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.
Common causes of ridges on nails. Nails are comprised of Keratin (protein) a tough substance that protects the end of each finger and toe. The following is a list of possible causes as to why vertical ridges may appear on the nails: 1  It is traditionally believed that ridge formation on the nails relates to a possible weakness in the digestive tract that results in compromised assimilation of nutrients (leaky gut, allergies, food sensitivities, maldigestion)