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.
Causes for different types of dark lines in fingernails. A thin, flimsy nail is also caused by a diet B12 insufficiency. Vertical ridges might be the results of in adequate diet and nutrient absorbency, and even kidney issues. But vertical ridges are very standard of negative circulate in problems such as rheumatoid arthritis.