Brittain Autopilot Systems

[SoMooney]

I have an accutrak I, but Im guessing its the same or similar. Ok so there are two circuits then, one for left and one for right and the voltage must shift depending on which way the course is? And this voltage is a standardized thing used by lots of avionics mfg's? Cause you can use multiple types of CDI's with different GPSs and NAVs right?

[MyNameIsNobody]

My AccuTrak is connected to the left right analog out of a GNC300XL GPS.

The separate Accu-Flite tracks a heading bug on the DG.

[Hector]

I have an accutrak I, but Im guessing its the same or similar. Ok so there are two circuits then, one for left and one for right and the voltage must shift depending on which way the course is? And this voltage is a standardized thing used by lots of avionics mfg's? Cause you can use multiple types of CDI's with different GPSs and NAVs right?

You have virtually the same setup I have. I have a GX60 with a KI209. The GX55/60 sends a very small voltage differential to the CDI. I think the voltage is in the range of 0-250 milli volts depending on CDI deflection (250 milli volts being full CDI deflection and -250 milli volts full deflection on the opposite side). If you have a KI209, and your GX55 and NAV radio are both connected to this CDI then it is relatively simple. The KI209 has an autopilot out (I believe pins 16 and 17) and you can connect NAV 1 of the Accutrack there. The Accutrack will now track the GPS or the NAV radio depending on which you have selected. You don't need any other boxes. Just connect nav1 of the Accutrack to pins 16 and 17 of the KI-209. Next, you will want to go into the settings in your GX55 and set the CDI sensitivity to maximum (I think is .3 miles full CDI deflection). This way the Accutrack will start correcting as soon as you start deviating from the magenta line. If you don't do this the Accutrack will be very sloppy wondering left and right of the centerline up to a couple of miles. My typical flight goes like this. I climb to my cruising altitude by hand flying. Once at cruise, and with PC on, I trim for level flight and trim aileron as well so it tracks straight. I will already have the GX60 tracking to my destination but at this point I press direct to and enter and this will center the CDI. I then immediately turn on the Accutrack and let her keep the CDI centered. It works remarkably well for an old system. You have my number so don't hesitate to call me with question.

[Guitarmaster]

Has anybody connected the accutrak to a KI525 HSI?  

[1524J]

38 minutes ago, Guitarmaster said:

Has anybody connected the accutrak to a KI525 HSI?  

That's what I've got. Accutrak II with Stec altitude hold.

[SoMooney]

Perfect! Thanks again Hector!

[yvesg]

SoMooney, how much did you pay for the BI-805? I am also looking for one. I have the Accutrak and would like to get this project going some day but could not locate one at a "reasonable" price.

Yves

[Yetti]

23 hours ago, SoMooney said:

I have an accutrak I, but Im guessing its the same or similar. Ok so there are two circuits then, one for left and one for right and the voltage must shift depending on which way the course is? And this voltage is a standardized thing used by lots of avionics mfg's? Cause you can use multiple types of CDI's with different GPSs and NAVs right?

Yep I have an Accutrack not a II   and they are the same.   Nav Select switches sources.   I believe the Brittain Manual tells you how it works.  I remember a variable voltage depending on deflection of course.  Yes it is standardized among manufactures.

[Guitarmaster]

On August 11, 2016 at 9:44 AM, yvesg said:

SoMooney, how much did you pay for the BI-805? I am also looking for one. I have the Accutrak and would like to get this project going some day but could not locate one at a "reasonable" price.

Yves

I paid about $690 if memory serves.  Then I sent it to Brittain for the overhaul.  The Accutrak computer + overhaul of BI805 was $750.  

[yvesg]

50 minutes ago, Guitarmaster said:

I paid about $690 if memory serves.  Then I sent it to Brittain for the overhaul.  The Accutrak computer + overhaul of BI805 was $750.  

Thanks Matt. This will help me gage how much roughly someone can ask for when I find an available one.

Yves

[211º]

On 7/19/2016 at 11:31 PM, carusoam said:

check all the hoses for flexibility and sealing.  The harder they get, the less they hold the Vaccuum....

Took things apart in the tail yesterday and found that the hoses are all holding the vacuum well - down about 0.5" (from 5" to 4.5" in about 10 minutes). The vacuum also moved the control surfaces.

 

On 7/21/2016 at 9:48 AM, MyNameIsNobody said:

Can you trim out the down pitch with trim wheel?  Will it then hold level flight?

No - the pitch down is past the ability to trim out of it. When I spoke Kevin today, he thought that it sounded like the bellows in the altitude hold box were stretched out/ruptured - he noted (as I think I've read elsewhere here) to make sure that Altitude hold is turned off when descending... or it'll stretch them out again pretty quickly.

 

On 7/22/2016 at 1:59 PM, N601RX said:

The easiest way to troubleshoot this is to get a small hand vac pump for harbor freight or auto parts store.  Disconnect the left side from the turn cordinator and connect the hose that runs out to the wing to the hand pump.  Verify that by using the hand pump you can deflect the aileron all the way in one direction and that it doesn't leak down or it at least takes several minutes to leak down

I've done this in the tail section, now I need to will myself to do it upside down on the pilots seat with my feet extending to the right wing.  I'll give it a go before much more work.

It appears that I must have two things going on - if I understand correctly,

(1) the altitude/pitch are controlled by vacuum alone via the altitude control box in the tail of the plane. My total problem or issue could be the bellows in the altitude "box" being stretched out.

(2) Left and right control (rudder and ailerons) are controlled by the an electrical input from the turn coordinator which controls vacuum pressure which controls (well) turning.  So I could have an issue with the electrical interface at the back of the turn coordinator or (as I read somewhere else) could simply have a blown fuse behind the B6 somewhere.

[Candy man]

Thought it was best to revive an old thread as opposed to start new because there is some great information here.

 

I'm lookin at a mid 60's C and a previous owner removed the wing leveler ( I have no idea why anyone would do that). My question(s) are as follows.

Can I replace the wing leveler for a reasonable price? It seems that if I have the wing leveler I can add the accutrak for not bank breaking money. If not what are the other options? I know that an approved autopilot can add 20 amu and recoup 3 when you sell/if you sell. I've also read about the FAA changing their stripes and approving a homebuilt AP that works well, is reliable, and cost effective.

Any and all advice is welcome, with the exception of buy a plane that has an AP installed already. 

 

Lawrence

[HRM]

17 minutes ago, Candy man said:

Thought it was best to revive an old thread as opposed to start new because there is some great information here.

 

I'm lookin at a mid 60's C and a previous owner removed the wing leveler ( I have no idea why anyone would do that). My question(s) are as follows.

Can I replace the wing leveler for a reasinable price? It seems that if I have the wing leveler I can add the accutrak for not bank breaking money. If not what are the other options? I know that an approved autopilot can add 20 amu and recoup 3 when you sell/if you sell. I've also read about the FAA changing their stripes and approving a homebuilt AP that works well, is reliable, and cost effective.

Any and all advice is welcome, with the exception of buy a plane that has an AP installed already. 

 

Lawrence

Ask Brittain. I believe you can just fly up there and they'll install it. At minimum they will give you the best advice on what to do next with your C.

[Andy95W]

IMO, you really shouldn't do anything for about a year or so until we find out more about some of the newer autopilots coming to market.  For what you put into installation and parts for the Britain (a great system, BTW) you could nearly have a 100% brand new actual autopilot with all the bells and whistles.

[carusoam]

In the days before MS... Old Mooney ownership was a dark, dark place....

With MS...

Now we know who Britain is, where they are located, know that getting their system fixed and upgraded doesn't cost very much...

If you need parts we have a vendor or two of old Mooney parts around here...

If you are going to wait... consider finding out how much the parts are going to cost to revive a wing leveler...

PP thoughts only.  My C flew around for a decade with all the parts installed, just not connected...(before MS)

Best regards,

-a-

[Hector]

I would have to agree here. Wait a bit to see what comes out within the next year with regards to TrueTrack and Trio autopilots. By the time you install a wing leveler and purchase and install an Accutrack and have it wired to your nav systems you'll be in $5K easily. Within a year or so you might be able to purchase a much more capable AP with altitude hold for about the same or a tad more. I love my Britain AP and it works wonderfully and reliably, but if I was going to start from scratch I would wait a bit for the better APs like TrueTrack or Trio

 

 

Sent from my iPad using Tapatalk

 

[lamont337]

4 hours ago, Candy man said:

Thought it was best to revive an old thread as opposed to start new because there is some great information here.

 

I'm lookin at a mid 60's C and a previous owner removed the wing leveler ( I have no idea why anyone would do that). My question(s) are as follows.

Can I replace the wing leveler for a reasonable price? It seems that if I have the wing leveler I can add the accutrak for not bank breaking money. If not what are the other options? I know that an approved autopilot can add 20 amu and recoup 3 when you sell/if you sell. I've also read about the FAA changing their stripes and approving a homebuilt AP that works well, is reliable, and cost effective.

Any and all advice is welcome, with the exception of buy a plane that has an AP installed already. 

 

Lawrence

Completely removed or just disconnected? The decision tree changes if you have all or most of the parts. Brackets might still be in place and turn coordinator is probably the same. It's a start.

[outermarker]

If you have a wing leveler (always on) and AccuTrak II, how does the system work? Is there some way to turn off the wing leveler?

[Yetti]

On older mooneys there is a manual release valve.  On the newer Mooney there is a vacuum solenoid that goes to ground when the switch on the yoke is pushed.  Vacuum is bled out of the system and then the plane is all yours.

[outermarker]

I understand that, however, if you turn on the AccuTrak, which is vacuum driven, and the wing leveler is also vacuum driven, with nav 1 selected and using the heading bug to fly a course, you shouldn't have to fly with the release valve on the yoke depressed. That doesn't make sense.

 

 

[carusoam]

OM,

It would help you to include some data about your plane, if able...

The Avatar area is a great place to put it once.

The wing leveler got changes about every other year from the vac release valve location to where your gyro is that controls the system.

 

My 65C used a yoke mounted button to relieve the vacuum that would disable the wing leveler. Its controlling gyro was mounted in the tail.

Two methods of disabling this button were a big rubber band found on vegetables like broccoli or a small plastic container Know to house 35mm film.

A few people have updated their plane with a panel mounted switch/valve that can stay open continuously.

Britain, The manufacturer of this system is still alive and can service your parts if you have them. They probably can help you get a copy of the manuals... that should also reside in your POH...

Hope this helps some.

Best regards,

-a-

 

 

Edited May 2, 2017 by carusoam

[MyNameIsNobody]

2 minutes ago, outermarker said:

I understand that, however, if you turn on the AccuTrak, which is vacuum driven, and the wing leveler is also vacuum driven, with nav 1 selected and using the heading bug to fly a course, you shouldn't have to fly with the release valve on the yoke depressed. That doesn't make sense.

 

 

No, that would not make sense.  The yoke valve is for maneuvering flight to "defeat the PC".  The Accu-Trak is electric taking inputs from a VOR or GPS and outputting left right analog signal that move the vacuum driven servos.  Accu-Flite uses a heading bug and control to do the same.

[outermarker]

So, and I'm just thinking out loud here, the wing leveler is always on unless the yoke valve is depressed. Got that. Now, if the AccuTrac system is turned on and it gets its signal from the heading bug which as you said also moves the vacuum driven servos also, could this not create a conflict between the two systems if you turn the trim adjustment knob on the yoke and what you have the heading bug set to? And yes, looking at drawings would clear things up. I know, I know, all the old-time Mooney guys with 1000's of hours are just rolling their eyes with this.

[MyNameIsNobody]

15 minutes ago, outermarker said:

So, and I'm just thinking out loud here, the wing leveler is always on unless the yoke valve is depressed. Got that. Now, if the AccuTrac system is turned on and it gets its signal from the heading bug which as you said also moves the vacuum driven servos also, could this not create a conflict between the two systems if you turn the trim adjustment knob on the yoke and what you have the heading bug set to? And yes, looking at drawings would clear things up. I know, I know, all the old-time Mooney guys with 1000's of hours are just rolling their eyes with this.

You can have an accu-Trak turned on and running a GPS course and the Accu-Flite running off an input from the Heading bug on the turn coordinator.  Yes, they would be working with/against one another if both on.  If you pushed the yoke button it would shut down both as they require the vacuum to work the servos in the wing leveler to control the direction as input.  There would be no reason to shut off while going cross country unless you wanted to maneuver with yoke.  You can always defeat with yoke inputs as the force to overcome is not significant...If the deviation was significant it might "lose track" and need to be brought back on course and then re-started to trak again.

Edited May 2, 2017 by MyNameIsNobody

[outermarker]

Thanks so much for clearing that up. I was reading the thread and that was the question that came to me. A few minutes ago I downloaded the Mooney PC Operation & Service Instructions Manual and began reading. It's all sticking like oat meal now! thanks!