BeechTalk - BT - FS:B-4 and B-5 Brittain Autopilots

Username Protected · **Posted:** 15 Oct 2024, 18:58

If your Bonanza has a nonfunctional Brittain Autopilot. I have the complete components to two working when removed autopilots. The first is B-4 and the second is a B-5. The B-5 has yellow tagged vacuum components
These are complete systems but would require new tubing. The picture below is the B-4 but more pictures are available.
$500.00 each

Username Protected · **Posted:** 15 Oct 2024, 20:19

HA I love the hospital suction.

Username Protected · **Posted:** 15 Oct 2024, 22:39

Yes. For Bonanzas it is required to have 7.5 to 8.0 Hg (vacuum)
It’s really ingenious.

Username Protected · **Posted:** 16 Oct 2024, 17:05

Since these were removed from a Bonanza, I assume the electronic portions of the B-4 are 14 volt. Switchable to 28 volt by any chance?

Username Protected · **Posted:** 16 Oct 2024, 21:03

Both the B-4 and the B-5 are 14 volt units. I don’t know if they can be converted to 24 volts.

Username Protected · **Posted:** 16 Oct 2024, 21:53

Username Protected wrote:

Both the B-4 and the B-5 are 14 volt units. I don’t know if they can be converted to 24 volts.

From the B-4 install/maint manual:

The Nav-Coupler amplifier and controller assemblies are available in both 12 and 24
volt models. Before proceeding with ground check of the Nav-Coupler system, make
certain that the controller and amplifier are the same voltage as the aircraft's electrical
system.
NOTE: If required to be compatible with the aircraft voltage, a modification kit,
with instructions and necessary components, is available, upon request,
which enables the conversion, in the field, of a 12-volt component to a
24-volt component and vice versa

Username Protected · **Posted:** 16 Oct 2024, 21:53

Username Protected wrote:

Both the B-4 and the B-5 are 14 volt units. I don’t know if they can be converted to 24 volts.

From the B-4 install/maint manual:

The Nav-Coupler amplifier and controller assemblies are available in both 12 and 24
volt models. Before proceeding with ground check of the Nav-Coupler system, make
certain that the controller and amplifier are the same voltage as the aircraft's electrical
system.
NOTE: If required to be compatible with the aircraft voltage, a modification kit,
with instructions and necessary components, is available, upon request,
which enables the conversion, in the field, of a 12-volt component to a
24-volt component and vice versa

Username Protected · **Posted:** 16 Oct 2024, 22:24

Username Protected wrote:

From the B-4 install/maint manual:

The Nav-Coupler amplifier and controller assemblies are available in both 12 and 24
volt models. Before proceeding with ground check of the Nav-Coupler system, make
certain that the controller and amplifier are the same voltage as the aircraft's electrical
system.
NOTE: If required to be compatible with the aircraft voltage, a modification kit,
with instructions and necessary components, is available, upon request,
which enables the conversion, in the field, of a 12-volt component to a
24-volt component and vice versa

I have never seen any other info on such a kit though.

Username Protected · **Posted:** 17 Oct 2024, 10:37

I have seen some components on eBay which were 24 volts. But I believe they were produced that way. Converting them is something else again. But more than likely some sort of a resistor to reduce the voltage.