What is a mistake prevention measure by designing the user interface in the aircraft's cockpit

ByDoug

A device that displays information or inputs instructions when a person operates a machine or a computerUser InterfaceIt is called an exceptionally important role to say that operability and actual performance are greatly influenced by the good design of its design. Based on the actual case of an airplane accident, one solution in UI design to prevent mistakes is stated.

Poor UI Design Can Kill - Air Inter Flight 148, a harsh lesson learned | Martin Doms
http://blog.martindoms.com/2011/01/24/poor-ui-design-can-kill/

On January 20, 1992,Ale AntaresOperated ITF 148 flight from France in Lyon towards Strasbourg International Airport located northeast of the country. As the destination approached, the aircraft started approaching for landing. The pilot inputs the descent rate of the aircraft to the autopilot and instructs the airport to lower the altitude.

The weather on the day was cloudy and the visibility by pilot's eyes was not so high, the aircraft started to descend as instructed. It was ITF 148 which was believed to have continued approaching smoothly towards the runway, but in the middle of the mountain which appeared from the cloud at the point before the airportA crashThen, 87 people out of 96 passengers were killed, accidents occurred.

At this time, the airbus that Ale Antoir served as a launch customerA 320As a civilian aircraft, it was a state-of-the-art high-tech machine as a civilian aircraft at that time when computer control was completely adopted for maneuvering the aircraft for the first time. Detect the approach to the ground and notify the risk of crashGPWSAlthough it was one of the reasons for the accident that was not installed (ground approach alarm device), it is known that the most important factor existed in the user interface of the pilot operated autopilot .

ByWikipedia

The cockpit of the A320 aircraft looks like this. The main instruments are displayed on six sides of the liquid crystal display placed in front of the pilot, as if to show the presence of a computer. In addition, when steering, the handle-type control stick is not used, and it is to operate a joystick type side stick placed diagonally in front of the pilot's seat. The operation of the pilot is not directly conveyed to the airframe, and the computer to which the instruction is input calculates the best operation and actually moves the airframeFly-by-wireSystem has been adopted for the first time in civilian aircraft.

ByWikipedia

And here is the "problematic" device used by the pilot of ITF 148 flight to set the descent rate of the aircraft for landing. A numerical value of "-2.8" indicating the descent rate is displayed at the tip of the arrow of the photo, and the numerical value is inputted by turning the dial under it.


Although the above figures are for reference, when an actual accident occurs, the ITF 148 flight pilot turns the dial to display "-3.3", "-3.3" and input the numerical value into the computer. However, the display method of this part includes "Flight Pass Angle (FPA) "And the vertical speed of" Vertical Speed ​​(VS) "There are two modes existed, it was difficult to distinguish by mere sight at a glance. This part will be recognized later as being a blind spot to ensure safety.

The pilot has made the number "-3.3"FPA modeI intended to set the descent rate of "-3.3 degrees", but the actual panel mode isVS mode, And the vertical speed per minute has been set to "3300 feet (about 1000 meters)" has been clarified in the result of the accident investigation.

In the original FPA mode, when set to -3.3, the vertical speed is 800 feet per minute (about 244 meters). The fact that the downward speed of more than four times is actually set by mistaking the mode change, ITF148 flight approaches the ground quadruple faster than originally and crashes to the middle of the mountain It has resulted in tragedy.

♦ "Mode error" invoked by the design to select the mode
Although the accident caused by the above-mentioned ITF 148 was a tragedy caused by mode switching of panel display, this kind of "Mode error"Is also scattered around familiar places. For example, when viewing the web using Google Chrome,Incognito modeSometimes you have tab open.


Secret mode does not start unless it selects itself, so it rarely happens that "it was opened without noticing", but if you continue browsing as it is, you forget to be in secret mode and it's normal Something that operates in a sensation. As a result, I closed carelessly the important page that I had opened, I could not forget to cry because of specifications that I do not want to open again, even if I want to open it again, I can delete my cookie and log in to a page I visited before It may happen that you are gone.

In order to avoid such a problem, the design philosophy "to eliminate mode selection as much as possible" has been cast even before. Although mode selection to display multiple pieces of information in one place is a factor that causes unnecessary problems, it is to eliminate hidden risks beforehand, but it is also difficult to realize in UI design constraints There is.

However, in such a case, the measures of the A320 aircraft mentioned above may be one of the hints. Since the accident, Airbus changed the display specification of the problem part and changed the indication in VS mode (vertical speed mode) to 4 digits. When the VS is 3,300 feet per minute, "-3300", When the FPA is -3.3 degrees,"-3.3"It has been changed to be displayed.

Although the mode selection itself is still left, it seems to be a lesson that you should not forget to devise measures to prevent misunderstanding.