Скачать 202.63 Kb.
An experimental wingless aircraft was launched by falling free from a B52. In its initial flight in July 1966, the test pilot tried to adjust the ratio control sensitivity. Unfortunately, he committed a control reversal that made the stick more sensitive rather than less. This resulted in a severe “pilot-induced oscillation,” predictable for an aircraft of this configuration. Almost too late, he desperately let go of the stick and the aircraft finally stabilized. He then realized what he had done (Casey, 2006).
2.20 Concorde Crash Precipitated by Runway Debris (control tower automation may reduce controller vigilance of airport surface)
The Air France Concorde, a supersonic passenger aircraft, crashed in July 2000 while attempting to depart from Paris. The crash killed all 109 on board and four people on the ground. Even though automation did not contribute to this particular crash, it is included in this paper because of current trends toward automation in air traffic control towers (e.g., “virtual” towers located away from the runways and depending on instrument surveillance). These virtual towers have the potential to divert attention from scanning the airport surface for debris, as controllers currently do today, while updating their awareness of aircraft position and movements. A landing gear tire on the Concorde encountered a 17-by-1-inch metal strip that had fallen from a DC-10 five minutes earlier.
The Concorde had a history of tire bursts and deflations 60 times higher than subsonic jets (e.g., one in 3,000 flights compared to one in 100,000 flights for the A340). Heavy, fast-moving pieces of the tire severed and shorted electrical wiring in the wing, igniting fuel adjacent to the wheel well, and a fire erupted when the fuel tank burst. The flight engineer idled the second left engine 12 seconds after its fire alarm began. The Concorde had gained less than 400 ft in altitude when the flight crew lost control, and the aircraft crashed four miles from the end of the runway. The Bureau Enquetes-Accidents (BEA), the French equivalent of the NTSB, attributed the crash in part to the performance of only two runway examinations at Charles de Gaulle International Airport, when three were specified in a service memo. However, the additional daily inspection may not have discovered the metal debris during the five minutes between its appearance and the Concorde departure. British Airways terminated Concorde service in October 2003 for reasons of profitability (Air Safety Week, 2002).
This example from the maritime industry illustrates the effects of over-reliance on automated systems.
The cruise ship Royal Majesty ran aground off Nantucket after veering several miles off course toward shallow waters. Fortunately, there were no injuries or fatalities as a result of the accident, but losses totaled $2 million in structural damage and $5 million in lost revenue. The automated systems in this ship included an autopilot and an automatic radar plotting aid that was tied to signals received by a GPS. Under normal operating conditions, the autopilot used GPS signals to keep the ship on its intended course. However, the GPS signals were lost when the cable from the antenna frayed (it was placed in an area of the ship where many sailors walked). As a result, the GPS and autopilot automatically and without warning switched to dead-reckoning mode, no longer correcting for winds and tides, which carried the ship toward the shore.
According to the NTSB report on the accident, the probable cause was the crew’s over-reliance on the automatic radar plotting aid and management’s failure to ensure that the crew was adequately trained in understanding the automation features, capabilities, and limitations. The report went on to state that “the watch officers’ monitoring of the status of the vessel’s GPS was deficient throughout the voyage …” and that “all the watch-standing officers were overly reliant on the automated position display and were, for all intents and purposes, sailing the map display instead of using navigation aids or lookout information.”
This accident represents a classic case of automation complacency related to inappropriately high trust in the automation. It also demonstrates the importance of salient feedback about automation states and actions. The text annunciators that distinguished between the dead-reckoning and satellite modes were not salient enough to draw the crew’s attention to the problem (Degani, 2004; Lee & See, 2004; see Degani for a more detailed account of the accident).
|Time 2 Beat 122 Entries (12” dogs judged by barbara Bounds; remainder judged by Sandy Moody)||Table Substance identity 2 XI Table Constituents 3 XI Table Impurities 3 XI|
|Appendix Bibliography (list of all articles cited and what chapter cited in)||Table Substance identity 2 VII Table Constituents 2 VII Table Overview of physico-chemical properties 3 VII|
|Round Table Table ronde The New Citizenship Guide. A round Table Le nouveau guide sur la citoyenneté||Note for Philip: Each section of the content is preceded by the columned table, copied over from your original document. The main body text for each section is outside of the table|
|Table structure for table `authors`||These publications cited papers and books authored and coauthored by S. A. Ostroumov|
Примеры работ, цитирующих публикации с авторством и соавторством д б н. С. А. Остроумова. These publications cited papers and books...
|Were medieval muslims really tolerant when judged by modern standards?||Were medieval muslims really tolerant when judged by modern standards?|