It's not a failure if it meets its stated goals. It's not trying to be a programmer's font, a terminal font, etc. It's specifically only trying to be a font for cockpit displays. On that front, there isn't really a context where I and l would be ambiguous in context. The only place I can think of would be waypoint names, but those are always all caps, so I and L don't present any problem.
On the other hand, putting crossbars on their I would make it much more visually similar to their 1 glyph. Mixing I and 1 (again, in waypoint names, for example), is much more likely and the strong visual difference in I and 1 by not having crossbars on the I seems like a better choice for the stated goals/applications of this font. ("...improve the display of information on the cockpit screens, in particular in terms of legibility and comfort of reading, and to optimize the overall homogeneity of the cockpit")
> It's specifically only trying to be a font for cockpit displays. On that front, there isn't really a context where I and l would be ambiguous in context.
So for example IATA and ICAO airport codes are not within the context of an airplane cockpit?
And the visual difference between "laa" and "Iaa" doesn't matter?
The first one is Lamar Municipal Airport, while the second one is Igarka Airport.
you are having too much of good faith in always-perfect assumptions when it comes to life-critical systems. I hope you are not involved in developing or designing such systems.
On the other hand, putting crossbars on their I would make it much more visually similar to their 1 glyph. Mixing I and 1 (again, in waypoint names, for example), is much more likely and the strong visual difference in I and 1 by not having crossbars on the I seems like a better choice for the stated goals/applications of this font. ("...improve the display of information on the cockpit screens, in particular in terms of legibility and comfort of reading, and to optimize the overall homogeneity of the cockpit")