Manual override: Difference between revisions

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A '''manual override (MO)''' or '''manual analog override (MAO)''' is a mechanism where control is taken from an [[automated system]] and given to the user. For example, a manual override in [[photography]] refers to the ability for the human photographer to turn off the automatic [[aperture]] sizing, [[automatic focus]]ing, or any other automated system on the camera.<ref>[http://www.ambitions4.com/Glossary-Pub-View-Topic-Details.asp?GlossaryID=339&strChar=M Manual override] {{webarchive|url=https://archive.today/20060513202632/http://www.ambitions4.com/Glossary-Pub-View-Topic-Details.asp?GlossaryID=339&strChar=M |date=2006-05-13 }}, Ambitions Photography Academy.</ref>

A '''manual override''' is a procedure where an otherwise automatic system is taken under manual control, usually from [[computer]] control.

Some manual overrides can be used to veto an automated system's judgment when the system is in error. An example of this is a [[Printer (computing)|printer's]] ink level detection: in one case, a researcher found that when he overrode the system, up to 38% more pages could be printed at good quality by the printer than the automated system would have allowed.<ref name=BBC>[http://news.bbc.co.uk/2/hi/technology/3035500.stm 'Raw deal' on printer ink], ''[[BBC]]'', 3 July 2003</ref>

== Examples of manual overrides in Fact ==

{{weasel}}

*Most [[safe]]s have manual overrides so instead of calling a locksmith to [[safe-cracking|crack the safe]], they can insert the manual override key and open it.

Automated systems are becoming increasingly common and integrated into everyday objects such as [[automobile]]s and [[domestic appliance]]s. This development of [[ubiquitous computing]] raises general issues of policy and law about the need for manual overrides for matters of great importance such as life-threatening situations and major economic decisions. The loyalty of such autonomous devices then becomes an issue. If they follow rules installed by the manufacturer or required by law and refuse to cede control in some situations then the owners of the devices may feel disempowered, alienated and lacking true ownership.<ref>{{citation |url=http://www.jjbohn.com/papers/langhein_aswemaylive_2002.pdf |title=As we may live – Real-world implications of ubiquitous computing |author1=Marc Langheinrich |author2=Vlad Coroama |author3=Jurgen Bohn |author4=Michael Rohs |name-list-style=amp |publisher=Institute of Information Systems}}</ref>

*[[Ink cartridges]] can be overrided, as some [[printer]]s refuse to print when they claim the ink is low <ref name=BBC> [http://news.bbc.co.uk/2/hi/technology/3035500.stm 'Raw deal' on printer ink], ''[[BBC]]'', 3 July 2003 </ref>. One ''[[Which?]]'' researcher who over-rode the system found that in one case he could print up to 38% more good quality pages, even though the chip stated that the cartridge was empty <ref name=BBC> [http://news.bbc.co.uk/2/hi/technology/3035500.stm 'Raw deal' on printer ink], ''[[BBC]]'', 3 July 2003 </ref>.

==Major incidents==

*On [[United States|US]] [[Submarine]]s armed with [[nuclear weapon]]s it is rumoured that the captain has final choice on whether to 'go nuclear', as the access codes are stored in the [[Captain's Chest]] (but opening the chest triggers alarms and the [[Pentagon]] is informed) hence a manual, or human, intervention.{{Fact|date=October 2007}}

[[China Airlines Flight 140]] crashed, causing many deaths, due to a misunderstanding about the manual overrides for the [[autopilot]]. The Take-Off/Go Around system had been activated to abort a landing. It was programmed to ignore manual controls in this situation but the human pilots tried to continue the landing. The conflicting control signals from the pilots and autopilot then resulted in the aircraft stalling and crashing. The autopilot for this aircraft type was then reprogrammed so that it would never ignore a manual override.<ref>{{citation |url=https://books.google.com/books?id=SG07muS_S2EC |page=151 |year=2004 |title=Taming HAL: designing interfaces beyond 2001 |isbn=978-0-312-29574-5 |author=Asaf Degani|publisher=Palgrave Macmillan }}</ref>

==See also==

== Examples of manual overrides in Fiction ==

*[[Big red button]]

*[[Communication cord]]

As a plot device manual override is often used in [[Sci-Fi]] because of the usual prevalence of advanced technology. For example;

*[[Dead man's handle]]

*[[Engine control unit]] (ECU)

*In [[Star Trek]] many automatic systems, such as the automatic navigation, or the 'site-to-site transporter' can be overridden. A slightly different type of manual override is used in the film ''[[Star Trek: Insurrection]]'', when acting Captain of the [[Starship Enterprise]] (E) William Riker asks the computer for the 'manual command column', in effect a [[joystick]] which gives him [[pilotage]] control of the ship.

*Full authority digital engine (or electronics) control ([[FADEC]])

*[[Panic button]]

*In [[Casino Royale]] (2006), a villan overrides the emergency [[fire sprinkler]]s at [[Miami airport]] and starts a distraction so that he can blow up a plane with a remote-controlled pipe bomb.

== References ==

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[[Category:TechnologyAutomation|&]]

[[Category:Safety equipment]]

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