

This section describes the steps required to complete radio mapping.

If you are uncertain about your channel mapping, obtain assistance from an 

experienced pilot or from Freefly Customer Support.

CONFIGURATION JUMPER

A small jumper is used to prevent motor operation while configuring radio mapping 

parameters. With the jumper in place, the motors may operate, but channel 

mapping is prevented. With the jumper removed, channel mapping may take place, 

but motor operation will be prevented.

To remove or replace the Configuration Jumper:

1. Locate the closeout panel where the jumper is installed

2. Remove the side closeout panel with the jumper using a 1.5mm hex driver
| USER MANUAL 36

3. Remove or replace the jumper

4. Reattach the closeout panel

MAPPING RADIO CHANNELS USING ALTA APP

Channel mapping is accomplished with the ALTA App. Prior to mapping channels, 

ensure your radio controller and receivers are properly installed. Refer to the Radio 

Installation section of this manual and your Radio Controller’s documentation.

1. Remove the Configuration Jumper

 WARNING

Always ensure the Configuration Jumper is removed prior to 

adjusting radio settings to prevent unintentional motor starts.

2. Power ALTA using a battery pack or by plugging in the included 

USB-Futaba cable into an available port on a Futaba receiver

3. Open the ALTA App and connect to ALTA

4. Open Configurations > Radio

5. Open each ALTA function and adjust the channel to the desired channel 

number, and use the toggle to invert the orientation of a control

6. Ensure proper channel selection by moving the control input on the radio 

controller and verifying the displayed graph in the ALTA App responds correctly

 WARNING

Ensure proper channel mapping prior to flight. Incorrect mapping

can lead to immediate loss of control.
| USER MANUAL 37

ONCE CHANNELS ARE MAPPED

7. Remove the battery or USB-Futaba cable from ALTA

8. Replace the Configuration Jumper

FUNCTION DESCRIPTIONS

The following functions can be mapped to radio controller channels. These are found 

in the Radio section of the Configurations menu in the ALTA App. Each function 

is also represented by a chart that responds to control input allowing for quick 

verification of mapping settings.

CONTROLLER

Use this to select the appropriate receiver. The following guide is compiled for 

convenience. For complete specifications and which mode will work with your 

receiver, refer to your radio controller or receiver manuals.

» DSM2/DSMX are typically used by Spektrum and some JR controllers.

» SBUS is typically used by Futaba controllers.

» PPM is a generic standard used by many controllers and receivers.

» PPM Invert is the same as PPM except channel inputs are reversed.

» PPM Graupner interprets Graupner radio PPM inputs.

PITCH/ROLL/YAW/THROTTLE

The Pitch, Roll, Yaw and Throttle controls are the basic flight controls and are 

mapped to the two radio controller sticks.

MODE

The required Mode Switch selects between the three different flight modes: Manual, 

Height and Position. A three-position switch is recommended to select the three 

different modes. However, a two-position switch may be used, but will only allow for 

selecting between Manual Mode and (depending on radio controller mixes) either 

Position Mode or Height Mode

HOME SWITCH

The optional Home Switch selects between the different Return-To-Home (RTH) 

functions. A three-position switch is required for the Home Switch functions to 

select between the Home Set, RTH Off, and RTH Enable functions.

VELOCITY AND CLIMB RATE CLAMP

Velocity and Climb Rate Clamps set the maximum ground speed or vertical speed 
| USER MANUAL 38

available in Height Mode and Position Mode. The clamps can be adjusted mid-flight. 

An analog dial or slider is recommended for the Velocity and Climb Rate Clamp 

Functions.

ARM ENABLE

Arm Enable is an optional safety feature that inhibits arming while on the ground, 

or disarming while in the air based on the position of the switch. When not mapped, 

ALTA may be armed or disarmed at any time following normal arming and disarming 

procedures. See the Arm Enable Switch section of this manual under Operating 

ALTA for more information on switch behavior.

A minimum two-position switch is required to make use of Arm Enable. A three 

position switch may be used to temporarily turn off the feature as both arm and 

disarm are allowed in the switch’s center position.

ALL FUNCTIONS

The meaning of the direction or position of the indicator is described in the following 

table for all mappable parameters. The top and right positions on the radio mapping 

indicators represent 2000μs, and the bottom and left positions represent 1000μs, 

and the middle position represents 1500μs.

FUNCTION

IN-APP 

INDICATOR 

POSITION

INDICATES

Pitch Top Nose Up

Bottom Nose Down

Roll

Left Roll Left

Right Roll Right

Yaw

Left Nose Left

Right Nose Right

Throttle Top High Throttle

Bottom Low Throttle

Mode

Top Position

Middle Height

Bottom Manual

Home

Top Set New Home Position

Middle RTH Off

Bottom Initiate RTH

Velocity Clamp Top Fast

Bottom Slow
| USER MANUAL 39

Climb Rate 

Clamp

Top Fast

Bottom Slow

Arm Enable 

Switch

Top Arm Enable / Disarm Disable

Middle Arm Enable / Disarm Enable

Bottom Arm Disable / Disarm Enable

TYPICAL CHANNEL MAPPINGS

The following are channel mapping configurations as set in the ALTA App. These 

are recommendations only. Depending on exact radio models, these may help as 

an initial configuration. However, it is up to the pilot setting up ALTA for flight to 

determine if these settings are appropriate.

FUTABA 14SG/8FG

FUNCTION CHANNEL NUMBER DIRECTION

Pitch 2 Normal

Roll 1 Normal

Yaw 4 Normal

Throttle 3 Reverse

Mode 5 Normal

Home Switch 6 Reverse

Arm Enable 9 Reverse

Velocity Clamp 8 Reverse

Climb Rate Clamp 7 Reverse

SPEKTRUM DX18

FUNCTION CHANNEL NUMBER DIRECTION

Pitch 3 Reverse

Roll 2 Reverse

Yaw 4 Reverse

Throttle 1 Normal

Mode 6 Reverse

Home Switch 7 Reverse

Arm Enable 8 Normal

Velocity Clamp 10 Normal

Climb Rate Clamp 11 Normal
| USER MANUAL 40

CONFIGURING TOP OR BOTTOM MOUNT

A MōVI can be attached to either the top or bottom of ALTA via the Freefly Toad In 

The Hole (TITH) quick release.

ALTA comes pre-configured for bottom mounting a MōVI.

BOTTOM MOUNT

1. Prepare your MōVI for bottom-mount flight (see MōVI manual)

a. Attach landing gear

b. Install TITH receiver on MōVI

2. Connect MōVI to bottom Toad

ADDING A TITH TOP MOUNT

 CAUTION

Top mounting is not supported by the MōVI M10.

1. Prepare your MōVI for top-mount flight

a. Remove landing gear (see MōVI manual)

b. Install TITH receiver on MōVI (see MōVI manual)
| USER MANUAL 41

2. Connect and secure the supplied inverted landing gear to the bottom Toad

3. Remove the four flat-head M3×6 bolts that secure the top handle

4. Attach the supplied Toad to the top plate using the four M3×8 bolts provided

5. Connect MōVI to the top Toad
| USER MANUAL 42

ISOLATOR CARTRIDGES

Different Isolator Cartridges can be used to fine tune vibration damping 

performance for different payload weights. Three isolation cartridge styles are 

provided with ALTA with the red for light payloads, teal for medium payloads, and 

black for heavy payloads. Flight testing may be required to determine the optimal 

isolator for a given setup.

To install, place the cartridges between the top chassis plate and the battery plate. 

Ensure they are engaged in the track features and are parallel with the chassis and 

battery plate. Push inwards fully until they click, indicating the cartridges are locked 

in place. Pull outwards on the cartridge to ensure it is locked in place.

 CAUTION

Always ensure isolator cartridges are locked in place before flying 

ALTA. Isolator cartridges that are not locked can cause the payload 

to loosen and change ALTA’s fundamental flying characteristics.

To remove, pinch the cartridge latch to unlock it from the battery and chassis plate. 

Simultaneously pull the battery and chassis plate apart while pulling the cartridge 

outward.
| USER MANUAL 43

BATTERY INSTALLATION

Batteries may be installed on either the top or bottom of an ALTA and are always 

mounted opposite of the payload location. In both locations, battery pack(s) are 

secured with silicone straps tensioned across the pack(s). The straps are secured 

using studs located on either side of the pack(s).

 WARNING

Always secure battery pack(s) with both battery retention straps.

 CAUTION

When installing two battery packs, ensure they are at a 

similar state of charge (a full pack voltage difference less 

than 0.5V). Plugging in two dissimilarly charged packs 

could cause one pack to rapidly discharge into the other 

and damage the batteries or cause a battery fire.

 CAUTION

When using two battery packs, only use packs that are 

identical in their capacity and at a similar condition. 

Using a pack with another that is larger, or has many 

more cycles, can damage the battery packs.

 CAUTION

Always refer to and follow the battery manufacturer’s instructions, 

recommendations and guidelines for battery handling.

 CAUTION

When plugging in battery pack(s), ensure the polarity is 

correct. Positive is indicated by a red power lead, and 

negative/ground is indicated by a black power lead. 

Reversing polarity will damage ALTA’s electronics.
| USER MANUAL 44

BOTTOM MOUNT

1. Place battery retention strap studs at the appropriate height for battery pack(s)

2. Adjust battery stops to fit battery pack(s)

3. Attach the single-hole end of the battery retention straps to the studs
| USER MANUAL 45

4. Place battery pack(s) on battery tray below handle

5. Tension and secure battery retention straps
| USER MANUAL 46

TOP MOUNT

 CAUTION

Always completely secure the inverted landing gear by closing 

the TITH quick release lever. Inverted landing gear that are not 

completely attached can rotate and unplug battery leads.

1. Adjust battery stops to fit battery pack(s)

2. Attach the single-hole end of the battery retention 

strap to a stud on the landing gear

3. Place battery packs(s) in landing gear

4. Tension and secure battery retention straps
| USER MANUAL 47

COMPASS CALIBRATION

For best results, it is recommended to perform manual compass calibrations away 

from ferrous objects, buildings and vehicles. In addition, concrete can contain steel 

rebar which may influence compass calibrations.

 WARNING

Verify ALTA is disarmed prior to performing a compass calibration. 

To ensure ALTA does not arm, set the Arm Enable Switch (if 

available) to disable, and remove the Configuration Jumper.

 NOTE

It is recommended to use two people to perform the 

compass calibration as it requires handling and rotating 

ALTA. Perform calibration without a payload attached.

 NOTE

Ensure a microSD card is installed in the GPS/compass 

module prior to performing compass calibration.

TO PERFORM A COMPASS CALIBRATION:

1. Secure a battery onto ALTA

2. Plug in the battery

3. Open the ALTA app

4. Select Configurations > More > Compass

5. Under Calibration, select Start Manual

6. Follow the on-screen instructions
| USER MANUAL 48

AUTOMATIC COMPASS CALIBRATION

Automatic Compass Calibration will use compass readings over time to resolve 

an accurate compass calibration. Manual calibration is recommended for more 

immediate results thus enabling better closed loop, GPS assisted flying. 

In the ALTA App, select Configurations > More > Compass. Change the Auto 

Calibration setting to On.
| USER MANUAL 49

PROPELLERS

FORWARD

The folding propellers include two carbon fiber propeller blades attached to prop 

hubs, which are themselves secured to the motors. The propellers installed on 

booms 1, 3 and 5 spin clockwise when viewed from above ALTA, and the propellers 

installed on booms 2, 4 and 6 spin counterclockwise when viewed from above.

For information on propeller installation and maintenance, refer to the Maintenance 

section of this manual.
| USER MANUAL 50

CHECKING PROP BOLT TIGHTNESS

Over time, the bolts that hold the propeller blades to the prop hub can loosen due to 

vibration. To check prop bolt tightness, twist the prop about its length. If there is free 

play, the prop bolt is too loose. Use the provided 2.5mm hex driver and wrench to 

tighten the bolt and nut that secure the prop blade just enough to remove the play.

 CAUTION

Do not overtighten, or the prop may fail to unfold completely 

during motor start up, leading to excessive vibration.
| USER MANUAL 51

FIRST PERSON VIEW (FPV)

ALTA and SYNAPSE can power a variety of first person view (FPV) cameras and 

transmitters, as well as add informational on-screen display (OSD) elements to aid 

in FPV flying. 

Two FPV transmitter cables are included. The cable with two connectors on one of 

the ends will run ImmersionRC and Fat Shark systems, and the cable with a single 

connector on the end will run Boscam and SkyZone systems. 

A single camera cable is provided, and is configured to run a Ready Made RC 

camera.

Camera and transmitter cables follow this wiring scheme:

CABLE COLOR FUNCTION

Red +12 VDC

Black Ground

Yellow Video signal

 WARNING

It is the responsibility of the pilot to see and avoid other aircraft, 

people or obstacles. Always maintain direct line of sight with ALTA 

during flight, use visual observers as operations require, and 

follow local regulations regarding see-and-avoid requirements.

FPV SYSTEM INSTALLATION

CAMERA

1. Mount FPV camera on the FPV mount on the front 

underside of ALTA or other preferred location.
| USER MANUAL 52

2. Locate the FPV camera cable included in the ALTA package.

3. Remove the front closeout panel with a 1.5 mm hex driver.

4. Pass the FPV cable through the grommet, and connect to the mating FPV 

camera lead inside ALTA. Connect the other end directly to the camera. 

5. Replace front closeout panel.
| USER MANUAL 53

TRANSMITTER

1. Mount FPV transmitter on the provided carbon fiber accessory mount plate.

2. Attach Accessory Mount to boom 5 with M3×8 flathead bolts.

3. Locate the appropriate FPV transmitter cable. The following cables are included:

a. ImmersionRC/Fat Shark (cable with two connectors)

b. Boscam/SkyZone (cable with one connector)

4. Remove the side closeout panel with the FPV 

transmitter lead using the 1.5mm hex driver.
| USER MANUAL 54

5. Pass transmitter cable through the underside of the 

hinge, and connect to the FPV transmitter lead.

6. Replace side closeout panel.

7. Zip tie the FPV transmitter lead to the boom cable bundle for strain relief. 

FPV ON SCREEN DISPLAY SETUP

A number of properties and components can be adjusted or added to the FPV On 

Screen Display (OSD) using the ALTA App.

PROPERTIES

NAME OPTIONS DESCRIPTION

Video Mode PAL / NTSC Indicates to the SYNAPSE the 

FPV video camera format

Units SI / Imperial Changes the displayed units

Horizontal 

Offset 0, 15, 30, 45, 60 Centers the OSD components horizontally

Vertical Offset 0, 8, 16, 24, 30 Centers the OSD components vertically

Borders 0, 1, 2, 3

Adds gaps between OSD components 

and the edges of the display, measured 

in character widths and heights
| USER MANUAL 55

TEXT COMPONENTS

The following components are displayed as text items, and can be configured to 

display as big or small letters, or no letters effectively turning off the display.

NAME DESCRIPTION

Height Displays the height of ALTA from its 

starting point in meters or feet

Vario Displays the vertical speed of ALTA in 

meters per second or feet per minute

Heading Displays the magnetic heading of ALTA 

and is measured in degrees

Distance Displays the distance ALTA is from the 

home position in meters or feet

Ground Speed Displays the ground speed of ALTA in 

meters per second or knots

Battery Displays the voltage of the flight battery pack

Time Displays the time of the flight in minutes and seconds

GPS Displays the number of GPS satellites in view

GPS Accuracy Displays the horizontal accuracy of the 

GPS signal in meters or feet

Lat/Long Displays the GPS derived latitude and 

longitude coordinates of ALTA

ARTIFICIAL HORIZON COMPONENTS

The artificial horizon displays pitch and roll information in the center of the FPV 

display in the form of a horizon line and accompanying elements.

NAME OPTIONS DESCRIPTION

Artificial 

Horizon

No Turns off all artificial horizon components

Basic Adds a horizon line that moves up and down 

as ALTA changes pitch, and rolls as ALTA rolls

Ladder Adds pitch marks at intervals defined 

by the Pitch Interval setting
| USER MANUAL 56

Roll Marker

Basic

Adds small dash marks on the left 

and right side of the artificial horizon 

that indicate changes in roll

Horizon Adds marks to include a full horizon line

Ladder

Adds small marks on either side 

of the artificial horizon ladder that 

roll with ALTA roll movements

Pitch and 

Roll Scaling 10, 20, 30, 40

Allows for scaling of the artificial 

horizon markings to compensate for 

FPV cameras of different field views

Pitch and 

Intervals 10, 20, 30, 40

Sets the number of degrees 

between pitch markings when the 

artificial horizon ladder is used

OTHER COMPONENTS

The following components can be turned on or off. There are no other options 

associated with these components.

NAME DESCRIPTION

Compass Arrow Displays an arrow that points in the direction of north

Home Arrow Displays an arrow that points in the 

direction of the home point

Vario Bar

Displays a bar on the right of the screen that scales 

with vertical speed. The bar will increase in length 

up to indicate a climb, or down to indicate a descent

Forward Velocity

Displays a bar on the left of the screen that scales 

with the forward/rearward velocity component

The bar will extend up to indicate forward velocity, 

or down to indicate a rearward velocity

Sideslip

Displays a bar on the bottom of the screen that 

scales with the side-to-side velocity component

The bar will extend left to indicate leftward 

velocity, or right to indicate rightward velocity
| USER MANUAL 57

TUNING ALTA 
| USER MANUAL 58

TUNING ALTA

ALTA comes pre-tuned for a wide variety of payloads and flying conditions. Generally, 

additional tuning is not required to fly ALTA, and additional tuning will only need to 

take place if more customization of control feel is desired. Default tuning values are 

included in Appendix A, Default Tuning Values.

Parameters fall into three categories - Attitude, Height and Position. Typically, 

tuning should take place in that order, ensuring Attitude parameters are set first, 

then moving to Height parameters, and finally Position parameters.

Tuning should take place as an iterative process by making only small changes, test 

flying the changes, observing the new flight behaviors, and repeating. Only tune a 

single parameter at a time during this process for best results.

To tune ALTA, open the ALTA App and select Configurations > Aircraft Dynamics.

 WARNING

Tuning can change the fundamental flying characteristics of ALTA. 

It is possible for ALTA to become unstable or even uncontrollable if 

values are set too high or too low. Only change tuning parameters 

in small increments and with caution. Always test new tuning 

configurations in open areas away from people or obstacles.

 NOTE

The ALTA App only allows tuning while ALTA is on the ground.

ATTITUDE TUNING

Attitude tuning adjusts how ATLA responds to control inputs and disturbances. 

Attitude directly controls responsiveness and changes ALTA’s fundamental flying 

behaviors. Attitude must be tuned acceptably before tuning height or position 

parameters.

When tuning attitude, the primary parameter to change is Stiffness followed by 

Strength.

STIFFNESS

Stiffness is adjusted for pitch and roll simultaneously, and yaw independently. It 

changes how stable ALTA is in these axes and is the primary variable to adjust when 
| USER MANUAL 59

tuning. When tuning Stiffness first, or making large stiffness changes, Hold Strength 

should be set to a low, non-zero value.

Higher Stiffness values give more responsive control. Values that are too high can 

cause instability or oscillation.

 WARNING

Excessively high stiffness values can cause ALTA to become 

unstable and difficult or even impossible to control.

Lower Stiffness values give less responsive control. Values that 

are too low can cause a vague or disconnected control response.

HOLD STRENGTH

Hold Strength controls how much ALTA will try to maintain a pitch/roll 

angle command, or a yaw heading command. It is adjusted for pitch and roll 

simultaneously, and yaw independently. A higher Hold Strength setting will give a 

faster control response and a more responsive feel. However, values that are too 

high can cause ALTA to overshoot pitch or roll commands, or even cause instability.

 WARNING

Excessively high strength values case cause ALTA to become 

unstable and difficult or even impossible to control.

Typically, this setting will not need to be changed from 

the default value, and only then in small increments.

HEIGHT TUNING

Tuning height parameters will adjust the control feel of ALTA’s height control while 

in Height and Position modes (for additional information on flight modes, see the 

Flight Controller Modes section of this manual). Tune height parameters only after 

satisfactorily tuning attitude parameters.

Similar to attitude tuning, stiffness is the primary tuning parameter.

If switching to Height Mode causes ALTA to fly in an unstable manner, switch back to 

Manual Mode, land and try reducing the values of height tuning gains if they are very 

high, or increasing them if they are very low.

VERTICAL STIFFNESS

Vertical Stiffness Gain modifies the vertical stability of the ALTA in Height mode. 
| USER MANUAL 60

Decrease this value if ALTA experiences vertical oscillation or vibration. Increase 

this value if ALTA is sluggish while accelerating to a desired climb or descent rate in 

Height mode.

HOLD STRENGTH

Hold Strength Gain tunes how much ALTA will attempt to stay on a desired altitude 

in Height Hold mode only. A higher value will result in height being held more 

precisely. Too high of a value can cause ALTA to overreact to winds, gusts or 

turbulent air.

CLIMB RATE STRENGTH

Climb Rate Strength adjusts how much ALTA will attempt to maintain a desired 

climb rate. Higher values will result in a more direct feel between pilot climb or 

descent commands and ALTA flying behavior. However, values that are too high may 

cause instability.

POSITION TUNING

Tuning position parameters will adjust how well ALTA maintains a desired ground 

speed or a position over the ground. Similar to attitude and height tuning, the 

primary value to adjust is stiffness.

HORIZONTAL STIFFNESS GAIN

This changes the horizontal stability of ALTA. Higher values increase ALTA’s 

resistance to wind gusts or turbulence from moving ALTA off its target position. 

Values that are too high can cause instability of ALTA. 

HOLD STRENGTH GAIN

This adjusts how much ALTA will attempt to maintain its place over a target position. 

A higher value will result in position being held more precisely. If too high, positional 

instability can result, causing ALTA to fly past a target position.
| USER MANUAL 61

ALTA FLIGHT PARAMETERS

Flight Parameters are different from tuning parameters in that the flight 

characteristics of ALTA will not change with their modification. However, they can be 

used to select neutral points using trim, or to set maximum or minimum values.

ATTITUDE

PITCH AND ROLL TRIM

Use Pitch and Roll trim settings to correct for tendencies of the ALTA to pitch or roll 

with a neutral control input.

Use the in-app pitch and roll trim settings instead of radio controller trim features 

as large radio controller trims could prevent position hold from engaging at neutral 

stick positions.

MAXIMUM PITCH/ROLL ANGLE

This sets the maximum angle the ALTA will be allowed to fly in all modes and in all 

flight conditions.

MAXIMUM YAW RATE

This is the maximum rate the ALTA will yaw (pan) when at full stick deflection.

HEIGHT

HOVER THROTTLE

Hover Throttle is a parameter that adjusts ALTA’s thrust at center throttle stick, and 

ensures ALTA does not climb or descend at the center stick position while flying in 

Manual Mode. A Hover Throttle setting that is too high or too low can cause ALTA to 

climb or descend when switching between Manual and Height Modes. 

 NOTE

Hover Throttle will need to be adjusted when 

changing the overall weight of the system, or when 

moving between very different elevations.

Adjust the Hover Throttle setting such that during a stable hover the required 

throttle position is at middle stick, or about 1500 μs in the App radio chart. Increase 

Hover Throttle if hover occurs above center stick, and decrease if hover occurs 
| USER MANUAL 62

below center stick.

Alternatively, if ALTA climbs when switching from Manual to Height mode, increase 

hover throttle, since a climb indicates a stick position that is higher than neutral in 

Manual mode. If ALTA descends, decrease hover throttle, since a descent indicates a 

stick position that is lower than neutral in Manual mode.

 NOTE

The ALTA App does not allow hover throttle 

adjustments while ALTA is flying.

MAXIMUM CEILING

This adjusts the highest altitude the ALTA is allowed to climb from its starting point 

while in Height or Position modes. If the maximum ceiling is exceeded in Manual 

mode, the Status Light will illuminate white.

MAXIMUM CLIMB RATE

This sets the maximum speed ALTA will climb at full throttle stick deflection in 

Height Mode or Position Mode

If Climb Rate Clamp is mapped to an radio controller channel, the parameter will 

adjust the fastest climb speed available to the Climb Rate Clamp feature.

GPS HEIGHT CORRECTION

With GPS Height Correction On, SYNAPSE will use both barometer and GPS sensor 

measurements to determine its altitude. It can be useful for assisting in windy or 

gusty conditions, but requires good GPS reception. It is recommended to keep this 

enabled unless GPS reception is problematic.

POSITION

MAXIMUM G

This sets the total maximum acceleration, in G’s, that the controller will place on the 

airframe. It is recommended to use lower G settings with heavier payloads.

This setting has no effect in Manual mode.

MAXIMUM GPS ANGLE

This sets the maximum pitch and roll angle the ALTA may fly under Position mode. 

This will not override the Attitude Maximum Pitch/Roll Angle. Instead, ALTA will 
| USER MANUAL 63

follow the lower of these two limits.

MAXIMUM GPS SPEED

Max GPS Speed sets the maximum speed ALTA will fly across the ground at full stick 

deflection in Position Mode.

If Velocity Clamp is mapped to an RC transmitter channel, the parameter will adjust 

the fastest ground speed available to the Velocity Clamp feature.

RANGE

Range sets the maximum distance ALTA may fly away from the home point while 

in Position mode. If the range is exceeded in Manual mode, the status light will 

illuminate white.
| USER MANUAL 64

OPERATING ALTA 
| USER MANUAL 65

FLIGHT CONTROLLER MODES

ALTA has three primary flight control modes: Manual Mode, Height Mode, and 

Position Mode. They are selected with the Mode Switch

 CAUTION

Always neutralize control inputs when 

switching between control modes.

MANUAL MODE

In Manual Mode, ALTA will only stabilize its attitude. At neutral control input (middle 

pitch and roll stick position), ALTA will attempt to remain level. Throttle control is 

direct. 

HEIGHT MODE

Height Mode changes the throttle stick behavior to command climb and descent 

rates. The higher the throttle stick position, the faster ALTA will climb. Conversely, 

the lower the throttle stick position, the faster ALTA will descend.

When the throttle stick is centered, ALTA will enter Height Hold. In Height Hold, 

ALTA will maintain a target altitude and try to correct for drift. If a disturbance 

moves ALTA away from this target altitude, ALTA will climb or descend to return to 

the target altitude.

POSITION MODE

Position Mode changes the pitch/roll stick behavior to command ground speeds. 

Pitch and roll stick deflection will command fore/ aft and left/right ground speeds 

respectively. Controlling altitude in Position Mode is the same as in Height Mode.

With pitch and roll controls centered, ALTA will enter Position Hold. In Position 

Hold, ALTA will maintain its position over a given point on the ground and correct for 

disturbances.

Position Mode requires a strong GPS signal. If a weak signal is present, ALTA will not 

enter Position Mode, and if the GPS signal degrades while in Position Mode, ALTA 

will automatically revert to Manual Mode.
| USER MANUAL 66

 CAUTION

Flight using Position Mode in areas of degraded GPS signal, 

such as near buildings or under dense tree cover, is not 

recommended. The automatic reversion to Manual Mode 

can cause unexpected, abrupt changes in flight behavior.

RETURN-TO-HOME

Return-To-Home Mode will command ALTA to fly back to the starting point of the 

flight or the last defined Home Point. When ALTA first acquires a GPS position, it 

sets this as the Home Point of the flight. The Home Switch on your radio controller 

can also be used to set a new Home Point. See the Radio Mapping section in this 

manual for more information on setting up the Home Switch.

RTH can be initiated manually by the Home Switch or be initiated with an LOS event.

When initiated with the Home Switch, ALTA will fly back to the Home Point, and the 

pilot will maintain control of ALTA’s altitude the entire time. ALTA will not Autoland 

if an adequate signal is detected. The pilot can cancel the RTH procedure by 

commanding a pitch or roll command or by retuning the Home Switch to the middle 

position. The Mode Switch must be in Position Mode to activate RTH manually.

During an LOS event, ALTA will first check its current altitude against Safe Height. If 

it is lower, it will climb to Safe Height, and if ALTA is above Safe Height, it will remain 

at its current altitude. Next, ALTA will fly back to the home position at the RTH 

Speed set in the ALTA App. Finally, upon reaching the home position, ALTA will begin 

Autoland.

SAFE HEIGHT IS USER DEFINED

ALTA App > Configurations > Safety > Safe Height
| USER MANUAL 67

AUTOLAND

The Autoland function will command ALTA to hover for 10 seconds and will then land 

in place. This only occurs if Autoland is selected as the Loss of Signal (LOS) event in 

the ALTA App, or at the end of an LOS Return-to-Home (RTH) event. If ALTA is above 

the app-configurable Safe Height setting, ALTA will first descend to the Safe Height 

at the Maximum Descent Rate. After reaching this height, ALTA’s descent will slow to 

the Autoland Descent Rate until landing.

HOME SWITCH

The home switch has three settings, Set Home, RTH Off and RTH On.

SET HOME

Set Home sets a new home point at ALTA’s current position. This could be useful for 

setting a point away from the initialization point, such as if the ALTA were started 

underneath an overhang or a tree. 

A new home point can only be set within 20 meters of ALTA’s starting point. 

Momentarily moving the Home Switch to the Set Home position sets a new home 

point. When a new home point is set, the Status Light will turn white to indicate the 

new home point was successfully set.

RTH OFF

This is the normal switch position and does not initiate an RTH command.

RTH ON

This manually initiates the RTH command. In a manual RTH, the pilot maintains 

control of height while the SYNAPSE will command ALTA’s position over the ground 

to the home point.

ARM ENABLE SWITCH

The optional Arm Enable Switch allows for added safety while working around and 

flying ALTA by disallowing arming during ground handling or disarming during 

flight. To set up an Arm Enable Switch, refer to Mapping Channels or the ALTA User 

Manual.

If used, the Arm Enable function should be mapped to a three-position switch.

SWITCH POSITION ARMING DISARMING

1 Possible Not possible

2 (middle) Possible Possible

3 Not possible Possible
| USER MANUAL 68

STATUS LIGHT

The rear-facing Status Light shows the status of ALTA as it boots, arms and flies. 

The following table shows the different meanings of the light in the various flight 

phases.

FLIGHT PHASE LIGHT COLOR MEANING

Booting Flashing Red 

+ White Flight controller is booting

Standby

Flashing White Flight controller is running 

and dis-armed

Flashing Red Flight controller is running 

and not ready to arm

Solid Red Flight controller boot unsuccessful

Armed Off Ready for Flight

Flight - all modes Solid Red

A flight controller error has 

occurred or Battery cell voltage 

below user-defined levels
| USER MANUAL 69

Flight - Manual 

Mode

Off Nominal flight status

No errors

Solid White Outside user-defined range, 

height or speed limits

Flight - Height 

Hold

Off Nominal flight status

Height hold inactive

Slow Flashing 

White Height hold active

Flashing Red Battery cell voltage below 

user-defined levels

Flight - Position 

Hold

Off

Nominal flight status

Height hold inactive

Position hold inactive

Slow Flashing 

White Height Hold or Position Hold Active

Fast Flashing White Height Hold and Position Hold Active

Flashing Red Battery cell voltage below 

user-defined levels
| USER MANUAL 70

ORIENTATION LIGHTS

BOTTOM VIEW

The boom-end mounted Orientation Lights indicate both the orientation of ALTA in 

flight and the status of the individual motor Electronic Speed Controllers (ESCs) 

during other flight phases. The following table shows the different meanings of the 

light colors in the various flight phases.

FLIGHT PHASE LIGHT COLOR MEANING

Booting Blue ESC booting

Standby Flashing Green ESC booted normally

Armed User-defined Nominal Status

Flight User-defined Nominal Status

Firmware Update Blue then Yellow ESC firmware is updating
| USER MANUAL 71

ALTA APP MONITOR

The ALTA App includes a flight status monitor that displays information about the 

health of the ALTA and the various controls that can be selected.

Boot indicates if the SYNAPSE booting process has completed successfully. Any 

issues that prevented a normal boot are indicated here.

Battery displays the voltage of the battery pack.

Status displays the state of the SYNAPSE flight controller.

Radio displays if the SYNAPSE detects a radio controller signal. A LOS (Loss Of 

Signal) warning is displayed if no signal is present.

GPS displays if SYNAPSE has resolved a GPS fix or not.

Sats displays the number of GPS satellites in view and being received.

Lock displays whether a position lock is ready, indicating a valid GPS fix and good 

heading. This is required before the SYNAPSE will allow switching into Position 

Mode.

Height displays the current height control mode: Manual, Vario if in Height or 

Position mode and climbing or descending, and Hold.

Attitude displays the current attitude control mode.

Position displays the current position control mode: Manual, Velocity if in Position 

mode and moving across the ground, and Hold

Compass displays the status of the compass and if the SYNAPSE believes the 

compass readings are good or bad. If Bad, the compass may require recalibration 

(see the Compass Calibration section in this manual).

Station displays if ALTA is currently over its commanded position over the ground, or 

if it attempting to fly to it.

Temp displays the temperature of the SYNAPSE flight controller board.
| USER MANUAL 72

NORMAL PROCEDURES 
| USER MANUAL 73

UNPACKING AND SETUP

1. Aircraft REMOVE from case

2. Prop protectors REMOVE

3. Boom retention clips STOW

4. Booms UNFOLD

5. Boom latches LOCK

6. Receivers and wiring CHECK

7. Isolator cartridges SELECT and INSTALL as necessary

8. Payload mounting location CONFIGURE as necessary

AMPLIFICATION

To set up ALTA for flight, remove it from the case and remove the prop protectors. 

Stow the six boom retention clips by folding them down. The clips only fold in one 

direction and are spring-loaded to stay in open and closed detented positions.

Unfolding the booms is most easily accomplished by unfolding opposite pairs 

partially. Then unfold the opposite boom pairs completely. ALTA can become 

unbalanced while unfolding booms individually, so unfolding opposite pairs reduces 

this possibility.

Once unfolded, push on the boom latches until they audibly click, indicating the 

booms are secure. There should be little to no slop in the hinge. Check that the 

receivers and the electrical connectors that attach to the receivers are secure.

For information on installing isolator cartridges and setting up payload mounting 

locations, refer to the Isolator Cartridges and Configuring Top or Bottom Mount 

sections of this manual.
| USER MANUAL 74

BEFORE STARTING

1. Payload SECURED

2. Isolator Cartridges CHECK

3. microSD Card INSTALLED

4. Props CHECK CONDITION, VERIFY TIGHT

5. Prop Hub VERIFY SECURE

6. Motors CHECK CONDITION

7. Radio Controller ON, VERIFY TX BATT

8. Radio Controller Model SELECT

9. Aircraft Placement AWAY from people and obstacles

10. Battery Pack Voltage VERIFY ABOVE 24V

11. Battery Packs SECURE

12. Battery Leads CHECK CONDITION and CONNECT

13. Aircraft KEEP STATIONARY

14. Flight Controller INITIALIZED

15. Status Light VERIFY SLOW FLASHING WHITE

16. Orientation Lights VERIFY FLASHING GREEN

17. Receivers VERIFY BOUND

18. ALTA App CONNECT

19. ALTA App Monitor VERIFY NO WARNINGS

20. Compass Calibration AS REQUIRED

21. Radio Control Range Check AS REQUIRED

AMPLIFICATION

Check that the payload is secure by checking that the Toad In The Hole quick 

release lever is pushed in, and that the payload does not slip. Check that all isolator 

cartridges are locked in place, especially if they have been recently replaced. A 

microSD card is required to be installed in the GPS/Compass module for reliable 

compass sensing and data logging.

The blades should be checked for damage, including nicks and scrapes. If a prop 

has been nicked enough such that it catches a fingernail, it should be replaced. 

Bolt tightness should be checked by rotating the blade about its length (blade pitch 

up and down). There should be no slop, and if there is, the bolt and nut should be 

tightened until the slop is removed. There should be no slop between the prop hub 

and the motor.
| USER MANUAL 75

Motors should spin freely, and there should be no grinding or scraping sound from 

the motor. The inside of the motor should be free of debris.

Always turn on the radio controller before plugging in ALTA. Follow the battery 

installation guidance in the Battery Installation section of this manual for battery 

installation instructions.

While the SYNAPSE flight controller initializes, keep the ALTA as stable as possible. 

If ALTA moves during initialization, it many not boot properly. Wedging a foam prop 

protector between the stationary gimbal or landing gear and the ALTA frame can be 

used to stabilize ALTA from spinning during this process.

When it is impossible to initialize ALTA without movement (such as booting on a 

boat), Motion Booting can be used. It is not recommended to use Motion Booting 

regularly. 

During initialization, the Status Light will quickly flash a sequence of red and 

white lights. At the end of this process, it will begin slow flashing white, indicating 

SYNAPSE is ready for arming. The Orientation Lights will also begin flashing 

green. Verify that all six motors are flashing green, indicating all ESCs initialized 

successfully.

Verify that there are no flight warnings by connecting to ALTA via the ALTA app and 

checking on its status from the App. For more information, see the ALTA App section 

of this manual.
| USER MANUAL 76

BEFORE TAKEOFF

1. Prop Area CLEAR

2. Mode Switch MANUAL

3. Home Switch CENTER POSITION

4. Radio Controller VERIFY CORRECT MODEL

5. Telemetry (if equipped) CHECK OPERATION

6. Arm Enable Switch ENABLE ARM

7. ALTA ARM

8. Status Light VERIFY OFF

9. Orientation Lights VERIFY USER-DEFINED COLOR

10. Motors START and VERIFY OPERATION

11. Flight Controls VERIFY CORRECT

12. Throttle ADVANCE

AMPLIFICATION

Prior to start, check the surrounding area to ensure people and objects are clear 

of ALTA and its props. Also ensure that there are no people or objects between the 

ALTA’s takeoff location and its intended flight path.

 WARNING

ALTA’s props spin at a high RPM, and the ends of the blades 

move at high speeds. ALTA’s props can cause severe injury 

or death or cause damage to objects while they are rotating. 

Always ensure the area surrounding the props and ALTA is 

clear of people or objects prior to starting the ALTA’s motors.

ALTA can only be armed for flight when it is in the Manual Mode, and the Home 

Switch is in the middle position. If an Arm Enable Switch is configured, it must be 

placed in an ENABLE ARM position. To arm, hold full low throttle and full left yaw.

 WARNING

Do not approach ALTA while it is armed.

To start the motors, hold full low throttle and full right yaw. Ensure that all the 
| USER MANUAL 77

motors are spinning. Keep the throttle in the lowest position and move the pitch, 

roll and yaw controls slightly. ALTA should pitch, roll and yaw slightly due to isolator 

cartridge flex. Ensure that the ALTA behaves as expected. If it does not, shutdown 

ALTA and ensure the props are installed in the correct orientation.

 CAUTION

Do not make large yaw commands while on the 

ground with the inverted landing gear installed. 

Large yaw commands can cause instability.

After checking flight control directions, advance the throttle to enter a hover.
| USER MANUAL 78

AFTER EVERY FLIGHT

1. Mode Switch MANUAL

2. Home Switch CENTER POSITION

3. Arm Enable Switch ENABLE DISARM

4. ESCs and Motors DISARM and STOP

5. Arm Enable Switch DISABLED

6. Orientation Lights VERIFY FLASHING GREEN

7. Status LED VERIFY SLOW FLASHING WHITE

8. ALTA App CHECK for warnings

9. Batteries DISCONNECT and REMOVE

10. Radio Controller Power AS REQUIRED

11. Aircraft Condition INSPECT

12. Motor and Prop Condition INSPECT

13. Battery Condition INSPECT

AMPLIFICATION

Upon landing, disarm the motors by holding full low throttle and full left yaw. This 

is typically done on the left radio control stick by moving it to the bottom left corner 

with mode 2 controllers. Disarming can only be done while in Manual Mode. If 

configured, set the Arm Enable Switch to ENABLE DISARM. Once the motors are 

disarmed, the Orientations Lights will flash green and the Status Light will slowly 

flash white, indicating it is safe to approach ALTA.

 WARNING

Only approach ALTA after confirming that it is disarmed by 

verifying the Status Light and Orientation Light colors.

The downwash from the props can disturb debris. This debris can be ingested by 

the props or motors and cause damage. After the flight, ensure there is no damage 

to the props and that the motors still spin freely and quietly. Take extra care when 

operating in areas with large amounts of debris, such as in sand, dirt, or gravel.

After flight is also a good time to check a battery pack’s condition. Always refer 

to the battery manufacturer’s recommendations for inspection and replacement 

intervals or requirements.
| USER MANUAL 79

AFTER LAST FLIGHT

1. Props FOLD and PLACE inline with booms

2. Prop Protectors INSTALL

3. Boom Latches UNLOCK

4. Booms FOLD

5. Boom Retention Clips EXTEND

6. Payload REMOVE

7. ALTA INSERT into case

AMPLIFICATION

Packing ALTA is similar to the unpacking process. Keeping ALTA on the payload or 

landing gear facilitates the process as ALTA may be turned on the Toad In The Hole 

adapter while folding the props and booms. Make sure that the handle is aligned 

front-to-back when putting ALTA in the included case, and that the battery leads are 

facing to the right.
| USER MANUAL 80

EMERGENCY 

PROCEDURES 
| USER MANUAL 81

EMERGENCY GUIDANCE

The emergency procedures listed in this section are the recommended practices for 

handling the aircraft in the event of an aircraft emergency. This guidance should be 

considered and applied as necessary.

The risk of an emergency occurring can be reduced substantially through proper 

aircraft maintenance, by performing thorough inspections before and after all 

flights, and with careful pre-flight planning.

Emergency situations are dynamic events, and not all conditions or procedures can 

be anticipated or applied during the event. These procedures are not a substitute for 

thorough understanding of aircraft systems and sound pilot judgement.

In general, if an emergency occurs, three basic actions can be applied to most 

situations:

Maintain aircraft control - Small emergencies can quickly escalate if the pilot is 

distracted attempting to determine or troubleshoot the problem. Always maintain 

visual contact with the aircraft during an emergency to reduce the likelihood of 

disorientation.

Analyze the situation - Once the aircraft is stabilized, begin to assess the cause of 

the emergency if practical.

Take appropriate action - In many cases, the appropriate action will be to land the 

aircraft as soon as possible. Always consider the safety of yourself and others before 

attempting to save the aircraft in an emergency.
| USER MANUAL 82

PILOT DISORIENTATION

1. Control Inputs NEUTRALIZE

2. Mode Switch POSITION

3. Yaw NOSE AWAY

4. Roll VERIFY DIRECTION

AMPLIFICATION

Regaining spatial orientation as quickly as possible is most important. In 

disorientation situations, control inputs will not give the expected result, so 

neutralize them. If a good GPS signal is available, enable Position Mode so ALTA will 

stay in a one place.

Use yaw only to reorient ALTA so the nose is pointed away, then use the roll control 

to verify the orientation of ALTA.
| USER MANUAL 83

UNEXPECTED FLIGHT CONTROLLER BEHAVIOR

1. Control Inputs NEUTRALIZE

2. Mode Switch MANUAL

If the problem persists

3. ALTA LAND as soon as possible

AMPLIFICATION

If the ALTA behaves unexpectedly, neutralize control inputs and observe ALTA. If it 

is still flying in an uncommanded manner, switch to Manual mode if it is in Height 

or Position modes. In most cases, unexpected behavior is due to erroneous sensor 

readings, or degraded GPS signal reception.

If the behavior occurred while in Manual mode, land as soon as possible and check 

the ALTA App for any warnings.
| USER MANUAL 84

BATTERY EXHAUSTION

If battery cell voltage is between Alarm Voltage and Land Voltage

1. Status Light Illuminates red (solid or blinking)

2. ALTA LAND as soon as possible

If battery cell voltage is below Land Voltage

1. ALTA Begins Autoland

2. Pitch and Roll MANEUVER away from people or objects

AMPLIFICATION

If the battery cell voltage drops below the Alarm Voltage, the Status Light will 

turn solid red in Manual Mode, or turn blinking red if holding position or altitude. 

Terminate the flight and land as soon as possible.

In the event the cell voltage drops below the Land Voltage, ALTA will begin to auto 

land. However, pitch and roll commands are still active. During the time ALTA is 

descending, use pitch and roll to avoid people or objects during the descent and 

landing.
| USER MANUAL 85

STATUS LIGHT WARNING INDICATOR ILLUMINATES

1. Mode Switch MANUAL

2. ALTA LAND as soon as possible

3. ALTA App OPEN MONITOR

AMPLIFICATION

The Status Light can turn red, indicating a warning, for a number of different 

reasons. It is always recommended to land as soon as possible and investigate the 

problem while ALTA is on the ground.
| USER MANUAL 86

LOSS OF RADIO CONTROL SIGNAL

1. Controller Battery CHECK

2. Controller Antenna REPOSITION

3. Mode Switch POSITION

4. Home Switch RETURN-TO-HOME

AMPLIFICATION

Loss of Signal (LOS) can occur if the radio controller stops transmitting a signal, 

or if ALTA is too far away to receive it. In the event ALTA detects a LOS, it will 

automatically execute a Return-to-Home or Autoland as configured in the App. 

However, it is always recommended to attempt to regain signal link with ALTA to 

keep the pilot in control of the aircraft.

Move the antenna orientation for best signal strength. Ensure the transmitter 

antenna matches the direction of the receiver antennae. Move the transmitter away 

from objects to get a clear line-of-sight to ALTA.

Setup the Mode and Home switches to enable Return-To-Home so ALTA will 

continue to approach the starting point and have a higher likelihood of regaining 

signal reception.

 NOTE

If efforts to regain control signal are unsuccessful, ALTA 

will begin the Return-To-Home and Autoland sequence.
| USER MANUAL 87

LOSS OF FPV SIGNAL

1. Control Inputs AS REQUIRED

2. Visual Contact ESTABLISH

3. ALTA POSITION for optimal signal reception

If visual contact or FPV signal is not reestablished

1. Mode Switch POSITION

2. Home Switch RETURN TO HOME

3. Throttle AS REQUIRED

AMPLIFICATION

An FPV Loss of Signal (LOS) can occur if the aircraft flies out of range, or if it flies 

behind an object that interrupts the signal line of sight. Regaining visual contact 

is the preferred method to reestablish control of the aircraft, either with the pilot 

seeing the aircraft, or by the use of a second visual observer.

Yawing the aircraft can help signal reception if the body of the aircraft is blocking the 

line of sight between the transmitter and receiver antennas.

If FPV signal or visual contact cannot be reestablished, enabling Return To Home 

can be used to bring the aircraft back to signal reception range. 

 WARNING

It is the responsibility of the pilot to see and avoid other aircraft, 

people or obstacles. Always maintain direct line of sight with ALTA 

during flight, use visual observers as operations require, and 

follow local regulations regarding see-and-avoid requirements.
| USER MANUAL 88

DATA LOGGING 

& PERFORMANCE 
| USER MANUAL 89

DATA LOGGING

ALTA automatically logs flight and control data when ALTA is armed for flight. Data is 

recorded as a .csv file at a rate of 25 Hz on a microSD card installed on the top of the 

GPS/Compass module. A table of recorded data is included in Appendix B.

PERFORMANCE

WEIGHT / ENDURANCE PERFORMANCE DATA

Conditions:

Altitude Sea Level, ISA

Winds Zero
| USER MANUAL 90

MAINTAINING ALTA 
| USER MANUAL 91

GENERAL INFORMATION AND TECHNIQUES

USE OF THREADLOCKER

Bolts and screws that are called out in this manual to regularly remove or replace 

typically do not require use of a threadlock compound. This includes the screws 

holding on the handle, battery retention strap studs, battery stops, closeout panels, 

the top male Toad In The Hole adapter. In addition, fasteners that attach to nuts with 

a nylon locking feature (nylock nuts) do not require threadlocker.

All structural fasteners require the use of threadlock. This includes chassis screws, 

lower male Toad In The Hole adapter and motor attachment fasteners. In addition, 

the four M3 x 8 socket head bolts that attach the folding propeller to the motor 

require threadlocker. Typically, a medium threadlocker (such as Loctite Blue 243) is 

used on structural fasteners.

BOLT INSTALLATION

The Freefly hex drivers included with ALTA are designed to help limit the torque that 

can be applied to each bolt. 

Thread all fasteners into their respective holes until “snug”. This is when the 

fastener head bottoms out and lightly clamps the two mating parts together

To prevent tightening the bolts excessively and damaging the bolts or parts, it 

is suggested to hold the wrench in your hand, and twist the wrench from the 

smaller dia knurled section of the tool between your thumb and index finger for 

small fasteners (under size M3) or with your thumb and two forefingers for larger 

fasteners (size M3 and larger).
| USER MANUAL 92

MAINTENANCE ITEMS

PROPELLERS

FORWARD

Propeller blades should be removed when making a change to the configuration 

of the ALTA to prevent propeller strikes in the event of unintentional motor starts. 

Propeller blades should be replaced on an as needed basis if they become damaged. 

Generally, a nick on the leading edge that is large enough to catch a fingernail 

indicates that the prop should be replaced. If the blade composite structure 

becomes delaminated, the propeller blade should be replaced.

Freefly makes folding propeller assemblies available that include the blades and 

prop hub fully assembled. They are available in clockwise and counter-clockwise 

orientations.

The folding props are installed on the motors with four M3×8 socket head bolts. 

 CAUTION

Always use a threadlocking compound on the bolt 

threads that attach the propeller hub to the motor.
| USER MANUAL 93

Odd numbered booms (1, 3 and 5) use clockwise rotating props when looking from 

the top down, and even numbered booms (2, 4 and 6) use counterclockwise rotating 

props.

 WARNING

Always check to ensure the correct prop rotation direction 

and correct propeller prior to flight. Props that spin in the 

incorrect direction will cause ALTA to be uncontrollable.

REPLACING PROPELLER BUMPERS

Under normal use, propeller bumpers may split and fall out of the folding propeller 

assembly. Six spare bumpers are provided with the ALTA. To replace the bumper, 

disassembly of the folding propeller is required.

Start by removing the M3 x 19 bolt and nylon nut. Pull off the upper prop adapter. 

The two bumpers are held in place by circular features in the lower prop adapter. 

Replace the worn or split bumper with a new one.

To reassemble, follow the part layout in the figure above. Note that there are two 

different types of washers, one made of nylon and the other made of PTFE. The 

nylon washer is smaller in width and thicker and is installed between the nut or 

bolt head and the two prop adapters. The PTFE washer is wider and thinner and is 

installed between the prop blades and prop adapters.
| USER MANUAL 94

EVERY 15 FLIGHTS

ALTA is designed to be as maintenance-free as is possible. 

It is recommended to check ALTA’s fasteners regularly. This check should 

occur roughly after every 15 flights, dependent upon the level of vibration ALTA 

experiences in flight or during handling. To check ALTA’s fasteners, apply a 

tightening torque to each fastener on the chassis using the supplied hex drivers. The 

fasteners should not slip. 

If a fastener does slip, tighten it using the methods described in the Bolt Installation 

section. Do not apply additional threadlocking compound unless the bolt has 

repeatedly come loose.

REPLACEMENT OF PARTS

Spare or replacement parts are available for sale separately at www.freeflysystems.

com. Please refer to the company store for a current listing of all available spare 

parts.
| USER MANUAL 95

FIRMWARE UPDATE PROCESS

 NOTE

Carefully follow in-app instructions for saving and restoring ALTA 

configuration settings during the firmware update process.

 WARNING

Remove propellers before performing a firmware update. 

Test radio channels, arming and disarming behavior after 

firmware updates to ensure radio mapping has been preserved. 

Incorrect radio mapping can lead to loss of control.

SYNAPSE firmware is updated using the ALTA App. New app updates may include 

new firmware installations. To update firmware:

1. Provide power to ALTA

a. Install and plug in a fully charged flight pack or

b. Plug in the USB-Futaba cable to an available receiver 

port (Futaba and PPM receivers only)

2. Open the ALTA App

3. Open Monitor > Updates

4. The latest firmware included with the app release is compared with the ALTA 

firmware. If a new release is available, the app will provide a notification

5. Tap the Install button in the App if an update is available

6. Wait until the firmware is loaded and ALTA has booted— 

Do not power down ALTA during this time

7. Reload saved configuration
| USER MANUAL 96

TROUBLESHOOTING 
| USER MANUAL 97

GENERAL WARNINGS

SYMPTOM POTENTIAL CAUSE POTENTIAL SOLUTION

Compass Warning

microSD card 

is missing Check the microSD card is installed

Compass 

calibration 

is invalid

Recalibrate the compass

GPS Warning

GPS/Compass 

Unit has become 

disconnected

Check the GPS/Compass 

unit wiring for damage

FLIGHT CONTROLLER

SYMPTOM POTENTIAL CAUSE POTENTIAL SOLUTION

ALTA will not arm

ALTA Home 

Switch not in 

middle position

Move Home Switch to middle position

ALTA Mode Switch 

not in Manual Move Mode Switch to manual

ALTA Arm Enable 

Switch not on 

Allow Arm

Move Arm Enable Switch to Allow Arm

Radio not bound Follow radio controller 

manufacturer’s binding procedure

Radio not mapped 

properly

Check ALTA App radio mapping 

charts for correct behavior

Adjust mapping as necessary

SYNAPSE boot 

not successful

Power cycle ALTA. Ensure it 

does not move during boot

If ALTA must move during boot 

(such as on a moving platform), 

use Motion Booting

Motors will 

not stop

ALTA Mode Switch 

not in Manual Move Mode Switch to manual

ALTA Arm Enable 

Switch not on 

Allow Disarm

Move Arm Enable Switch 

to Allow Disarm
| USER MANUAL 98

FLIGHT BEHAVIOR

SYMPTOM POTENTIAL CAUSE POTENTIAL SOLUTION

ALTA does not 

maintain level 

pitch or roll

Pitch or Roll Trim 

position not set

Use the ALTA app to set the 

appropriate pitch and roll trim

ALTA does not 

maintain heading

ALTA yaw 

during boot

Re-initialize SYNAPSE while keeping 

ALTA stationary in all directions

ALTA circles 

a point in 

Position Mode

Compass 

calibration 

is invalid

Recalibrate the compass

Position Hold 

tuning values 

too high

Reduce Position Hold tuning values, 

starting with Position Hold Strength

ALTA does not 

track straight in 

Position Mode

Compass 

calibration invalid Perform a manual compass calibration

Unexpected 

flight behavior

Tuning too high 

or too low

Revert tuning to the last known 

working configuration

Set tuning back to default values
| USER MANUAL 99

APPENDIX 
| USER MANUAL 100

APPENDIX A. DEFAULT TUNING VALUES

PARAMETER 

GROUP PARAMETER DEFAULT VALUE

Attitude

Pitch/Roll Stiffness 65

Pitch/Roll Hold Strength 50

Yaw Stiffness 100

Yaw Hold Strength 100

Roll Trim 0

Pitch Trim 0

Maximum Pitch/Roll Angle 40°

Maximum Yaw Rate 100°/sec

Height

Vertical Stiffness 20

Hold Strength 80

Hover Throttle 14.0V

Ceiling 118 meters

Climb Rate 3 meters/sec

GPS Height Correction On

Position

Horizontal Stiffness 30

Hold Strength 40

Maximum G 0.3

Range 500 meters

GPS Angle 30°

GPS Speed 5 meters/sec

Safety

Alarm Voltage 3.5V

Land Voltage 3.2V

Safe Height 15 meters

Autoland Descent Rate -0.5 meters/sec

RTH Speed 3 meters/sec
| USER MANUAL 101

APPENDIX B. DATA LOGGING FIELDS

FIELD UNITS DESCRIPTION

Reading Unitless An indexed identifier 

assigned to data points

IMU Time Seconds The number of seconds 

from arming ALTA

GPS Time HH:MM:SS The Universal Coordinated Time 

determined by received GPS signals.

GPS Longitude Degrees * 10^7 GPS determined longitude 

multiplied by 10^7

GPS Latitude Degrees * 10^7 GPS determined latitude 

multiplied by 10^7

GPS Height meters Height above the WGS84 

reference ellipsoid

GPS Course degrees The ground track of ALTA in 

degrees from true north.

GPS Position 

North meters

The distance ALTA traveled north 

from the starting point. A negative 

number indicates southward travel.

GPS Position East meters

The distance ALTA traveled east 

from the starting point. A negative 

number indicates westward travel.

GPS Position Up meters

The distance ALTA traveled above the 

starting point. A negative number 

indicates downward travel.

GPS Velocity 

North meters / second The GPS derived northward 

velocity component of ALTA.

GPS Velocity East meters / second The GPS derived eastward 

velocity component of ALTA.

GPS Velocity Up meters / second The GPS derived upward 

velocity component of ALTA

GPS Acceleration 

North meters / second^2 The GPS derived northward acceleration

GPS Acceleration 

East meters / second^2 The GPS derived eastward acceleration

GPS Acceleration 

Up meters / second^2 The GPS derived upward acceleration, 

without gravitational acceleration
| USER MANUAL 102

IMU Position 

North meters

The IMU derived dead-reckoned 

distance ALTA has traveled northward

IMU Position East meters

The IMU derived dead-reckoned 

distance ALTA has traveled eastward

IMU Position Up meters

The IMU derived dead-reckoned 

distance ALTA has traveled upward

IMU Velocity North meters / second The IMU derived northward 

velocity component of ALTA.

IMU Velocity East meters / second The IMU derived eastward 

velocity component of ALTA.

IMU Velocity Up meters / second The IMU derived upward velocity 

component of ALTA.

IMU Acceleration 

North meters / second^2 The IMU derived northward acceleration

IMU Acceleration 

East meters / second^2 The IMU derived eastward acceleration

IMU Acceleration 

Up meters / second^2 The IMU derived upward acceleration, 

without gravitational acceleration

IMU Roll degrees The IMU derived roll angle where 

positive values indicate roll right

IMU Pitch degrees The IMU derived pitch angle where 

positive values indicate pitch up

IMU Yaw degrees

The IMU derived yaw angle where 

positive values are eastward and 

negative values westward 

IMU Roll Rate degrees / second The IMU derived roll rate where 

positive values are roll rightward

IMU Pitch Rate degrees / second The IMU derived pitch rate where 

positive values are pitch upward

IMU Yaw Rate degrees / second

The IMU derived yaw rate where 

positive values are clockwise 

looking down on the vehicle

IMU Acceleration 

X G

The IMU derived body acceleration 

where positive values are in 

a forwards direction

IMU Acceleration 

Y G

The IMU derived body acceleration 

where positive values are in 

a rightwards direction
| USER MANUAL 103

IMU Acceleration 

Z G

The IMU derived body acceleration 

where positive values are in an upwards 

direction and excludes gravity

Compass X Unitless

A component of a unit magnetic vector 

with positive values directed to the 

front when front is pointing Northward

Compass Y Unitless

A component of a unit magnetic vector 

with positive values directed to the 

right when front is pointing Westward 

Compass Z Unitless

A component of a unit magnetic 

vector with positive values directed 

to down when the underside 

is pointing Northward

Position 

Command North m

The position control loop set 

point in a Northerly direction 

referenced to take-off location

Position 

Command East m

The position control loop set 

point in an Easterly direction 

referenced to take-off location

Position 

Command Up m

The position control loop set point 

in an Upwards direction referenced 

to the take-off location

Velocity Command 

North m/s The velocity control loop set point 

in an Northwards direction

Velocity 

Command East m/s The velocity control loops set 

point in an Eastwards direction 

Velocity 

Command Up m/s The velocity control loop set 

point in an Upwards direction

Acceleration 

Command East m/s^2 The acceleration control loop set 

point in a Easterly direction

Acceleration 

Command North m/s^2 The acceleration control loop set 

point in a Northerly direction 

Acceleration 

Command Up m/s^2 The acceleration control loop set 

point in an Upwards direction

Roll Command deg The roll control loop set point where 

increasing values are roll right right

Pitch Command deg The pitch control loop set point where 

increasing values are pitch up

Yaw Command deg

The yaw control loop set point where 

positive values are for an Easterly 

heading and negative for Westerly
| USER MANUAL 104

Roll Rate 

Command deg/s

The roll rate control loop set 

point where positive values 

are for rolling rightwards

Pitch Rate 

Command deg/s

The pitch rate control loop set 

point where positive values 

are for pitching upwards

Yaw Rate 

Command deg/s

The yaw rate control loop setpoint 

where positive values are rotating 

clockwise looking from the machine top

Radio Roll us RC pulse width 1000-2000us where 

increasing values are for roll right

Radio Pitch us RC pulse width 1000-2000us where 

increasing values are for pitch up

Radio Yaw us

RC pulse width 1000-2000us 

where increasing values are 

for yaw to the right

Radio Throttle us

RC pulse width 1000-2000us 

where increasing values are 

for increased throttle

Radio Mode us

RC pulse width 1000-2000us 

where values near:

1000us = Open Loop

1500us = Closed Loop - height hold

2000us = Closed Loop - height 

and position hold

Roll Control a.u. Control loop calculation for roll axis

Pitch Control a.u. Control loop calculation for pitch axis

Yaw Control a.u. Control loop calculation for yaw axis

Climb Control a.u. Control loop calculation for lifting thrust 

Motor Command 

1-6 Unitless Scaled 0-1 representing 

demanded thrust from motor

Motor speed 1-6 RPM Propeller speed at last telemetry update

Motor Voltage 1-6 Volts Bus voltage measured at ESC 

from last telemetry update

Motor Current 1-6 Amps Motor field current measured at 

ESC from last telemetry update

Motor Power 1-6 Watts Measured ESC power consumption
| USER MANUAL 105

Motor Energy 1-6 Watt-hours

Integrated ESC power consumption 

- can be used to compare motor 

efficiencies or thrust skew

Motor Accel 1-6 a.u.

High pass filtered RMS vibration level 

measured at ESC - can be used to 

compare motor / propeller imbalance 

Motor Temp 1-6 °C ESC temperature measured 

from last telemetry update

Motor Status 1-6 bit-field ESC fault condition monitor

GPS Sats Satellites Number of satellites used for 

position calculation by GPS

GPS Hacc meters Horizontal position accuracy 

reported by GPS 

GPS Sacc meters / second Horizontal speed accuracy 

reported by GPS

Voltage Volts Main battery voltage measured 

by the flight controller

Current Amps Total battery current inferred 

from ESC measurements

Power Watts Total battery power 

Energy Watt-hours

Integrated battery power - to be used 

in conjunction with battery recharge 

measurements - ascertaining battery 

health and expected flight times

Temperature °C Flight controller PCB temperature

Barometric 

Altitude meters Height above take-off location 

derived by pressure measurement 

Status a.u. Flight controller status - indicating 

things like auto-land

Fail bitfield Machine alarm register indicating 

particular system failures 

GPS Loss 

of Signal binary Declared if GPS signal is not 

adequate for safe position hold

Radio A Drops number Accumulated signal drops from radio A

Radio B Drops number Accumulated signal drops from radio B

Magnetometer 

Bad binary Alarm indicating compass 

magnitude is corrupted

Position Lock binary Status indicating position 

estimation filter has locked

Heading Lock binary Status indicating heading lock is active
| USER MANUAL 106

Attitude Mode register Status indicating angle or 

rate control mode

Position Lock 2 register Status indicating position control mode

Height Lock register Status indicating height control mode

CRC Failures number Internal communication errors