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.
Parts manufactured for use on aircraft do face much tougher guidelines on design, construction, and quality control than those used in most industrial applications. A typical hydraulic pump used on an aircraft may cost between $4,000 and $25,000, compared with a comparable industrial pump's cost of $400 or less.