View Full Version : dual ahrs, three efis-how many airspeed and aoa connectors

01-01-2011, 06:33 AM
I'm installing a AF-4500EE & AF-4500EF and a slave 3400. All are linked by ARINC. Dual AHRS and independent power supplies.

Does each unit require a separate pitot-static line input in case of failure of a different unit?

Does each unit require separate AOA inputs?

Seems that both the 4500 units would require the pitot-static input but I'm not sure whether the slave 3400 does since it's getting most info from the 4500's?

As to the AOA input, is it unique to one of the 4500's with info sent by ethernet link to the other units? If so, do I need to run AOA tubing to the other units? If it's not unique, then my question is similar to the pitot-static input question, AOA tubing to both 4500's and does slave 3400 also need AOA input from tubing?

Thanks in advance,
Tom Hanaway

01-01-2011, 04:51 PM
From memory, I think you'll need to plan for pitot, static and AoA lines to the EE and EF units, but not the 3400MFD. The MFD just has the Ethernet connection plus a very sparsely populated d-sub just providing power and ground.
Note that with 3 units you'll also need an Ethernet hub to allow all the units to talk to each other. Also note that the secondary/redundant power pin by default is not populated in the standard harness.

I'm sure Trevor and/or other experts will confirm or correct me if I've given incorrect info.

Trevor Conroy
01-04-2011, 09:50 AM
Steve is correct. Thanks for the response to Tom. Each unit with AOA and Pitot/Static ports needs its own hose. The MFD has no air data input. You will end up calibrating the AOA on both the EE and EF at the same time.