Airborne Information Systems

APPENDIX c

DJI s900 User’s Manual
AIRBORNE INFORMATION SYSTEMS DJI S900 USER’S MANUAL

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DJI Spreading Wings S-900 

SPECIFICATIONS

Frame

Diagonal Wheelbase 35.4 inches

Frame Arm Length 14.1 inches

Frame Arm Weight (Including Motor, ESC, Propeller) .7 pounds

Center Frame Diameter 10.7 inches

Center Frame Weight (With Landing Gear Mounting Base, Servos) 2.6 pounds

Landing Gear Size Length 18.1 inches

Width 17.7 inches

Height 14.2 inches

Motor

Stator Size 1.6 x .6 inches

KV 400rpm/V

Max Power 500W

Weight (With Cooling Fan) 6.6 ounces

ESC

Working Current 40A

Working Voltage 6S LiPo

Signal Frequency 30Hz ~ 450Hz

Drive PWM Frequency 8KHz

Weight (With Radiators) 1.2 ounces

Foldable Propeller (1552/1552R)

Material High strength performance engineered plastics

Size 15 × 5.2 inches

Weight .4 ounces

Flight Parameters

Takeoff Weight 10.4 ~ 18.1 pounds

Total Weight 7.3 pounds

Battery LiPo (6S、10000mAh~15000mAh 15C)

Max Power Consumption 3000W

Hover Power Consumption 1000W (@6.8Kg Takeoff Weight)

Hover Time 18min (@12000mAh 15 pounds TO Weight)

Working Environment Temperature -10 °C ~ +40 °C

Gain Value Settings (A2 Flight Controller)

Basic: Roll 110%

Pitch 110%

Yaw 120%

Attitude: Roll 220%

Pitch 220%

Vertical 120%
AIRBORNE INFORMATION SYSTEMS DJI S900 USER’S MANUAL

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FLIGHT CHARACTERISTICS AND FEATURES

 Automatic one motor fail compensation 

 Return to launch feature

 Rotation around a GPS waypoint

 Automatic descent and land

 Loss of communication RTL

TELEMETRY

 Speed

 Altitude

 Distance from transmitter

 Distance from launch

 Battery remaining

 Voltage

LINKING PROCEDURES

1. Turn on the transmitter, it begins to send signals after 1.5 seconds

2. Power on the flight control system, configure the Receiver type as DR16 in the Assistant software

3. Press the LINK button, hold for 2 seconds, wait until the LED blinks Red

4. Release the LINK button, the LED turns Green indicating successful linking

GPS ANTENNA ORIENTATION

1. The DJI logo should be facing the sky, with the orientation arrow pointing directly to the nose of 

the aircraft; otherwise it may lead to takeoff failure.

2. Fly the aircraft in an open space and away from buildings and trees; otherwise it may have an 

effect on the GPS.

3. The compass is sensitive to magnetic interference. It should be far away from electronic devices, 

otherwise it may lead to abnormal flight.

4. Always keep the compass module away from magnetic fields; otherwise it may damage the 

compass module and cause abnormal control.

COMPASS CALIBRATION 

The compass can assist the GPS to position the aircraft. The compass is very sensitive to electromagnetic 

interference, and can cause abnormal compass data and lead to poor flight performance. Compass 

calibration must be performed prior to the first flight of each day. Calibration must occur outdoors and 

after the controller unit finds 6 or more GPS satellites. Regular calibration enables the compass to keep 

optimal performance. 

CAUTION!

DO NOT calibrate the compass where there is strong magnetic interference, such as 

magnetite or steel reinforced concrete.

DO NOT carry ferromagnetic materials, such as keys or cell phones with you during 

calibration.
AIRBORNE INFORMATION SYSTEMS DJI S900 USER’S MANUAL

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Calibration Procedures

Choose an open space to carry out the following procedures.

Situations Requiring Recalibration

Situations Descriptions

Compass Data abnormal LED blinks yellow and green alternatively (∝)

Flying field altered Flying field has changed over a long distance

Mechanical alteration The mounting position of GPS-COMPASS PRO module changes

Electronic units such as Controller Unit, CAN-HUB, battery etc. have been 

added, removed, remounted 

Mechanical structures of the aircraft have changed

Drifting during flying Evident drifts occur in flight. For example, the aircraft doesn’t fly straight

Attitude errors LED often blinks error indicator when the aircraft turns around

PREFLIGHT INSPECTION CHECKLIST

 The Transmitter battery is fully charged

 The aircraft battery is fully charged

 Aircraft is loaded within limitations

 All parts are in good condition, no aging or damaged components

 Motor rotation direction correct

 Propeller installed correctly

 Mixer Type set in assistant software

 IMU and GPS-COMPASS PRO mounting orientation correct

 Transmitter channel mapping and stick movement correct
AIRBORNE INFORMATION SYSTEMS DJI S900 USER’S MANUAL

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 Compass calibration completed

 ESC connection correct

 IMU and GPS-COMPASS PRO firmly mounted

PREFLIGHT CHECK

 Power on the Transmitter and flight control system. 

 Toggle the control mode switch to each position and check for correct indication.

Control Mode LED indicator 

Control 

Mode 

Switch

Up - GPS Center - ATTI 2 Down - Manual

LED Stick not in midpoint (2) Stick not in midpoint (2) No LED indicator

Set Put the Control Mode switch to GPS position for basic flying test

Note: when the GPS signal LED indicator is bad (2) , very bad (3) , or lasts for more 

than 3 seconds, the flight control system will enter into ATTI 2 Mode.

 GPS signal indicator blinks after every change in control mode. 

CAUTION: Flight with less than 5 satellites is not recommended.

GPS signal LED indicator

Very Bad: <5 Satellites Bad: 5 Satellites Good: 6 Satellites Very Good: >6 Satellites

3 Red Blinks 2 Red Blinks 1 Red Blink No Indication

Motor Starting Methods

CSC (Combination Stick Commands) are used to start/stop motors instead of moving the throttle stick

forward.

Under the conditions stated below, the motors will stop in ATTI 1/ATTI 2/GPS mode:

 The throttle is under 10% for more than 3 seconds after motors start

 The throttle is under 10% for more than 3 seconds after landing

 The throttle is under 10% for more than 3 seconds and the angle of aircraft exceeds 70°
AIRBORNE INFORMATION SYSTEMS DJI S900 USER’S MANUAL

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BEFORE FLIGHT CHECKS

 With the aircraft at least 10 feet away from the transmitter, wait until the receiver has acquired 

at least 6 satellites. (Red LED goes out.)

 Push throttle forward to accelerate motors

The LED (∝) will illuminate indicate the home point has been recorded. 

NOTE: The home reference will automatically be recorded 30 seconds after power is 

turned on, 10 seconds after 6 satellites are acquired, and when throttle is advanced to 

takeoff power.

 After the home point is recorded successfully and the distance from aircraft is less than 25 feet,

the LED indicator will blink violet continually when the GPS signal is good. 

RUNUP
AIRBORNE INFORMATION SYSTEMS DJI S900 USER’S MANUAL

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WARNING!

 Rapidly blinking Yellow or Red LED: Low voltage

 Blinking Blue LED: Fail Safe

 Yellow and Green LED alternating: Abnormal compass data

 Green LED blinks 4 times: Abnormal IMU data

TEST FLIGHT CHECKS

Fail Safe and Go Home Procedures