N3 DJI Flight Control Unit (FCU)

The DJI website (DJI, N3 Designed for reliability, n.d.) features the N3 flight controller which is part of the NAZA series of DJI family of control units that caters to both industrial and hobbyists drone applications. The function of the flight control unit is the overall flight system and command of a drone that replicates the controls of the pilot. The N3 system consists of a flight control unit, GPS compass antenna and Power Management Unit (PMU).

The N3 flight controller (DJI, N3 Designed for reliability, n.d.) supports a wide spectrum of upgradability with DJI’s eco system of products such as camera gimbals like the DJI Ronin-MX series (DJI, RONIN-MX, 2024) and flight devices such as Lightbridge 2 (DJI, LIGHTBRIDGE 2, 2024) and TAKON™ series (DJI, TAKYON SERIES , 2024) for electronic speed controllers.

Its software feature is a fault tolerance control that allow UAS to execute a controlled decent in an event of an imminent crash. This is a notable safety feature that is built into the flight controller that will not only minimize damage during crash but would also prevent drones from gaining lethal momentum that could lead to casualties.

The DJI N3 flight controller is a reliable, robust, safe platform for custom built drones, and it is highly recommended in operating in a densely populated country like Singapore. However, a successful flight mission would still depend on skills and intuitive judgement of a drone operator albeit the sophistication of the FCU and its safety features.

The flight controller contains a dual Inertial Management Unit (IMU) for built in redundancy which enhances flight reliability. For example, if one of the IMU is down the secondary unit can regain control which prevents the UAS from crashing or moving in an undesired direction.

In addition, the flight control unit also has a robust 8GB industrial black box that records performance and real time flight data. This allows pilot to troubleshoot potential issues and fine tune the aircraft for a safer flight. The aircraft can be configured using software such as DJI Assistant 2 or phone application DJI GO. Singapore is known for to be a concrete jungle that is densely packed with buildings hence it could risk a signal lost or GPS jamming due to metal structures. Having a dual redundancy system on a drone would be an important asset in drone operation in Singapore.

The Unmanned Aerial System (UAS) can use the GPS GNSS antenna to gain a reference to maintain a stable flight path during operations. It is a CAAS requirement for operators to provide details of drone flight path when applying for permit. A GPS system would mean that drone would have a reference on its positioning which would allow it to actively traverse its planned flight path.

Hence, this makes the N3 DJI flight controller a formidable choice for drones to operate in Singapore and adhering to the guidelines of CAAS.

A Straits Times news article reports a drone had deviated from its planned route due to a faulty positioning sensor which resulted in a crash on the grounds of One-North Residences.

(Lim, 2024) reports a company suspended from drone operations after device crash-lands on one-north condo grounds. The Straits Times.

Being a drone operator myself incidents like these deeply resonates with me as this undesired situation can happen to both new and highly experienced pilots. DJI’s N3 flight controller has a feature called fault tolerance control which allows the drone to execute a controlled decent in an event of a crash due to propulsion lose with one or two of its rotors. The caveat is that this feature would only work on hexacopters and octocopters as these drones have sufficient rotors to stabilize themselves in an event of a propulsion failure.

If the pilot experiences a propulsion failure while flying a quadcopter, he or she would experience an inevitable crash. As drone systems get progressively sophisticated packed with features like autonomous flying, tracking and the ability to avoid objects with its sensors. A drone may still lose GPS signal due to interference from jammers or metal structures of the building that causes the drone to switch from GPS mode to altitude mode. Hence companies providing UAV services cannot rely entirely on the autonomous features of the drone for a safe flight mission. A certified drone operator is trained to execute necessary protocols in an event of sensors failure and lose of GPS signals. he or she can control the drone in adverse wind conditions to stay within safe flight path. The skillset and training of the pilot will be critical in piloting the drone during an emergency to ensure a safe landing to prevent crashes which results in serious incidents. This makes a drone operator imperative when conducting any flight operations in Singapore.

In conclusion, the technology behind the FCU packed with safety features may be impressive. But the vigilant of a drone operator and their skillset is what stand between a successful flight mission or a crash incident