Smoothing Runway Travel to Improve Safety and Lower Maintenance Costs -A New Type of Aircraft Landing Gear Promises Safer and More Comfortable Travel- 2005-01-3416
When an aircraft wheel touches the stationary runway at high speed, great force from the forward direction suddenly pushes on the tires and landing gear. The widely used vertical shock absorber, known as an oleo strut, is unable to buffer this forward shock. This results in smoking and severe wear of aircraft tires on landing. Therefore, in contrast to automobiles, expensive aircraft tires need to be replaced frequently, adding considerably to maintenance and transportation costs.
We first presented new technology for solving this problem during the international conference 2001WAC, and in further detail in 2003WAC. We proposed a new type of landing gear that uses a crank element to absorb horizontal shock from the forward direction.
The next focus of attention was the problem of increased weight, resulting from introduction of the crank element. Computer simulations using a basic model of the landing gear showed a 62.1% decrease in the maximum bending moment. (Bending moment is the force that can cause an oleo strut to bend or break.) The maximum bending moment is reduced by more than half. The sliding friction work that causes smoking and excessive wear of the tires dropped to 30.1% - a reduction of 69.9%.
To determine vibration characteristics, we also conducted tests of frequency response including resistance to forward movement when taxiing along the runway. Test results showed that, similar to conventional landing gear, performance of the new type of suspension is determined by oscillation mode and natural frequency. Additionally, road tests of the new suspension on motorcycles passing over a corrugated surface confirmed improvement of riding comfort.
Citation: Yoshioka, K., Sone, A., Masuda, A., and Yamashita, H., "Smoothing Runway Travel to Improve Safety and Lower Maintenance Costs -A New Type of Aircraft Landing Gear Promises Safer and More Comfortable Travel- ," SAE Technical Paper 2005-01-3416, 2005, https://doi.org/10.4271/2005-01-3416. Download Citation
Koji Yoshioka, Akira Sone, Arata Masuda, Hiroya Yamashita
SUS21 AMERICA Inc., Kyoto Institute of Technology
Aerospace Technology Conference and Exposition
SAE 2005 Transactions Journal of Aerospace-V114-1