Abstract
A hard landing in aviation is a term used to describe an undesirable landing, which occurs when the vertical velocity of the landing exceeds 6.2 ft per second (Why It’s Hard To Make A Smooth Landing In An Empty Jet 2020). Hard landing can happen by a variety of factors, including weather, conditions, mechanical problems, overweight aircraft, pilot error, and pilot decision-making error. Hard landing can result in damage to both aircraft and passengers, ranging from mild discomfort to structural failure, injury, and even loss of life. This paper explores the dangers of landing on the human spine. This study focusses on forces applied to the spine during an airplane landing. This paper studies the physics and interactions of main landing gear, seat belts, and spine biomechanics.
For this study, the airplane reference is an A321NEO for hard landing simulations. This is an Airbus passenger airplane. The configurations or dimensions come to use in this paper from Aircraft Characteristics Airport and Maintenance Planning. This paper discusses the dimensions of different A321 aircraft. There is not enough data on landing gear geometry and physics. Therefore, the landing gear design comes from dimensions on the aircraft plus design equations. Furthermore, the damper and spring physical reactions are exponential reactions. The spring and damper had to be linearized for simulations.
The conclusion is that landing gear is essential for passenger safety. Furthermore, hard landing forces have negligible effect below 6.2 ft/s for forces applied on the spine found on simulations reported on this thesis. Landing vertical speeds need to exceed 6.2 ft/s by quite a bit to damage the spine. Landing speed needs to exceed 30 ft/s for the human spine to have a small chance of damage for a properly operating landing gear according to the results presented on this thesis.