According to the National Oceanic and Atmospheric Administration (NOAA) Severe Storms database, there were 4,610 major hail storms in 2018. The depot repair expenses of airliners caused by collisions of foreign matters are up to USD 3-4 billion each year all over the world, leading to flight delay and aviation accidents which further create immeasurable economic losses. Current preventative measures require nearly 10-15 people and approximately 3 hours to deploy covers on the airplane. Humans are exposed to severe weather during these operations. However, in-flight prevention is based around pilot procedure, “When deviating around storms, maneuver on the upwind side so wind is not carrying the storm toward you, and to avoid hail that might spew from the anvil top.” Pilots rely on weather forecast information from air traffic controller (ATC) but hailstorms can not be predicted until last minute with good accuracy. The main motivation behind this study is to maximize efficiency in taking preventive measure to mitigate the effects of hail on airplanes on ground and mid-flight.
What it does
This problem is studied in two perspectives, the first case includes the preventive measures for on-ground airplanes and the second case includes risk mitigation for in flight airplanes. The on ground operations require development of infrastructure for building temporary shelters for airplanes during hailstorm. Risk mitigation for mid-air airplanes is achieved by reinforcing the critical structural components by using advanced materials.
How we built it
We propose a semi-autonomous rover based system which can be deployed to construct a shelter around the plane in advance once the critical weather information is received. Polypropylene material is slippery, moisture resistant and polypropylene tarps can be used for this application. Our application requires approximately 8100 sq m material based on Boeing-747 dimensions. This material costs $ 1.20 sq m and the tarp will cost approximately $9700 for one shelter. The system consists of two sets of rovers on either side of the airplane. The rovers tracks a predefined way-point trajectory. The speed of the rover system is approximately 0.2 m/s, comparable to NASA's Crawler-Transporter which travels at 0.44 m/s in loaded condition. Each rover is equipped with proximity sensors for emergency braking and warning system during operation. This is a semi-autonomous system and the operator can take decisions for deployment and retraction of the system based on the weather. We have created a simulation in SolidWorks to demonstrate the basic functionality of the system and we have developed a hardware prototype of the rover too.
Risk mitigation from hailstorms during flight is proposed to be achieved by using advanced materials which can reinforce the critical components of the aircraft. The primary critical components affected by hail storms are wing leading edges, control surfaces such as ailerons, flaps, slats, elevator and rudder, fuselage nose, engine cowlings and nacelle. Graphene is the strongest material ever tested and it can provide enhanced aerodynamics capabilities. We have created some CAD designs to show this application on actual aircraft components. Graphene based aircraft has already been flight tested on a RC-plane by researchers from University of Central Lancaster in England and the system showed improved flight performance. This material definitely shows better physical and aerodynamic properties as compared to the conventional aircraft materials.
Challenges we ran into
Identify the problem and define the scope of our proposed solution because we had to address on ground as well as in-flight airplanes.
Coming up with a design of the shelter around the plane and operating mechanism due to large and variable dimensions of the planes. Researching a suitable material for creating tarps was also a challenge.
We faced challenges in creating the CAD model animations and during preparation of our poster due to some coding issues.
The scope of risk mitigation in-flight was very large and we had to deal with trade-offs in terms of aerodynamic performance and safety of the aircraft. Researching a suitable reinforcement material was also challenging as we had to compare various physical properties wit respect to the conventional aircraft materials.
Accomplishments that we're proud of
We are extremely proud that we developed our idea from a white board sketch to an actual simulation, prototype. We were proud of our combined thinking and effort as a team that we able to narrow down the scope of our project as a result of intensive discussions.
What we learned
We all came together as a team from different universities and we were very comfortable working with each other on this awesome project. We learned system thinking after a lot of brain storming and how to bring out ideas to life. We learned to respect each others preferences and opinions. An inter-disciplinary team can bring out most creative solutions to the problem as each member contributes with a certain set of skills and we experienced this during the Skyhack hackathon.
What's next for Challenge 2: Protection from Hail
We explored and developed methods for ground operations and risk mitigation for airplanes during hailstorms. It was an amazing experience to create the initial designs. The future work will involve a pilot project for ground based operations and detailed feasibility studies for using advanced materials in aircraft construction.