Installation manual

Avidyne | DFC90, 100 FAQs (Last updated: 26 June 2012)

(DFC90, 100) Are there any autopilot calibrations required? No, there are no autopilot

calibrations required after installation. This is part of the “digital dividend”.

(DFC90, 100) Should I still put in a roll servo in my Cirrus? We understand that a

sizeable number of potential Cirrus DFC90 customers have performed the roll servo mod

and as of DFC90 Release 2, we have added support for that configuration. For the

DFC100, the roll servo has always been supported. Many owners find that the roll trim

motors tend to degrade in performance over time and this has a noticeable effect on the

autopilot tracking performance. Some owners also find they can inadvertently hit the

built-in mechanical limit switch in a roll trim motor thereby affecting the autopilot

performance. Both of these possibilities are dramatically reduced in roll servo equipped

aircraft. (updated 10 Oct 2011)

(DFC90, 100) What if I already had the roll servo upgrade to my Cirrus? For the

DFC90 (as of Release 2) and all DFC100 configurations, the installer will merely select

that type of servo during the installation process and the DFC100 will be able to take

advantage of the benefits the roll servo provides over the roll trim motor. (updated 10

Oct 2011)

(DFC90, 100) Do I need to keep the turn coordinator? No, you don’t need to but in the

case of single Avidyne (or Aspen) PFD installations in Cirrus or Piper PA-46 that are

replacing the S-TEC 55 autopilot, the installation requires the retention of the turn

coordinator as an extra comparator since the software and approved STC wiring are

already in place. From a regulatory perspective, Change 1 of AC 23.1311-1B does not

require the use of an independent attitude source serving as a comparator if the primary

AHRS has sufficient self-monitoring and alerting, which both the Avidyne and Aspen

systems do. For those systems where an AHRS-TC comparator is currently in operation,

the DFC90/100 software was changed in Release 2 such that it will no longer disconnect

the autopilot in the event of a miscompare with the turn coordinator. (updated 17 April

2012)

(DFC90, 100) How can I be sure the DFC autopilot is right for my aircraft? Avidyne

has provided installers with instructions on how to perform a quick check of your aircraft

rigging and the servo health to ensure your aircraft is properly configured to take

advantage of all that the DFC autopilot has to offer. (updated 24 July 2011)

(DFC90) What other kind of installation “gotchas” have you heard about from the

field?

For aircraft equipped with PFD Release 8.0.2, some installations have neglected to enable

Underspeed protection and/or have inadvertently changed the setting for the aircraft

reference symbol (“Flying W” or “Delta”) during the PFD software upgrade. Service

Information Letter SIL-606-00006-001 dated 29 July 2010 instructs installers on how to

avoid this issue. PFD Release 8.0.3 was created in mid-August 2010 to ensure

Underspeed is always enabled in DFC90 equipped aircraft.