22.214.171.124.1 Transilluminated displays. The luminance
level of dedicated transilluminated signals and legends shall be
compatible with the expected surrounding luminance and operating
conditions and shall have a discernible contrast to ensure that alert
messages can be perceived by the crewmember under all expected lighting
126.96.36.199.2 Electronic displays. The luminance and
contrast of electronic displays shall have a discernible contrast to
ensure that alert messages can be perceived by the crewmember under all
expected lighting conditions.
188.8.131.52 Lettering. All characters shall be
upper case except on integrated displays, on which lower case characters may
be used. All letters and numbers on dedicated signal assemblies shall be in
accordance with MIL-M-18012. Letters and numbers on electronic displays
should be in conformance with the labeling requirements of MIL-STD-1472.
Character dimensions shall be as specified in 5.2.9.
184.108.40.206 Visual signal
flash rate. Flashing presentations should be avoided; however, where
they are required for their alerting value, they shall have a flash rate
between three to five Hz. The "ON" time shall be approximately equal to the
"OFF" time. No more than two flash rates shall be used. Where two flash
rates are used, the second rate shall be one to two Hz. Flashing
presentations which could be simultaneously active should have synchronized
220.127.116.11 Test systems.
A single test switch shall be provided for testing all dedicated displays
and, where possible, all subsystem circuitry within a given crew station. A
test switch is not necessary if the function is automated within an
integrated alert display. Blank signals, provided for a growth capability on
the annunciator assembly shall also be included as part of the test
signals. The system should be designed to minimize the effects of
undetected, false, or nuisance alerts, or any condition which would cause a
crewman to perceive an alert signal to be energized when it is not.
18.104.22.168 Cancellation of
master warning/caution signal. The master warning signal and master
caution signal shall remain "ON" until it is cancelled by the crewman or
cancelled automatically when the problem has been corrected. Audio portions
of alerting signals shall be automatically cancelled within ten seconds if
not previously cancelled by a crewmember. Upon cancellation, the master
warning/caution signal shall be reset automatically to be able to annunciate