11362 Joseph Casavant

Montreal, Quebec,

H3M 2B7

Canada

+1 (514) 213-8032 

info@exponentcg.com

www.exponent-ts.com

RPAS User Operations Manual

Version 1.1

 

Danijel Jovanovic, Manager - Manager UAS 

Asam Khan - Chief Operating Officer

08-Apr-2015
RPAS USER OPERATIONS MANUAL

1 |	Page

DOCUMENT CONTROL LOG

Name Title Version # Section Change/Modification Date

Danijel Jovanovic UAS Manager 0-1 All Initial Draft 12-Jan-15

Asam Khan Chief Operating 

Officer 0-2 Emergency Procedures

Addition of Manned Aircraft 

in Vicinity 14-Jan-15

Danijel Jovanovic UAV Manager 0-3 All Review of all sections 28-Jan-15

ASAM KHAN

CHIEF 

OPERATING 

OFFICER

1-0 ALL

FINAL REVIEW AND 

APPROVAL FOR 

RELEASE

05-FEB-15

Asam Khan Chief Operating 

Officer 1-1 UAS Performance

Updated UAS Flight 

Times 08-Apr-15
RPAS USER OPERATIONS MANUAL

2 |	Page

TABLE OF CONTENTS

PERFORMANCE SPECIFICATIONS ............................................................................................................ 3

MOTORS .................................................................................................................................................... 5

ELECTRONIC SPEED CONTROLLERS.................................................................................................... 5

PROPELLORS............................................................................................................................................ 5

TERMINOLOGY............................................................................................................................................. 5

GENERAL MULTIROTOR UNMANNED AERIAL SYSTEMS (UAS) FRAMES.......................................... 5

CONFIGURATIONS.................................................................................................................................... 6

ABBREVIATIONS ....................................................................................................................................... 6

LIMITATIONS................................................................................................................................................. 7

AIRSPEED LIMITATIONS .......................................................................................................................... 7

WEIGHT LIMITATIONS .............................................................................................................................. 7

POWER LIMITATIONS............................................................................................................................... 7

CENTER OF GRAVITY LIMITATIONS....................................................................................................... 7

MANOEUVER LIMITATIONS ..................................................................................................................... 7

TEMPERATURE LIMITATIONS ................................................................................................................. 7

In cold temperatures................................................................................................................................ 7

In warm temperatures ............................................................................................................................. 7

WEATHER LIMITATIONS........................................................................................................................... 7

EMERGENCY PROCEDURES ...................................................................................................................... 8

MOTOR FAILURE....................................................................................................................................... 8

COMMUNICATION FAILURE..................................................................................................................... 8

RADIO CONTROL LINK FAILURE............................................................................................................. 9

LOW BATTERY POWER............................................................................................................................ 9

GROUND CONTROL STATION FAILURE............................................................................................... 10

COMPASS CALIBRATION ERROR ......................................................................................................... 10

ON BOARD FIRE...................................................................................................................................... 10

FORCED LANDINGS................................................................................................................................ 10

MANNED AIRCRAFT IN THE VICINITY................................................................................................... 10

NORMAL PROCEDURES............................................................................................................................ 11

PREFLIGHT CHECKLIST......................................................................................................................... 11

VALIDATE CENTER OF GRAVITY (CG) ................................................................................................. 11

COMPASS CALIBRATION PROCEDURE ............................................................................................... 13

TAKEOFF.................................................................................................................................................. 14

POST LANDING ....................................................................................................................................... 15

AIRCRAFT LOG BOOK......................................................................................................................... 15

AIRCRAFT MAINTENANCE LOG BOOK ............................................................................................. 15

PILOT LOG BOOK ................................................................................................................................ 15

UAS PERFORMANCE................................................................................................................................. 15
RPAS USER OPERATIONS MANUAL

3 |	Page

FLIGHT TIMES ......................................................................................................................................... 15

WIRELESS TRANSMISSION ................................................................................................................... 16

WEIGHT AND BALANCE............................................................................................................................ 16

CENTER OF GRAVITY (CG).................................................................................................................... 16

WEIGHT.................................................................................................................................................... 17

UAS DESCRIPTION..................................................................................................................................... 17

FLIGHT BATTERY REQUIRED................................................................................................................ 17

WIRELESS COMMUNICATIONS............................................................................................................. 18

HANDLING, SERVICE AND MAINTENANCE............................................................................................. 18

PROPELLER CARE.................................................................................................................................. 18

BATTERY CARE AND USE...................................................................................................................... 18

PREVENTATIVE MAINTENANCE .............................................................................................................. 21

ANNUAL INSPECTION (SUGGESTED)................................................................................................... 21

500 HOUR PM (SUGGESTED) ................................................................................................................ 21

PERFORMANCE SPECIFICATIONS

Make: Align

Model: M690L

Diagonal wheel base: 875mm
RPAS USER OPERATIONS MANUAL

4 |	Page

Frame arm length: 350mm

Center frame diameter: 240mm

Landing gear size: 350mm (Length) x 320mm (Width) x 340mm (Height)

PERFORMANCE SPECIFICATIONS (cont.):

Frame arm weight including ESC, Motor and Propeller: 356g

Center Frame weight: 550g

Landing Gear weight including battery tray: 600g

Maximum take-off weight: 6000g – 9000g
RPAS USER OPERATIONS MANUAL

5 |	Page

Total frame weight 3450g

Battery Power 6s Li-PO (10000mah – 22000mah minimum 

15C)

Max power consumption 3000W

Hover power consumption 800W (AUW 6800g)

Hover time Maximum 26minutes (22000mah @ 7600g 

AUW)

MOTORS

Stator Size: 41x14mm

KV: 370rpm/V

Max power: 550W

Weight with cooling fan: 185g

ELECTRONIC SPEED CONTROLLERS

Current: 40AMP OPTO

Voltage: 6S Li-Po

Signal Frequency: 30HZ-450HZ

Drive PWM Frequency: 8 KHz

Weight with radiators: 35g

PROPELLORS

Material: Engineering plastic

Size: 14x5 inch

Weight: 18g

TERMINOLOGY

GENERAL MULTIROTOR UNMANNED AERIAL SYSTEMS (UAS) FRAMES

Tri Copter – Multi-rotor based on 3 electric engines and 1 servo 

Quad – Multi-rotor based on 4 electric motors 

Hex – 6 motors multi-rotor

Octo – 8 motors multi-rotor
RPAS USER OPERATIONS MANUAL

6 |	Page

CONFIGURATIONS

Quad copter: X or +

Hexa copter: V Hex, I Hex, Y Hex and IY Hex 

Octo copter: V Octo, I Octo, X8 

ABBREVIATIONS

AP – Aerial Photography

FPV – First Person View

LZ - Landing Zone 

CW – Clock Wise

CCW – Counter Clock Wise

ATTI - Altitude control mode 

FLS - Failsafe Mode 

FC – Flight Controller

GCS – Ground Control Station

IMU - Inertial Measurement Unit 

IOSD - Intelligent On Screen Display

GCU - Gimbal Control Unit

PMU - Power Management Unit

VTX - Video Transmitter

VRX - Video Receiver

TX - Control Transmitter

RX - Control Receiver

Li-Po - Lithium Polymer
RPAS USER OPERATIONS MANUAL

7 |	Page

LIMITATIONS

AIRSPEED LIMITATIONS

Maneuvering Speed - 5m/s

Maximum Horizontal Speed - 15m/s

Maximum Vertical Speed - 6m/s

Max tilt Angle -30°

Max Yaw Angular Velocity -150 deg/s

WEIGHT LIMITATIONS

Maximum All Up Weight -9.0kg

POWER LIMITATIONS

Motor Maximum draw -40amps

40 Amps max per speed control -40aps

320 Amps max total 

Maximum Voltage -6s Li-Po, 22.2V 

Maximum Capacity - 22000mah

Max Power Consumption -3000W

CENTER OF GRAVITY LIMITATIONS

3mm from the center of any of the three pairs of arms 

Must be checked before every flight to ensure batteries were installed in the proper location. 

Check all 3 pairs of arms before flight

MANOEUVER LIMITATIONS

This aircraft is intended for non-aerobatic operations 

G-loading maximum: 2G

TEMPERATURE LIMITATIONS

Operating Temp Range: -10°C to +50°C 

In cold temperatures

Keep IMU at room temperature if possible before the flight 

Keep Batteries above 5°C before flight 

Do not fly with any frost or ice on the propellers 

In warm temperatures

Batteries heat up when discharged 

The higher the discharge rate the higher the temperature increase during use 

At temperatures above 45°C, use of 2 or more batteries is required to lower the load on any one battery 

pack and ensure that all batteries stay within the proscribed operating temperature limits

WEATHER LIMITATIONS

Light dust and light rain require the use of a shield for the electronics in the center section

Light dust and light rain are acceptable for the unshielded motor and ESC

Maximum Wind Resistance 45km gusts 
RPAS USER OPERATIONS MANUAL

8 |	Page

EMERGENCY PROCEDURES

MOTOR FAILURE

Operation is possible with one motor/ESC/propeller failure 

The two adjacent motors/ESCs will be increased in thrust automatically by the flight controller to overcome 

the loss 

In cases where the airframe is highly loaded the maximum rating of 40 amps may be exceeded by these 

two motors/ESCs 

Operation should be terminated as soon as possible to reduce the possibility of damage to the remaining 

motors 

COMMUNICATION FAILURE

Video link failure 

5.8 GHZ being the shortest wavelength in general AV use has the least ability to penetrate. This link should 

be the first to be lost. 

It is best to lose video first! It is the least likely to cause a crash when it fails. 

5.8 GHZ can lose link with little warning. 

Ensure that the GCS station antennas are perpendicular to the AV. Do not point the antenna at the AV. 

Yaw the AV to change the antenna position 

Other links should still be good. 

Return back to the GCS until link is restored. 

Transmitters produce heat when in operation. When overheated they may have thermal protection which 

interrupts use temporarily. Use of a heat sink or fan may be required especially with high ambient 

temperatures. 

Higher gain antennas may be used, but do so with caution. High gain antennas are directional. 

Multiple antennas using “diversity” can be used. Diversity is a technique, which determines the best signal 

to use based upon its strength.

5.8 GHZ even at high wattages theoretically has less range than lower frequencies. 
RPAS USER OPERATIONS MANUAL

9 |	Page

EMERGENCY PROCEDURES (cont.)

RADIO CONTROL LINK FAILURE

2.4 GHZ antennas can lose link with little warning. 

Anything in between the two antennas can cause temporary signal loss especially an individual. 

Hold the transmitter up in the air and walk in the general direction of the UAS. 

Ensure that the antenna is vertical. Do not point the antenna at the AV. 

The failsafe on the RC link should be set so that the UAS returns to home. Should this require a heading 

change, the antenna may move into a more desirable position and link will be restored. 

The onboard equipment may block the signal. Yaw the UAS so that the antennas point towards the GCS. 

A LRS (long range system) can be used as a permanent solution. This is higher in Wattage and usually on 

433 MHz 

DATA LINK FAILURE

900 MHz signals do not lose link without some warning. When drop-outs are noticed it is best to switch to a 

higher frequency that is still within the limit of the operational range of the UAS.

If using 900 MHz, this may be a cell phone frequency. If a cell tower is nearby it can swamp the signal. 900 

MHz may not be usable in that area. Change to a different frequency or remain closer to the UAS.

LOW BATTERY POWER

Fail safes can be set such that in the event of low battery power, either due to a failure or too long of a 

flight, the warning light on the UAS will constantly flash amber. This is the first level of warning. 

The second warning level is red flashing light. 

Auto landing will occur when battery power is low. It may land in a tree or a lake, so this is not desirable. 

Landing with 80-90% of battery depleted is best. 

For Example: Flying with a 20,000 mah battery - landing with at least 3,000 mah remaining of a 20,000 mah 

battery is desirable. 

Batteries should be drawn down equally when in use if they are both charged equally and both in relatively

the same condition/age. 

Do not mix partially charged batteries. Only use completely charged batteries. 

Excess discharging of a battery below 19.8V can permanently damage the battery. 
RPAS USER OPERATIONS MANUAL

10 |	Page

EMERGENCY	PROCEDURES (cont.):

GROUND CONTROL STATION FAILURE 

Takeover by the external pilot should happen ASAP using the RC link. 

Most often happens due to a low battery. 

Keep a spare 3 cell Li-Po battery with the appropriate plug to plug into the charge jack for emergency use. 

Most chargers are 19V output, which is roughly equivalent to a 4-cell battery. 3-cell batteries may work. 

COMPASS CALIBRATION ERROR

If the compass is out of calibration the warning light will flash red. This is the same signal as low voltage. If 

the voltage is correct, there is a calibration error. 

Recalibrate the compass following the instruction manual.

ON BOARD FIRE

Fires can occur due to a short circuit or battery failure. 

Disconnect the battery ASAP unless there is danger in doing so if there is any electrical issue. 

It is not possible to put out a battery fire. 

Do not attempt to put out a battery fire. Use a fire extinguisher to put out fires surrounding the battery. 

A CO2 fire extinguisher is better than the powder or chemical type extinguishers. 

CO2 does not leave a residue. Water can be used though it may cause other electrical component failures. 

FORCED LANDINGS

If alternate emergency landing zones should be chosen ahead of time. 

Be sure that the LZ is clear of people to avoid any incidents. 

Land in the nearest LZ, which is clear of people. 

Announce your intentions of landing as loud as necessary to alert people of the incoming UAS

MANNED AIRCRAFT IN THE VICINITY

On hearing another manned aircraft (VISUAL SIGHTING IS NOT REQUIRED) - LAND THE UAS 

IMMEDIATELY

Select a LZ that is clear of all obstacles, property and individuals

Manoeuver the UAS to an altitude approximately 10 meters above the LZ

Keep the UAS in LOS at all times

Proceed to land the UAS expeditiously in the selected LZ

Conduct Post Flight procedures

No further flights are permitted until the area has been visually cleared of all manned aircraft.
RPAS USER OPERATIONS MANUAL

11 |	Page

NORMAL PROCEDURES

PREFLIGHT CHECKLIST

Confirm all communication radios are operational 

Establish radio contact with ATC (if available and/or required)

Establish radio contact with other members in the group 

Set a perimeter of 100 meters 

Area must be clear of people to avoid potential injuries/fatalities

Check for overhead power lines and other obstacles to avoid 

Check structural integrity of UAS

In event of prior crash, inspect all booms, props and motor mounts for excessive flex indicating structural 

fatigue/failure 

Prepare a manual flight plan avoiding obstacles. 

Load auto flight plan if using one via Ground Control Station

Be sure that the total flight time is under 10 minutes to avoid low battery 

Ensure that the straps are tight and the Velcro keeps the batteries from moving which will avoid a shift in 

the CG (Center of Gravity – or that it balances evenly) 

VALIDATE CENTER OF GRAVITY (CG)

Lift the copter on each of the 3 pairs of arms. The UAV should remain leveled. If not, do not fly. 

Rearrange the equipment such that the CG is correctly balanced

IMU pointing forward - the Inertial Measurement Unit is set so that it must face forward 

GPS/Compass installed, limited free play, pointing forward - this device must be installed with a screw to 

hold it in place. It should not vibrate easily. 

If it does not point forward, the in-flight auto corrections in ATTI and GPS mode will be incorrect.

The FC will provide a warning with constant flashing white lights. 

Level copter using a bubble level with front pointing in correct direction for course lock – do not turn on 

Keep in mind the best angle for pointing the landing gear in the direction that will keep the landing gear out 

of the shot when flying. 

Turn on Pilot Transmitter (TX) - If using the rate gyro, set it at the correct position. This is usually a slider 

switch. Gains should have the range set from 200 – 350. Use the highest gain possible, which does not 

cause 

Oscillation. 

Check Model Selection on TX to be M690L

Throttle on TX - Full Down Position

Return to Home switch - OFF

Adjust gain to correct position (if required) 

Manual Flight Mode Switch to MANUAL (not ATTI or GPS mode) 

Flight Path Switch - Off – Not Course or Home or POI 

Check TX battery voltage - Must be above 7.5v
RPAS USER OPERATIONS MANUAL

12 |	Page

NORMAL	PROCEDURES (cont.):

These settings above are required to initialize the copter properly. If the switches are in the incorrect 

position, it will not initialize properly which may cause some of the functions like course lock or GPS mode 

to not operate properly.

If the copter does not function properly after takeoff, land immediately and disconnect the multi-copter

power. Then put all the switches in the proper position for initialization and Turn the power back on to the 

copter. 

Engage power to copter - Plug in the 2 battery packs. Typically the battery packs use red T-style 

connectors in a Parallel wire harness. This Y-harness has a yellow connector. It is preferable to connect the 

batteries to the Y-harness first, and then plug in the yellow connector. This reduces (but does not eliminate) 

electrical arcing. 

6 quick chirps should be heard confirming 6S Li-Po batteries are recognized by the Electronic Speed 

Controllers. 

Hearing less than 6 chirps indicates fewer cell battery packs are being recognized which is incorrect. Check 

for improper or damaged batteries. 

Do not move or vibrate the UAS until 30 seconds after full GPS Lock 

Initial 3 red blinks is normal meaning no GPS lock. No red flashes indicates full GPS lock. 

Continue with checklist as you are waiting for full GPS lock, but do not move the copter. 

If the GPS takes more than 5 minutes to lock, there is a problem with the area. It is not receiving the proper 

signals from the satellites. GPS signals are weak, so trees, people, buildings, terrain, weather, have an 

effect. 

Move the copter into a more open area where it can more easily see the satellites. 

Check Copter Voltage from both TX’s (transmitters) 

The transmitters receive a signal from the corresponding receivers. The voltages are regulated to about 5v. 

If the voltage is below 4.4v or above 6v - do not fly. There may regulation issues. The receivers cannot 

work outside this voltage consistently. Also there is some issue if the voltage is outside that range which 

should be resolved before flying. 

Engage Attitude Mode – Must achieve double amber flash 

Engage GPS Mode – Must achieve double purple flash 

Engage course cock mode – Must achieve double green flash 

Disengage course lock mode. Must achieve double purple flash. Stay in this mode until just prior to takeoff, 

after takeoff at any time, or do not use. 

Do not engage motors. Set throttle to center position. Must achieve single purple flash when in GPS mode. 

To verify that the sticks are all centered properly:
RPAS USER OPERATIONS MANUAL

13 |	Page

NORMAL PROCEDURES (cont.):

With throttle in the center position, use the trim buttons on the transmitter to check that the sticks are 

centered. Trim the roll (the stick located on the right side of the Transmitter when moved to the right and 

left) to the right, counting the number of clicks until a double flash occurs. Then center the trim. Then move 

the trim to the left, counting the number of clicks until a double flash occurs. An equal number of clicks 

should be counted each side of center. 

Do this check for the 3 stick movements other than throttle. Center the trim such that when the stick is in 

the neutral position that there are equal numbers of clicks in each direction. This ensures that when the 

sticks are neutralized that the flight controller will recognize this signal and engage GPS mode.

COMPASS CALIBRATION PROCEDURE

Calibrate GPS/Compass before the first flight each day or if receiving continuous red blinks or continuous 

white blinks. 

Flip the GPS mode switch 7 times very quickly from manual to GPS. End with the switch in the manual 

position. The indicator light will be blue. Rotate the copter about 1.5 turns in a horizontal position. A green 

flashing light indicates that this is complete. 

Then hold the copter vertically and rotate about 1.5 turns. A white flashing light indicates that this is 

complete. Repeat if necessary until this is completed. 

After calibration, reset the copter by cycling battery with copter pointed in the correct heading for course 

lock. 

Engage Camera HDMI switch on

Verify data link if installed - Roll the copter about 45 degrees on its side by lifting one side of the copter and 

resting one side of the landing gear on the ground. A corresponding roll should be seen on the gauge. 

If the copter is rolled to the right, it will appear on the gauge that the horizon rolls to the left – not the right 

because the view from inside the copter is that the horizon rolls in the opposite direction of the copter. 

Verify altitude is about 0 via gauge on computer 

If it is not about 0, the altitude settings for the waypoints will be off by this amount. 

This could cause the copter to fly at 10 meters or 30 meters if the waypoint is set for 20 meters and the 

altitude is off by 10 meters one way or another. If the copter thinks it is at 10 meters when it is on the 

ground, then it will only rise 10 meters above the ground to achieve what it believes it to be 20 meters 

above the ground. 

The altitude can be reset using the ground control software by going to altitude offset. 

NORMAL PROCEDURES (Cont.):
RPAS USER OPERATIONS MANUAL

14 |	Page

TAKEOFF

Confirm clear for takeoff with ATC (if required)

Engage GPS mode – Double purple flash when the throttle is down. 

Switch to Course Lock flight mode if required. Purple flashes are replaced with green flashes. 

Flying in course lock is not required, but helpful in many instances. 

Announce loudly: “CLEAR PROP” 

Move both of the sticks to the bottom left corners to engage the motors. Within 1 second move the throttle 

up 1/8 – 1/4. The copter should not lift off until about 1⁄2 stick is reached. 

Verify data and video links before lifting off. If anything is not working properly, move the throttle stick to low 

to disengage the motors and determine a solution. 

If all flight checks are passed, announce loudly: “TAKING OFF” 

Advance throttle to about 3/4. UAV must jump off of the ground to avoid one skid coming up before the 

other skid, and the skid on the ground getting caught and flipping the UAV over sideways. 

Ascend to 3 meters. Then decrease throttle to 1⁄2 to engage the GPS hold:

Verify links, GPS, Attitude, etc. Should be single purple flash. 

Verify that the copter is holding position within .5m in all directions. 

Verify camera operation 

Verify course lock is operational by rotating 90 degrees and pushing forward on stick. 

Verify UAV stability. If unstable, land and reset gains, recalibrate, or retest as necessary. 

Proceed with manual mission or for autopilot operation:

Ascend to 10 meters 

Command Ground Station Controller to proceed with mission. 

Pilot should say “Your Aircraft” 

Response from Ground Station Controller should be “My Aircraft” 

Manual pilot/observer must monitor the informational LED and be ready to take over in manual mode when 

necessary:

White flashes indicates flight controller issue 

Amber flashes indicates low battery 

Red flashes indicate loss of GPS or severe battery condition 

Quick decisions are required when red flashes are indicated 

10 seconds or more of loss of GPS signal will stop waypoint guidance and any further auto flight

GPS hold and put into manual mode - Red indicator light battery warning requires immediate landing 

Manual pilot to request copter flight battery voltage readout from AVO periodically. 

Reset the first and second indicator lights as required for your set up. 

NORMAL PROCEDURES (cont.)

When recharging the batteries, the goal is to put 4,000 mah into a 5,000 mah battery pack. Adjust the 

voltage warnings to your style of flying. Also use the countdown timer on the transmitter. This gives a good 

indication of battery level because the current used is fairly constant during the flight. 
RPAS USER OPERATIONS MANUAL

15 |	Page

POST LANDING

Note flight time from transmitter. Write this down in the log book. 

Note battery power used during the flight. Write this down in the log book. 

ALWAYS disconnect the main power to the UAS first, THEN turn off the transmitter.

Check motor temperatures by touching them with your fingers. Any motors, which are excessively hot,

should be further inspected and possibly replaced. 

Check battery temperatures by touching them with your fingers. Battery temperatures should not be hot to 

the touch. Battery temperatures should be slightly above ambient. 

Inspect all components especially the propellers for wear. 

Note in logbook which batteries were used to calculate life cycle

AIRCRAFT LOG BOOK

Keep a log of all flights. 

- Date 

- Time of Day 

- Time in Operation (in hours) 

- Battery serial numbers 

- Mah used in flight 

- Location 

- Pilot, Observer, Sensor Operator Names 

- Flight Objective 

- Remarks 

AIRCRAFT MAINTENANCE LOG BOOK

Keep a log of significant inspections, tests, repairs, alterations, and equipment changes. 

- Date maintenance is performed 

- Accumulated hours of operation 

- Remarks 

PILOT LOG BOOK

Keep a log of all flights. Include the following: 

- Aircraft flown 

- Aircraft serial number 

- Date 

- Time of Day 

- Time in Operation (in hours) 

- Location 

- Flight Objective 

- Remarks

UAS PERFORMANCE

FLIGHT TIMES

The UAV is designed to hover at high efficiency. Hovering is much less efficient than flying using a fixed 

wing, thus flight times are low compared to fixed wing aircraft. 
RPAS USER OPERATIONS MANUAL

16 |	Page

All the weight of the UAV is supported by power from the batteries. As the batteries are used in a flight, the 

amount of power available decreases. Therefore the power reserve is constantly decreasing as the battery 

is being used. Thus loading a rotorcraft above its limit is not recommended. While the UAV may have 

enough power to lift off initially on a full charge, the power reserve at partial charge may be too low to allow 

for maneuvering and will result in an uncontrolled flight and possible uncontrolled impact with terrain and/or 

obstacles.

High lateral speeds will add lift to slightly improve efficiency. The rotors act similar to fixed wings at higher 

speeds. This increase in efficiency may be negated by the increased power consumption of forward flight. 

High winds or gusts decrease efficiency/flight time. The motors work harder to hold position. 

As weight increases flight times decrease. 

WIRELESS TRANSMISSION

Refer to the specific manuals for performance ratings. 

Wireless communications utilized provide acceptable communication for Line of Sight. In general: 

- LOS is required 

- The higher the GCS antennas, the better the range 

- Any frequency may have severe degradation due to location to other factors such as cell towers 

- RSSI (Received Signal Strength Indication) should be monitored for indication of communication 

drop out.

WEIGHT AND BALANCE

CENTER OF GRAVITY (CG)

CG is critical to the efficient operation of any UAS

When components are shifted, the CG will be altered. 

The main components, which are moved on a regular basis, are the sensors and the batteries. 

The sensors are typically in the front of the UAS, and the batteries are located in the correct position to 

offset all the components on the UAS. 
RPAS USER OPERATIONS MANUAL

17 |	Page

The CG must be tested after any change to the components or their placement. 

The CG should be tested by lifting the UV with fingers on the bottom of the arms. Check all 3 pairs of arms. 

The CG should be no more than 2mm off in any on the 3 checks. 

The closer the CG is to the centerlines of the arms the more efficient and the more stable the UAS will be. 

WEIGHT

Weight is critical to the operation of any aircraft 

Weight is especially critical to a rotor wing aircraft. At full throttle the motors have a finite amount of thrust. 

All the weight is lifted by the battery power, there is no wing to assist in providing lift. 

As the batteries are operated, they lose power. At full charge they have about 25v. At 20% remaining 

capacity they have about 21v. This is a loss of 8% of the power available which is significant. 

Do not overload the aircraft or there will not be sufficient reserve power to maneuver at low battery levels.

UAS DESCRIPTION

FLIGHT BATTERY REQUIRED

Manufacturers: Various COTS suppliers 

Battery chemistry recommended: Lithium Polymer 

Battery Capacity: up to 21,000 mah or greater depending on max gross weight 

Battery cell count required: 6S (6 cells in series) 

Battery Voltage: 21V minimum during hover, 22.2V nominal, 25.2V maximum 

Battery Minimum Rated Discharge Rate: 20C minimum 
RPAS USER OPERATIONS MANUAL

18 |	Page

Battery Minimum Charge Rate: 1C (3C preferable) 

Battery Rest Time between discharging and charging: 0-30 minutes 

Batteries used simultaneously: typically 1 

Recommended Battery Discharge Amount: 80-90% 

WIRELESS COMMUNICATIONS

Refer to the specific manuals for performance ratings. 

Never power a video transmitter or receiver without an antenna connected or overload failure will occur. 

Wireless communications utilized provide acceptable communication for LOS. 

In general: 

LOS is required. 

Lower frequencies penetrate objects such as trees better than higher frequencies. 

Lower frequencies have longer range than high frequencies 

Higher frequencies can transfer more data than lower frequencies

Higher frequencies use smaller/shorter antennas 

The higher the GCS antennas, the better the range and reception 

Any frequencies at may have severe degradation due to location to other admitters such as cell towers 

Range must be constantly monitored. 

Alternate antenna types may be utilized to improve link/range. Patch, helical, Omni, etc. can be substituted. 

They must be verified before use. 

Alternate frequencies may be utilized to improve link/range.

HANDLING, SERVICE AND MAINTENANCE

PROPELLER CARE

Propellers must be checked each flight for nicks or cracks 

Propellers are designed to last indefinitely if they do not impact dust, dirt or more. 

BATTERY CARE AND USE

Refer to instruction sheet included from the battery manufacturer. Typical information follows. 
RPAS USER OPERATIONS MANUAL

19 |	Page

Batteries are highly flammable and can explode, especially when fully charged. Improper charging, 

vibration, impact, high discharge, etc. can lead to explosion and fire. Batteries must be charged under 

constant supervision and using proper precautions. 

Batteries fully charged must be handled with extreme care. 

Any battery which puffs up is considered damaged and must not be used. It is in a dangerous state. Never 

charge a puffed up battery. 

Any battery which holds less than 80% of its rated capacity should be discarded. 

Cycle test each battery after every 50 cycles or if a battery is suspected to have lost as significant amount 

of its capacity to determine the current capacity. 

Properly dispose of batteries. First discharge the battery fully using a battery cycler. Bring to a recycler 

such as a home improvement store. 

Always charge flight batteries under “balance” mode. 

Flight Battery Recommended Charge Rate: 1C which takes approximately 1 hour to charge 

Flight Battery Maximum Charge Rate: May exceed 5C. Charge rates higher than 1C will decrease life 

cycles. 

Maximum charge rating per the manufacturer will provide 300+ cycles. 

Use the lowest charge rate which is practical. 

Battery Rest Time between discharging and charging: 30 minutes minimum, 1 hour maximum. 

Do not charge if the battery is more than 2°C warmer than ambient, especially if the temperature is above 

20°C. The outer surface is cooler than the inner core after use. Damage will occur when charging a warm 

battery. 

Do not exceed 80-90% discharge of rated battery capacity 

Do not charge batteries which are warmer than air temperature 

Allow batteries to cool after use before charging 

Leave an air gap between batteries when multiple batteries are used simultaneously Recommended 

Battery Discharge Amount: 80%. Using more of the capacity of the battery will decrease the life cycles 

HANDLING, SERVICE AND MAINTENANCE (cont.)

As battery temperature approaches freezing the capacity of Lithium Polymer batteries decrease. Keep 

warmer than 5°C before installing into the UAS. 

Battery capacity decreases at higher discharge rates. Using more batteries decreases the discharge rate of 

each battery thereby extending individual battery capacity slightly. 

Lower discharge rates improve the life cycles. 

Batteries are rated at greater than 300 life cycles. 1,000+ life cycles are possible. 

Batteries must not be stored above 60% charged state for extended periods. 
RPAS USER OPERATIONS MANUAL

20 |	Page

Batteries should be stored below 25°C for extended periods 

Store batteries between 40% - 60% charged state. Fully charge just before use. 

Fully charged batteries which are not to be used within 24 hours should be discharged to 40% 

- 60% charged state using the battery discharger. 

Using more than one battery at a time requires the proper wiring harness so that the voltage is no more 

than 25.2V. Over voltage will cause serious damage to electrical equipment.
RPAS USER OPERATIONS MANUAL

21 |	Page

PREVENTATIVE MAINTENANCE

ANNUAL INSPECTION (SUGGESTED)

If the airframe has in excess of 300 hours in a one year period, an annual inspection must be completed by 

an approved technician. 

An approved technician should disassemble the AV and inspect all components for wear and replace any 

components as required. 

Test all batteries for capacity. 

Upgrade firmware and software to latest revisions 

500 HOUR PM (SUGGESTED)

An approved technician should disassemble the AV and inspect all components for wear and replace any 

components as required. 

Replace all motors. 

Test all batteries for capacity. 

Upgrade firmware and software to latest revisions.
RPAS USER OPERATIONS MANUAL

22 |	Page