Three eleventh-grade students, Ko Chen Lam, Li Pui Shan and Wu Ga Kei from SKH Li Ping Secondary School invented “Aircraft Nut Tension Monitoring Washer”. If there’s any loosened screw, the system will make an alarm so that the mechanic can easily see the damage and fix it as soon as possible, ensuring the plane can fly in the sky safely.
The “Aircraft Nut Tension Monitoring Washer” uses the principle of spring. The spring is connected to the bottom of the screws and the washer, if the two washers aren’t fastened, which means screws may be loosened, the upper washer will give a red alarm. Li Pui Shan mentioned, the staff can observe the condition of screw through visual inspection or telescope without climbing in the plane to check them one by one. As for how to determine whether the screws are loosened, through different experiments, they discovered that when dynamic is higher than 5N, screws will loosen. They also carried out a temperature test, putting screws into fridges and ovens to make sure screws can endure different extreme temperatures. The result shows that the screw can function normally between -14°C and 130°C。
Ko Chen Lam said, the advantage about this invention is its low cost and wide usage. Since all the materials are magnetic-free, aircraft signal won’t be influenced. Basically, all kinds of machine can adapt to it. She claimed that they had presented their work to HAECO. The company agreed with their concept, and yet it is still not in practical use.