PITOT / STATIC SYSTEMS Aim To understand the principles of operation behind a pitot / static system, considering the possible errors and limitations involved. Application • Used when relying on the pressure instruments. • ASI, ALT and VSI. Overview Revision Static Pressure • pressure due to weight of air molecules pushing down. Reduces with increased altitude. Revision Dynamic Pressure • pressure due to relative movement. Depends on density and velocity. Total Pressure • PT = Definitions • Static Vent Definitions • Pitot Tube Definitions • Alternate Static Source Principles Principles • Airspeed Indicator Principles Principles • Altimeter Principles Principles • Vertical Speed Indicator Principles • VSI Considerations Instrument Errors • due to imperfections in the design and installation. Instrument Lag • response time of pressure instruments can be slow due to long lines or rapid pressure changes. Position Error • poor design and placement of vents may not be representative of the free atmospheric pressure. Considerations - Review • Blockages Descent Static Climb Blockage Descent - - Pitot Climb - - Blockage ASI ALT VSI Over read Under read Under read Over read Over read Under read Zero Zero Airmanship • Know where the alternate static source is located • Always check pitot and static vents during pre-flight Review作者: 猪也能飞 时间: 2013-10-28 19:12:08