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.
They may be a sign of: a previous illness â the line forms at the time of the illness chemotherapy a previous injury previous exposure to extremely cold temperatures, if you have Raynaud's disease Illness, injury or cold temperatures can interrupt nail growth and cause nail grooves to form at the base of the nails.