FIRE SPRITE FIXED WING 

UNMANNED AIRCRAFT 

OVERVIEW AND OPERATIONS MANUAL 

12 August 2015 

Revision: 01.1 

AcuTech 

AcuTech Proprietary Information and Export Notification

This document contains technical information that is proprietary in nature and is intended for 

use only by the customers and partners of AcuTech. Technical data in this document may 

also fall under specific export control laws. Information in this document should not be 

transferred to a foreign person without prior authorization from the appropriate government 

agencies.
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 2

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Table of Contents 

Scope........................................................................................................................................................ 6

Safety ....................................................................................................................................................... 6

Manual Sections...................................................................................................................................... 6

Support Documentation.......................................................................................................................... 7

Abbreviations and Acronyms.................................................................................................................. 8

REVISION HISTORY ................................................................................................................................. 10

General Description ............................................................................................................................... 12

Aircraft Specifications and Performance Characteristics....................................................................... 14

Autopilot and Avionics Overview........................................................................................................... 15

Command and Control ........................................................................................................................... 16

Electrical System Overview .................................................................................................................... 18

Propulsion System.................................................................................................................................. 19

Flight Control and Actuators.................................................................................................................. 20

Aircraft Payload...................................................................................................................................... 22

Mission Planner Software Overview/ Operation ................................................................................ 23

Mission Planner Description .............................................................................................................. 23

Mission Planner Setup........................................................................................................................ 24

Caching Map Data .................................................................................................................................. 26

How to Plan a Mission........................................................................................................................ 26

Setting Failsafesfor the Mission ........................................................................................................ 30

System Assembly and Setup................................................................................................................. 32

Aircraft Assembly ............................................................................................................................... 32

Aircraft Parts Included ....................................................................................................................... 33

Battery Mounting................................................................................................................................... 38

Aircraft Inspection.................................................................................................................................. 39

Aircraft Structure ............................................................................................................................... 39

Aircraft Battery .................................................................................................................................. 39

Propellers........................................................................................................................................... 39

Motor................................................................................................................................................. 39

Aircraft Center of Gravity....................................................................................................................... 40

Control Surface end point adjustment............................................................................................... 40

Payload............................................................................................................................................... 41

Ground Control Station Assembly.......................................................................................................... 42

Telemetry Radio................................................................................................................................. 42

Remote Video Terminal Setup ........................................................................................................... 43

Aircraft Launch Procedures .................................................................................................................. 47

Normal Operational Procedures........................................................................................................... 49

Flight Limitations:............................................................................................................................... 49

Aircraft Failsafe and Non‐Normal Flight Procedures...................................................................... 51

Aircraft Battery Failsafe ..................................................................................................................... 51

Loss of GPS Signal............................................................................................................................... 52

Geo‐Fence Excursion.......................................................................................................................... 53
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EKF/ Inertial Navigation Health.......................................................................................................... 54

Telemetry/ GCS Link Failsafe.............................................................................................................. 55

RCTx Link Failsafe ............................................................................................................................... 56

Aircraft Recovery and System Disassembly......................................................................................... 58

Appendix A ‐ Flight Mode Description ................................................................................................... 60

Appendix B ‐ Maintenance Schedule Matrix.......................................................................................... 61

Appendix C – Preflight Briefing Guidelines ............................................................................................ 62

Airspace Coordination........................................................................................................................ 62

Flight Objectives................................................................................................................................. 62

Safety Items ....................................................................................................................................... 62

Non‐Normal Flight Procedures........................................................................................................... 62

Preflight Procedures.......................................................................................................................... 63

Ground Station Assembly................................................................................................................... 63

Remote Video Terminal (RVT) Assembly ........................................................................................... 63

Aircraft Assembly ............................................................................................................................... 64

Radio Control Transmitter Setup ....................................................................................................... 64

Aircraft Preflight................................................................................................................................. 64

Flight Plan Building............................................................................................................................. 65

Aircraft Launch ................................................................................................................................... 65

Normal Flight Procedures................................................................................................................... 66

Non‐Normal Flight Procedures/ Aviate ‐ Navigate ‐ Communications.............................................. 66

Aircraft Recovery and Disassembly .................................................................................................... 66

Notes ..................................................................................................................................................... 67

Table 1‐Abbreviation and Acronyms ....................................................................................................... 8

Table 2  FIRE SPRITE Aircraft General Specifications.......................................................................... 14

Table 3 ‐ PixHawk Autopilot Specifications......................................................................................... 15

Table 4 ‐ Radio Frequency Matrix........................................................................................................ 16

Table 5 –Specifications........................................................................................................................... 19

Table 6 ‐ Electronic Speed Controller Specifications.......................................................................... 20

Table 7 ‐ Tools and Hardware Required for Aircraft Assembly ......................................................... 32

Table 8 ‐ Aircraft Inventory Sheet........................................................................................................ 32

Table 9‐Aircraft Battery Failsafe Details.............................................................................................. 51

Table 10 – Loss of GPS Failsafe Details................................................................................................ 52

Table 11 – Geo‐Fence Failsafe Details................................................................................................. 53

Table 12 – EKF Variance Failsafe Details............................................................................................. 54

Table 13 – Telemetry/ GCS Link Failsafe ............................................................................................. 55

Table 14 – RCTx Link Failsafe................................................................................................................ 56

Table 15‐ Flight Mode Descriptions..................................................................................................... 60

Table 16 ‐ FIRE SPRITE Maintenance Schedule................................................................................... 61
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Figure 1  FIRE SPRITE Fixed Wing Aircraft............................................................................................ 12

Figure 2  FIRE SPRITE Fixed Wing View Drawing.................................................................................... 13

Figure 3‐ Aircraft Electrical System Overview........................................................................................ 18

Figure 4 – FIRE SPRITE Motor............................................................................................................... 19

Figure 5‐ GoPro 3‐axis Gimbal ............................................................................................................... 22

Figure 6‐ Mission Planner Overview.................................................................................................... 23

Figure 7‐ Mission Planner Configuration  Window.............................................................................. 24

Figure 8– Mission Planner Time in Air Selection ................................................................................ 25

Figure 9‐ HUD showing Time in Air...................................................................................................... 25

Figure 10‐ Mission Planner – Autopilot Communications ................................................................. 27

Figure 11‐Mission Planner Heads Up Display ........................................................................................ 28

Figure 12‐ Flight Planner Window........................................................................................................ 29

Figure 13‐ Failsafe Configuration Window ........................................................................................... 30

Figure 14‐Aircraft components.............................................................................................................. 33

Figure 15‐Wing root............................................................................................................................... 34

Figure 16‐ Tail boom .............................................................................................................................. 34

Figure 17‐Tail boom tightening ............................................................................................................. 35

Figure 18‐Elevon connector.................................................................................................................... 35

Figure 19‐Complete Wing Assembly...................................................................................................... 36

Figure 20 Wing Assembly Mount to Fuselage ....................................................................................... 37

Figure 21 Assembled Aircraft................................................................................................................. 38

Figure 22‐Aircraft Center of Gravity ...................................................................................................... 40

Figure 23‐ Telemetry Radio .................................................................................................................. 42

Figure 24‐ Remote Video Terminal Example....................................................................................... 43

Figure 25 ‐ RCTx Setup .......................................................................................................................... 44

Figure 26‐ RCTx Switch Mapping.......................................................................................................... 45

Figure 27‐ Auto Mode Selection in MP................................................................................................ 48
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 6

Scope 

This manual contains the system description, aircraft assembly and disassembly 

procedures, operator’s responsibilities during normal and non-normal operations, 

and a condensed version of these procedures (operations checklist). 

Safety 

Varying levels of safety warnings are called out in this manual with the definitions 

as follows: 

Note - An operating procedure, practice, or condition, etc., which is essential to 

emphasize. 

Caution - An operating procedure, practice, or condition, etc., which if not 

strictly observed, may cause damage to the equipment. 

Warning - An operating procedure, practice, or condition, etc., which may 

result in personnel injury or death if not carefully observed or followed. 

Manual Sections 

This manual contains the following major sections: 

1. Aircraft Description – A brief description of the aircraft and the 

performance and physical specifications to include flight controller and 

propulsion system information. 

2. Mission Planner Software Overview/ Operation– Description of the 

Mission Planner operating software, setup and basic functionality. 

3. System Assembly and Setup– Procedures outlining the aircraft, GCS 

and RVT assembly. 

4. Operational Procedures – Overview of the proper preflight, in flight and 

recovery procedures for the FIRE SPRITE aircraft. 

5. System Disassembly – Procedures outlining the aircraft, GCS and RVT 

disassembly. 

6. Non-Normal Procedures – Descriptions and how to perform aircraft and 

ground station emergency procedures. 

7. Appendix – List of various charts, tables and special procedures. 

8. FIRE SPRITE Operations Checklist – Condensed version of the 

Operational 

Procedures. 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 7

Support Documentation 

Support documentation and additional material regarding the autopilot and 

functionality can be found online at: http://www.plane.ardupilot.com
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 8

Abbreviations and Acronyms 

Table 1-Abbreviation and Acronyms

Abbreviation Definition

ACAlternating Current

AES Advanced Encryption Standard

AGL Above Ground Level

AhAmp Hours

AP Autopilot

ASL Above Sea Level

ATP Acceptance Test Procedure

AVAir Vehicle

AVO Air Vehicle Operator

CM Centimeter

DADensity Altitude

dBm Power Ratio in Decibel

DC Direct Current

DEG Degrees

DTED Digital Terrain Elevation Data

ELOC Electronic Loss of Communications

EO Electro-Optical

EO/IR Electro-Optical / Infrared

EPExternal Pilot

ESC Electronic Speed Control

ESD Electro Static Discharge

FOD Foreign Object Debris

FMU Flight Management Unit

FW Firmware

GCS Ground Control Station

GHz Gigahertz

GPS Global Positioning System

GSE Ground Support Equipment

GTOW Gross Take-off Weight

GUI Graphical User Interface

HDOP Horizontal Dilution of Precision

IAS Indicated Airspeed
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IR Infrared

In Inch

INS Inertial Navigation System

ISM Industrial, Scientific, and Medical

I2C Inter Integrated Circuit

Kg Kilogram 

KHz Kilohertz 

Km Kilometer 

Kw Kilowatt 

Kv RPM/ Volt 

Lbs Pounds 

LED Light-Emitting Diode 

LOS Line of Sight 

M Meter 

mA Milliamp 

mAh Milliamp-Hour 

MHz Megahertz 

mm Millimeter 

mW Mill watt 

MP Mission Planner 

MSL Mean Sea Level 

m/s Meters per second 

nm Nanometer 

NM Nautical Mile 

NTSC National Television System Committee 

OAT Outside Air Temperature 

OZ Ounce 

PAL Phase Alternate Line 

PPM Pulse Position Modulation 

PWM Pulse Width Modulation 

RCTx Radio Control Transmitter 

RF Radio Frequency 

FIRE SPRITE Remotely Operated Air Vehicle 

RSSI Received Signal Strength Indicator 

RVT Remote Video Terminal 

TCP Transmission Control Protocol 

SPI Serial Peripheral Interface 

UAS Unmanned Aerial System 

UART Universal asynchronous receiver/transmitter 

UAV Unmanned Aerial Vehicle 
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UPS Uninterruptible Power Supply 

USB Universal Serial Bus 

V Volts 

VAC Volts Alternating Current 

VDC Volts Direct Current 

W Watt 

WP Waypoint 

V Volts 

VAC Volts Alternating Current 

VDC Volts Direct Current

W Watt

WP Waypoint

 

REVISION HISTORY 

Revision

Level Release Date Description of Change

Affected

sections/ 

Pages

Rev. A 12 August 2015 Initial document release All 

      
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General Description 

The Fire Sprite is a fixed wing, aerial vehicle produced by AcuTech of Vancouver, 

Washington, USA. The aircraft is designed to carry several payloads to perform 

various commercial tasks such as industrial inspection and mapping. 

The airframe is comprised of lightweight carbon fiber frame cover wing EPO foam 

to achieve an optimal strength to weight ratio. The airframe and subcomponents 

have been designed and tested to withstand the stress loadings witnessed in 

normal flight conditions while retaining ample safety factors. 

Figure 1 FIRE SPRITE Fixed Wing Aircraft
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Figure 2 FIRE SPRITE Fixed Wing View Drawing 
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Aircraft Specifications and Performance Characteristics 

Table 2 FIRE SPRITE Aircraft General Specifications

Parameter Value (Imperial) Value (Metric)

Gross Takeoff Weight (GTOW) 10 lbs 4,530 g 

Wing Span 81 In 2060 mm 

Length 55 In 1410 mm 

Fuel Type Electric/ Lithium Polymer Batteries 

Nominal Payload Capacity ~2 lbs ~907 g 

 Payload Option 36x zoom EO and/ or Infrared sensor 

Trillium HD25 Payload EO/ IR - E. Stab and Inertial stab. 

Command and Control (C2) Manual Control via RCTx operating on 2.4 GHz,

frequency hopping 

Command and Control Range 2 NM 3.7 Km 

Aircraft Telemetry Up to 1 watt, discrete, frequency agile, ISM 

band, bi-directional radio modem (Rx/ Tx) 

Aircraft Telemetry Range ~2 NM 3.7 Km 

Video Transmitter 600mW Analog or 27dBm Digital Link 

Video Transmitter Range ~ 2 NM 3.7 Km 

Launch Type - Procedure Vertical Takeoff – Manual or Auto 

Recovery Type - Procedure Vertical Landing – Manual or Auto 

Navigation - Horizontal GPS / INS

Navigation - Vertical Barometer / INS

Nominal Mission Altitudes 

(AGL) 

20 - 400 ft 6 - 121 m 

Service Ceiling (@GTOW) 8,000 ft MSL 2,400 m 

Nominal Mission Endurance ~1.5 Hours 

Cruise Ground/ Airspeed 25 kts 12 m/s

Maximum Ground/ Airspeed 55 kts 28 m/s 

Max Climb Rate 1,000 fpm 5.0 m/s 

Max Descent Rate 500 fpm 2.5 m/s 

Headwind Limitation 20 kts 10.3 m/s 

Crosswind Limitation 10 kts 5 m/s 

Turbulence Rating Light

(OAT) Operating Range 20° F - 100° F 

Shipping Container Size - 

Weight 

52 x 22 x 15 inches 

70 lbs 

1.32 x .56 x .38 m 

31.75 Kg 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 15

Autopilot and Avionics Overview 

The aircraft flight stabilization and navigation management is accomplished by the 

PixHawk autopilot system, which runs a flight control firmware stack called 

ArduPlane 3.2.x in the NuttX operating system. 

The PixHawk autopilot boasts a suite of sensors where incoming data is 

managed by a robust inertial measurement unit (IMU) utilizing an extended 

Kalman filter (EKF) algorithm. This logic makes efficient use of the single and 

redundant sensors creating a reliable system with fail-back capabilities. 

Table 3 - PixHawk Autopilot Specifications

Processor

32-bit ARM Cortex M4 core with FPU, 168 MHz/ 256 KB RAM/ 2 MB Flash 

32-bit STM32F103 failsafe co-processor 

Sensors

Dual 3 axis 16-bit ST Micro L3GD20H gyro for determining orientation. 

Dual 3 axis 14-bit accelerometer and magnetometer for determining outside influences and 

compass heading. 

Provision for external magnetometer with automatic switchover if desired. 

MEAS MS5611 barometric pressure sensor for determining altitude. 

Built in voltage and current sensing for battery condition determination. 

Options for dual externally mounted UBLOX LEA GPS for determining absolute position. 

I/O Interfaces

Fourteen PWM servos or ESC speed control outputs. 

Five UART (serial ports), one high-power capable, 2x with HW flow control. 

Two CAN I/O ports (one with internal 3.3V transceiver, one on expansion connector) 

PPM sum signal input. 

RSSI (PWM or voltage) input. 

I2C and SPI serial ports. 

Two 3.3 volt and one 6.6 volt analog inputs. 

Internal microUSB port and external microUSB type-B port extension. 

Contains its own onboard microcontroller and stacks with the FMU. 

Power System

The PixHawk is supplied with an in line power supply with voltage and current sensor outputs. 

Ideal diode controller with redundant power supply inputs and automatic fail-over. 

Servo rail high-power (max. 10V) and high-current (10A+) ready. 

All peripheral outputs are over-current protected and all inputs are ESD protected. 

The provided external safety button enables safe motor activation / deactivation. 

Piezo buzzer audio warnings, Flight status indicators and driver for high 

brightness external multicolored LED 
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Command and Control 

There are a total of three radio frequency (RF) links that control and 

communicate with the autopilot/ aircraft. All links are operating within the ISM 

bands provided for industrial use and operate simultaneously without 

interference. 

Mission plan data is transmitted via Mavlink (a serial telemetry data protocol) on 

the GCS/ Telemetry radio link and is received by an identical radio which 

communicates data to the Mission Planner GUI. 

Safety pilot commands are transmitted to the vehicle on 2.4GHz and are 

received onboard by a separate recevier (typical RC equipment). The PWM 

signal reveived is then converted to PPM and sent to the flight management unit. 

Table 4 describes the RF link(s) functionality and operating frequencies. 

Table 4 - Radio Frequency Matrix

Description

Transmission

Device – Power

Magnitude

Function Frequency

GCS/ Telemetry 

Radio 

Bi Directional 

serial, UART radio 

modem with 128 

bit AES encryption 

available – 

Adjustable up to 1 

Watt

Ground station to 

aircraft 

communications 

for health 

monitoring and 

flight plan 

management 

902 – 928 MHz, 

frequency hopping 

over 50 channels 

Video Link 

Commercial grade

analog video 

transmitter - 600 

mW

Video downlink to 

the remote video 

terminal (RVT) 

5.8 GHz 

Radio Control 

Radio Control 

hand held 

transmitter -120 

mW

Camera 

manipulation and 

safety pilot/ 

manual control 

2.4 GHz 
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Electrical System Overview 

The FIRE SPRITE is an electrically powered aircraft that receives power for 

propulsion and onboard systems from dual Lithium Polymer battery packs. The 

battery pack are in the fuselage and provides a nominal voltage of 14.8VDC and 

has a capacity of 20.0 Ah. This produces a flight time of ~1.5 hours with 20% 

battery capacity in reserve. 

The avionics system requires 5V and draws approximately 800 mA. The propulsion 

system draws 38 amps on takeoff and at cruise groundspeed, with a maximum of 

15 amps observed in high wind scenarios. 

Payloads typically require 5-12V and draw approximately 2 amps or less. On- board 

voltage, current, and battery percentage monitoring provides power system 

health status to the pilot through the telemetry radio and is displayed on the Mission 

Planner GUI. 

Figure 3- Aircraft Electrical System Overview 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 19

Propulsion System 

Table 5 –Specifications 

KV..................................................................................................................400

Configu ration......................................................................................12N14P

Stator Diameter......................................................................................35mm

Stator Length..........................................................................................20mm

Shaft Diameter.........................................................................................4mm

Motor Dimensions (Dia.*Len)......................................................Φ42.5×42mm

Weight (g)..................................................................................................194g

ldle current(10)@10v(A)...........................................................................1.2A

No.of Cells (Lipo)......................................................................................4-8S

Max Continuous current (A) 180S..............................................................38A

Max Continuous Power (W) 180S........................................................1140W

Max.-efficiency-current..............................................................(.10-23A)>83% 

internal resistance..................................................................................82mΩ

Figure 4 FIRE SPRITE Motor 
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Flight Control and Actuators 

The FIRE SPRITE is controlled via surface deflection of the four control surface 

using commanded servo positing. An electronic speed controller (ESC) is dedicated 

to the motor to apply power and change RPM as directed by the autopilot. 

The ESCs used on the FIRE SPRITE feature dynamic PWM and motor advance 

timing algorithms and 490 Hz refresh rate for high-speed response to flight control 

commands. Critical components of the ESC are protected by two thermal-epoxy 

bonded aluminum heat sinks. Table 6 lists the specifications of the ESCs. 

Table 6 - Electronic Speed Controller Specifications

Refresh rate 600 Hz PWM Rate 16 KHz 

Maximum

Current

100 a (5s burst) Advance

Timing

22-30 deg 

Maximum Power 2790 W (5s burst) Weight 32 g (54g with 

wires/bullets) 

Continuous

Current

80 A Power Leads 13 AWG, 200 deg C 

Continuous

Power

1625+ W Motor Leads 15 AWG, 200 deg C 

Maximum

Efficiency

>98% ESC Lead 22 AWG, 3-wire JR 

Voltage Range 7.4 – 29.6 V Maximum

RPM

210,000 RPM 
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Aircraft Payload 

The FIRE SPRITE can carry various cameras on an external 2 or 3-axis 

gimbal platform mounted beneath the nose section. Figures 5 show 3-axis gimbal 

with a GoPro Hero-4. For instructions on a specific payload please see the 

operations checklist and manufacturer data. 

Figure 5 GoPro 3-axis Gimbal 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 23

Mission Planner Software Overview/ Operation 

Mission Planner Description 

Mission planner (MP) is the command and control graphical user interface (GUI) 

between the operator and the aircraft for running in a Windows environment. This 

software is used to plan autonomous missions, monitor aircraft health, dynamically 

re-task the aircraft in-flight and setup aircraft functionalities; e.g. failsafe’s, sensor 

calibration and camera configurations. 

Figure 6 Mission Planner Overview
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 24

Mission Planner Setup 

Mission Planner is a free download that can be found at 

ardupilot.com/downloads/. The Downloads portion of the website is always 

updated with links to the latest download for your specific operating system. 

Once downloaded, navigate to the “Downloads” folder and extract the zipped file to 

the directory of your choice. 

1. Double click the MP installer executable and follow the steps through the 

installation process. 

2. After installing MP, open the application. 

3. Select the Config/ Tuning Page from the top-level menu and then select the 

“Planner” Tab on the left. 

Figure 7 Mission Planner Configuration Window

4. Select the appropriate units of measurement for distance and speed for your 

area and air traffic control. 

5. Check the “Enable Speech” box to enable audible alerts. 

6. Select the Flight Data page from the top-level menu. 
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7. Right Click in the HUD and select “User Items” from the drop down box. 

8. Check the “Time in Air” box to add a flight timer into the HUD. 

Figure 8 Mission Planner Time in Air Selection

9. The time in Air data field will then be populated as shown in figure 11. 

Figure 9 HUD showing Time in Air 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 26

Caching Map Data 

Satellite imagery of the area you intend to fly is only available in the field if the 

user has cached the imagery for the area. This is accomplished from the 

Planning window found in the top-level menu. 

1. Open the Planning Window 

2. Ensure that an Internet connection is available and navigate the map to the 

area to be flown. 

3. Zoom in as far as possible until the area to be flown fills the entire screen. 

4. Right click anywhere on the map and select “Map Tool” from the drop down. 

5. Select the “Prefetch” option and answer yes to the next popup window. 

Figure 10 GEO Map 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 27

How to Plan a Mission 

1. Connect the GCS/ Telemetry radio to an open USB port on the GCS 

computer. 

2. Select the appropriate comm port from the communications drop down 

located in the upper right hand corner of MP. This will typically be the only 

comm port available. 

3. Select a baud rate of 57600 from the drop down window to the right of the 

comm port drop down. 

4. Press the connect icon to the right of the baud rate drop down and MP will 

then begin to connect and pull parameters from the autopilot. 

Figure 11 Mission Planner – Autopilot Communications
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 28

5. After the connection is complete the user can see information in the artificial 

horizon such as: battery voltage, altitude and indicated airspeed start to 

populate and change. 

Figure 12 Mission Planner Heads Up Display
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 29

6. Select the Planner window to begin planning an autonomous mission. 

7. Set the “Default Alt” to your desired altitude of the flight plan. Keep in mind 

that the altitude for the waypoints are recorded in above ground level (AGL) 

Relative to the altitude when the aircraft in armed. 

8. Left click a location on the map where a waypoint or command point is to be.

Continue to do this until all of the waypoints and command points for the 

mission are populated. 

9. Open the waypoint matrix window by selecting the double arrows on the right

hand side of the waypoints bar, located below the map window. This is 

highlighted in figure 16. 

10. Configure the waypoints and commands points as necessary and send the 

flight plan to the aircraft by selecting the “Write WPs” button. 

11. You can verify that the WP’s were received by requesting the flight plan data 

from the aircraft by selecting the Read WP’s button. 

Figure 13 Flight Planner Window 
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Setting Failsafes for the Mission 

There are several failsafe settings available for multiple types of failure modes. 

System failsafe can be set from the Failsafes tab located in the Initial Setup 

window. A full description of failsafe conditions and events is described in tables 

9 through 14 under the Failsafe’s and Non-Normal Operations section of this 

manual. 

Figure 14 Failsafe Configuration Window
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                                           WARNING

System Assembly and Setup 

Loss of aircraft or injury to personnel or property can occur if 

these steps are not followed carefully.

Aircraft Assembly 

This section of the manual describes how to correctly assemble the FIRE SPRITE 

aircraft in preparation for flight. The operator should always follow the prescribed 

preflight checklist before every flight. 

The tools and hardware for aircraft assembly are described in Table 7. 

Table 7 - Tools and Hardware Required for Aircraft Assembly

Quantity Description

1 Hand Operated Screwdriver 

4 M3 x 40mm arm bolts 

1. Inventory the aircraft and aircraft parts. The inventory sheet can be found in 

the lid of the aircraft case. 

Table 8 - Aircraft Inventory Sheet

FIRE SPRITE Aircraft 

Quantity Description

1 FIRE SPRITE Aircraft 

1 Aircraft Manufacturing and Data Log 

1 Aircraft Flight Log 

1 GCS/ Telemetry Radio 

2 GCS/ Telemetry Radio Antenna 

1 Radio Control Transmitter 

1 FIRE SPRITE Tool Kit 

2. Remove the aircraft from the case by lifting up on the aircraft components. 
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 Aircraft Parts Included

Figure 15 Aircraft components 

 Fuselage

 Right and Left Wings

 Right and Left elevons

 Tail Booms
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1. Locate assembled main wings and CF spars 2B & 3B

a. Insert CF spar 2B into forward spar on one wing until it stops. 

b. Insert CF spar 3B into rearward spar on one wing until it stops. 

c. Slide opposite wing onto spars until wings meet as shown. 

Figure 16 Wing root 

2. Fully insert male stereo side of tail boom into boom anchors under main 

wing.

Figure 17 Tail boom 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 35

a. Once fully inserted, tighten down clamps with 2.5mm tool. 

Figure 18 Tail boom tightening 

3. Slide Elevons onto rear portion of tail booms

a. Tighten clamps once fully inserted and no gaps in foam are showing. 

b. This may be more difficult during the first installation. 

b. Plug male servo leads into female plugs in rear of tail boom. 

Figure 19 Elevon connector 

c. You should now have fully assembled the wing and tail portions. 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 36

4. Plug in “Y” servo cables from E11 for ailerons and flaps if you have 

chosen to install them. 

Figure 20 Complete Wing Assembly
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 37

5. Place wing and tail on top of assembled fuselage. 

a. Locate wing mount bolts and washers from E8. 

b. Make sure that servo wires are not smashed between surfaces. 

b. Fasten longer bolts in front and shorter bolts towards rear of wing. 

Figure 21 Wing Assembly Mount to Fuselage
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 38

Figure 22 Assembled Aircraft

Battery Mounting 

1. Remove a charged battery from the storage/ shipping case. 

2. Attach the battery to the inside of the fuselage ensuring the Velcro strap firmly 

against the mounting plane. 

3. Connect battery power to aircraft main power cable when ready to begin the 

preflight process. 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 39

Aircraft Inspection 

Aircraft Structure 

1. Inspect the aircraft for integrity and secureness. Signs of wear and fatigue 

should be noted in the aircraft logbook and addressed before flight.

2. Check that all fasteners are present and secure on the entire airframe. 

Aircraft Battery 

1. The battery should be free of punctures, swelling and other signs of visible 

damage. Do not use the batteries if they are exhibiting signs of wear or visible 

damage. 

2. The battery and aircraft main power connections should be clean and free of 

FOD. If the connectors are blackened from connection arching, replace the 

connector(s) before flight. 

Propellers 

1. Inspect propellers for cracks or delamination. Do not fly the aircraft with a 

compromised propeller. 

2. Propeller fasteners should be tight and secured with thread locker

Motor 

1. The aircraft motor should spin freely without noticeable friction. Ensure the 

motors spin smoothly and they are free of FOD. 

2. Check that all fasteners are present and secure.
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 40

Aircraft Center of Gravity 

After attaching all equipment and batteries, be sure to check for proper center of 

gravity before taking off for the first time. The best CG we have found is at 45mm 

measured from behind the leading edge flap shown below. This measurement is 

slightly behind the main spar. For your first flight, we recommend setting CG directly 

on the main spar (slightly nose heavy). 

Figure 23 Aircraft Center of Gravity

Control Surface end point adjustment 

 For our personal preference, we use 100% travel on all of our end points for the 

Anaconda. We suggest that if your RC transmitter has the capability, to use a 2 or 

3 position switch to set throws at 60% and 80%. This will allow you to change midflight if you find that you have too much or too little control over the aircraft. If you 

are using flaps, you may wish to have a 5-10% downward mix in the elevator. This 

will help eliminate any “ballooning” effect when applying flaps. Experiment with the 

flaps at higher altitude before attempting to land to see how the plane reacts to your 

setup. 

As a reminder, please DO NOT attempt to hand launch this aircraft. It is simply too 

large and unwieldy to try it. 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 41

Payload

1. Inspect the payload mounting points and hardware ensuring that all fasteners 

are secure. 

2. Ensure that the isolation dampeners are properly installed and free of cracks 

or signs of aging. 

3. Check the movement of the sensor along all the axes of rotation, ensuring 

smooth movement and there is no FOD present. 

4. Wipe the lens with an appropriate cloth to remove dust and debris. 

5. Check all fasteners are present and secure. 

6. Check movement and ensure that all moveable intersections are clean.
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 42

Ground Control Station Assembly

Telemetry Radio 

This section of the manual describes the steps to properly assemble the ground 

control station (GCS) for the FIRE SPRITE. The operator should always follow the 

prescribed preflight checklist before every flight. 

1. Inspect the GCS shipping case and ensure that all parts are present. If there 

are parts of the GCS missing, do not fly. 

2. Setup the GCS computer on a stable and clean surface. 

3. Power on the GCS computer and ensure the battery level is adequate for 

operations. If available, plug the computer into a power source. 

4. Inspect the USB connection on the telemetry radio for FOD then plug the 

telemetry radio into the GCS computer. 

5. Place the telemetry radio up and away from obstructions that may block RF 

signals. 

6. Orient the antennas vertically and offset to each side, creating a “V” shape. 

This will help ensure that the GCS antenna polarity matches the aircraft while in 

flight. 

7. Launch the Mission Planner program

Figure 24 Telemetry Radio 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 43

Remote Video Terminal Setup 

As there are many payload options for the FIRE SPRITE; there are equally 

abundant options for receiving the video on the ground. Generalized procedures 

for setup are listed below. For details about a specific part or component, please 

see the manufacturers’ information sheets. 

1. Inspect and inventory all parts of the Remote Video Terminal (RVT) system. 

2. Setup the video display on the mount provided with the system. This could be a 

tripod or table mounted display. 

3. A video receiver (Rx) will be mounted to the display or integrated into the 

display. The antennas will be inspected for FOD before being installed onto 

the receiver. Orient the antennas in a manner that will allow for best 

reception/ coverage. 

4. Secure the battery or power source for the display and Rx. 

5. Connect the power source to the display and Rx. 

Figure 25 Remote Video Terminal Example 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 44

Radio Control Transmitter (RCTx) Setup 

The FIRE SPRITE aircraft comes with a radio control box that is used by the 

External Pilot (EP) for manual control flight modes, autonomous mode 

augmentation and flight abort procedures. As it is an integral part of the system 

and many flight modes are reliant on it, special care and handling is required. 

Setup procedures are listed below and inspection points highlighted in Figure 23. 

1. Inspect the radio ensuring that all switches and gimbals (joysticks) are 

functional. Excessive dirt or dust that collects in the gimbal mechanism can 

inhibit movement, which can cause control issues in manual flight mode(s). 

2. Power on the radio and confirm that the internal battery is fully charged or 

adequate for the length of operations. 

3. As most modern RC transmitters are capable storing information for multiple 

models, the user must ensure that the correct model is selected. If the 

incorrect model is active, the RC transmitter will not communicate with the 

receiver on the aircraft side. 

4. For safety and to preparation to arm the aircraft, set the throttle stick at the 

lowest setting. 

5. Set all moveable switches to the position furthest away for the user as he/ she 

is holding the transmitter. This ensures that the flight mode and other functions 

are in a preflight state. Figure 24 shows the RCTx switch functions. Switches 

not listed are inhibited. 

Figure 26 RCTx Setup 

Verify correctr 

model and 

adequate 

battery.

Check joystick 

functionality 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 45

Figure 27 RCTx Switch Mapping 

2-Position switch used 

for camera change, if 

applicable. 

3-Position switch for 

changing flight modes 

 Away= Stabilize 

 Middle=Loiter 

 Toward=RTL 

Rear left Slider used 

for camera pitch 

control 

3-position switch used 

for camera zoom, if 

applicable. 

Rear Right Slider 

userd for camera yaw 

control with a 3-axis 

gimbal 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 46

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AcuTech Fire Sprite OPERATIONS MAN. – REV. A 47

                                            WARNING

Aircraft Launch Procedures 

Loss of aircraft or injury to personnel or property can occur if these steps 

are not followed carefully.

1. Determination of the wind direction is critical for launch. The aircraft should 

never be launched downwind as it could cause a vortex ring state situation. 

2. The AVO should once again verify that all the aircraft systems are within 

acceptable limits. 

3. For arming and safety, the aircraft should be in the Stabilize flight mode. The 

EP will verify this on the RCTx and the AVO will confirm this in the MP HUD. 

4. The EP will power the payload and check that is operational. 

5. The EP will now clear all personnel from the launch area and disable the 

safety switch. The safety switch will glow solid red when it is disabled. 

6. If applicable, begin recording the sensor data on the onboard DVR. 

7. The EP will power on the navigation lights at the time. 

8. The EP will arm the aircraft by holding the left stick on the RCTx down and to 

the right for >5 seconds. The propellers will spin upon arming. The AVO will 

also see “ARMED” in large red text in the MP HUD indicating that the aircraft is 

armed. 

8.1. During the arming sequence, the Autopilot status LED will flash Red-Blue 

rapidly indicating that the gyros and barometric sensor are being calibrated. It 

is critical that the aircraft is not moving during this phase. 

9. The AVO will now set the aircraft flight mode to AUTO by pressing the AUTO 

button in the Actions Tab. Confirmation of this is depicted in Figure 29.
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 48

Figure 28 Auto Mode Selection in MP

10. The EP will now give a verbal warning that the aircraft is launching and raise the 

throttle on the RCTx to launch the aircraft.

Auto mode selection “Auto” displayed after 

flight mode is 

changed. 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 49

Normal Operational Procedures 

Flight Limitations: 

1. The aircraft should not be flown in the proximity of high voltage power lines, 

certain types of radar any other high power emitting devices. 

2. A thorough site survey should be accomplished before any flights occur. 

Airspace and vertical obstructions should be well known and briefed prior to 

flights. 

3. See Table 2 – FIRE SPRITE Aircraft General Specifications for environmental 

limitations. 

4. The AVO and/ or EP will not intentionally place the aircraft into a non-normal 

state of operation. 

5. While in flight, the EP and observers should not lose visual line of sight with 

the aircraft. In the event of an airspace incursion, the EP will take manual 

control of the aircraft and manually fly the aircraft to a safe airspace or 

perform a flight abort procedure. 

6. The AVO will monitor the aircraft’s system health and flight tracking during 

normal operations. Large deviations in flight path tracking or altitudes may be 

indicative of a system malfunction. If this is witnessed, the AVO will alert the EP 

to take over manually. 

7. The AVO will also ensure that the battery voltage doesn’t reach a state of 

low voltage or a < 20% capacity. If a higher than normal battery depletion 

rate is witnessed, the AVO will notify the EP to take over manually and 

land the aircraft as soon as is reasonable. 

8. As GPS is the primary source for position information and augments 

other sensors in the flight controller, a healthy GPS solution is critical. If 

the VO witnesses a state where the visible satellite count drops below 5 

or the HDOP raises above 2.5, he will notify the EP so the aircraft could 

take over manually. 

9. Proper communication between the AVO, EP and other flight crewmembers is 

crucial for sufficient situational awareness during flight operations. It is also 

important to ensure a “sterile cockpit” so communications are not inhibited in any 

way.
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 50

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AcuTech Fire Sprite OPERATIONS MAN. – REV. A 51

Aircraft Failsafe and Non-Normal Flight Procedures

In the event of a state of emergency or non-normal flight, the AVO and EP shall 

perform the following procedures to mitigate risk of damage to personnel, 

property or the aircraft itself. It is imperative that the flight crew first establishes 

that the aircraft is flying and navigating well. If not, communication between the 

flight crewmembers and non-crewmembers must cease. 

Aircraft Battery Failsafe 

The battery failsafe can be setup and changed in the mandatory hardware tab 

under the Initial setup window. The operator has the option of setting a low 

voltage and/ or a capacity reserve (mAh) that will trigger the failsafe when the 

threshold is met. Characterization of the discharge curve will be necessary to 

establish viable threshold numbers. 

Table 9-Aircraft Battery Failsafe Details

Failure Type Low Main Battery Power

Condition Battery voltage exceeds low limit for more than 10 seconds 

or Estimated battery consumed exceeds. 

Warning Low voltage audible alert – Battery voltage text in HUD 

colored in red – Aircraft onboard buzzer tone. 

Operator Action

Autonomous Flight: Based on failsafe settings aircraft will 

autonomously Return to Launch or Land. Operator will 

monitor aircraft through landing sequence. 

Manual Flight: External Pilot will engage Stabilize flight 

mode and navigate the aircraft to a safe landing area. 

Flight Termination Procedure: RCTx throttle stick will be 

lowered to minimum position and Stabilize Flight mode 

engaged to stop motors. 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 52

 Loss of GPS Signal 

The GPS failsafe is activated by default, but can be disabled by the user if 

necessary. Failsafe actions are adjustable by the user in the Full Parameters 

Window. 

Table 10 – Loss of GPS Failsafe Details

Failure Type Loss of GPS Signal

Condition 3 dimensional lock is lost or a glitch is detected that lasts 

longer than 5 seconds. 

Warning “BAD POSITION” displayed in red text in HUD. 

Operator Action

Autonomous Flight: Aircraft stops navigation and Lands or

Aircraft switched to ALT HOLD flight mode. 

Manual Flight: External Pilot will engage Stabilize flight 

mode and navigate the aircraft to a safe landing area. 

Flight Termination Procedure: RCTx throttle stick will be 

lowered to minimum position and Stabilize Flight mode 

engaged to stop motors. 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 53

 Geo-Fence Excursion 

The geo-fence function provides the operator with an invisible ceiling and/ or 

horizontal wall that prevents the aircraft from continuing on excursions outside of 

the specifications of the fence. The dimensions of the fence are user adjustable 

with the ceiling being measured from the ground altitude relative to the aircraft 

when it is armed (0 AGL), to the ceiling or altitude specified. The horizontal walls 

are built in a circular fashion radiating outward from the point of where the aircraft 

is armed and are also adjustable by the operator. 

In the event of a fence breach the failsafe function will engage per the operator’s 

settings as noted in the table below. It is possible for the operator to attempt 

manual control of the aircraft after the geo-fence failsafe has been activated and 

in that case a backup fence is erected 20 meters further out and up from the 

original fence. If the aircraft continues on a trajectory away from the HOME 

position and the backup fence is breached, the failsafe will once again become 

engaged. 

The operator is given every opportunity to regain control of the aircraft before an 

uncontrolled landing is commanded; however, in the event of a rouge flight where 

the aircraft cannot be commanded HOME, the aircraft will be forced to land once 

it reaches 100 meters distance out from the original fence wall. 

Table 11 Geo-Fence Failsafe Details

Failure Type Geo-Fence Breach

Condition Vehicle travels outside of Geo-fence boundary 

Warning “Geo-Fence Breach” is displayed on HUD 

Operator Action

Autonomous Flight: Based on failsafe settings aircraft will 

autonomously Return to Launch or Land. Operator will 

monitor aircraft through landing sequence. 

Manual Flight: External Pilot will engage Stabilize flight 

mode and navigate the aircraft to a safe landing area. 

Flight Termination Procedure: RCTx throttle stick will be 

lowered to minimum position and Stabilize Flight mode 

engaged to stop motors. 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 54

 EKF/ Inertial Navigation Health 

The GPS failsafe is activated by default, but can be disabled by the user if 

necessary. Failsafe actions are adjustable by the user in the Full Parameters 

Window. A detailed description of the EKF Variance failsafe is described in 

Table 12. 

Table 12 EKF Variance Failsafe Details

Failure Type EKF Variance

Condition Position and velocity measurements conflict with the EKF 

for more than one second. 

Warning Yellow color displayed on the autopilot status light and “EKF 

Variance” displayed in HUD. 

Operator Action

Autonomous Flight: Aircraft is switched to a manually 

augmented flight mode. The aircraft will then begin the 

landing sequence. The EP will control aircraft attitude and 

position until landing. 

Manual Flight: External Pilot will ensure Stabilize Flight 

mode and navigate the aircraft to a safe landing area. 

Flight Termination Procedure: RCTx throttle stick will be 

lowered to minimum position and Stabilize Flight mode 

engaged to stop motors. 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 55

 Telemetry/ GCS Link Failsafe 

If the link between the GCS and the aircraft is lost the aircraft will activate the GCS 

failsafe based on the operator’s settings. The aircraft will not return to the mode it 

was in before the loss of communication; however, and the operator will have to 

change the flight mode out of the failsafe flight mode to retake control. 

Table 13 Telemetry/ GCS Link Failsafe

Failure Type Telemetry/ GCS Link Failsafe

Condition Loss of Telem/ GCS link for more than 5 seconds. 

Warning No data updates in MP and a red “X” will cover the RSSI 

graphic. 

Operator Action

Autonomous Flight: Based on user settings the aircraft will 

continue with the autonomous mission or Return To Launch. 

If the aircraft is within 6.5 feet of the home position and GPS 

is lost, the aircraft will Land autonomously. 

Manual Flight: When in line of sight - External Pilot will 

engage Stabilize Flight mode and navigate the aircraft to a 

safe landing area. 

Flight Termination Procedure: RCTx throttle stick will be 

lowered to minimum position and Stabilize Flight mode 

engaged to stop motors. 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 56

 RCTx Link Failsafe 

The operator has the option to set a failsafe function that is activated when the 

contact between the radio controller (RC) and the RC receiver is lost. There are 

several scenarios where the RC signal can be lost and the function of the 

failsafe will change accordingly: 

Table 14 RCTx Link Failsafe

Failure Type RCTx Link Failsafe

Condition Communication from the RCTx to the autopilot stops 

Warning No data updates in MP and a red “X” will cover the RSSI 

graphic. 

Operator Action

Autonomous Flight: Based on user settings the aircraft will 

continue with the autonomous mission, Land at the point, 

which the failsafe is engaged, or Return To Launch. 

Manual Flight: Maintain a throttle stick position higher than 

minimum. If possible, manual control will re-establish itself 

when in range. 

Flight Termination Procedure: No flight termination 

procedure available. 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 57

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AcuTech Fire Sprite OPERATIONS MAN. – REV. A 58

Aircraft Recovery and System Disassembly 

Extra awareness is required during the recovery phase of flight. It is best practice to 

ensure that non-flight crewmembers are clear of the recovery area during recovery. 

1. The AVO will command the aircraft to RTL and begin the landing sequence or 

this will happen automatically if a RTL command point is built into the flight plan. 

2. The EP and observers will ensure visual line of sight throughout the recovery 

phase of flight. 

3. When the aircraft reaches the "Land" way point it will lower the throttle and 

begin a glide to the predetermined point. 

4. The EP will arm the safety switch on the aircraft. The switch will flash when 

armed (in safe mode). 

5. Power down the payload and navigation lights at this time. 

6. Remove power to the aircraft by disconnecting the aircraft battery. 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 59

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AcuTech Fire Sprite OPERATIONS MAN. – REV. A 60

Appendix A - Flight Mode Description 

There are multiple flight modes available in ArduCopter 3.2; however, there 

are four primary modes used in normal mission profiles. These flight modes 

are described in Table 15. 

Table 15 Flight Mode Descriptions 

STABILIZE

Stabilize mode is what can be considered closest to manual flight 

mode and what would be used in an emergency recovery when the 

aircraft is in visual LOS. Stabilize automatically levels the vehicle and 

maintains the current heading, while allowing the pilot full control over 

the throttle and axial control up to the bank angle maximums. 

LOITER

In loiter mode; the vehicle maintains a consistent location, heading, 

and altitude. This can be adjusted by using the sticks on the pilot 

handheld controller: 

• Horizontal location can be adjusted with the Roll and Pitch 

control stick. 

• The aircraft heading can be set with the Yaw control stick.

• Altitude can also be adjusted with the Throttle control stick 

operating as a variable rate control. 

RTL

In return to launch (RTL)

mode, the plane navigates 

from its current position to 

final approach above the home 

position. The behavior of RTL

mode can be controlled by 

several adjustable parameters. 

AUTO

In autonomous (Auto) mode, 

the vehicle will follow a preprogrammed mission script 

stored in the autopilot, including

autonomously navigated 

waypoints, commands, and 

events. 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 61

Appendix B - Maintenance Schedule Matrix 

Table 16 FIRE SPRITE Maintenance Schedule

FIRE SPRITE Inspection and Maintenance Schedule

Service 

 Interval 

Before 

Every 

Flight 

As Needed 150 hours 

Propellers 

Inspect for damage

X 

Electronic 

Speed 

Controllers

X 

Motors Inspect for

wear & FOD 

X 

Inspect fasteners 

and structure

X 

Propellers 

Replace

X 

Motors 

Replace

X 

Servos Inspect X X 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 62

Appendix C – Preflight Briefing Guidelines 

Airspace Coordination 

Contact all applicable air-authorities and notify them of your intentions. This should include 

date and times of flight, altitudes and airspace. 

Flight Objectives 

• Aircraft and sensor(s) ................Cover aircraft/ sensor specifics, limitations 

• Flight Profile .................... Altitude, Range, Endurance, LOS/ RF concerns 

• Risk Mitigation ......... Loss Comms plan, Battery failsafe/ Voltage, crew rest 

• Flight Crew ...........................................Identify AVO, EP and back up pilots 

• Ancillary personnel.... Identify observers, communications and safety officers 

Safety Items 

• Environmental ...... Conditions within operational limits and favorable forecast 

• Takeoff and launch area.......Identity vertical obstructions and LOS concerns 

• Non-Essential Personnel ............................................. Clear from launch area 

• Propellers ................. Personnel must stay out of the arch and standoff 20 ft. 

• Other hazards.................... Wildlife, sun/ heat, tripping hazards, food – water 

• PPE ..................................... Personnel will don safety glasses, hardhats, etc. 

• Fire extinguisher ..Manned in the event of a downed aircraft or charging hazards 

Non-Normal Flight Procedures 

Ensure that all flight crewmembers are familiar with the procedures and rehearse possible 

situations. 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 63

                                             WARNING

                                                 CAUTION  

Preflight Procedures 

Failure to follow the directions prescribed in this checklist can lead 

to loss of aircraft and/ or injury to personnel and property. 

The Non-Normal flight procedures should be committed to memory 

to ensure proper execution of a procedure in the case of an in-flight 

emergency. 

Ground Station Assembly 

 Laptop/ Tablet.................................................................................. Power On 

 Battery life/ Power Source/ Back up Power Source Adequate for operations with 

safety margin 

 Telemetry Radio .....Connect to ground station and orient antenna vertically 

 Mission Planner ................................................................................... Start 

Remote Video Terminal (RVT) Assembly 

 Video Display.......................................................................Setup and secure 

 Video Receiver ......................................................Setup and install antennas 

 Monitor/ Receiver Power Source ........... Connect power source to power ON 

 Mount/ Secure Monitor/ Receiver............Connect power source to power ON 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 64

Aircraft Assembly 

 Airframe and structural connections .................................................... Inspect 

 Propellers......................................Inspect for damage and fastener tightness 

 Motors ........................................... Inspect function, fasteners and clear FOD 

 Payload ............................................................................ Inspect functionality 

 Aircraft Power Source ........................... Install Batteries/ Ensure secureness 

Radio Control Transmitter Setup 

 Inspect Radio .................Check that all gimbals and switches are operational 

 Power On ... Ensure battery life is adequate for operations with safety margin 

 Model Selection ........................................... Ensure proper model is selected 

 Throttle Stick ................................................................. Set to lowest position 

 Switches ............................................................................................ All away 

Aircraft Preflight 

 Aircraft Propellers .......................................... Clear all objects and personnel 

 Aircraft ................................................. Connect battery to aircraft main power 

 Mission Planner ..................................................................Select Com Port # 

 Mission Planner ........................................................ Select Baud Rate 57600 

 Mission Planner ........................ Press Connect to establish communications 

 Communications ............................................................. RSSI value is > 90% 

 Battery Level .....................................Greater than 16.8 volts / 100% capacity 

 Flight Mode ................................................................Confirm Stabilize in MP 

 HUD Aircraft attitude/ heading ............. Check pitch, roll movement matches in the 

HUD 

 GPS ............................... 3D Fix displayed in HUD / > 5 satellites and < 2.5 HDOP 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 65

Flight Plan Building 

 Planner Window..................................................................................... Select 

 Home Location Link ........................... Select Home Position link to move map to 

aircraft’s current position 

 Clear Mission......................................................... Select – Write WPs Default 

 Alt ...............................................................Set desired altitude for waypoints 

 Waypoints and Command Points ....................................... Add as necessary 

 Takeoff and Land WPs .................................... Ensure that the TO and Land WPs are 

higher than the tallest vertical objects 

 Waypoints ..........................................................Write WPs 

 Mission Planner ..............................................Close Flight Planner window 

Aircraft Launch 

 Wind Direction ................................................ Confirm appropriate for launch 

 Aircraft ........................................ Battery, GPS, RSSI all within specifications 

 Flight Mode ......................................................Stabilize / Confirm in MP HUD 

 Payload ..............................................................Power and confirm operation 

 Navigation Lights .............................................................................. Power On 

 Arming Safety Switch............................................. Disarm – Clear personnel 

 Payload ................................................................................... Start recording 

 Aircraft ........................ EP - Arm with Transmitter 

 AVO confirm ARMED in HUD 

 Mission Planner .................Select Auto – Confirm in HUD - 0>1 - Announce to EP R/C 

transmitter 

 .Increase throttle to Mid-stick position to launch aircraft 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 66

Normal Flight Procedures 

 External Pilot and Observers ...... Maintain visual line of sight with the aircraft 

 AVO ................................................ Monitor WP tracking and aircraft Altitude 

 Battery Health ........................................................................ >15.0 volts 

 GPS ....................... 3D Fix displayed in HUD / > 5 satellites and < 2.5 HDOP 

 Communications .........................AVO and EP will relay pertinent information 

Non-Normal Flight Procedures / Aviate - Navigate - Communications 

 Battery ......................................................Voltage < 14.8 = RTL immediately 

 GCS Loss Comm ............. Monitor aircraft flight path and RSSI in HUD RCTx 

 Loss Comm. ...............................Monitor aircraft RTL + Mid. throttle position 

 EKF Variance........................... Stabilize flight mode and/or flight termination 

 Bad GPS........................................ Stabilize flight mode and land in safe area 

 Uncontrolled Flight........................... Stabilize flight mode + flight termination 

Aircraft Recovery and Disassembly 

 Aircraft .................................................................................... Command RTL 

 End of flight .............. Monitor aircraft through the autonomous landing phase 

 Aircraft touchdown ......Ensure the aircraft disarms by lowering throttle to Min 

 Arming Safety Switch............................................. Arm (ensure blinking light) 

 Payload and Light Switch ................................................................. Turn OFF 

 craft Battery ............................................................................... Disconnect 
AcuTech Fire Sprite OPERATIONS MAN. – REV. A 67

Notes