BU instrument panel location

[PTK]

A question regarding bu instrument panel placement in glass panels. I've been told by avionics installers that the required bu instruments (the AAA's) MUST be placed within some pilot viewing angle. This, they say, puts them in front of the pilot as we see in many G500 installations for example. Yet I see all the glass airplanes that came from Kerville have the bu AAA on the right panel! Is there a regulation for this? Just curious!

[peter]

Advisory Circular AC 23.1311 provides guidance on backup instrument placement. This advisory material is used by the STC/TC applicant when developing their design and showing compliance. Once STC'd or TC'd, the specific requirments for that equipment/airframe are governed by the STC/TC data. For example, The G500/600 STC requires that the backups be immediately adjacent to the G500/600 bezel.  Aspen's STC provides more flexibility, requiring that the instruments be as close as practicable to the PFD, but in no case may they be more than 21" from the PFD.  The Mooney factory configuration specifies an exact location that was found acceptable as part of the Type Design approval.  Other OEM's have similar specific locations that have been found acceptable.

[PTK]

Thank you Peter!