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.
Lack of Moisture Can Cause Ridges on Nail or Vertical Lines on Nails: This is one important factor leading to ridges on nails. Lack of moisture causes drying of the nails, cuticle and the hands and result in the ridges.