ATTACHMENT 9 
AFM 1‐3

Lynx UAS

Aircraft Flight Manual

   
AFM 1‐3

Record of Revisions

AFM 1‐1 14 April 2013

AFM 1‐2 27 July 2013

AFM 1‐3 20 July 2014
AFM 1‐3

Table of Contents

General Information and System Description..........................................1

Performance and System Limitations......................................................4

Normal Procedures ..................................................................................5

Emergency Procedures ..........................................................................21

Field Repair Instructions ........................................................................27

   
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Section 1: General Information and

System Description

Introduction

Lynx is an Unmanned Aerial System (UAS) primarily used for aerial imagery collection. It is

made from durable foam and Kevlar to withstand field use and hard landings. Lynx consists

of six main parts:

 3 Wing Sections

 1 Fuselage

 1 Stabilator

 1 Payload Module

 1 Autopilot Module

Lynx is hand‐launched and can be recovered using either a belly landing or near‐vertical

deep‐stall. To minimize damage from a deep‐stall, the wings and stabilator are designed to

separate from the fuselage. In extraordinary landings, certain parts are designed to break.

Spares of these parts, as well as the tools to replace them, are included in the field

maintenance kit.  

Lynx can be assembled without tools and launched in minutes from unprepared terrain. The

self‐stabilizing airframe and roll‐stabilized camera payload provide consistent imagery

collection. It is equipped with a high‐resolution digital camera for creating orthorectified

photomaps. Flight endurance is 90 minutes on a rechargeable Lithium‐Polymer (LiPo)

battery pack.

Lynx should be operated by a two person crew: a Safety Pilot (SP) and Aircraft Operator

(AO).  

   
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Aircraft

Airframe

Lynx UAS is constructed from durable Kevlar over various foams and reinforced with

embedded carbon fiber supports. The main airframe components are assembled

without tools. Most subcomponents can be replaced in the field using basic tools, which

are supplied in the field repair kit. Repair procedures are detailed in Section 5, Field

Repair Instructions.  

Flight Control Surfaces

Lynx uses two control surfaces: a rudder and stabilator. The Rudder is a vertical control

surface used to roll the airframe left and right in order to turn the aircraft to a desired

heading. The stabilator is used to pitch the airframe up and down in order to climb or

descend to a desired altitude. The stabilator is also used to deep‐stall the airframe for

near‐vertical landings. Deep‐stall is achieved by deflecting the stabilator approximately

45 degrees up.  

Propulsion System

The propulsion system consists of an electric motor (brushless, maintenance‐free), the

electronic speed controller (ESC), spinner and propeller. The propeller folds back to

prevent damage upon landing and for transport. Lynx flies for 90 minutes using a high

density, rechargeable LiPo battery.    The battery pack consists of 12 cells wired in a 6

series/2 parallel configuration (6S2P). The result is an 11,000 milliampere‐hour (mAh) 6

cell battery.  Operating voltage is 19.8 to 25.2 volts.

Avionics

Lynx is controlled by direct manual Safety Pilot (SP) controls or by Aircraft Operator (AO)

commands to an onboard autopilot.  

Guidance Navigation Control

Lynx is controlled by the Ardupilot 2.6 autopilot. The autopilot stabilizes the airframe

and navigates it to defined three‐dimensional waypoints. It consists of an Inertial

Measurement Unit (IMU), Global Positioning System (GPS), three‐axis magnetometer,

airspeed sensor, and pressure sensitive altimeter.  

Communications Equipment

Lynx utilizes two command and control (C2) frequencies. Safety Pilot (manual) controls

are transmitted with a Spektrum DX7s handheld transmitter on the 2.4 GHz band. The
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Aircraft Operator utilizes a two‐way data radio on 915 MHz to upload flight plans to the

Air Vehicle (AV), monitor AV position and health, and configure the flight control system

settings.  

Information Displays

The Ground Control Station (GCS) is the Aircraft Operator’s interface to the air vehicle.

Using the GCS, the AO configures the aircraft for flight, creates and uploads flight plans

to the AV, and monitors AV position and health.  

User Interfaces

The GCS software shall be installed on a laptop or desktop computer running Windows.

The software, APM Mission Planner, is open‐source and is available for free download at

planner.ardupilot.com.  

   
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Section 2: Performance and System

Limitations

Propulsion Electric

Wing Span 8.25 Ft.

Empty Weight   8.3 Lbs.

Maximum Gross Takeoff Weight 10.3 Lbs.

Payload Bay Dimensions 8.25” x 4” x4.75”

Stall Speed 9 m/s

Cruise Speed 16‐18 m/s

Never Exceed Speed (VNE) 22 m/s

Endurance 90 minutes (with mapping payload)

Range 1 Mile (approx.)

Takeoff Hand launch

Landing Belly land or deep‐stall

Low Battery Voltage 19.8 volts (3.3v per cell)

ESC Cutoff Voltage 18.0 volts (3.0v per cell)

Battery Charge Limit 1C

Battery Discharge Limit 3C continuous, 6C burst (<15 seconds)

Wind Limitation 15 Knots continuous, gusting to 25  

Prohibited Maneuvers  Takeoff or landing with any tailwind

 Flight into known icing conditions

 Flight into visible moisture

 Flight beyond Safety Pilot’s visual line‐of‐

sight (LOS)

   
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Section 3: Normal Procedures

This is an expanded explanation of the procedures outlined in the Operator’s and

Crewmember’s Checklist, CL 1‐3. This manual is intended to be used for training

purposes, and the abbreviated checklist is to be used during flight operations.  

The lines of the Operator’s and Crewmember’s Checklist follow a standard format: Item‐

Action. It first states the object to be checked, then the action that is taken to ensure it

is in the correct condition.  

The preflight takes place in three phases:

1. Air Vehicle (AV) Inspection‐ Hands‐on inspection of the aircraft components.

2. GCS Preflight Checks‐ Checks and configuration of the autopilot.

3. Systems Checks‐ Physical tests of the AV’s responses to GCS commands.

With experience, sections 1 and 2 may be performed concurrently by two personnel,

and section 3 is performed by both personnel working together.  

Preflight Section 1: Aircraft Inspection

Publications

1. Checklist ‐ Verify

Always ensure the checklist is the correct version, and appropriate to the

equipment being used.  

GCS Power Up

1. Laptop ‐ Turn On and Connect Power

Turn the laptop being used as the GCS on. Ensure that there is sufficient battery

power remaining for the mission. If possible, connect the GCS computer to a

power source and ensure that it is charging.  

Note: While the GCS computer is necessary for pre‐flight checks, the computer

may be shut down during flight in mapping missions to conserve battery power.  

2. Telemetry Radio ‐ Attach
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Ensure the 2.4 GHz antenna is securely attached to the 3DR telemetry module.

Connect a Micro USB cable to the 3DR power module and plug the cable into the

GCS computer. Observe the green indicator light‐ flashing green indicates there

is no compatible 3DR telemetry module in range. A solid green light indicates

there is a compatible 3DR telemetry module in range.  

Caution: Powering on the 3DR telemetry module with no antenna attached may

result in equipment damage and/or malfunction.

3. Mission Planner ‐ Start

Ensure Mission Planner is installed, and start the program.  

AV Preflight Inspections

1. Battery – Inspect/Check and Install

Inspect the battery’s protective heat shrink for any cuts, punctures, or gashes

that expose individual cells. Do not fly a battery with exposed cells. Check the

level of the battery using the handheld battery tester. Pack voltage should be

between 24.6 and 25.2 volts when full. Using the Cell button, check the voltage

of all six cells. A battery may be flown until voltage per cell has reached 3.3 volts,

at which point the AV should be landed immediately. If the difference between

any two cells is greater than 0.1 volts, place the battery on the charger and run

the balance function. Do not fly the battery until it is properly balanced. Typical

spreads of a charged and balanced battery are less than 0.05 volts.  

Note: The battery percentage indicator on the handheld battery tester is not

indicative of actual battery levels. Refer only to voltages.

2. Battery Connector ‐ Inspect

Visually check the condition of the battery’s connector and the power connector

in the aircraft. Inspect for damaged/cracked housing, damaged pins or sockets,

and exposed/frayed wiring. If any part of the connector shows any damage as

described do not fly the system until the damaged component has been

repaired/replaced.

3. Fuselage ‐ Inspect

Visually check the surface of the fuselage, looking for abrasions, cracks, or stress

concentrations. The Kevlar surface will show early signs of wear in the form of a

wrinkle, accompanied by light‐colored discoloration.   
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4. Skid Pads ‐ Inspect

Ensure both pads are adhered to the fuselage. Visually check for any major rips,

dents, or missing pieces of foam. Normal wear and tear can be patched with

gaffer’s tape. A pad will remain useable until large pieces of foam are missing.

5. Propellers and Motor ‐ Serviceable

Inspect the propeller assembly. Check each propeller blade for chips and cracks,

and ensure they are tightly mounted to the propeller hub. If the propeller blade

moves fore and aft freely without resistance, tighten the mounting bolt until

resistance is felt. The propeller blade should still be movable, such that on

landing it can fold back, but fairly stiff to hold its position otherwise. Inspect the

mounting hub and plastic cover (spinner) for cracks or deformations. Ensure the

entire propeller assembly spins freely with no obstructions seen, felt, or heard.

Grasp the spinner and ensure that the propeller assembly and motor are rigidly

mounted to the aircraft and that the propeller hub is not scraping the fuselage. If

the hub is scraping, ensure that the motor bulkhead is not pushed back and/or

adjust the location of the propeller hub on the motor’s shaft. Inspect the motor

and bulkhead screws for security.

6. Stabilator ‐ Inspect and attach

Inspect the stabilator surface for cracks and deformations. Check the tail clips for

cracks and deformations. Stress concentrations will appear as white lines, which

over time may turn into cracks. Ensure the tail clips are rigidly mounted to the

stabilator. Inspect the stabilator mounting hardware on the fuselage. Check that

the mount points on the fuselage are present and secure, and the carbon fiber

stabilator arm is in serviceable condition. If the arm is bent or broken, replace it

(see section 5). With the labeled side facing upward, slide the stabilator onto the

end of the fuselage until the detent on the tail clip is felt.  

7. Pitot Tube ‐ Inspect and Attach

Insert the pitot tube into its clip on top of the vertical tail. Ensure that the hoses

between the pitot tube and airspeed sensor are securely attached and free of

kinks. The central tube, which measures ram air, connects to the sensor on the

port farthest from the circuit board. The outer tube, which measures static air,

connects to the sensor on the port nearest the circuit board.  

8. Rudder ‐ Inspect

Inspect the vertical stabilizer surface for condition, looking for any deformations.

Inspect the rudder for freedom of movement. Ensure the Kevlar hinge on the

rudder is intact.  
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9. Servos ‐ Check Attachment and Linkages

Move each servo through its normal range of movement, feeling for any

obstruction to movement. The gearing of the servo will normally provide light,

steady resistance to movement. Any abrupt resistance to movement requires

further inspection, as this may be indicative of a broken tooth in the servo.  

Caution: Flying with a possibly broken servo may result in aircraft failure/loss.

10. Wing Bolts ‐ Present and Spaced

Check that all four wing bolts are installed. Set the correct gap using the supplied

socket and spacing tool.  

11. Wings ‐ Assemble and Inspect  

Inspect the surfaces of the wings for condition, looking for cracks, deformation,

or wrinkles (some wrinkling is normal on the center wing after extended use).

Inspect the four carbon fiber spar joiners (“wishbones) for breaks and

delamination. Insert the wishbones into the center wing spars, angled up. Attach

the outboard wings to the center wing by sliding the wishbones into the

outboard wing spars. Ensure the wings’ leading and trailing edges are aligned by

adjusting the wishbones. Secure the outboard wings to the center wing using

gaffer’s tape (approx. 9 inches each wing). Set the wings aside.  

Caution: On windy days, secure the wings so that they cannot blow away. Failure

to do so may result in wing damage.  

Note: The wings and stabilator are constructed from relatively soft foam that

may dent if pinched or pressed into.

Preflight Checks

1. DX7s Transmitter ‐ On

Turn on the transmitter. Ensure that the model selected is correct (1: Lynx). If

the model is incorrect, power off the transmitter. Hold the menu button and

power on the transmitter to enter the sub‐menu. Scroll to Model Select, select

the correct model, and press back twice.  

2. Throttle Safety Key ‐ Attach

Ensure the throttle safety key is inserted fully.

Warning: Failure to fully insert the throttle safety key may result in inadvertent

propeller startups, which can cause equipment damage and/or personnel injury.
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The throttle safety key is intended as a secondary safety device. It is not

intended to replace safe practices or careful handling of your Lynx UAS.

3. AV Battery ‐ Connect

Ensure all personnel are clear of the propeller. Supply power to the air vehicle

(AV) by connecting the battery. Make sure the connector is fully seated. The

motor should emit a tone, followed by six short beeps (1 for each battery cell). If

no tones are heard, check the wires connected to the motor, located under the

battery. Secure the battery and connector with the Velcro strap. Install the

battery door with the pull‐tab facing the rear.  

4. Flight Surfaces ‐ Check Movement

Directly after the battery is connected, move the right stick on the transmitter to

test flight surface movement.  

Caution: If the servos do not respond to manual inputs, the aircraft may enter

Return to Launch (RTL) mode. In RTL, the autopilot may command the propeller

to spin. If the throttle safety key is not inserted, the propeller may rotate,

causing equipment damage and/or personnel injury.  

5. New Field ‐ Range Check/ Magnetometer Calibration

When operating at a field for the first time, it is recommended to perform a

radio control range check to identify unknown sources of interference. On the

DX7s transmitter, press the menu button and scroll down to Range Check. The

radio screen will give instructions to press and hold the black trainer button to

check the range. Walk 30 meters (30 paces) away while maintaining line‐of‐sight

with the aircraft. At this distance, control should be maintained. If control is lost,

check for external sources of electromagnetic interference, such as nearby

transmission equipment or power lines.  

When operating in a new geographic location, it is important to perform a

magnetometer calibration to ensure correct navigation. Go to the Initial Setup

tab, expand the Mandatory Hardware tab on the left, and open the

Magnetometer menu. Click Live Calibration to begin the calibration process.

Rotate the plane about all axes, and observe the on‐screen display. The display

portrays a sphere of points. The sphere should be completely and evenly

covered with data points. It is recommended to collect at least 1,000 data points,

as indicated on the screen. Click the Complete button when done. Observe the

heading indications on the Flight Data Screen to ensure the indicated heading is

correct.  
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Preflight section 2: GCS Checks

Section 2 involves configuring the autopilot. To the greatest extent possible, the

checklist moves through the GCS menus top to bottom, left to right. This permits the

use of “flows,” or logical, memorized progressions through the menus. Experienced

operators use flows to perform short series of steps from memory, then consult the

checklist to make sure none of the steps were missed.

Note: checklist lines in bold indicate when to switch to a different Mission Planner tab.

Flight Data Screen

6. Mission Planner ‐ Connect

Check the 3DR telemetry radio and ensure that the green light is solid, indicating

that it is communicating with the AV. In the top right corner of Mission Planner,

set the correct COM port for the 3DR telemetry radio*, set the baud rate to

57600, and click connect. The dialog box in the middle of the screen should

display parameters, then the box will disappear.  

*The COM port for the 3DR radio can be determined by expanding the COM port

list, detaching and re‐attaching the radio. The COM # will be added to the list

when the radio is attached. Alternately, search for the 3DR radio in the Device

Manager of Windows.  

7. HUD ‐ Verify Level and Responsive

Verify that the Heads‐Up Display (HUD) is showing the current orientation of the

airframe. Tilt the aircraft to verify that the HUD is responsive, indicating that link

is established.  

Initial Setup Screen

8. Compass‐ Enable, Check Declination and Rotation (ROLL 180)

On the Initial Setup tab, expand the Mandatory Equipment tab on the left. Select

the Compass tab. Ensure the Enable box is checked. If the Auto Declination box is

checked, ensure that the declination is correct for your geographical region. If

not, uncheck the Auto Dec box and manually set the compass declination.

Rotation should be set to ROLL_180. If not, select the button for “External

Compass” and ROLL_180 should be set automatically.  
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9. Flight Modes‐ Set

Open the Flight Modes tab on the left. Ensure that the flight modes are correctly

set. Flight mode 1 should be set to RTL, and mode 4 should be set to Auto. If any

changes are made, Press the Save Changes button.  

10. Failsafe‐ Disabled

Open the Failsafe tab on the left. Ensure that all failsafe modes are disabled (all

boxes unchecked).  

11. Airspeed‐Enable and Use

Expand the Optional Equipment tab and select the Airspeed tab. Check the two

boxes labeled “Airspeed Enable” and “Airspeed Use.”

Config Tab

12. PIDs ‐ Check Correct  

Open the Basic Tuning tab on the left. Perform a brief check of the PID values to

ensure they are correct.  

13. Nav Angles ‐ Check Correct

Observe the values under the Nav Angles heading. Factory limits are Roll: 45,

Pitch: +20, ‐15.  
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14. Throttle Settings ‐ Check Correct

Check the values under the Throttle heading. Factory settings are Min: 0, Max:

75, Cruise: 50.  

15. Airspeed Settings ‐ Check Correct

Check the values under the Airspeed setting. Cruise can be set to 16‐18 meters

per second. 16 will result in higher endurance, 18 will result in faster ground

coverage and better wind performance. Factory settings for Fly by Wire (FBW):

Min‐ 11, Max‐ 22.  

16. Planner ‐ Correct Units

Open the Planner tab on the left. Check the distance units and speed units.

When Mission Planner is first downloaded, these will be set to Meters and MS.

Change as desired.

Caution: If units are not set correctly, AV could climb or descend to an altitude

other than desired, possibly resulting in loss of visual contact with the AV or

flight into terrain. Check the Mission Planner units every flight.

Flight Planning Screen

17. Default Altitude ‐ Set

Expand the green waypoint bar at the bottom of the flight planning screen. Type

the default altitude for the flight in the default altitude window. 300‐400 feet is

recommended.  

18. Loiter and Waypoint Radius ‐ Set

Type the desired loiter radius in the loiter radius window. This is the turning

radius used while loitering in Guided Mode, and when the plane returns to

launch (RTL Mode).  

19. Mission ‐ Create/Load  

Create a mission and press Write WPs. Even if no flight plan is required, it is

necessary to load a mission to fully test the autopilot’s functionality.  

Caution: Creating/Loading a mission in the preflight overwrites any previous

missions. Failure to create/load a mission in the preflight could cause the AV to

navigate to the mission area of a prior flight, possibly causing an inadvertent fly‐
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away and subsequent RTL.  

Flight Data Screen

20. Flight Plan Waypoints ‐ Verify

Go to the Flight Data tab, and confirm that the mission that was just created

appears on the map display. This is a confirmation that the mission was

successfully loaded to the AV.  

Preflight Section 3: Systems Checks

The final section of the preflight involves physical checks of the AV’s systems to physical

stimuli. These checks involve two crewmembers‐ the Aircraft Operator on the GCS, and

the Safety Pilot holding or moving the aircraft. With experience, these steps can be

performed from memory, but always consult the checklist afterward to ensure that no

steps were missed.  

1. Flight Surface Checks ‐ Perform

Using the transmitter, move the flight surfaces to their limits. Announce the

control surface being moved and the direction being commanded‐  “Pitch Up,

Pitch Down, Roll Right, Roll Left.” Both AO and SP should watch the flight

surfaces and confirm correct movement. Engage the deep‐stall switch and

ensure that the stabilator deflects 45 degrees up.  

2. IMU Test ‐ Perform

For the Inertial Measurement Unit (IMU) Test, change the autopilot mode to

FBWA, then; deflect the mode switch on the transmitter to auto. Hold the AV,

and test the flight surfaces’ response to rotations in all three axes: pitch, roll, and

yaw. The flight surfaces should oppose the movement in each direction. I.e.,

when the plane is pointed down, the stabilator should command the plane to

pitch up. The rudder should oppose both roll and yaw movements.  

3. Auto Check ‐ Perform

On the GCS Flight Data screen, under the Actions tab, select the Auto button. In

the lower right corner of the HUD, check that the flight mode changes to Auto,
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and the AV is headed to waypoint 1 (## > 1, i.e. 1280 > 1). Then, verify that the

yellow line on the map is pointed towards waypoint 1.  

4. Return Home Check ‐ Perform

Hold the AV firmly in a safe direction and ensure the throttle safety key is

inserted. Turn off the transmitter, and confirm that the autopilot mode changes

to RTL. Check the distance to the RTL point in the lower right corner of the

Heads‐Up Display (HUD). It reads ##>0, i.e. 16>0, where 16 is the distance and 0

is the RTL point. The RTL point should be near where the AV was powered on. If

not, cycle power to the AV.  

5. Propeller‐ Extended and Clear

Ensure that propeller blades are extended and the propeller arc is clear.  

6. Full Throttle Check ‐ Perform

Hold the AV firmly, pointed in a safe direction and into the wind (if applicable).

Remove the throttle safety key, and listen for the throttle arming tone. Using the

transmitter, smoothly advance the throttle to full. Hold full throttle for one to

two seconds, then reduce throttle to off. Replace the throttle key. Advance the

throttle to mid to ensure that the motor does not spin.   

Warning: Rotating propellers can cause serious injury or death. Keep body parts

clear of the propeller arc. Stay out of danger zones which include directly in front

of the AV, and to the right and left of the propeller.  

Caution: If excessive vibration is felt or excessive noise is heard during the full

throttle check, reduce the throttle IMMEDIATELY and check for the cause.

Excessive vibration can be destructive to the airframe and power components.

Ensure that all motor and propeller hardware is tightened, and the AV is facing

into the wind (performing the full throttle check with a tailwind may cause the

propeller to stall, resulting in noise and possibly destructive vibration).

7. Magnetometer ‐ Correct and Responsive

Using known landmarks on the GCS map, determine that the displayed heading

is correct. Turn the AV in a series of four 90 degree turns, ensuring that the

displayed AV heading on the GCS map is correct and responsive. If heading is

incorrect or unresponsive, check magnetometer settings and declination, and/or

perform a magnetometer calibration.  

8. Preflight Calibration ‐ Perform
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While shielding the pitot tube from any wind, perform a preflight calibration on

the GCS. Preflight calibration may be found on the Flight Data Tab, under the

Actions tab, in the first pull‐down box. Select PREFLIGHT CALIBRATION, then

press the Do Action button beside it. Wait two seconds, and ensure the altitude

and airspeed zeroize.  

Note: If launch becomes delayed, it may be necessary to perform another

preflight calibration before takeoff. Changes in weather will cause the altitude

and airspeed to drift.  

Caution: Do not perform a preflight calibration in flight. Doing so will cause the

AV to climb and increase speed, possibly resulting in AV damage/loss.  

9. Airspeed Test ‐ Perform

To ensure the airspeed sensor is functioning, blow over the pitot tube and

observe the airspeed increasing on the GCS screen. Speeds greater than 12 m/s

should be observed.

10. Payload Checks ‐ Perform

Perform all necessary checks to ensure that the payload is mission‐ready. For

mapping missions, ensure that the camera mount is stabilizing and stowing

properly. Ensure that the camera has sufficient battery power and memory

space. Check that the camera is rigidly mounted. If a data logging board is in use,

check that it is functioning properly. Make sure that the camera is taking

properly exposed and focused photographs. Check that the lens is clean. Replace

the lens cover until just before launch to prevent smudges or damage to the

lens.  

11. Wings ‐ Attach

Place the wings on top of the fuselage. Align the label on the center wing to the

fuselage and slide the wings to the rear until they are fully seated.

Note: The center wing should slide onto the fuselage with little resistance to

ensure separation upon a deep‐stall impact.

AV Launch  

The AV Launch Checklist is a final verification of critical systems, and a systematic

procedure for safely launching the aircraft.  

1. Payload ‐ Ready for Takeoff  
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Determine that the payload is mission‐ready.

2. Data Links ‐ Verify

Confirm that both data links (manual control and telemetry) are functioning.

3. Wind ‐ Check

Confirm that wind is within limitations, and observe the wind direction. Launch

will be performed into the wind.  

4. Final Walkaround ‐ Complete (SP)

The Safety Pilot, who is the Pilot in Command (PIC), will perform a final visual

inspection of the AV.  

5. RBFI ‐ Remove

“Remove Before Flight Items” (RBFI) shall be removed. These normally consist of

the throttle safety key and lens cover.  

6. Mode ‐ Manual (SP)

The Safety Pilot will ensure that the autopilot select switch is set to Manual

(pulled towards the pilot).  

7. Timer ‐ Start (SP)

Start the flight timer by pressing the black button on the top‐left of the

transmitter. Any alternate time recording device may be used.

8. Launch Area ‐ Clear

Visually determine that the desired launch area is appropriate and safe for the

launch, and that the area is clear.  

9. Prop – Extended and Clear

Ensure that the propeller blades are extended, and the propeller arc is clear.

10. Ready For Takeoff ‐ Announce (SP)

11. Ready For Takeoff ‐ Confirm (Thrower)

This is a challenge‐response between the Safety Pilot and the crewmember

throwing the AV. No other phraseology should be used so that no

miscommunication can occur.  

12. Full Throttle ‐ Verify
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The safety pilot will smoothly advance the throttle to full, and ensure that AV full

throttle is observed and heard.  

13. AV ‐ Launch Into Wind

Grasp the AV at the bottom of the tail, and support the front of the fuselage with

the other hand. With the AV pointed horizontal or slightly up, throw the AV with

the rear hand like a javelin. Concentrate on throwing the AV as straight as

possible, with no movement to the right or left. Form is more important than

strength.  

Note: If the AV is inadvertently thrown into an unusual attitude or stall, the

Safety Pilot must quickly make a go/no‐go decision. The Safety Pilot must either

attempt to recover from the unusual attitude and climb out, or reduce power

and land. Experience will dictate which course of action is more favorable.

Replaceable parts, such as wing bolts and tail clips, are designed to fail on impact

and can possibly prevent airframe damage in this scenario.  

AV Recovery

Lynx should be landed after 90 minutes of flight or until battery voltage as dropped to

3.3 volts per cell, whichever comes first. The ESC will momentarily cut power to the

motor whenever cell voltage drops below 3.0 to protect the battery. Use of full throttle

at voltages lower than 3.3 volts per cell, such as in a go‐around or wave‐off situation,

may result in a temporary loss of power due to voltage sag triggering the ESC cutoff.

1. Weather/Winds ‐ Verify

Check the wind direction and speed.

2. Mode ‐ Manual

Pull the autopilot switch on the transmitter towards the pilot for Manual mode.  

3. Recovery Site ‐ Select (SP)

Choose a suitable site for recovery. If utilizing deep‐stall, only a small space (≥ 50

ft diameter) is needed. Select a site with long grass or foliage if possible, as this

will cushion the deep‐stall landing and lengthen the life of the airframe. The

angle at which the plane will deep‐stall down is dependent on the wind. A strong

headwind will result in a near‐vertical deep‐stall. No headwind will result in

about a 45 degree glide slope.  

If a traditional belly landing is to be used, utilize a large (≥ 300 ft. long) field, free

of obstacles on the approach side. The approach angle of the plane will be very

shallow (~ 3 degrees).  
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4. Recovery Site Clear ‐ Verify (Observer)

Ensure that the recovery site and the approach path are clear of obstacles and

personnel.  

Deep Stall Recovery

5. AV Altitude ‐ >100 ft  Above Ground Level (AGL)

For successful deep‐stall recovery, engage the stall at above 100 ft AGL. This will

ensure the AV is in a level flight attitude by the time it reaches the ground. It also

gives the Safety Pilot time to abort the deep‐stall if necessary.  

6. Heading ‐ Into Wind

Align the AV into the wind and approach the landing site.  

7. Throttle ‐ Off

Just before engaging deep‐stall, reduce throttle to off.  

Note: Throttle is programmed to automatically turn off during deep‐stall,

however it is prudent to also manually reduce the throttle.  

8. Deep Stall ‐ Engage (SP)

Remove the safety cover, if installed, and deflect the deep‐stall switch to engage.  

9. Heading Into Wind ‐ Maintain

Ensure the aircraft’s heading remains into the wind by steering the AV with large

deflections of the rudder. Typically the aircraft will weathervane into the wind

and little pilot input is required.

10. Timer‐ Stop (SP)

Manual Landing

5. Manually Land AV‐ Into Wind

To perform a manual landing, navigate the AV about 1,000 ft away downwind

from the landing area, reduce throttle to zero, and circle to descend. When the

AV reaches about 150 ft AGL, turn towards the landing area. Hold the pitch level,

and allow the AV to descend. If the AV overshoots the desired landing area,

either continue the landing descent (if obstacles permit), or climb to a safe

altitude and reattempt the landing.
AFM 1‐3

19

Caution: Landings that result in Lynx resting out of sight of the Safety Pilot may

cause the aircraft to enter RTL due to ground interfere with the 2.4 GHz manual

control link.

6. Timer‐ Stop (SP)

Stop the flight timer by pressing the black button on top of the transmitter.

Record the flight time displayed on the screen.

Deep Stall Abort

1. Deep Stall – Disengage (SP)

Deflect the deep‐stall switch so as to disengage the deep stall. If safety cover is

installed, push the cover down to disengage.  

2. AV – Climb Gently (SP)

Increase the pitch attitude to initiate a go‐around.

3. Power – Apply (SP)

Increase throttle as needed.

Caution: Aborting a deep stall is not recommended below 100 ft AGL.

Disengaging the deep‐stall will cause the AV to pitch down suddenly.  

Post Flight

1. AV Battery ‐ Check/Disconnect

Using the handheld battery tester, check the voltage of the battery. Pack voltage

should be at least 19.8 volts. Check each individual cell by pressing the cell

button repeatedly. Each cell should be greater than 3.3 volts. If an individual cell

shows greater than 0.1 volt difference from the rest, there may be a problem

with that cell. Monitor the battery closely post‐flight and feel for any heat that

continues to originate from the battery (the pack will be warm after normal use).  

Warning: LiPo batteries are flammable and can ignite without external sources of

ignition. If the Lithium battery feels hot post‐flight, place the battery in a safe

location away from flammables.  

Note: Discharging a LiPo battery below 3.0 volts per cell may cause permanent

battery capacity loss and physical deformation (swollen, puffy, etc.)

Note: Storing LiPo batteries at high capacity or in high temperatures for long

durations can result in permanent battery capacity loss and physical deformation
AFM 1‐3

20

(swollen, puffy, etc.). Store batteries at half capacity or approximately 3.7v per

cell.  

2. Transmitter ‐ Off

When the AV battery is disconnected, the transmitter may be powered off.  

3. AV ‐ Disassemble/Inspect

While disassembling the AV, be sure to inspect all the parts, looking for damage.

Carefully remove the gaffer’s tape from the wings, and remove the outboard

wings from the center wing. Ensure that all four wishbones are accounted for

and place them in the spares kit. If applicable, remove the center wing by placing

your hand atop the surface (palm down, fingers spread); apply light pressure and

slide it forward. Remove the stabilator by pulling it to the rear. Deflect the

stabilator arm upward for transport. Pull the pitot tube out of its clip, leaving it

attached by its tubing. Place all AV components in the large case. Avoid kinking

the airspeed tubing.

4. GCS Applications ‐ Close

Close the Mission Planner and any other software running on the GCS computer.  

5. GCS ‐ Power Down/Stow

Command the GCS to shut down or sleep, disconnect power, and stow the GCS

for transport.  

   
AFM 1‐3

21

Section 4: Emergency Procedures

The following section details the likely best course of action to take in the event of some

emergencies. Not all emergencies can be planned for, and the situation will always

dictate the best course of action. You, as the operator, must think quickly during an

emergency to make the right decision(s). Your first priority in an emergency is to protect

human life‐ both that of your crew, and that of the public. Your second priority is to

minimize damage to equipment and property.

In the following emergency procedures, the lines that are underlined are “immediate

action items,” and should be performed from memory. In any emergency situation,

while one operator is performing the immediate action items, the other operator should

turn to the appropriate page in the checklist. Using the checklist, confirm that the

immediate action items were performed correctly, and see if there are any additional

steps.  

Motor Failure Below 100 feet AGL

1. Control‐ Manual (SP)

Deflect the autopilot switch on the transmitter to manual and take control of the

aircraft. The flight surfaces should be operational, but no throttle will be

available.  

2. Safe Heading‐ Establish (SP)

Descent to a desired landing spot will not be possible, so attempt to point the AV

in a safe direction.  

3. Deep Stall‐ Engage (SP)

Remove the safety cover, if applicable, and engage the deep stall switch.  

4. AV‐ Recover (ALL)

All crewmembers should go to recover the AV. If there are bystanders, attempt

to keep them away from the AV. Insert the throttle safety key as soon as

possible. If possible, disconnect the AV battery.  

Warning: If a LiPo battery is punctured or ruptured, use extreme caution in

handling. Exposed Lithium may catch fire without external sources of ignition.

Keep away from flammable materials. If the battery is in any way compromised,

inert the battery by placing it in a bucket filled with salt water. In 24‐48 hours,

the battery may be safely discarded as household garbage.
AFM 1‐3

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Motor Failure Above 100 feet AGL

1. Control‐ Manual (SP)

Deflect the autopilot switch on the transmitter to manual, and take control of

the aircraft. The flight surfaces should be operational, but no throttle will be

available.  

2. Throttle‐ Reduce (SP)

Immediately reduce the throttle to off. If the battery is temporarily depleted

because of voltage sag, it may recover a small amount of voltage during the

landing glide. As a result, there may be a small amount of power available during

the final approach, but do not rely on it.  

3. Safe Heading‐ Establish

Immediately point the AV in a safe direction, preferably away from persons or

property and viable for landing. Keep the AV within visual line of sight.  

4. Recovery Site‐ Select (Observer)

Determine the optimal place to recover the AV.

5. Land or Deep Stall‐ ASAP

Perform a deep‐stall or belly land as soon as possible. Recover the AV.  

AV Fire on Ground

1. FIRE, FIRE, FIRE on AV‐ ANNOUNCE

As soon as a fire is seen, announce clearly and loudly to all personnel.  

2. Control‐ Manual (SP)

Deflect the transmitter autopilot switch to manual.  

3. Throttle‐ Reduce (SP)

Reduce the throttle to zero.  

4. Fire‐ Extinguish‐ (ALL)
AFM 1‐3

23

Attempt to extinguish the fire using a chemical fire extinguisher and/or dirt.

Because of the lithium batteries and electrical system, DO NOT use water to

extinguish the fire. If the fire cannot be contained, call for help.  

5. Batteries‐ Secure

When the fire is put out, carefully secure the Lithium battery. If the battery is in

any way compromised, inert the battery by placing it in a bucket filled with salt

water. In 24‐48 hours, the battery may be safely discarded as household

garbage.  

Uncontrolled Flight

1. Control‐ Manual (SP)

Deflect the transmitter autopilot switch to Manual

2. Controllability‐ Assess (SP)

Quickly determine if the aircraft responds to Safety Pilot controls.  

If AV is uncontrollable:

3. Deep Stall‐ Engage

Remove the safety cover, if installed, and engage the deep stall.  

4. Batteries‐ Secure  

Carefully check the battery for any punctures or ruptures. If the battery is in any

way compromised, inert the battery by placing it in a bucket filled with salt

water. In 24‐48 hours, the battery may be safely discarded as household

garbage.

Safety Pilot Low Battery

The transmitter will signal its battery is low by emitting a beeping noise, vibrating, and

giving an on‐screen warning that the battery is low. This is a critical emergency, and the AV

must be recovered as soon as possible. Avoid this by either charging the transmitter fully

before the flight, connecting the charger in‐flight, or purchasing a lithium transmitter

battery from Spektrum.  

1. Control‐ Manual (SP)

Deflect the transmitter autopilot switch to manual.  
AFM 1‐3

24

2. Safe Heading‐ Establish (SP)

Point the AV in a safe direction, away from persons or property.

3. Deep‐Stall‐ Engage (SP)  

Remove the safety cover, if installed, and engage the deep‐stall switch.  

4. AV‐ Recover (ALL)

Recover the aircraft. Keep bystanders away, and insert the throttle safety key

immediately. Inspect the aircraft for damage, and carefully inspect the batteries.

Safety Pilot Uplink Failure

If the Safety Pilot loses the ability to control the aircraft, the AV will Return to Launch (RTL)

and orbit at the default altitude. As the AV comes closer, attempt to regain Safety Pilot

control. If control cannot be regained, the Aircraft Operator must create and execute an

autonomous landing flight plan.   

1. RTL‐ Verify  

Upon loss of Safety Pilot uplink, the AV should Return to Launch. Verify that the

AV is proceeding to the RTL point at the default altitude.  

2. Control‐ Auto (SP)

The Safety Pilot should place the autopilot mode switch into the Auto position.

This will ensure that the AV completely returns to the launch point, which will

aid in regaining control of the AV.  

3. Uplink‐ Re‐Establish (SP)

Re‐establish control with the transmitter. Control may be re‐gained

automatically when the AV comes within radio range. If control cannot be

established, cycle the power on the transmitter.  

4. Autoland‐ As Appropriate (AO)

Create a flight plan on the GCS that commands the AV to land. The second to last

waypoint should be 1,000 feet away, at 150 feet of altitude, and downwind. The

final waypoint of the flight plan should be a LAND waypoint (selectable in the

flight plan list), and the altitude for that point must be 0.

GCS Comms Fail
AFM 1‐3

25

Note: This procedure, while abnormal, is not a critical emergency.  

1. 3DR Radio‐ Power Cycle

Check the 3DR radio to see if the green light is solid, indicating link to the

aircraft. Unplug and re‐plug the 3DR radio, watch for the solid green light. If the

green light continues to flash, land the AV manually as soon as practical. If the

green light is solid, proceed with the checklist.  

2. Mission planner‐ Restart

Close Mission Planner and re‐open it. Attempt to connect again. If link is

unsuccessful, continue with the checklist.  

3. Laptop‐ Restart

Command the laptop to restart, re‐open mission planner, and attempt to

connect. If link is still unsuccessful, try alternate equipment (such as a different

laptop).  

4. Control‐ Manual (SP)

5. Land‐ As Soon As Practical (SP)  

If attempts to regain GCS link fail, take manual control and land as soon as

practical. If the AV is completing a mission, it is acceptable to allow the AV to

complete its mission before landing.

GPS Failure

When the GPS fails, the AV will continue to try to navigate using “dead reckoning.” This is an

estimation of position based on angular velocities and lateral accelerations. Dead reckoning

is highly inaccurate, and will become exponentially erroneous over time. Use dead

reckoning only as an aid to situational awareness, and do not rely on it to continue the

mission or to navigate the AV to home.   

1. GPS Failure‐ Announce

When GPS failure is recognized, announce to all crewmembers. GPS failure will

be signaled by a red warning on the Heads‐Up Display (HUD), saying “Bad GPS

Health.” If GCS audible alerts are configured, it will announce “Warning: Bad GPS

Health.”  

2. Control‐ Manual (SP)

Deflect the transmitter autopilot switch to manual.  
AFM 1‐3

26

3. Land AV‐ As Soon As Practical

Once manual control is gained, the AV is no longer in danger. Perform a manual

landing or deep‐stall.  

GCS Electrical Power Failure

This procedure details what to do when the GCS laptop’s power has failed or is about to fail.

This is often not a critical emergency.  

1. Screen Brightness‐ Reduce

If the laptop is still running, reduce the screen brightness to conserve battery

power.  

2. Power Source‐ Check  

If the laptop is plugged in, check to see why it is not charging. Check cables and

connectors. If the power outlet is in an outdoor location, press the Ground Fault

Interrupter (GFI) reset button on the outlet.  

3. Land‐ As Required

If necessary, take manual control of the aircraft and land. If possible, it is usually

practical to continue the mission without the GCS.  

   
AFM 1‐3

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Section 5: Field Repair Instructions

This section describes the procedures able to be performed by operators to repair the air vehicle (AV) in a field

environment.  

 Replacement of a propeller

 Replacement of a broken wing bolt

 Replacement of a tail clip

 Replacement of a stabilator arm

 Adjusting the motor mount (after a nose impact)

 Re‐Binding the DX7s Transmitter

 Replacement of a servo

 Replacement of the motor

 Replacement of a skid pad

 Repairing wing delamination

 Adjusting camera bracket level

 Adjusting camera bracket endpoints

In addition, a reference table for replacement hardware is listed.

Aside from normal inspections before and after flight, Lynx does not require any regular, scheduled maintenance.  

   
AFM 1‐3

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Replacement of a Propeller

If the propeller is broken, cracked, or chipped, it must be replaced. A chipped propeller may cause harmful

vibrations to the airframe. The cause for a broken propeller is usually a failed hand launch or hard belly land.

Always reduce the throttle immediately before impact to minimize propeller damage.  

It is possible that one propeller blade will break, and the other will remain intact. Replace only the broken side.

Make certain that the two propeller blades are identical. Raised lettering near the center of the propeller indicates

the diameter and pitch (i.e. 15 x 10).

To replace a propeller blade, use the crescent wrench and flathead screwdriver to remove the nut and bolt

attached to the propeller yoke. Place the new propeller blade with the hub in the slot, ensuring that the printing

on the propeller is facing forward. Insert the bolt, and thread the lock nut onto the bolt; use the crescent wrench

and flathead screwdriver to tighten. Tighten until the propeller has enough friction to remain in place when

extended.

Remove a propeller using the crescent wrench and flathead screwdriver.   
AFM 1‐3

29

Replacement of a Broken Wing Bolt

During hard landings, the wing bolts protruding out of the fuselage may break off. This is normal and prevents

structural damage to the fuselage and wings. To replace a broken bolt, attempt to use pliers to twist off the broken

shaft. If the bolt is completely recessed, insert the tip of an X‐Acto blade into the plastic bolt and twist counter‐

clockwise to remove the bolt. It may be necessary to tap the backside of the knife to bury it deeper into the bolt.  

An X‐Acto blade removing a broken wing bolt.

If the bolt remains difficult to remove, drill a small hole into the center of the broken shaft and tap an X‐Acto blade

into the hole. The drilled hole will provide extra leverage for the blade when twisting.

   

Left: Broken wing bolt removed. The bolt will typically shear at the base of the hex cap. Right: Wing bolt spacer.

Insert the new wing bolt and turn clockwise. Use the wing bolt spacer and socket (if difficult to turn). Tighten down

the new wing bolt until it touches the spacer. The spacer leaves the correct gap for the center wing to slide on.

   
AFM 1‐3

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Replacement of a Tail Clip

If one or both of the tail clips become cracked or broken, they must be replaced. To remove the broken tail clip,

use the Phillips screwdriver to remove the screw inside the clip. Insert the screw into the replacement tail clip and

reinstall with the Philips screwdriver.  

   

Left: A cracked tail clip with screw removed. Right: Two clips ready to be installed.

A spare tail clip is installed with a Philips screwdriver.   
AFM 1‐3

31

Replacement of a Stabilator Arm

If the carbon stabilator arm becomes cracked or broken, it must be replaced. Use the Phillips screwdriver and

crescent wrench to remove the control rod from the stabilator arm. Ensure the control rod does not spin.  Spinning

the control rod will change the aircraft’s pitch trim. Use the Phillips screwdriver to remove the pivot spacer from

the tail. With the spacer removed, the stabilator arm will come free. Insert the new stabilator arm into its slot,

lining up the hole on the pivot point. Reinstall the pivot spacer and tighten until resistance is felt. Reattach the

control rod to the stabilator arm.

     

Left: Remove the control rod from the stabilator arm using the crescent wrench and Philips screwdriver. Note the

offset nut on the right and the lock nut on the left. Right: Remove the pivot spacer with a Philips screwdriver.  

Pivot spacers and stabilator arm removed.    
AFM 1‐3

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Adjusting the Motor Mount (After a Nose Impact)

Depending on the severity of the incident, a nose‐first impact may result in a pushed‐in or loose motor mount,

broken spinner, broken propeller(s), and/or bent motor shaft. This procedure will focus on a pushed‐in or loose

motor mount.  

The motor bulkhead (black, metal) is secured to the outer motor housing (yellow, plastic) with four nylon screws.

These screws are designed to shear in the event of a hard impact. The screws are threaded into press‐fit inserts

that may back out. All of this allows the bulkhead to give and thus minimize damage to the permanently mounted

motor housing. Typically the propeller will not spin freely if the motor is pushed back.

First open the battery bay and remove the battery. Disconnect the three ESC wires connected to the motor.

Remove the four metal counter‐sunk screws holding the motor in place using a Philips screwdriver. Slide the motor

forward and out.  

  

Left: Looking into the battery bay. The ESC and motor connect with three wires. Right: Four counter‐sunk screws

fasten the motor to the bulkhead.

       

Left: With the screws removed, the motor will slide out the front. Right: The bulkhead attaches to the outer motor

housing with four nylon screws.

Next remove the motor bulkhead by loosening any intact nylon screws. Sheared screws will be missing their Philips

head and can be removed with a needle‐nose plier or finger tips once the bulkhead is gone.

Observe the four, gold‐colored metal threaded inserts in the yellow motor housing. After a nose impact, these may

protrude from the housing. Use a small, blunt object, such as the handle of the crescent wrench, to push the

threaded inserts back in until flush.

Reattach the motor bulkhead using four intact nylon screws.  
AFM 1‐3

33

Motor bulkhead and motor removed.

Insert the motor in from the nose, ensuring that the three motor wires are facing down and inside the bottom

trough of the motor housing. The wires should enter the battery compartment. Attach the motor to the bulkhead

with the four metal counter‐sunk screws.  

Connect the motor and ESC wires, ensuring the wires are connected red‐red, black‐black, and blue‐white. Mixing

the wire order will cause the motor to spin in reverse.

Power the transmitter and aircraft. Remove the throttle key and test the throttle. Ensure no rubbing occurs

between the propeller hub and the fuselage. Ensure the propeller spins clockwise when viewed from behind.
AFM 1‐3

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Re‐Binding of the DX7s Transmitter  

If the transmitter is not connecting with the AV, it may need to be re‐bound. Binding is a precise procedure, and

must be followed exactly.   

1. Turn the AV off by disconnecting the battery.  

2. Press the roller button on the DX7s to enter the Setup menu. Scroll down to Servo Setup and press the

button. Change the first item to Servo Travel, second item to Rudder, and third item to 150. Press Back

twice to exit the Setup menu.

3. Turn off the DX7s transmitter.

4. Slide the autopilot tray out, and insert the bind plug into the Spektrum receiver port labeled “Bind/Data.”

5. Ensure the throttle key is inserted, and turn the AV on by connecting the battery. The receiver in the

autopilot tray should rapidly flash orange.

6. Remove the bind plug.  

7. On the DX7s transmitter, hold the left stick in the bottom left corner. Flip the autopilot switch to Auto.

Press and hold the black button on the top left of the radio.  

8. Turn the DX7s transmitter on. The screen will say Binding.  

9. As soon as the screen says Transmitting, release the black button on the top left of the radio.  

10. Watch the receiver in the autopilot tray for the orange light to change from rapidly flashing to solid. When

the light is solid, release the left stick, change the autopilot switch to Manual, and check the right stick for

servo control.  

11. Enter the Servo Setup menu again, and reduce Rudder servo travel back to zero. Press back twice to exit

the menu.  

12. Test autopilot switch functionality.  

13. Test RTL functionality by turning off the DX7s transmitter and observing the flight modes on a laptop GCS.  

   
AFM 1‐3

35

Replacement of a Servo

If a servo is immobile, has stripped or partially stripped gears, makes a clicking noise, or cannot hold its position

properly, it must be replaced. The same procedure is used for either servo.

First remove the payload. Partially slide out the autopilot tray into the payload bay. On the top right side of the

autopilot tray, identify the correct servo wire labeled either Rudd (Rudder) or Elev (Elevator). Disconnect the wire

from the multiplexor. Attach a string or wire to the end of the servo connector. The string should be approximately

three feet in length and will serve as a guide when installing the replacement servo.

Autopilot tray partially removed showing servo wires connected to the multiplexor.

Disconnect the control rod using a Philips screwdriver and crescent wrench. Do not twist the control rod as this will

affect the aircraft’s trim. Then remove the two nylon screws holding the servo in place. Grasp the servo arm and

slide the servo out from its tray.  

   

Left: Remove the two nylon retaining screws. Right: Servo removed from its tray.

Pull the servo and its wire out of the tail just until the string appears. Disconnect the servo connector from the

string.  
AFM 1‐3

36

Using a Philips screwdriver, remove the servo arm connected

Attach the replacement servo’s connector to the string. Pull the string from the payload bay until the connector

appears in the autopilot tray. Connect the wire in the same place as the original servo, ensuring that connector’s

orientation matches adjacent wires.

Slide the servo into the tail, and simultaneously pull on the wire in the autopilot bay to take up slack. Be careful not

to pinch the servo wire around the servo tray. When the servo is seated, secure it with the two nylon screws.

Reattach the control arm using a screwdriver and crescent wrench.  

Power the transmitter and aircraft. Test the control surface.  

   
AFM 1‐3

37

Replacement of the Motor

If the motor does not spin freely, has a bent shaft, or makes a loud whining noise, it must be replaced.  

First open the battery bay and remove the battery. Disconnect the three ESC wires connected to the motor.

Remove the four metal counter‐sunk screws holding the motor in place using a Philips screwdriver. Slide the motor

forward and out.

Remove the white plastic nose cone (spinner) with a Philips screwdriver. Remove the propeller nut using the

crescent wrench. With the nut removed, grasp the motor and twist the hub off. Never attempt to pry the hub off

by leveraging a screwdriver between the fuselage and propeller hub.

   

Left: plastic spinner removed. Right: Motor removed with propeller hub still attached.

Insert the replacement motor in from the nose, ensuring that the three motor wires are facing down and inside the

bottom trough of the motor housing. The wires should enter the battery compartment. Attach the motor to the

bulkhead with the four metal counter‐sunk screws.  

Connect the motor and ESC wires, ensuring the wires are connected red‐red, black‐black, and blue‐white. Mixing

the wire order will cause the motor to spin in reverse.

Slide the propeller hub onto the motor shaft. Leave an appropriate gap to ensure the hub spins freely without

rubbing the fuselage. Tighten the propeller nut using the crescent wrench. A loose prop nut will cause the

propeller to launch forward when throttle is applied. Attach the spinner using a Philips screwdriver.  

   

Left: Spinner and propeller hub disassembled. Right: The prop nut fastens the hub to the motor.   

Power the transmitter and aircraft. Remove the throttle key and test the throttle. Ensure no rubbing occurs

between the propeller hub and the fuselage. Ensure the propeller spins clockwise when viewed from behind.
AFM 1‐3

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Replacement of a Skid Pad

Normal wear (cuts, abrasion, dents) of the skid pads can be patched with gaffer’s tape.

If a skid pad has large pieces of foam missing, or is missing entirely, it is necessary to replace it.  

To replace a skid pad, first remove what remains of the old one. Remove the gaffer’s tape around the edge, if

present. Forcibly pull the skid pad material off as thoroughly and cleanly as possible. Use a flathead screwdriver or

rounded‐tip knife to scrape away any remaining foam, tape, or glue. Paint may be scraped but the Kevlar skin will

remain resilient as long as it is not cut.

Adhere gaffer’s tape to the flat side of the skid pad. Use the tape to bend the pad such that it matches the

underside of the fuselage. Trim any excess tape. Attach the replacement skid pad using a hot glue gun. Apply hot

glue around the perimeter of the skid pad and attach it to the aircraft making sure it conforms to the fuselage.

Apply pressure to the pad until the glue has cooled. Finally, add gaffer’s tape around the edges of the skid pad.

   

Left: Gaffer’s tape applied to the flat side of a replacement skid pad. Note how the tape holds a bend in the pad.

Right: Skid pad with trimmed Gaffer’s tape.

Front skid pad attached to the fuselage and seamed with Gaffer’s tape.   
AFM 1‐3

39

Repairing Wing Delamination

If the Kevlar skin on the wings or stabilator begins to lift or delaminate from the underlying foam, it should be

repaired. Delamination typically occurs near a wing’s rib and at the corners of the trailing edge.  

When in the field, use gaffer’s tape to pinch down the Kevlar skin until a repair can be performed.  

Left: Gaffer’s tape around the trailing edge. Right: Gaffer’s tape removed showing delamination.

To repair the wing, pull back the lifted Kevlar skin and apply a foam safe glue (i.e. Gorilla Glue) or epoxy to the

exposed foam. Smear the glue with a paper towel until a light film evenly covers the foam.  

   

Left: Kevlar skin pulled back exposing wing foam. Right: Gorilla Glue being applied beneath the Kevlar.

Apply gaffer’s tape or masking tape to the glued area. The tape is used to clamp down the lifting skin and to

minimize the amount of glue that may seep between the Kevlar weave (important for glues that expand).

Additional clamps or weight may be used for stronger adhesion.

The wing is taped and clamped until dry.

Once dry, remove the tape and peel away or sand any remaining glue.
AFM 1‐3

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Adjusting Camera Bracket Level

The camera bracket may need to be adjusted to achieve a more precise level. This can be done using the supplied

hex key tool.  

For Lynx with autopilot installed: Power the aircraft and transmitter on and wait for the autopilot’s sensors to

initialize. Ensure the throttle safety key is inserted and deflect the autopilot switch on the transmitter to Auto. The

camera gimbal will attempt to stabilize the camera to level. If the level is incorrect, use the supplied hex key to

loosen the clamping hub. Manually rotate the camera gimbal to level, and tighten the clamping hub.  

For Lynx without autopilot: Power the aircraft and transmitter on. Ensure the autopilot switch on the transmitter

is deflected to Manual. Using the rotary switch on the top right of the transmitter, spin the knob to Deploy. If the

camera level is incorrect, use the supplied hex key to loosen the clamping hub. Manually level the camera gimbal

to level, and tighten the clamping hub.  

Loosening the bracket’s set screw will allow the bracket to spin freely around the servo shaft.
AFM 1‐3

41

Adjusting Camera Bracket Endpoints

If a camera other than the supplied camera is used in the payload bracket, the stabilization values may need to be

adjusted in order to maximize roll stabilization and/or to avoid seeing the payload’s sidewalls during turns.  

Power the aircraft and transmitter on, and wait for the autopilot’s sensors to initialize. Ensure the throttle safety

key is inserted, and deflect the autopilot switch on the transmitter to Auto. Power the camera on and remove the

lens cap. Roll the plane to the right and left, and observe the camera’s screen. The black sidewalls of the aircraft

should not be visible in the camera’s field of view.  

The black sidewall is visible at the top of the camera’s screen.

The endpoints of the camera bracket can be adjusted by changing servo PWM values in Mission Planner

(Config/Tuning tab>Optional Hardware Tab>Camera Gimbal). Roll the plane until the maximum degree of

stabilization is reached. Adjust the roll gimbal Max and Min values to fine tune the endpoints.  

When the endpoints have been set, go to the flight data screen. Manually roll the plane, watch the camera gimbal

and observe when it reaches its endpoints, and record the degrees of roll on the Heads Up Display. Enter these

degree values into the Camera Gimbal setup menu. This will ensure that the camera remains facing straight down

(nadir) in all angles of stabilization.  

Adjusting Camera Endpoint Values

    
AFM 1‐3

42

List of Replacement Hardware

Wing Bolt Nylon 1/4" ‐20 x 1” hex cap screw or,

Fiberglass 1/4" ‐20 x 1” hex cap screw

Motor Bulkhead Screw Nylon 6‐32 x 3/8” Philips pan head screw

Servo Retaining Screw Nylon 6‐32 x 3/8” Philips pan head screw

Throttle Key Retaining Screw Nylon 6‐32 x 3/8” slotted flat head screw

Tail Clip Screw Steel 4‐40 x 1/2” Philips pan head screw

Servo Linkage Screw Steel 4‐40 x 1/2” Philips pan head screw

Servo Linkage Retaining Nut Steel 4‐40 nylon‐insert hex locknut

Servo Linkage Offset Nut Steel 4‐40 hex nut

   
AFM 1‐3

43

Appendix 1

Flight Control Surface Throws

Stabilator Up +5o

Stabilator Down  ‐ 5o

Stabilator Trim 0o(trim as needed for level cruise flight)

Stabilator Deep‐Stall   +45o

Rudder Right +16o

Rudder Left  ‐16o

Rudder Trim 0o (trim as needed for straight cruise flight)

Note: When a deep‐stall is engaged in flight (into the wind), the aircraft should pitch up sharply and immediately

settle into a stable, steep descent where the aircraft’s pitch and roll remains level. If the aircraft enters an

oscillating stall or spins, the deep‐stall deflection is too low. To recover, disengage the deep‐stall switch, apply

opposite rudder (if in a spin), and advance throttle only after the aircraft has returned to straight and level flight.

Belly land the aircraft and adjust the deep‐stall throw.

Battery Cell Discharge Curve  
AFM 1‐3

44

Photomapping Camera Settings

The following is a list of best practices for camera settings developed by Swift Radioplanes from photomapping

experience.

Shooting Mode Shutter Priority

ISO Speed (Sensor Sensitivity) Auto

Aperture (Depth of Field) Auto

Shutter Speed (Exposure)  ≥ 1/1000 second. A fast shutter speed will reduce

motion blur.

White Balance Daytime, Cloudy, or Auto. Select the appropriate white

balance based on current lighting conditions.

Dynamic Range Optimization (DRO) Low Level or Off. The DRO function analyzes the

contrast and produces an image with optimal

brightness and recovered shadow detail. Useful in low

light situations where long shadows may obscure

details.  

High Dynamic Range (HDR) Off

Focus Manual. Manual focus will reduce image blur and

enable faster shooting. Before flight, focus on a distant

object that is farther away than the planned mission

altitude. Do not bump the focus ring before takeoff.

View Finder   Disabled. Disabling the OLED viewfinder will prevent the

camera from inadvertently entering viewfinder mode

during flight. Viewfinder mode will disable remote

control commands.

Remote Control Remote Ctrl On. Enabling the remote is required when

using an IR shutter.

LCD Screen Brightness As low as possible. Reducing LCD brightness will

increase camera battery life. This is essential for long

photomapping flights.