Why is the FOV of the Synthetic Vision of the Prodigy Flight Deck asymmetric?

I am just reading through the manual of the Prodigy® Flight Deck 100 and came to the chapter about the synthetic vision. The document states:

[...] The field of view is 30 degrees to the left and 35 degrees to the right. [...]

Source (Page 510)

  • What is the reason and what are the advantages of having such a FOV with 30° to the left and 35° to the right?
  • 1
    $\begingroup$ Can you summarize the portion of the manual related to this feature instead of sending people to the 688 pages document? $\endgroup$ – mins Jun 27 '17 at 12:55
  • $\begingroup$ Just a quick guess, but perhaps it reflects the field of view of a pilot in the left seat. $\endgroup$ – selectstriker2 Jun 27 '17 at 13:30
  • $\begingroup$ Seems to be that the PFD center is not at the center of the screen, leaving more space on the right, hence the resulting dissymmetry. $\endgroup$ – mins Jun 27 '17 at 14:19

According to the FAA's AC 25-11B, there is no requirement for the asymmetrical SVS field-of-view.

It's not a feature either, as in there is no benefit. Whereas an Enhanced Vision System (EVS) system benefits from an offset overlay to match the sensor's deviation to the different flight deck seat positions.

With that said, here's my guess on why it sees 5° more on the right side.

From the FAA AC linked above:

The display can depict the scene from the pilot’s view looking through the front window (egocentric) or from outside the aircraft (exocentric). However, if implemented on a primary display, then the display must depict the scene from the pilot’s perspective looking through the front window.

This means the SVS is egocentric, which leads me to conclude* that the left seat is more-or-less aligned with the attitude indicator's centerline. But because of the display's size, the attitude indicator itself is off center, resulting in the bigger angle (5° in this case) to the right.

Which would explain the equal distances shown in white below. They could have been adjusted to allow a centered attitude indicator with the altitude tape being wider than the speed tape.

enter image description here
(Source; added arrows)

* My conclusion is based on the assumption they would want the SVS graphics to share the center of rotation of the attitude indicator. This poses a question with regard to the right seat, because as I can see from this image, the seating position is not accounted for (unlike with EVS).

But since SVS is not meant for barnstorming, I just might be overthinking it. Also, SVS does not need to show everything:

SV depictions on the PFD have the potential to provide pilots with enhanced terrain and landmark awareness during non-precision and precision approaches. However, the display may not provide depth perception and may not provide a field-of-view for pilots to know what is to the left and right of the display view area.


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