Digital Altimeter Setting Indicator (DASI) Operational Test and Evaluation (OT&E) Integration and OT&E Operational Test Procedures

Abstract : The Digital Altimeter Setting Indicator (DASI) is a system which measures the atmospheric pressure and converts the measured pressure value into the actual sea level pressure based on the United States (U.S.) Standard Atmospheric Table. The value then computed is known as the Altimeter Setting Indicator (ASI) value and is presented to the operator, who is air traffic control (ATC), in a digital format, e.g., 29.50 inches of mercury (inHg). The ASI value is then transmitted by the air traffic controller to an aircraft pilot for use in setting the altimeter in the aircraft. If a perfectly calibrated altimeter is set to the ASI value existing at any given station whose elevation is designated as Hp, the pointer of the altimeter instrument will indicate an altitude of Hp when the instrument is at the altitude of the sensor in the DASI system. (Hp is an elevation in geopotential meters above mean sea level of the altimeter setting indicator pressure sensor.) The purpose of this Operational Test and Evaluation (OT&E) Test Procedure is to describe the Test and Evaluation activities which will ensure the DASI system meets all the requirements of the DASI Specification, FAA-E-2569B, and integrates properly into the National Airspace System (NAS). The OT&E procedure includes the test cases, responsibilities, Test Support Hardware and Software, and Test Conduct associated with the testing of the DASI. The DASI test is developed and executed in accordance with the current FAA Test and Evaluation Policy Order, FAA Order 1810.4B. Digital Altimeter Setting Indicator (DASI), Altimeter Setting Indicator (ASI), Sensor Translator (S/T), Digital Display Panel (DDP).