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.
Trauma, pt 1. Some doctors believe that repetitive trauma to the fingernails causes them to regenerate, or grow, at an accelerated rate. This means that people who bite their nails are more likely to have nails that grow faster than people who don't bite their nails.