From a Human Factors (HF) perspective, there are many elements to consider in the design process of displays. Displays, signs, banners, etc. are a part of our daily lives; and more often than not, are in place to provide information to make our life safer. Whether the display is in the cockpit or on
the side of the home fire extinguisher, information should be communicated clearly and concisely with the user in mind. Sometimes a display will be for a small population of people sharing several common factors. Other times, a display must serve the needs of large, diverse populations which may consist of variances in age or languages spoken. To design the right display for the right application, all of these demographical factors must be taken into consideration. Next, we must take into consideration the environmental factors involved around the display. Are we designing for the cockpit of a fighter jet, or a mine shaft? These would be two very different environments with very different considerations required to produce a good design.
This paper does not intend to explore all of the factors needed for display design in general. Rather four specific examples of display requirements in very different environments to be utilized by very different people will be explored. The displays under evaluation include an inoperative elevator, directions for international passengers at a Korean airport, automobile oil pressure warning, and notification to prepare for ejection from the Space Shuttle Orbiter.
The display needed for an inoperative elevator in a thirty-story building may seem simple enough. When the demographics of those who normally use the elevator and the environment are taken into consideration, questions arise. There are a wide range of people who need to easily understand that the elevator is out of service. We need to accommodate those who are young, old, illiterate, or who do not speak English fluently. We also must take into consideration that the lighting in front of the elevators is not optimal.
The key here is correct placement and color of the sign. The sign should be placed with a chain across the front of the elevator doors on each floor. This provides a physical barrier to entering the elevator, and will serve as a warning in itself to those who are illiterate or do not speak English fluently that the elevator is inoperative. Next, the sign itself should be in colors that are eye catching. This will ensure one’s attention is drawn to the sign while their eyes are adjusting to the dimly lit corridor. The language used on the sign will be in English with an ANSI approved “Attention” note at the top, and a simple statement that the elevator is inoperative. The design also has a photograph of an elevator on it with a red slash to indicate no access. Reference Fig. 1.
Figure 1. Inoperative Elevator Sign (designed with freeware from www.stclaire.com)
International Passengers Arriving In Korea
The displays to guide international passengers after deplaning in Korea will actually be a series of four. Placement and size are key factors to ensure proper routing for the passengers. As a general rule, signs in Korean airports and on Korean roads are in Korean and English. Since our signs cannot possibly address every language spoken that comes through the airport, we will follow the traditional format.
The first sign will be placed at the gate to direct passengers to walk the 60.96m to the stairway. Note the conversion from feet to meters since the metric system is utilized by most all countries outside the US. Reference Figure 2. A second sign will be placed at the stairway directing the passengers to go down the stairs. Reference Figure 3. At the bottom of the stairs, there will be a third sign pointing the passengers in the direction of the 30.48m trek to the international baggage area. Reference Figure 4. Last, there will be a sign at the entrance of the international baggage area to notify the passengers they are in the right place. Reference Figure 5.
The size of each sign is three by five feet. The placement will be twelve feet off the ground at each location, just above the desired pathway. Background color is a pleasant orange and font color is black. The insignia of the Korean Customs Agency is on all signs, as well as the AIGA insignia for international air transportation.
Figure 2. Korean Airport Sign #1
Figure 3. Korean Airport Sign #2- Top of Stairs
Figure 4. Korean Airport Sign #3- Bottom of Stairs
Figure 5. Korean Airport Sign #5- Entrance to Baggage Area
Oil Pressure Indicator
The non-technical consumer is the key factor in this design. We need a design that is as simplified as possible. For this, we will choose a simple gauge and lighted indicator system. When the pressure gets just below 20 psi, the needle will be in the orange area and the indicator light in the bottom right corner will come on. At 5 psi, the needle goes into the red area. Reference figure 6.
This design would assume that the person who knows little about the operation of cars would seek a service center when the indicator light illuminates.
Figure 6. Oil Pressure Gauge
Crew Module Ejection- Space Shuttle Orbiter
This design is likely what would have been incorporated into the Space Shuttle Orbiter cockpit as an indicator had NASA chosen to implement a crew escape system that allowed the inner shell of the crew module to be jettisoned from the rest of the ship. To elaborate, the structure of the forward section of the Orbiter should be explained. There is an outer shell or skin with an inner shell encompassing the crew module that is attached to the outer shell via shock absorbers. These shock absorbers allow the inner crew module shell to move within the outer skin. Because of this design, the astronauts are only subjected to a maximum of 3 g’s of force. The jettison system design would consist of pyrotechnic devices at the location of each of the shock absorbers, as well as along the circumference of the bulkhead at the beginning of the payload bay. Sensors placed in all systems of the Shuttle, would monitor during ascent and re-entry. Any dangerous values would send a signal to the Orbiter’s General Purpose Computers, which in turn would command the Power Control Assemblies to activate the jettison pyrotechnic circuits to allow for safe ejection of the whole crew module. After ejection, a parachute system would guide the ship safely back to earth. Since this is not a paper about the system, this explanation is only for general purposes and is not a description of the whole system.
The indicator light would be in three places. One would be in the mid-deck on the forward lockers in view of the three crew members sitting there. The other two would be on the forward flight deck, panels F6 and F8. F6 is the Commander’s side and F8 is the Pilot’s side. The size would be 1.5” by 1.5”; the same as the “Range Safe” indicator that alerts the crew that the Air Force Range Safety Officer will be taking command of the vehicle, which would only happen in situations where the ship is an imminent danger to land.
The nomenclature used would read “Crew Mod Jett”, and be illuminated in red lettering, as is traditional for emergency warnings in the Orbiter. Reference figure 7. The reason for the modified wording is the space available in such a small area. This shortening of the words would be in line with other areas of panel and indicator nomenclature inside the crew module. The crew would already be aware from their training that when this light illuminates, the jettison will occur in 10 seconds.
Taking into consideration the fact that ascent and entry are high workload times for the crew, it would be essential to provide an audible alarm with the illuminated light. The audible would be a different tone than any of the other four tones the crew might hear as part of the Caution and Warning system.
Figure 7. Space Shuttle Orbiter Crew Module Jettison Indicator