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.
Fingernail ridges can indicate vitamin or mineral deficiencies as well as general malnutrition or other illness if they run horizontally, but are usually benign if they run vertically. Nutritional deficiencies can also cause fingernails to become misshapen, discolored or brittle, breaking easily.