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Old 11th December 2008 | 07:52
  #16 (permalink)  
Nigd3
 
Joined: Jul 2003
Posts: 445
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From: Canada
Cyclone

For displays in general there is pilot involvement all the way through from the equipment manufacturer, aircraft OEM and the certifying authorities.

Sometimes what the pilots would like is not financially possible, implementable or even certifiable.
Sometimes what the engineers would like is financially possible, implementable or even certifiable.
If you designed a display to the exact letter of the FAR requirements, that are sometime 20 years old, but hence certifiable, you end up with a system that both engineers and pilots dislike.

Engineers define the standard things like contrast ratios, panel/display luminance, symbology (in accordance with guidance material), formats, functions, tactile feedback and moding etc.
The pilots and cert authorities should by involved from the beginning to help ensure that the end result is operationally acceptable but also certifiable.

It ends up with compromises from all sides, which is one of the reasons why certain systems have "quirks" in them that as end user operators you maybe cannot quite understand why. They are quite possibly in there to satisfy a FAR requirement but operationally not that great.

The extract below is from a certification presentation I have and may go some way to explain what I have said above

FIRST LAW of certification:
REGULATIONS AND PROCEDURES ARE SET TO AVOID PERSONAL
INTERPRETATIONS

SECOND LAW of certification:
VERIFICATION OF COMPLIANCE IS ESTABLISHED VERSUS APPLICABLE & SPECIFIC REQUIREMENTS AND PROCEDURES. Any other interpretation is pure
SPECULATION

PS apologies for digressing, this is aimed at Cyclones question about the design process
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