Air data computer
An air data computer (ADC) or central air data computer (CADC) computes altitude, vertical speed, air speed, and Mach number from pressure and temperature inputs.
Air data computers usually also have an input of total air temperature. This enables computation of static air temperature and true airspeed.
In
On the Embraer Embraer E-Jet family the concept has been refined further by splitting air data acquisition and measuring – performed by combined pitot/static "air data smart probes" with integrated sensors – and computation of parameters performed by "air data applications" (ADA) executed on non-dedicated processing units. As all information from the sensors is transmitted electrically, routing of pitot and static pressure lines through the aircraft and associated maintenance tasks can be avoided.[4]
In simpler aircraft and helicopters the Air Data Computers, generally two in number, and smaller, lighter and simpler than an ADIRU, may be called Air Data Units, although their internal computational power is still significant. They commonly have the pitot and static pressure inputs, as well as
Apart from commercial ADCs implementation, there are available do-it-yourself, and open-source implementations.[6]
History
Electrical-mechanical air data computers were developed in the early 1950s to provide a central source of airspeed, altitude, and other signals to avionic systems that needed this data. A central air data computer avoided duplication of sensing equipment and could be more sophisticated and accurate.[7] The first air data computer was built by Kollsman Instruments for the B-52 bomber.[8] Bendix started producing a central air data computer in 1956 for use on US Air Force jet fighters. [9] Garrett AiResearch developed early central air data computer systems that integrated pneumatic, electrical, and electronic components.[10]
The late 1960s saw the introduction of digital air data computers. In 1967, Garrett AiResearch's ILAAS air data computer was the first all-digital unit.
From the late 1980s much of the
See also
- Acronyms and abbreviations in avionics
- F-14 Central Air Data Computer, used on the F-14
References
- ISBN 0-89116-792-7.
- ^ Kim Wiolland (January 2015). "Air Data Computer" (PDF). Avionics News.
- ^ "What Is an Air Data Computer?". Wisegeek.com. Retrieved 2015-06-25.
- ^ Embraer 195 Airplane Operations Manual, Volume 2, chapter 14
- ^ "ESCADU". Archived from the original on 2018-10-11. Retrieved 2019-02-02.
- HACKADAY, Tom Nardi, 2018-01
- ^ Klass, Philip (28 Sep 1953). "Single Computer Combines Flight Data". Aviation Week: 45–48.
- ^ "From the first to the latest". Air Force Magazine (Nov 1985): 115.
- ^ Hamlin, Fred; Miller, Eleanor (1957). The Aircraft Year Book for 1956 (PDF). Washington, DC: The Lincoln Press. p. 171.
- ^ "Air Data Computer System". Aviation Week: 5. 2 May 1955.
- ^ "Fly by the numbers" (PDF). Electronics. 40 (21): 42. 16 Oct 1967.
- ^ Corey, Frederick (17 Mar 1969). "DC-10's air data system casts a long shadow" (PDF). Electronics. 42 (6): 125–130.
- ^ "New Avionics Standardization Initiative - Standard Central Air Data Computer (SCADC)". Feedback. II (1). Wright-Patterson Air Force Base: 3. 1979.
- ^ Standard Central Air Data Computer (PDF). GEC Avionics. 1985.
- ^ "Standard Central Air Data Computer [SCADC, 1987] :: Rochester Avionic Archives".
- ^ "ISD Queen's Award Ceremony :: Rochester Avionic Archives".