Warning Caution and Advisory Colours
Thread Starter
Joined: Mar 2004
Posts: 11
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From: Australia
Warning Caution and Advisory Colours
Hello flight testers,
A technical question related to flight test via FAR25. Part 25.1322 describes colours for warning, caution, safe operation and any other lights on the flight deck. Colours are red, amber, green and any other not including the above (to avoid confusion). Have been looking at some Boeing stuff which appears to use amber for both caution and advisory lights, and adds another group called 'pilot memo' which is white. This issue appears to be the desire to have two categories of caution for NNP (non-normal procedures) which are either system related (e.g. system hyd failure) or operationally related (e.g. VNAV disconnect). Of interest is that the 737 also uses blue alerts for system status information (e.g. APU power available, generator power available but not being used).
Colour convention that I can follow for 737NG (all?) might be:
Red for warnings
Amber for cautions
White for advisories (also armed FMA modes)
Green for safe aircraft config (also active FMA modes)
Blue for safe but ambiguous system states (could be good/bad...depending)
Magenta for selected values
Would love to hear the thoughts of flight testers on what is a good colour convention for flight deck alerting. Have reviewed AC25-11 which seems pretty dated. Specifically interested in how we should deal with lower level cautions that are more than advisories.
Regards,
A technical question related to flight test via FAR25. Part 25.1322 describes colours for warning, caution, safe operation and any other lights on the flight deck. Colours are red, amber, green and any other not including the above (to avoid confusion). Have been looking at some Boeing stuff which appears to use amber for both caution and advisory lights, and adds another group called 'pilot memo' which is white. This issue appears to be the desire to have two categories of caution for NNP (non-normal procedures) which are either system related (e.g. system hyd failure) or operationally related (e.g. VNAV disconnect). Of interest is that the 737 also uses blue alerts for system status information (e.g. APU power available, generator power available but not being used).
Colour convention that I can follow for 737NG (all?) might be:
Red for warnings
Amber for cautions
White for advisories (also armed FMA modes)
Green for safe aircraft config (also active FMA modes)
Blue for safe but ambiguous system states (could be good/bad...depending)
Magenta for selected values
Would love to hear the thoughts of flight testers on what is a good colour convention for flight deck alerting. Have reviewed AC25-11 which seems pretty dated. Specifically interested in how we should deal with lower level cautions that are more than advisories.
Regards,
Joined: Apr 2002
Posts: 734
Likes: 0
From: Nirvana South
Adsto,
The actual colors used are, to a certain extent, whatever the Avionics vendor uses as his standard palette - there are two basic ones from SAE standards (Brand H & Brand C originally I beleive). But to answer your question about "minor" Cautions. Generally these will be covered by flight phase (e.g. Takeoff & Landing) inhibits in a modern EICAS. Otherwise they may be covered by system logic & electrical bus failure inhibits - in reality the system decides when & if the pilot will even know there's a problem for the majority of CAs messages at least compared to a simple idiot light.
How we did it when we put together the original CAS list on a Regional was to:
(a) ask the system specialist what drove his fault lights (often an eye-opener for them - a lot have never really thought about it)
(b) ask them what the pilot's action would be & how critical was it - this drives whether it's a Warning (immediate) Caution (knowledge but not immediate) etc.
and
(c) what might cause a false alert.
The latter is often the most difficult as it involves power supplies, redundant systems, specific failure cases etc. Another overall consideration is the type of aircraft - in general in RJs messages tend to get let through the filter more than Biz jets as its reckoned the crew are better at discriminating the severity of fault - but that's definitely a judgement call on behalf of both the team & the Project Pilot.
The actual colors used are, to a certain extent, whatever the Avionics vendor uses as his standard palette - there are two basic ones from SAE standards (Brand H & Brand C originally I beleive). But to answer your question about "minor" Cautions. Generally these will be covered by flight phase (e.g. Takeoff & Landing) inhibits in a modern EICAS. Otherwise they may be covered by system logic & electrical bus failure inhibits - in reality the system decides when & if the pilot will even know there's a problem for the majority of CAs messages at least compared to a simple idiot light.
How we did it when we put together the original CAS list on a Regional was to:
(a) ask the system specialist what drove his fault lights (often an eye-opener for them - a lot have never really thought about it)
(b) ask them what the pilot's action would be & how critical was it - this drives whether it's a Warning (immediate) Caution (knowledge but not immediate) etc.
and
(c) what might cause a false alert.
The latter is often the most difficult as it involves power supplies, redundant systems, specific failure cases etc. Another overall consideration is the type of aircraft - in general in RJs messages tend to get let through the filter more than Biz jets as its reckoned the crew are better at discriminating the severity of fault - but that's definitely a judgement call on behalf of both the team & the Project Pilot.
