These are particularly interesting:
NASA’s List of Design Recommendations
-
Sans-serif fonts are usually more legible than fonts with serifs.
-
Avoid using a font that has characters that are too similar to one another, as this will reduce the legibility of the print.
-
Avoid using dot matrix print for critical flight-deck documentation.
-
Long chunks of text should be set in lower case.
-
If upper case is required, the first letter of the word should be made larger in order to enhance the legibility of the word.
-
When specifying font height, or accessing graphs to determine the size of a lower-case character, the distinction between “x” height and overall size should be made.
-
As a general recommendation, the “x” height of a font used for important flight-deck documentation should not be below 0.10 inch.
-
The recommended height-to-width ratio of a font that is viewed in front of the observer is 5:3.
-
The vertical spacing between lines should not be smaller than 25–33% of the overall size of the font.
-
The horizontal spacing between characters should be 25% of the overall size and not less than one stroke width.
-
Avoid using long strings of text set in italics.
-
Use primarily one or two typefaces for emphasis.
-
Use black characters over a white background for most cockpit documentation.
-
Avoid using white characters over a black background in normal line operations. However, if this is desired:
- Use minimum amount of text.
- Use relatively large typesize.
- Use sans-serif to minimize the loss of legibility.
-
Black over white or yellow are recommended for cockpit documentation.
-
Avoid using black over dark red, green, and blue.
-
Use anti-glare plastic to laminate documents.
-
Ensure that the quality of the print and the paper is well above normal standards. Poor quality of the print will effect legibility and readability.
-
The designer must assess the age groups of the pilots that will be using the documentation, and take a very conservative approach in assessing information obtained from graphs and data books.