With the development of general aviation. the urban aircraft is around the corner. The urban aircraft with composite is considered as an ultralight vehicle and the crashworthiness is of vital importance for such an ultralight aircraft. Composites are being widely and increasingly used in the aerospace industry because of their advantages that include the high specific strength and sti... https://www.roneverhart.com/DigiWeigh-Notebook-Digital-Pocket-Scale-1000g-x-0-1g/