3D Robotics Aero Operational Risk Management

The 3DR Aero is a small fixed-wing airplane constructed primarily of Styrofoam with carbon fiber reinforcement. It is widely used in third-world countries for conservation efforts. A Pixhawk autopilot performs the flight control and mission execution functions. The electric-powered aircraft is capable of carrying a wide range of small cameras pointed downward to perform mapping flights. It is launched by hand and can perform a mission in manual mode or entirely autonomously.

Figure 1. 3D Robotics Aero mapping platform.

Preliminary Hazard List (PHL)

            To my knowledge, an ORM document does not exist for the 3DR Aero. Working from personal experience with the platform, I listed the safety issues that could arise during each stage of the flight. Organization of the PHL was conducted from the template in Introduction to Unmanned Aircraft Systems by Marshall, et. al (2011). Each stage of flight is lettered, and each safety issue is numbered with Roman numerals. Risk levels were calculated via guidelines from MIL-STD-882E (2012), so higher numbers and letters indicate lower risk.

Preliminary Hazard Analysis (PHA)

            To accomplish a PHA, each issue was provided with a possible mitigating action. A residual risk was then calculated. Because this hazard analysis has not been completed before, an additional column was added to capture success of mitigating factors to make future changes to operational risk management techniques.

 

Table 1. 3DR Aero PHL/PHA.

Operational Risk Management (ORM) Assessment Tool

            The “3D Robotics Aero Flight Risk Assessment” is loosely based on the PHA but primarily focuses on environmental factors that could lead to damage or loss of the aircraft. This ORM assumes visual line of sight operation under a U.S. civil/commercial Part 107 operation with a valid night waiver and required equipment. Three basic mission types are presented, with risk for each being higher at night in all areas. This is due to the reduced situation awareness and ability to maintain separation from obstacles. As with the PHA risk mitigation factors above, the ORM would need to be tested operationally to determine the accuracy of the risk values, particularly with crews of varying experience.

3D Robotics Aero
Flight Risk Assessment
Mission Details
Date:		RPIC:
Mission:		VO:
Mission Planning					Total:
Mission Type					Day	Night
Test					3	4
Training					2	3
Support					1	2
Environmental Conditions (Forecast or Current)					Total:
Cloud Layers					Day	Night
>1000'					1	2
800-1000'					2	3
700-800'					3	4
Wind					Day	Night
1-5 kts steady, gusts <10 kts					1	2
5-10 kts steady, gusts <15 kts					2	3
10-15 kts steady, gusts <20 kts					3	4
Dewpoint Spread					Day	Night
>5 C					1	2
3-5 C					2	3
1-3 C					3	4
Mission Details					Total:
Flight Mode					Day	Night
Manual Landing					3	4
Auto Landing					2	3
Crew Selection					Total:
Experience Level					Day	Night
<10 hrs					3	4
10-30 hrs					2	3
30+ hours					1	2
Prohibited Conditions (auto no-go):				Risk Value Summary:
Clouds below 700', visibility < 1 SM				Low Risk xx-xx
Known or forecast precipitation				Medium Risk xx-xx
Relative Humidity >95%				High Risk xx-xx

References

Ardupilot Dev Team. (2016). APM: plane. Retrieved from http://ardupilot.org/plane/index.html

Department of Defense. (2012, May). Department of Defense standard practice – system safety (MIL-STD-882E). Wright-Patterson Air Force Base, OH: Air Force Materiel Command.

Marshall, D. M. B. R. K. (2011). Introduction to Unmanned Aircraft Systems. Baton Rouge: CRC Press. Retrieved from https://ebookcentral.proquest.com/lib/erau/ detail.action?docID=1449438