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.
This is a common condition. It is due to separation of the nail plate from the nail bed. Each time you clean under your nail with a fingernail file or a toothpick, you cause a tiny separation between the nail plate and the nail bed. Repeated cleanings cause a dead space to form where moisture and germs collect and grow.ransverse ridges are usually caused by an inflammation of the skin around the nail due to skin diseases such as eczema and allergic dermatitis, or sometimes by an injury which stops the growth of the nail. A habit of picking or rubbing the base of the nail or improper manicuring may damage the nail matrix.