2.5 - Weeding out a Solution

Scenario Analysis

The biggest problem to this scenario is the weight constraints that revolves around the two subsystems which are acquired off-the-shelf (OTS). Being OTS, that means the designs are not catered to fit the specific requirement of the precision crop dusting UAS.  Safety was highlighted as a concern should there be any change in the fuel margin and this is of paramount importance compared to the adequacy of fertilizer for the crop dusting operation.

Cutting the weight

As a system engineer, I will need to gather both teams together and explore whether is there any possibility of cutting off some weight from the OTS hardware. In most circumstances the likelihood of doing so is high since both OTS subsystems might not have been designed with weight-savings as priority. At the same time, these subsystems may have other functional hardware that are not applicable and can be removed. Moreover, even though these two subsystems have gone beyond their allotted weight limits, reducing the weight of these two subsystems might not be the only viable solution. The other subsystems such as the airframe, propulsion, etc., could use other alternative parts which are lighter. For example, the airframe of the UAS might be using aluminum which might require other supporting mechanical structures since aluminum is light but not as strong as other composites. This subsystem can be replaced by carbon fiber which has much better strength to weight ratio, making it a better material for making the airframe than aluminum (Dragonplate, 2016).  This will then allow doing away with the supporting mechanical structures, resulting in further weight savings.

Safety

As a system engineer, the ultimate goal is to manage the project in a way that allows the safe operation of the completed UAS. Even if the various subsystems are designed to integrate seamlessly together in a unit that provides the best performance, it is unacceptable if the crop dusting cannot be done safely. Therefore, there is always a need to perform verification and validation to ensure that the system can perform in the most optimized and safe manner. The certificate of authorization (COA) for the commercial crop dusting operation can only be issued by FAA if the proposed operation “can be conducted at an acceptable level of safety” (Austin, 2010, p. 88).

Future prospects and challenges

The crop dusting UAS can be further customized to include the capability of carrying other thermal IR sensors to monitor the health of the crops. This will enable the same UAS to be used for both crop health monitoring and crop dusting, thus a dual use capability by just swapping out the payload for the chosen application. This can be further discussed with the customers. Future roles of system engineers can get more challenging due to the increasing complexity of aircraft systems. Traditional system engineering methods may not work as well as the past, and system engineers’ abilities to predict the outcome of any decisions and actions may erode (Pennock & Wade, 2015).

References

Austin, R. (2010). Unmanned aircraft systems: UAVs design, development and deployment. West Sussex, UK: John Wiley & Sons.

DragonPlate (2016). What is carbon fiber? Strength, stiffness and comparison with other materials. Retrieved from https://dragonplate.com/sections/technology.asp

Pennock, M.J., & Wade, J.P. (2015). The top 10 illusions of system engineering: A research agenda. Procedia Computer Science, 44(1), 147-154.