In 1971 VR-30 joined the Jet Age with two North American CT-39 Saberliners for high-speed executive airlift. In May 1973 the squadron received the first of four C-9B Skytrain II's to further improve its logistics support capability.
Vertical ridges can also be caused by nail injury and certain diseases, including rheumatoid arthritis, according to Rich. If, instead of a series of ridges, there's a single vertical streak, cautions Krant, this could be a sign of a tumor growing at the root of the nail.
Ridges in fingernails. Vertical ridges sometimes appear along the length of the fingernails. Sometimes marks, discoloration or pits or grooves on a fingernail, such as those that run from side to side (known as Beau's lines), can be an indication of a nail injury or a health problem.