PILOT OPERATING HANDBOOK

DJI S-900/Zenmuse H3-3D Gimbal

http://www.airvidz.net
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Document Change Log

Change Record

Date Page/Paragraph Description of Change Change Author:

9/10/2015 Entire Document Initial Release Mark A. Olivet

9/15/2015 Entire Document Formatting Mark A. Olivet
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DJI S900 Specifications

The DJI S900 is designed as a “heavy carrier” for equipment such as the Panasonic GH3/4 cameras, the Blackmagic 

Cinema camera, or the Canon Mark II/III cameras. However, this particular S900 owned by AirVidz LLC has been 

retrofitted for a smaller gimbal and camera, the Zenmuse H3-3D and GoPro Hero 3+ camera. The following are 

specifications for the DJI S900, including this customized configuration:

Frame

 Diagonal Wheelbase 900mm

 Frame Arm Length 358mm

 Frame Arm Weight(with Motor, ESC, Propeller ) 316g

 Center Frame Diameter 272mm

 Center Frame Weight (with Landing Gear Mounting Base, Servos) 1185g

 Landing Gear Size 460mm(Length)×450mm(Width)×360mm(Height)

Motor

 Stator Size 41×14mm

 KV 400rpm/V

 Max Power 500W

 Weight (with Cooling Fan) 158g

ESC

 Working Current 40A

 Working Voltage 6S LiPo

 Signal Frequency 30Hz ~ 450Hz

 Drive PWM Frequency 8KHz

 Weight (with Radiators) 35g

Foldable Propeller (1552/1552R)

 Material High strength performance engineered plastics

 Size 15×5.2inch

 Weight 13g

Flight Parameters

 Takeoff Weight 4.7Kg ~ 8.2Kg

 Total Weight 3.3Kg

 Power LiPo Battery (6S,10000 mAh, 25C or 6S,16000 mAh, 25C)

 Max Power Consumption 3000W

 Hovering Power Consumption 1500W (@6.8Kg Takeoff Weight)

 Hovering Time 22min (@16000mAh& 6.8Kg Takeoff Weight)

 Working Environment Temperature -10 ~ +40 C
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Take Off Weights

 With Zenmuse H3-3D Gimbal and GoPro Hero 3+ Camera

o With Pulse 16000 mAh Battery: 14 lbs

o With Pulse 10000 mAh Battery: 13 lbs

Flight Times

 With Zenmuse H3-3D Gimbal and GoPro Hero 3+ Camera

o With Pulse 16,000 mAh Battery: 20+ minutes

o With Pulse 10,000 mAh Battery: 12+ minutes

NOTE: These times are averages, and are based on LIPO usage of no more than 15% (3.6v remaining per cell).
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Checklists

DJI S900 Bench Setup and Tests – To Be Conducted at Beginning of Each Operational Day

☐ All screws/bolts are tight.

☐ Timer alarm for flight time to not exceed 80% battery capacity.

☐ For PULSE 16,000 mAh Battery: Set Tx Timer to 20 minutes.

☐ For PULSE 10,000 mAh Battery: Set Tx Timer to 12 minutes.

☐ Batteries are secure.

☐ Antennas are secure.

☐ Props balanced.

☐ Props aligned.

☐ Props not chipped.

☐ Check blades, arms, etc. for cracks/damage.

☐ Wiring strapped down and protected from abrasive surfaces.

☐ No excessive flexing of motors or booms.

☐ Booms/motors will not twist.

☐ Center of gravity is correct.

☐ DJI A2 software is at CURRENT VERSION.

☐ DJI iOSD Mark II software is at CURRENT VERSION.

☐ DJI Zenmuse Gimbal software is at CURRENT VERSION

☐ DJI A2 IMU Calibrated.

☐ DJI A2 Compass Calibrated.

☐ Warning lights set for low battery:

☐ DJI A2 Controller First Level Alert: 21.6v (yellow flashes; approximately 5 minutes flight time 

remaining, proceed to landing).

☐ DJI A2 Controller Second Level Alert: 21.0v (aircraft will automatically reduce power for immediate 

descent; pilot must expedite landing).

☐ Flight batteries FULLY charged (minimum of 24.0 Volts for 6S LiPo). Replace any battery which cycles below 80% 

of rated capacity.

☐ Laptop battery charged (minimum of 12.0 Volts for 3S Lipo).

☐ Video Monitor Battery (minimum of 12.0 Volts for 3S Lipo).

☐ RC Tx Battery (minimum of 12.0 Volts for 3S Lipo).

☐ Video Rx Battery (minimum of 12.0 Volts for 3S Lipo).

☐ Spare laptop battery.
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DJI S900 PreFlight Checklist – To Be Conducted Prior to EACH Flight

☐ Ground station setup and READY

☐ Ground station video Rx ON

☐ Ground station monitor ON

☐ Verify video Rx and video monitor battery voltages 

☐ Identify take-off location

☐ Verify take-off location CLEAR of power lines, trees, structures, vehicles, and debris

☐ Position S900 in take-off location

☐ Extend propeller arms

☐ Verify all propeller arms LOCKED

☐ Remove foam propeller locks, extend propellers

☐ Camera Lens CLEAN

☐ Identify emergency landing zone

☐ Verify wind LESS than 15 mph constant speed

☐ Visually verify S900 radio and video antennae SECURED

☐ Flight battery INSTALLED and LOCKED

☐ Center of gravity is CORRECT

☐ Radio Tx: all switches UP

☐ Radio Tx: ON, 

☐ Radio Tx: VERIFY battery voltage

☐ Camera lens caps OFF

☐ Camera SD card INSERTED

☐ Camera ON

☐ Camera set to RECORD

☐ UAS Power ON

☐ VISUALLY confirm home location LOCKED (20 blue flashes after minimum of 30 seconds)

☐ Set FLIGHT MODE to ATTITUDE for take-off; verify via LED and ground station monitor

☐ Set Intelligent Orientation (IOC) Mode OFF

☐ Test camera and gimbal

☐ Set gimbal to FORWARD VIEW for take-off

☐ Verify on ground station monitor UAS FLIGHT BATTERY VOLTAGE > 24.0

☐ Verify on ground station monitor ALTITUE = ZERO

☐ Verify on ground station monitor AIRSPEED = ZERO

☐ Verify on ground station monitor GPS SATELLITE LOCK > = 8

☐ Ground Observer in position and READY
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Take Off Checklist

☐ Ground Observer – in position and READY

☐ Timer set to START

☐ Set FLIGHT MODE to ATTITUDE

☐ Motor startup/checks

☐ Take-off

☐ Verify horizontal and vertical controls are FREE and CORRECT

☐ Landing gear UP

Landing Checklist

☐ Set FLIGHT MODE to ATTITUDE

☐ Landing zone CLEAR

☐ Landing gear DOWN

☐ Execute landing

☐ Engine throttle OFF

☐ Set timer to STOP

Post-Flight Checklist

☐ UAS flight battery DISCONNECT

☐ NOTE flight time on radio Tx

☐ Turn radio Tx OFF

☐ REMOVE UAS flight battery

☐ Camera recording OFF

☐ Camera power OFF

☐ Camera lens caps ON

☐ Ground station video Rx OFF

☐ Ground station monitor OFF

☐ Fold propellers and apply foam prop locks

☐ Unlock propeller arms and fold down

☐ Update UAS flight log

☐ Update battery log
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Error Messages and Abnormal UAS Flight Behavior

1.White flashes on LED

a. Indicates an IMU malfunction. Land IMMEDIATELY and determine cause. 

b. Possible causes:

i. GPS/Compass not pointing forward

ii. IMU not pointing forward

iii. Setup of X, Y, Z for location of IMU and compass is incorrect

2. Excessive rocking/instability. Possible causes:

a. Weak motor

b. Structure flexing from fatigue or cracks

i. Motor mount

ii. Main frame

iii. Booms

c. Loose Bolts causing flexing or misalignment

i. Props

ii. Mounts

d. Props out of balance

e. Props misaligned

f. Excessive wind speeds or gusts

g. Excessive Gains

h. Excessive motor power. Max motor power must a little more than typical ascent power.

3.Red Flashes on LED (1, 2 or 3 flashes with pauses)

a. GPS loss (3 is more serious). Land if loss lasts for more than 30 seconds. 

b. Possible causes

i. Clouds

ii. Structures

iii. GPS malfunction

iv. GPS too close to electrical components

v. GPS vibration

vi. Radio frequency interference on 1575.42 Mhz
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Section 1 – General

In an effort to minimize costs and maximize spare parts availability, many COTS (commercial off the shelf) 

components have been utilized. Some may have slight modifications to better suit this application. Most COTS 

products have separate data sheets, assembly manuals and instruction manuals. They are reference in this 

document, with key factors being emphasized.

As with all high technology products utilizing constantly evolving software, it is important to periodically check for 

online upgrades to the COTS components, including hardware, firmware and software.

WARNING: Great care must be taken with the batteries. Much of this manual and supplemental information is 

devoted to the use and care of the batteries, especially the flight batteries. They are less volatile than gasoline, 

though they should be treated with the same respect. Become very familiar with proper techniques of their use.

General Characteristics

 Primarily for ISR (Intelligence, Surveillance, and Reconnaissance)

 Economical due to extensive use of COTS products

 Low Visual Signature

 Low Aural Signature

 Quick Launch and Recovery

 Short Training Period

 Simple Operation

 Waypoint Navigation

 VTOL

 Quick Repairs

 Redundant Flight Systems

 Safety Return to Home during lost link or low battery

 High Degree of Mission Success

 GPS navigation aid

 Various sensors

 18 lb max takeoff weight

 Operating Temp Range: -5°C to +60°C

 Flight Modes: Manual and GPS aided waypoint navigation

 Maximum Operating Altitude: 400 feet AGL (per FAA Title 14 Regulations)

 Maximum Operation Wind Conditions: 12mph sustained

 Propulsion System: LiPo batteries

 Takeoff: Manual 

 Landing: Manual or Automatic

 Takeoff/Recovery Area: 5m square
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Important Dimensions

 Distance rotor to rotor across the center: 35” 

 Height with GPS/Compass folded down: 21” 

 Height with GPS/Compass up: 25”

 Length of landing gear skids: 17”

 Distance between landing gear skids: 18”

 Collapsed size: 22” x 19”

Important Weights

 No Gimbal

o 13.5lbs = S900 NO Gimbal and TBM 21000

o 12.3lbs = S900 NO Gimbal and TBM 15000

 GH3/GH4 Gimbal

o 17.68lbs = S900 with GH3/GH4 and TBM 21000

o 16.48lbs = S900 with GH3/GH4 and TBM 15000

Motors

 Manufacturer: DJI-Innovations

 Number of motors: 8

 Motor type: 41mm x 14mm

 Motor Model Number: 4114-11

 Motor KV/RPM: 400

 Motor max @ 25.2V: 10,000 rpm

 Motor Max Power: 500 Watts

 Power rating: 3000 Watts maximum power consumption for all 6 motors

 Current Max: 100 amps

 Amp Draw Typical Average: 55 amps

Propellers

 Manufacturer: DJI-Innovations

 Material: Composite

 Number of propellers: 6

 Propeller model number: DJI 15 x 5.2

 Number of blades: 2 - folding

 Propeller Diameter: 15”

 Propeller Pitch (fixed): 5.2”

 Max rpm: 10,000 rpm

Electronic Speed Controllers (ESC)

 Manufacturer: DJI-Innovations o Number of speed controls: 6

 Speed control model number: DJI 40A Opto

 Rating in amps: 40 Amps continuous

 Signal Frequency: 30 - 450 Hz

 Drive PWM Frequency: 8 KHz

Flight Control System

 Manufacturer: DJI-Innovations

 Autopilot Model Number: DJI A2
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 Components: GPS/Compass, IMU, Master Controller, Power Distribution System, LED Indicator Lighting System, 

Data Transceiver, GCS Software

 Power Consumption: 5W

 Operating Temp Range: -10°C to +40°C

 Software Compatible: Windows 7, Windows 8

 Hovering Accuracy: Vertical : ± 0.5m; Horizontal: ± 2m

Analog Wireless Links (Video)

 Frequencies:

o 2.4 Ghz datalink with WiFi

o 2.4 Ghz Command & Control

o 1.2 Ghz Video

 Power Consumption: <1 watt

 Usable Range: <2 km.

Flight Battery

 Manufacturer: PULSE 

 Battery chemistry: Lithium Polymer

 Battery Capacity: up to 16,000 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 Rated Discharge Rate: 25C minimum

 Battery Charge Rate: 1C

 Battery Rest Time between discharging and charging: 15 minutes

 Batteries used simultaneously: 1

 Recommended Battery Discharge Amount: Not to Exceed 80%

Flight Parameters

 Flight Time: 20+ minutes typical

 Payload Max: 9.5 lbs for battery, camera and gimbal

WARNINGS

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

 Read all information regarding batteries contained in this manual and supplements.

 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.

 Store LiPo batteries at 3.85v per cell. Fully charge just before use.

 Fully charged LIPO batteries which are not to be used within 24 hours should be discharged to 3.85v per cell.

 Discharging LIPO batteries in excess of 80% of their rated capacity can cause harm to the batteries. NEVER 

discharge a LIPO battery below 3.5v per cell.

 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.

 Using more than one battery at a time requires weight and balance checks. Proper CG is critical to performance. 

Airframe must not be overloaded.

 GPS/Compass must be facing forward.
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 Do not use GPS Mode without GPS lock (minimum of 6 satellite locks).

 Use low strength (blue) thread locking compound on all screws.

 Wireless Video and Data ranges vary considerably on many factors including weather, equipment, and 

obstructions. Be prepared for communication failures.
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Section 2 – Limitations

Airspeed Limitations

 Vne – Velocity to Never Exceed: 15 m/s (34 mph)

 Va – Typical Maneuvering Speed – 5 m/s (11 mph)

Power and Powerplant Limitations

 40 Amps max per motor

 40 Amps max per speed control

 320 Amps max total

 Do not exceed 80% discharge of rated LIPO battery capacity (3.5v per cell).

 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

Weight Limits

 Maximum take-off weight: 18 lbs

 UAS weight must be checked prior to takeoff if any change in equipment is made

Center of Gravity Limits

 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

Maneuvering Limits

 This aircraft is intended for non-aerobatic operations

 G-loading maximum: 2G

Temperature Limits

 Operating Temp Range: -10°C to +40°C

 Allow UAS to acclimate to outside ambient air temperature for at least 20 minutes prior to flight

 In cold temperatures

o Keep IMU at room temperature if possible before the flight

o Keep Batteries above 5°C before flight

o Do not fly with any frost or ice on the propellers

 In warm temperatures

o Batteries heat up when discharged

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

Weather Limits

 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 demonstrated wind speed tolerance: 15 mph sustained.

Range Limits

 Fuel

o Fuel capacity (battery capacity) is a primary limiting factor.
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 Flying into the wind will use more battery power to travel the same ground distance. Higher air speeds will be 

required to penetrate the wind which used more battery power. Take this into account when flying a mission.

 Where possible, fly upwind at the start of a mission and downwind at the end to avoid depleting the battery 

before returning to base. Have alternative landing sites available in case of emergency landing.

Wireless Link Limitations

 Wireless links will be stable in LOS (line of sight) in most conditions

 Wireless links are always susceptible to shorter ranges due to

 Atmospheric conditions

 Other transmission devices in the area

 Jamming

 Antennas not aligned properly

 Improper voltage

 Antenna blockage from AV in certain positions

 Multipath reflection off buildings or ground which cause multiple signals to arrive at different times and/or 

phase.
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Section 3 – 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

o 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.

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

o 5.8 Ghz can lose link with little warning.

o 1.2 Ghz AV can penetrate obstacles much better than 5.8 Ghz; however, be sure that the “lost link” 

feature on the DJI A2 is set so that the UAS will CLIMB to an altitude at least 20 feet higher than the 

tallest obstacle in the area prior to returning to the HOME location.

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

o Yaw the AV to change the antenna position

o Other links should still be good. Return back to the GCS until link is restored.

o 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.

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

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

and uses that.

 RC link failure

o 2.4 Ghz antennas can lose link with little warning.

o Anything in between the two antennas can cause temporary signal loss especially a person.

o Hold the transmitter up in the air and walk in the general direction of the AV (aerial vehicle).

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

o The failsafes on the RC link should be set so that the AV returns to home. Should this require a heading 

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

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

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

433 Mhz.

Low Battery Voltage

 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 AV will constantly flash amber. This is the first level of warning.

 The second warning level is red flashing lights

 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 85% (3.6v per cell) of battery depleted is best. Therefore landing with 13,600 mah used and 2,400 
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mah remaining of a 16,000 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.

 NEVER discharge a LIPO battery below 3.5v per cell, since this can permanently damage the battery.

GPS 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 LiPoly 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 Failure

 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

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. CO2 does not leave a residue. Water can be used 

though it may cause other electrical component failures.

Forced Landings

 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.
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Section 4 – 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 Usage

 Refer to instruction sheet included from the battery manufacturer. Typical information follows.

o 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.

o Batteries fully charged must be handled with extreme care.

o 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.

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

o 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.

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

such as a home improvement store.

o 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.

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

cycles

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

than 5°C before installing into the UV (unmanned vehicle).

 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.

 Batteries should be stored below 25°C for extended periods

 Store batteries at 3.85 volts per cell. Fully charge just before use.

 Fully charged batteries which are not to be used within 24 hours should be discharged to 3.84 volts per cell

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.

Preventative Maintenance

 Annual Inspection

o An approved technician should disassemble the AV and inspect all components for wear and replace 
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any components as required.

o Test all batteries for capacity.

o Upgrade firmware and software to latest revisions.

o Perform test flight prior to executing any missions.

o Document all maintenance performed in the UAS maintenance logbook.

 500 Hour Preventive Maintenance

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

any components as required.

o Replace all motors.

o Test all batteries for capacity.

o Upgrade firmware and software to latest versions.

o Perform test flight prior to executing any missions.

o Document all maintenance performed in the UAS maintenance logbook.

 10 Hour Inspection

o An approved technician should visually inspect all UAS components for wear and replace any 

components as required.

o Ensure that all firmware and software is upgraded to the latest versions.

o Recalibrate the DJI A2 Inertia Measurement Unit (IMU).

o Recalibrate the DJI A2 Compass.

o Visually inspect propellers for damage and replace as necessary.

o Perform test flight prior to executing any missions.

o Visually inspect all exposed wires for abrasions and replace as necessary.