Your CD4 count. These cells are a type of white blood cell that is destroyed by HIV. A healthy person's count varies from 500 - over 1,000. If you have fewer than 200 CD4 cells, then your HIV has progressed to AIDS.
Aircraft fluid lines are usually made of metal tubing. or flexible hose. Metal tubing (also called rigid fluid. lines) is used in stationary applications and where long, relatively straight runs are possible. They are widely. used in aircraft for fuel, oil, coolant, oxygen, instru-. ment, and hydraulic lines. Flexible hose is generally. used with moving parts or where the hose is subject. to considerable vibration. Occasionally, it may be necessary to repair or replace. damaged aircraft fluid lines.
These changes, required by the aircraft man-. ufacturers, are known as modifications to the. fluid specification ... or simply as Type I, II, III and now Type IV fluids. SkydrolÂ® LD-4 and SkydrolÂ® 500B-4. hydraulic fluids are Type IV fluids formulated. to exceed the rigid specifications of the aircraft. manufacturers. They have been in commercial. usage since 1978 and have demonstrated. outstanding performance.