The Gale system is an instrument that helps to carry out the necessary measurements of cyclones in the tropics. The Gale Unmanned Aircraft System’s (UAS) goal is to provide continuous measurements of the tropical cyclone boundary layer environment to address the essential low altitude data gap in tropical systems. While difficult to detect “50+ feet of sea, over 100 knots of wind, dense clouds”, the hurricane boundary layer environment is critical to a better understanding of storm processes (“Gail’s Unnamed Aviation System,” n.d.). Although over the past 15 years, the error in predicting the trajectory of a hurricane has decreased by 50%, still, there has been no significant improvement (“Gale Unnamed Aircraft System,” n.d). In the past, land-based UAS solutions, such as the Aerosonde, have been considered, but they are ineffective and unworkable today.
The range of the mother ship, the potential of the onboard Gale UAS system for significant personnel and cost savings, no risk of entry and exit, and higher range are advantages of this system over others. The ultimate goal of Gale was to create a drop zone that would be flyable and smart and help address the insufficiencies of other systems (Embry-Riddle Aeronautical University [ERAU], n.d.). Gale will also provide a deployable WP-3D Orion unmanned aerial vehicle that can be deployed from one of the NOAA Hurricane Hunter P-3 aircraft into a tropical cyclone to measure on-site meteorological data.
Challenges
The security challenge due to the introduction into the airspace was discovered even before the development of the system, but methodologies have been developed that are aimed at ensuring the safe operation of drones. The technical problem was failures in the phases and subphases that controlled the operation of the drone and the solution was to refine the system of the apparatus. Prior to the development of this system, there were some novel challenges that the development team had to address. Therefore, as part of the procedure for approving and before providing the operating authority, the FAA conducts a safety review of a UAS and its proposed operations. This procedure, however, happens a posteriori, or after the UAS has been created. Thus, it is difficult to obtain the Certificate Authorization for such missions. Next, according to Gundlah (2012), “effective UAS design must assume much more than system performance” mainly, factors such as reliability, availability, maintainability, and supportability must be considered as well (p. 666). This project addressed this by designing a cost-effective and reusable system.
A previous attempt by Aerosonde to collect more data during a storm resulted in an aircraft loss. In addition, obtaining an authorization certificate was difficult for this system. Opportunities exist in the Gulf of Mexico’s Naval Warning Area off Key West and in the non-FAA flight information sector of Barbados. Furthermore, prolonged ingress and egress, coastal launch, and storm transition caused difficulties. This is because high winds increase the risk of aircraft loss or damage (Nazarudeen & Liscouët, 2021; Princeton University, n.d.). Vehicle endurance was lost in the transition to a large extent. Furthermore, the platform’s expense, the insurance’s underwriting, and the operational costs of having a team from AAI fly out of Australia were problems (Embry-Riddle Aeronautical University, n.d.). The performance metrics that were considered for Gale were the launch from the P-3 free fall chute, operation time of 60 minutes, and acquisition of data from a sensor board at a 2Hz rate (Embry-Riddle Aeronautical University, n.d.). The operation of the balloons at extremely low altitudes was not recommended, since it is assumed that they can be restored.
Performance
The performance indicators for Gale are wingspan, length, wing area, aspect ratio, speed, and weight. Important metrics are operating time, sensor board rate, storm transition, winds, and other indicators that can affect the takeoff. The urge to incorporate unmanned aircraft systems (UAS) into the National Airspace System has grown along with the use of UAS. UAS has distinct airworthiness characteristics across several technological fields (Cook, 2011). The requirements were developed based on the previous challenges that crewless aircraft faced and the data that Gale would need to collect, as well as the weather conditions and flight conditions the system should sustain. Wind tunnel analysis of the preliminary design has helped detect some of the issues with this system and redesign aspects such as mounting plates (Embry-Riddle Aeronautical University, n.d.). The concept and technology were developed using CFD and CAD analysis.
Development
The project had several post-systems launch upgrades, meaning that some changes were made to this project after the launch of the final product. This showed that the design of the final product could be further improved after the project was completed. The case study discusses the safety of airspace for different types of equipment. As additional lessons on UAC design, it can be highlighted preliminary design, virtual prototyping, and development sprint. The challenges when making an airworthiness case for Gale UAS based on the system elements are the rigidity of the aircraft and its reusability (Denney et al., 2012). The formulation is to acquire knowledge about the safety aspects of the use of unmanned aircraft systems. The requirements are to develop a methodology for analyzing the causes that may violate security. The concept and technology lie in the fact that the tool will perform several functions such as remote examination, remote placement of sensors and others. The development consists of the process of designing systems following the preliminary design. Then there is virtual prototyping and sprint development. The preliminary design is based on the design as an experiment of a flexible software process. There is an analysis of the risks that need to be eliminated. The implementation is at the experimental level to trace the dangers and correct them most clearly. About 23 models of unmanned aircraft were created, all different to select the most optimal model. Manufacturing and assembly must be carried out by professionals, using special parts such as safety glasses, and hermetically sealed strong housings, with fire protection. Testing is carried out at the landfill for general safety.
References
Cook, S. P. (2011). Tailored airworthiness standards for unmanned aircraft systems. 2011 IEEE/AIAA 30th Digital Avionics Systems Conference, 5A5-1-5A5-9.
Denney, E., Pai, G., Ippolito, C., & Lee, R. (2012). An integrated safety and systems engineering methodology for small Unmanned Aircraft Systems. AIAA, 2012-2572.
Embry-Riddle Aeronautical University. (n.d.). Gale UAS: Case study [Power Point slides].
Gale Unmanned Aircraft System. (n.d.).
Gundlah, J. (2012). Designing unmanned aircraft systems. AIAA, 10.
Nazarudeen, S. B. & Liscouët, J. (2021). State-Of-The-Art and directions for the conceptual design of safety-critical uncrewed and autonomous aerial vehicles. 2021 IEEE International Conference on Autonomous Systems (ICAS), 1-5.
Princeton University. (n.d.). General safety guidelines.