5.2.3 Number and location of displays. The number of
displays shall be based upon the informational requirements of the aircrew and
the reliability of the displays. Unless otherwise specified, all warning,
caution and advisory messages shall be presented within the operator's 30
degree (total included angle) forward cone of vision, on a single display
surface. If more than one display is present at a crew station, the display
farthest to the left should display all warning, caution and advisory
messages. Warning, caution and advisory messages may be presented on a head-up
display only with acquiring activity approval (see 6.3.1). The location of the
display(s) and the viewing angle(s) should be such that the readability is not
degraded, even in illumination up to 10,000 fc through the aircraft windows.
If interactive control functions are included with the display, they shall be
within the anthropometric reach of the operator using them, as constrained by
the crew station installation for the particular air vehicle involved. The
requirements for control and display integration and for the specific display
under consideration shall be as specified in MIL-STD-1472.