By Loren Thompson, Forbes: “Concurrency is defined as the overlap in the development and production phases of the acquisition program. Concurrency introduces the risk that aircraft built in early production lots will require modification due to discoveries made during qualification, flight and ground tests, or as a result of engineering analysis.”
F-22 Raptor vs China's J-20
By Dave Majumdar, The National Interest: “Perhaps the most compelling evidence that would point to the J-20 being optimized for the strike role is the fact that the airframe is enormous but has relatively small wings. It’s also seems to have huge weapons bays. While such a configuration works well for a fast supersonic strike aircraft, it’s not ideal for an air superiority fighter that needs be able to sustain high rates of turn.”
The History of Body Armor, From Medieval Times to Today
By Sam Bocetta, Small Wars Journal: “The invention of true “body armor” directly followed the development of ranged weapons. As soon as muskets became widely used in the 16th Century, soldiers sought some form of protection against projectiles.”