CL 2-4

Lynx M

Unmanned Aircraft System

Operator and 

Crewmember Checklist
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PACKING LIST

 Fuselage 

 Wings 

 Stabilator 

 Battery 

 Battery Tester

 Handheld Transmitter

 GCS Device

 Ground Telemetry Radio & Antenna

 Micro USB Cable

 USB OTG to Micro USB (If Req.)

 Castle Link & Cable

 Gaffer’s Tape 

 Wishbones (x4)

 Camera

o Charged Battery

o SD Card

o UV Filter Lens Cover

o Lens Brush

 Spares:

o Props

o Stabilator Arms

o Tail Clips

o Pitot Clips

 Bind Plug 

 Tools

o Exact-O Knife

o Screwdrivers 

o Crescent Wrench
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NORMAL PROCEDURES

Aircraft Preflight Inspections

1. Fuselage - Inspect

2. Wing Bolts - Present and Spaced

3. Skid Pads - Inspect

4. Propellers and Motor - Serviceable

5. Propeller- Extended and Clear

6. Pitot Tube – Inspect and Attach

7. Servos - Check Movement and Linkages

8. Battery - Inspect and Install 

9. Stabilator - Inspect

10. Wings - Inspect

Aircraft Power On

1. Handheld Transmitter - On

2. Handheld Transmitter - Verify Manual

3. Throttle Safety Key - Attach

4. Flight Battery - Connect

5. Flight Surfaces - Check Movement

GCS Checks

GCS Power On

1. GCS Device - Power On

2. Telemetry Radio - Attach

3. Mission Planner - Start

Flight Data Screen

4. Mission Planner - Connect 

Initial Setup Screen

5. Compass - Enable, Check Declination, 

Calibrate if Needed

6. New Field - Range Check/ Magnetometer 

Calibration

7. Flight Modes - Set 

8. Failsafe - Disabled

9. Airspeed - Enable and Use

10. Battery - Enable and Verify

Flight Planning Screen

11. Default Altitude - Set
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12. Loiter and Waypoint Radius - Set 30, 105

13. Takeoff - Create

14. Mission - Create/Load 

15. Rally points - Create/Load

16. Waypoints - Read Back and Verify

Flight Data Screen

17. Camera Synchronization - Perform

Preflight Systems Checks

1. Autopilot Arm - Verify

2. HUD - Verify Level and Responsive

3. Magnetometer - Correct and Responsive 

4. Flight Surface Checks - Perform

5. Mode Select - Verify

6. AP Pass-Through Check - Perform

7. IMU Test - Perform

8. Auto Check - Perform

9. Return To Launch (RTL) - Perform

10. GPS - Verify at Least 6 Satellites

11. Preflight Calibration - Perform

12. Airspeed Test - Perform

13. GCS HUD - No Errors/Warnings

14. Stabilator - Attach

15. Wing - Assemble and Attach

16. Full Throttle Check - Perform

Takeoff

1. Payload - Ready for Takeoff

2. Wind - Check

3. Launch Direction - Into Wind

4. Launch Area - Clear

5. Mode Manual - Verify (SP)

Manual Takeoff

6. Propeller - Clear (Thrower)

7. Throttle Safety Key - Remove (Thrower)

8. Ready for Takeoff - Announce (SP)

9. Ready for Takeoff - Confirm (Thrower)

10. Timer - Start (SP)

11. Full Throttle - Set (SP)
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12. Full Throttle – Verify (Thrower)

13. Aircraft - Launch Into Wind (Thrower)

Auto Takeoff

6. Mission - Restart and Verify (AO)

7. Propeller - Clear (Thrower)

8. Throttle Safety Key - Remove (Thrower)

9. Ready For Takeoff - Announce (SP)

10. Ready For Takeoff - Confirm (Thrower)

11. Timer - Start (SP)

12. Mode - Auto (SP)

13. Half Throttle - Set (SP)

14. Full Throttle - Verify (Thrower)

15. Aircraft - Launch Into Wind (Thrower)

Landing

1. Weather/Winds – Verify (AO)

2. Recovery Site - Select (SP)

3. Recovery Site Clear - Verify (Observer)

Deep-Stall Landing

4. Altitude - Greater than 30 meters AGL (SP)

5. Heading - Into Wind (SP/AO)

6. Throttle - Off (SP)

7. Deep Stall - Engage (SP)

8. Heading Into Wind - Maintain (SP)

9. Timer - Stop (SP)

Belly Landing

4. Manually Land AV - Into Wind (SP)

5. Timer - Stop (SP)

Post Flight

1. Flight Battery - Disconnect/Check

2. Handheld Transmitter – Off (SP)

3. Aircraft - Disassemble/Inspect

4. GCS - Shutdown (AO)
EMERGENCY PROCEDURES

Motor Failure Below 30 meters AGL

1. Control - Manual (SP)

2. Safe Heading - Establish (SP)

3. Deep-Stall - Engage (SP)

Motor Failure Above 30 meters AGL

1. Control - Manual (SP)

2. Throttle - Reduce (SP)

3. Safe Heading - Establish (SP)

4. Recovery Site - Select (Observer)

5. Land or Deep-Stall – ASAP (SP)

Uncontrolled Flight

1. Control - Manual (SP)

2. Controllability - Assess (SP)

If AV is uncontrollable

1. Deep- Stall – Engage (SP)

2. Batteries -Secure

If AV is controllable

1. Land - As Soon As Practical (SP)

Safety Pilot Low Battery

1. Control - Manual (SP)

2. Safe Heading - Establish (SP)

3. Land or Deep-Stall - Immediately(SP)

Safety Pilot Uplink Failure

1. RTL - Verify (AO)

2. Control - Auto (SP)

3. Uplink - Re-Establish (SP)

4. Autoland - As Appropriate (AO)

GPS Failure

1. GPS Failure - Announce (AO)

2. Control - Manual (SP)

3. Land AV - As Soon as Practical (SP)
GCS Low Battery

1. Screen Brightness - Reduce (AO)

2. Power Source - Connect (AO)

3. Land - As Soon as Practical (SP)

GCS Telemetry Fail

1. Distance from AV - Check (AO)

2. Comms - Restart (AO)

If telemetry cannot be restored

3. Land - As Soon As Practical (SP)

Deep-Stall Abort

1. Deep Stall - Disengage (SP)

2. AV - Climb Gently (SP)

3. Power - Apply (SP)
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Table 1. Speed Conversions

Meters/

second

Knots Kilometers/

hour

Miles/

hour

1 1.9 3.6 2.2

2 3.9 7.2 4.5

3 5.8 10.8 6.7

4 7.8 14.4 8.9

5 9.7 18 11.2

6 11.7 21.6 13.4

7 13.6 25.2 15.7

8 15.6 28.8 17.9

9 17.5 32.4 20

10 19.4 36 22.4

11 21.4 39.6 24.6

12 23.3 43.2 26.8

13 25.3 46.8 29.1

14 27.2 50.4 31.3

15 29.2 54 33.6

16 31.1 57.6 35.8

17 33 61.2 38

18 35 64.8 40.3

19 36.9 68.4 42.5

20 38.9 72 44.7

21 40.8 75.6 47

22 42.8 79.2 49.2
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Table 2. Distance Conversions

Feet Meters

50 15

100 31

150 46

200 61

250 76

300 91

350 106

400 122

450 137

500 152
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Table 3. ESC Beep Codes

Tone Meaning Description

“Castle 

Power” 

tune with 

beeps 

correspond

ing to 

number of 

cells

Power up 

notice

ESC plays Castle signature tone and beeps out 

the number of cells attached to controller. 

Note: when Auto-LiPo detection is disabled 

by the user, ESC will not beep the number of 

cells. ESC will not run motor until it receives 

an arming signal from the radio via the 

throttle lead

Arming 

Tone

ESC ready to 

run motor

ESC plays the Castle arming tune once it 

receives a signal from the receiver. Controller 

is ready to run the motor at this point.

* Powered ESC 

notice

ESC beeps motor every 10 seconds to remind 

user that power is connected to the ESC. This 

notice may be disabled in Castle Link.

*- Low Voltage 

Cutoff

Main battery voltage dropped below the 

cutoff value. The default is Auto-LiPo which 

sets the cutoff value based on the detected 

cell count. Other settings may be entered in 

Castle Link

*-* Over 

Temperature

ESC reached an overtemp condition. Occurs 

when operated under too high a load or 

operated without proper cooling airflow

*-- Excessive 

Load

ESC detected very high current spikes. Causes 

may include damaged wiring leading to, or 

inside, the motor, or the use of too large a 

motor for the controller.

Remove power from the controller and check 

for shorts. If none are found, verify the 

controller can handle the motor’s current 

load. As a safety feature, if multiple Excessive 

Load errors are detected, beeping will be 

disabled.

If error continues, contact Castle Tech 

Support.

** Start Fail ESC was unable to start motor

**- Radio Glitch ESC detected unusual signals or loss of signal 

on throttle wire.

*** Motor 

Anomaly

ESC detected a sudden interruption of the 

motor’s rotation.

-* Over-Current ESC detected operating currents that exceed 

the cutoff value.

-** AUX Wire 

Glitch

ESC detected unusual signals or loss of signal 

on the AUX line.
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Table 4. Pixhawk LED Codes

LED Status Meaning

Flashing Red & 

Blue 

Initializing

Double Flashing 

Yellow

Error. System refuses to arm

Flashing Blue Disarmed, searching for GPS.

Flashing Green Disarmed, GPS lock acquired.

Ready to arm

Solid Blue Armed without GPS lock. Do not 

fly

Solid Green Armed with GPS lock. Ready to fly

Solid Red Failed to boot or read the microSD 

card

Flashing Yellow RC failsafe or battery failsafe 

activated

Flashing Yellow 

& Blue

GPS glitch or GPS failsafe activated

Table 5. Telemetry Radio LED Codes

LED Status Meaning

Blinking Green Searching for another radio.

Solid Green Link has been established with 

another radio.

Blinking Red Transmitting Data.

Solid Red In firmware update Mode.
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Table 6. Camera Information

Mode Setting

Shooting Mode Shutter Priority

ISO Speed (Sensor Sensitivity) Auto

Aperture (Depth of Field) Auto

Shutter Speed (Exposure) 1/2500 second. 

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 Mode Single-shot AF

Focus Area Wide

LCD Screen Brightness As low as possible. Reducing LCD 

brightness will increase camera 

battery life. This is essential for 

long photomapping flights.

Auto Exposure Lock (AEL) On

Camera Image 

Width 

(Pix)

Image 

Height 

Sensor 

Width 

(mm)

Sensor 

Height 

Focal

Length 

(MM)

Canon EOS M 5184 3456 22.3 14.9 22

Sony NEX-7 6000 4000 23.5 15.6 20

Sony a5100 6000 4000 23.5 15.6 20

Sony Alpha 7R 7360 4912 35.9 24 35
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Figure 1. GCS Comms Failure Flowchart
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Figure 2. Battery Discharge Graph
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PERFORMANCE DATA

General

Wingspan 2.3 m

Propulsion Electric

Empty Weight 2.0 kg

Battery 1.3 kg

Payload .7 kg

Maximum Gross Takeoff Weight 4.0 kg

Center of Gravity Limits -6.0 to -9.5 cm (center wing leading 

edge datum)

Performance

Cruise Speed 16 m/s

Never Exceed Speed (VNE) 22 m/s

Stall Speed 9 m/s 

Endurance 180 min (with a5100 payload)

Range 1.5 km (approx.)

Takeoff

Takeoff Method Hand launch

Auto Takeoff Climb Angle 20 degrees

Distance to clear 18 meter obstacle 40 m (with 5 m/s headwind)

Distance to clear 50 meter obstacle 100 m (with 5 m/s headwind)

Landing

Landing Method Belly land or vertical deep-stall

Electrical

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 

Safety Pilot Frequency seconds) 2.4 GHz

Telemetry Frequency 915 MHz

Environmental

Wind Limitation 8 m/s gusting to 12 m/s (15-25

knots)

Precipitation none

Prohibited Maneuvers:

 Launch or landing with any tailwind, including 

deep-stall

 Flight into known icing conditions

 Flight into visible moisture

 Flight beyond Safety Pilot’s visual line-of-sight

(LOS)
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Notes
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Notes