Brittain Autopilot Systems

[takair]

16 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.

They are tied together and integral.  The Accutrac controls and electropnuematic valve that biases a turn and partially defeats the wing leveler gyro.  When the valve goes to neutral, the gyro acts to bring the aircraft to level.  It is really cool, in a nerdy way, how these things are integrated and how well they work when well tuned.  Pushing the yoke button disables both.  On a modern jet, it would be called "control wheel steering".  A modern GA autopilot has a "blue button" to bring wings level.  You pay extra for that.  Mooney and Brittain were doing this over 50 years ago...they just didn't market it as well.

 

[Hank]

2 hours ago, MyNameIsNobody said:

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.

I fly often using the AccuTrak, and very rarely with the AccuFlite. Can't remember which year I last pressed the yoke disconnect button, it may have been 2008 (I bought my C in '07). It's not difficult to overcome, and the slight additional force reminds me to not bank steeply in the pattern. It's not like I make a lot of turns between departure and approach . . .

Edited May 2, 2017 by Hank

[yvesg]

14 minutes ago, Hank said:

I fly often using Google the AccuTrak, and very rarely with the AcccuFlite. Can the remember which year I last present the yoke disconnect button, it may have been 2008 (I bought my C in '07). It's not difficult to overcome, and the slight additional force reminds me to not bank steeply in the pattern. It's  other like I make a lot of turns between departure and approach . . .

You Googled the Accutrak? I am having trouble reading your text Hank... too much beer? No I got it... the autocorrect again!

[Marauder]

You Googled the Accutrak? I am having trouble reading your text Hank... too much beer? No I got it... the autocorrect again!

That was a strange response. Hope he is okay.


Sent from my iPad using Tapatalk Pro

[Hank]

1 hour ago, Marauder said:

 

That was a strange response. Hope he is okay.


Sent from my iPad using Tapatalk Pro

 

Doggone it! I proofread that twice!! My Samsung Tab A uses "opt out" spelling changer, just like my iThings, but my Galaxy phone  uses "opt in," where you get to actually see my typos if I miss them instead of hitting the spacebar not C, B or N and having the durn thing make a whole new word out of the next letter! 

Any idea why some random words get Capitalized, and others get turned into ALL CAPS? This latter event usually happens just before either "?" or "!"

But this post fixed. Glad to know people care. I'm fine--honest, occifer, I'm not as thunk as drinkle peep I am. (If you can say that accurately, you ain't drunk. Just don't test yourself at a roadblock . . .   )

[carusoam]

For some reason Turbo always gets a cap. There is a way to fix this at the device level for all devices.  So I read last week or so...

I just blame Siri and move on....  happens several time in each post.  Some get by.  Some are so bad, I don't even know what the sentence was supposed to mean.  

Best regards,

-a-

[outermarker]

Has anyone actually replaced all the hoses and filters on the PC wing leveler and AccTrak systems? I have a feeling that what I have is original and I guess now is a good time to replace everything. I downloaded all the information I could find and it "seems" to be pretty straightforward. So, second, third or even fourth opinions on the labor side, hints, tricks, whatever is very much appreciated before I order tubing.

[Hank]

At some point,mother ubing needs to be replaced. Not long after I bought my Mooney, all of the joints, connectors and elbows had to be replaced to pass the pitot static test. Thankfully I wasn't involved--brand new owner busy at work, earning money to fly . . .

[Yetti]

The only hint or trick I can say is that Brittain did mine in Tulsa.  The port tubing seems to fail more often. What about the vacuum servos.  Do it during annual since you have to open the whole wing up.

Edited May 3, 2017 by Yetti

[TheTurtle]

ive been slowly rebuilding my PC system.  Replaced all the red and green tbing and fittings.  Retaped the servos.  brittian overhauled my pilot valve and thumb button.  PC system works pretty well now.  roll trim is still not quite right though.  Then I had the autopilot rebuilt and just put it in.  I only tested it for a couple minutes last week and it seemed to be reallllly slow to turn on course when using the heading button so Ill be doing some more testing and also see if the trk and cap works.

last thing is the turn coordinator.  It could be causing some problems they said but it aint cheap to fix and its the one part of the system I cant fly without so I dont want to pull it for overhaul yet.  Also Im broke  ;(

[outermarker]

@ Turtle...how much time would you say you have invested in changing all the tubing? Is it a job one person can do? Any special tools required? Did you test the system using an external vacuum pump or with the engine running?

[TheTurtle]

On 5/4/2017 at 7:31 AM, outermarker said:

@ Turtle...how much time would you say you have invested in changing all the tubing? Is it a job one person can do? Any special tools required? Did you test the system using an external vacuum pump or with the engine running?

half a day probably.  Its not to bad of a one man job but would have been easier with two.  Theres some tight bends you have to feed and pull at the same time.  No special tools needed.  Didnt test the system at all.  flew it and found out it wasnt working so then figured out one of my servos was blown and had to retape it.  Its a real bitch getting the new hose onto the wing servos because you cant see and have to do it all by feel. 

[HRM]

Any suggestions on an external vacuum pump for testing the Brittain system sans engine?

[cliffy]

You can pull each tube off of the turn coordinator (tubes that go to each servo) and pull a vacuum with an automotive hand pump vacuum tool. You will see the servo suck in and if you can hold the vacuum you can see if each line and servo leak down. The tubing gets brittle with age. 

There is an adjustment pot inside the Accutrac that adjusts the sensitivity of actuation. If it rolls slow or doesn't track fast enough you adjust that. You can get manuals on the internet for free of even from Brittain for a reasonable fee. 

[SkyTrekker]

This seems to be the Brittain Autopilot thread with the most activity, so I'll share my discoveries and questions here.  As you might guess, I'd like to add autopilot capabilities to my E.

My Positive Control system is working really well, so based on what I've read, any or all of the Brittain AP upgrade options are worth considering. I'm most interested in the heading bug (B-12 Accuflite) option, but the GPS/VOR navigation tracking (B-11 Accutrak) option only adds <1 AMU to the equipment cost, so I'm considering that, too. Following your recommendations, I contacted Brittain directly. You folks weren't kidding when you spoke highly of their customer service: Accessible, responsive, friendly, and very helpful.  I've spoken with and emailed Cecilia (and Kevin) and learned a good bit.  

In talking with them I've learned that there is an alternate part for the 'unicorn' BI-805 servo valve.  Others probably already know this, but it was news to me that the 'EVT' version of the TC-100 turn coordinator includes the servo valve function.  Our basic wing-leveling version of the TC-100 is the 'EVS' model. To support either the B-11 or B-12 Accutrak/Accuflite AP options, we can replace our EVS turn coordinator with the EVT version instead of installing a separate BI-805. It does extend the length of the TC-100 by an inch or so, but eyeballing the space behind my panel, it doesn't seem like that will be an issue at all.  Attaching images of EVS and EVT models below for reference.

This approach comes with the added requirement of a field approval, but Brittain has provided previously executed field approval examples and a letter from Mooney stating that the EVT replacement system is compatible with specific M20 model years. While I was unable to find a single BI-805 in a month of looking, I was able to find 2 serviceable EVT versions of the TC-100 on my first try (on ebay and Hangarswap).  I also learned that a TC-100's voltage rating is largely immaterial.  Brittain is able to overhaul either voltage to the other. 

So here are my questions, fellow Mooneyites:

1. Are there any recommendations for mechanics in the Central Texas area who are very familiar with the Brittain systems?  I'm new to Mooney ownership and am still developing my network.  I hope to assist in the installation process if it can be done at my home field, ACT.
2. I've read some of the FAA field approval documentation, methods, etc. and I'm nothing but confused.  Assuming there is precedent (care of the Brittain documents mentioned above), should I expect that the field approval is generally do-able?  Or can this process be problematic?  I purchased a used EVT TC-100 for $250 (listing reviewed by Brittain), but am holding off on the equipment overhaul/calibration/tagging expense until I have some level of confidence in the field approval process.

Thanks for any input here!

-Sia

Top Diagram: EVS Model     Bottom Photo: EVT Model

[MyNameIsNobody]

I have a TC-100 ready if my BI-805 ever 'craps out'.  I would consider flying up to Tulsa and participating with Kevin on the install.  I rarely use my Accu-Trak, but I use the Accu-Flite every x-country I take.  If you already have a GPS the Accu-Trak is a nice solution.  My A&P installed both.  Brittain overhauled each.  I put in the PC disconnect electric solenoid too.  It was inexpensive and works great.  Need a yoke upgrade to get the switch on the yoke and make the STC from Brittain a "go".

[cliffy]

One item I have found helpful is to do nothing to the airplane until you show your idea/paper work to the FSDO you are going to work through and get an initial approval to do the job. Make an appointment and bring all your drawings documents for them to look at. It smooths things. They don't like to see all the work done and then you bring in the paper work for the field approval. 

Some FSDOs are more "agreeable" than others. Each one has its own personality. I'm not saying to shop for an agreeable one but? Asking questions really helps. 

I have an Accutrac II hooked up to my KX155 VOR on one side of the switch and my GPS 155 on the other. I use the GPS side almost exclusively. After installation you will be adjusting the gains to get a smooth tracking unit but that part is easy. The system works like a dream. I don't need no stinkin' heading bug :-) :-)

Now if all goes well and I pop for a Trutrac or Trio shortly I'll have a complete Brittain ready for sale that works perfect! BTW, Brittian has repaired my AccuTrac in years past, I have visited their shop and found them to be all everyone says they are- truly professional and courteous. Great people to work with. 

[SkyTrekker]

8 hours ago, MyNameIsNobody said:

I have a TC-100 ready if my BI-805 ever 'craps out'.  I would consider flying up to Tulsa and participating with Kevin on the install.  I rarely use my Accu-Trak, but I use the Accu-Flite every x-country I take.  If you already have a GPS the Accu-Trak is a nice solution.  My A&P installed both.  Brittain overhauled each.  I put in the PC disconnect electric solenoid too.  It was inexpensive and works great.  Need a yoke upgrade to get the switch on the yoke and make the STC from Brittain a "go".

Good point. The idea of flying up to Tulsa and helping Kevin with an install holds a lot of appeal for me.  I'll call them today to see how far out they're booked and how long I would need to plan to be there to accomplish that. 

6 hours ago, cliffy said:

One item I have found helpful is to do nothing to the airplane until you show your idea/paper work to the FSDO you are going to work through and get an initial approval to do the job. Make an appointment and bring all your drawings documents for them to look at. It smooths things. They don't like to see all the work done and then you bring in the paper work for the field approval. 

Some FSDOs are more "agreeable" than others. Each one has its own personality. I'm not saying to shop for an agreeable one but? Asking questions really helps. 

I have an Accutrac II hooked up to my KX155 VOR on one side of the switch and my GPS 155 on the other. I use the GPS side almost exclusively. After installation you will be adjusting the gains to get a smooth tracking unit but that part is easy. The system works like a dream. I don't need no stinkin' heading bug :-) :-)

Now if all goes well and I pop for a Trutrac or Trio shortly I'll have a complete Brittain ready for sale that works perfect! BTW, Brittian has repaired my AccuTrac in years past, I have visited their shop and found them to be all everyone says they are- truly professional and courteous. Great people to work with. 

Good idea, Cliffy. I guess if I were to work with Kevin at Brittain on the install, I would also work with him on to develop the paperwork for a pre-work approval from the FSDO, like you suggest.

 

[Browncbr1]

If you have a trusting AI and feel you can do it, it's not a difficult install as long as you study the system well enough to know exactly what you are doing before you start.   I have alt hold, accuflite and accutrack for around $3500 all in.

The TC with integrated control valve simplifies install, but complicates paperwork due to involving FSDO.   

[SkyTrekker]

1 hour ago, Browncbr1 said:

If you have a trusting AI and feel you can do it, it's not a difficult install as long as you study the system well enough to know exactly what you are doing before you start.   I have alt hold, accuflite and accutrack for around $3500 all in.

The TC with integrated control valve simplifies install, but complicates paperwork due to involving FSDO.   

$3500 for 3 axis AP including labor is crazy amazing.  Well-done!   

I'd love to do it all myself and have an AI sign off on it.  Problem is, this is my first plane, I've never worked on one before, and I don't have a relationship with an AI yet.  Even if I did, I would not trust me (yet) if I were him/her.  I would love to spend a day with a great AI, working from the nose to the tail on my E and learning as much as I could about everything in between.  Maybe do a couple of service or maintenance jobs with them.  Then I think I'd be ready for taking on something like installing an autopilot system.  I guess I'll print out the documentation that Brittain sent and study up.  Either way I go, knowing everything about the system will be a good thing.

In the meantime, I've emailed Cecelia to get a quote for Brittain installing the B-11 and B-12, with me assisting.  We'll see what they come back with.

-Sia

[MyNameIsNobody]

Sky Trekker: My "All in" price is somewhere in between Brown and Dave for parts and installation.  I paid under .2AMU's for Accu-Trak (part); Found the Accu-Flite on Ebay for about .7 AMU's (Heading Bug and control head/parts).  The guy had an F model.  A few flights and GUMPed it.  Insurance company totaled.  He got the units and was reselling them.  Brittain had just overhauled.  I watched Ebay daily for "deals" while in the "hunt".  The altitude hold was about 2.5 AMU's with parts and installation.  Found parts on Ebay.  Brittain yellow-tagged and installed.

Good luck with your search.  Now that upgraded (new) Autopilot systems are on the horizon, not sure I would do Brittain again, but VERY satisfied for my use with cross country VFR flights of 2-3 hours being normal mission.

NO GPS STEER/approach for these so if doing IFR I would go a different route perhaps?  I think the SAM system will integrate but don't think it would be "legal" on approaches?

[cliffy]

There is a limitation in my Accutrac book that specifically says 'No Approaches approved" We're talking enroute only use here. Will it track an ILS or VOR during a VFR test? YUP but it ain't approved. The other systems have some approach approvals. 

[Browncbr1]

1 hour ago, cliffy said:

There is a limitation in my Accutrac book that specifically says 'No Approaches approved" We're talking enroute only use here. Will it track an ILS or VOR during a VFR test? YUP but it ain't approved. The other systems have some approach approvals. 

yea, it's not approved for approaches, but it does actually track a LOC very well...   I don't bother tracking VORs really because of the radial signal bending that often occur, especially at lower altitudes .. it's better just to use the heading bug...  If you have a GPS, it will track pretty well, as the signal is stable.

[Browncbr1]

2 hours ago, SkyTrekker said:

$3500 for 3 axis AP including labor is crazy amazing.  Well-done!   

I'd love to do it all myself and have an AI sign off on it.  Problem is, this is my first plane, I've never worked on one before, and I don't have a relationship with an AI yet.  Even if I did, I would not trust me (yet) if I were him/her.  I would love to spend a day with a great AI, working from the nose to the tail on my E and learning as much as I could about everything in between.  Maybe do a couple of service or maintenance jobs with them.  Then I think I'd be ready for taking on something like installing an autopilot system.  I guess I'll print out the documentation that Brittain sent and study up.  Either way I go, knowing everything about the system will be a good thing.

In the meantime, I've emailed Cecelia to get a quote for Brittain installing the B-11 and B-12, with me assisting.  We'll see what they come back with.

-Sia

I think I remembering paying $1200 for the accuflite, $1000 for altitude hold, $100 for the DG, then had it overhauled for $400... All of these were off market..   then got the STCs and the accutrack box for $700..   This might be off, but it is ballpark.    

If you are adding up in the $7k ballpark, consider the Trio.

[cliffy]

All I've needed for years is the altitude hold but I haven't found one yet. I'd buy it today if I could find one.

You guys must be luckier than me to find one.