An integrated standby instrument system (ISIS) is an electronic aircraft instrument. It is intended to serve as backup in case of a failure of the standard glass cockpit instrumentation, allowing pilots to continue to receive key flight-related information. Prior to the use of ISIS, this was performed by individual redundant mechanical instrumentation instead. Such systems have become common to be installed in various types of aircraft, ranging from

airliners An airliner is a type of aircraft for transporting passengers and air cargo. Such aircraft are most often operated by airlines. Although the definition of an airliner can vary from country to country, an airliner is typically defined as an ai ...

helicopter A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes ...

s and smaller

general aviation General aviation (GA) is defined by the International Civil Aviation Organization (ICAO) as all civil aviation aircraft operations with the exception of commercial air transport or aerial work, which is defined as specialized aviation services ...

aircraft. While it is common for new-built aircraft to be outfitted with ISIS, numerous operators have opted to have their fleets retrofitted with such apparatus as well.

Details

An ISIS is designed to combine the functions of separate equivalent mechanical instruments that had previously been included as backup in such cockpits, including

altimeter An altimeter or an altitude meter is an instrument used to measure the altitude of an object above a fixed level. The measurement of altitude is called altimetry, which is related to the term bathymetry, the measurement of depth under water. The m ...

airspeed indicator The airspeed indicator (ASI) or airspeed gauge is a flight instrument indicating the airspeed of an aircraft in kilometers per hour (km/h), knots (kn), miles per hour (MPH) and/or meters per second (m/s). The recommendation by ICAO is to use km ...

, and

attitude indicator The attitude indicator (AI), formerly known as the gyro horizon or artificial horizon, is a flight instrument that informs the pilot of the aircraft orientation relative to Earth's horizon, and gives an immediate indication of the smallest o ...

. Various aspects of ISIS are defined by its function of being a backup to conventional instrumentation. In accordance with this principal, it has been designed to operate with a high level of availability and reliability, as well as being as independent as possible from the aircraft's primary instrumentation and sensors alike. It is commonplace for an ISIS to work in conjunction with provisions for auxiliary power (typically a

battery Battery most often refers to: * Electric battery, a device that provides electrical power * Battery (crime), a crime involving unlawful physical contact Battery may also refer to: Energy source *Automotive battery, a device to provide power t ...

unit), as well as harnessing embedded sensors for its readings wherever possible. When all onboard instrumentation is performing normally, the readings indicated by an ISIS are identical to that of the primary flight display. Advantages presented by ISIS over traditional systems include improved safety, greater ease of operation, and reduced operating costs. A number of aircraft have been produced with relatively sophisticated integrated standby systems which may include additional functions. For example, the

Rockwell Collins Rockwell Collins was a multinational corporation headquartered in Cedar Rapids, Iowa, providing avionics and information technology systems and services to government agencies and aircraft manufacturers. It was formed when the Collins Radio Comp ...

Pro Line 21 flight deck, which is fitted to aircraft such as the Cessna Citation XLS+

business jet A business jet, private jet, or bizjet is a jet aircraft designed for transporting small groups of people. Business jets may be adapted for other roles, such as the evacuation of casualties or express parcel deliveries, and some are used by pu ...

, features a standby navigation display and engine gauges.

Thales Group Thales Group () is a French multinational company that designs, develops and manufactures electrical systems as well as devices and equipment for the aerospace, defence, transportation and security sectors. The company is headquartered in Paris' ...

produce their own ISIS, which is installed on the

Airbus A320 The Airbus A320 family is a series of narrow-body airliners developed and produced by Airbus. The A320 was launched in March 1984, first flew on 22 February 1987, and was introduced in April 1988 by Air France. The first member of the famil ...

narrow-body A narrow-body aircraft or single-aisle aircraft is an airliner arranged along a single aisle, permitting up to 6-abreast seating in a cabin less than in width. In contrast, a wide-body aircraft is a larger airliner usually configured with mu ...

and

Airbus A330 The Airbus A330 is a wide-body aircraft developed and produced by Airbus. Airbus conceived several derivatives of the A300, its first airliner in the mid-1970s. Then the company began development on the A330 twinjet in parallel with the A340 ...

wide-body airliner A wide-body aircraft, also known as a twin-aisle aircraft, is an airliner with a fuselage wide enough to accommodate two passenger aisles with seven or more seats abreast. The typical fuselage diameter is . In the typical wide-body economy cabin ...

s amongst other aircraft; it allowed for one single instrument to replace four standby instruments that had been traditionally used. Thales also produced an Integrated Electronic Standby Instrument (IESI) dedicated for use on

s; in excess of 6,000 such units have reportedly been sold as of July 2020. Another such system is manufactured by

L3Harris Technologies L3Harris Technologies (L3Harris) is an American technology company, defense contractor, and information technology services provider that produces C6ISR systems and products, wireless equipment, tactical radios, avionics and electronic systems, ...

, intended for both helicopters and

purposes. Additional companies specialising in avionics, such as

GE Aviation GE Aviation, a subsidiary of General Electric, is headquartered in Evendale, Ohio, outside Cincinnati. GE Aviation is among the top aircraft engine suppliers, and offers engines for the majority of commercial aircraft. GE Aviation is part of t ...

Smiths Group Smiths Group plc is a British, multinational, diversified engineering business headquartered in London, England. It operates in over 50 countries and employs 14,600 staff. Smiths Group has its origins in a jewellery shop, ''S Smith & Sons'', ...

, and

Meggitt Parker Meggitt (formerly Meggitt plc) is a British international company specialising in components and sub-systems for the aerospace, defence and selected energy markets. It was listed on the London Stock Exchange and was a constituent of the ...

, have also marketed ranges of standby instrumentation using both standalone and ISIS-compliance principles. Several companies have produced

patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A ...

able innovations related to ISIS, including large aerospace players such as

Airbus Group Airbus SE (; ; ; ) is a European multinational aerospace corporation. Airbus designs, manufactures and sells civil and military aerospace products worldwide and manufactures aircraft throughout the world. The company has three divisions: '' ...

. In addition to such technology being adopted upon new-build aircraft, several operators have opted to retrofit their existing aircraft fleets with current generation ISIS, such as UPS's

Airbus A300 The Airbus A300 is a wide-body airliner developed and manufactured by Airbus. In September 1967, aircraft manufacturers in the United Kingdom, France, and West Germany signed a memorandum of understanding to develop a large airliner. West ...

freighters. Along these lines, Rockwell Collins developed a retrofit package for the

Boeing 757 The Boeing 757 is an American narrow-body airliner designed and built by Boeing Commercial Airplanes. The then-named 7N7, a twinjet successor for the 727 (a trijet), received its first orders in August 1978. The prototype completed its mai ...

and Boeing 767 that incorporates ISIS. During the 2010s, the cost of performing such cockpit display retrofits reportedly dropped substantially.

References

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External links

Industry Scan via aviationtoday.com

Chapter 2: Electronic Flight Instruments via faa.gov

Electronic Flight Instrument System via skybrary.aero
Aircraft instruments