Multiple EFISs+AP74 DSAB Service Bulletin
Date: January 7, 2010
Installations Affected: Only airplanes that have TWO D10/D100 series EFISs (EFIS-D10A, EFIS-D100, FlightDEK-D180), an AP74, and autopilot servos, connected together via DSAB and configured to communicate are affected. SkyView is not affected by this bulletin.
Firmware Versions Affected: All versions up to and including 5.2.
Time of Compliance: Before further flight.
Problem Description: When two or more EFISs (FlightDEK-D180, EFIS-D100, and EFIS-D10A models), an AP74, and servos are connected together and configured to share information with each other via DSAB, there exists the possibility for one or both screens to reboot during flight.
Because this multiple EFIS and AP combination is typically used in IFR-capable aircraft, Dynon is recommending that immediate action is taken to eliminate the possibility of this occurring.
There is no known problem with a single EFIS connected to an AP74 and servos, or for two EFISs and servos connected without an AP74.
Methods of Compliance.
Any of the following methods of compliance will eliminate this issue:
1) Isolate one of the EFISs from the DSAB network.
a. Physically remove the DSAB connection between the two screens, ensuring that they can not communicate with each other.
b. Alternatively, you may leave the physical DSAB wires connected, but you can reconfigure the system so that the two screens do not communicate with each other via DSAB. To do this:
i. Apply power to all devices (EFISs, Autopilot components, etc.). Choose the screen that you want to control the autopilot from and power the other screen off. Configure DSAB by going to SETUP>DSAB>CONFIGURATION. Confirm that all of the powered on devices are configured by going to SETUP>DSAB>STATUS and scrolling through the devices that were found during configuration. Make sure that the screen that is powered down is no longer listed here.
ii. Power down everything that was on in the previous step (i) and power on the remaining screen by itself. Configure DSAB by going to SETUP>DSAB>CONFIGURATION. Confirm that only the single screen is configured by going to SETUP>DSAB>STATUS and ensuring that the AP74, servos, and other screen are not listed.
iii. Though the units are still physically connected, they are no longer talking via DSAB and are no longer susceptible to this problem. Note that autopilot capability from one screen is maintained.
2) Update to firmware 5.3 when released. This is Dynon’s next planned D10/D100 Series firmware release, and is not yet available.