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.
Cause of Vertical Ridges on Fingernails. According to the Mayo Clinic, the nails are composed of laminated layers of a protein called keratin. This same protein is also found in the hair and skin. The nails are made up of several parts, including the nail beds, folds, cuticles and lunula.