Yaw Damper KFC225

[Jerry 5TJ]

Is the Yaw Damper option available with the KFC225 system in long body Mooney airplanes?

My 2000 Ovation has the King 225 autopilot with most of that system's options but no yaw damper. 

Anyone know if it may be installed?  

[carusoam]

The O has a powered tail trim.  I don't remember it being attached to anything other than the tail trim switch.

The more simple KAP150 does turn in a pretty well coordinated fashion.  Is it using the powered tail trim to coordinate the turn?

Putting those two ideas together...  It is possible that a higher end Flight Director could drive a yaw management system...

Does or would the long body benefit from such a yaw damping system?

Best regards,

-a-

[Guest Mike261]

the KFC 225 does have an optional yaw damper...dont know about retrofitting. When installed the AP head comes with yaw damper (YD) button right on it.

mike

[Jerry 5TJ]

On a couple of bumpy cross-country legs in recent weeks I really noticed lack of yaw damping.

My P46T with KFC200 system had yaw damper & it made a big difference, especially in aft seats. 

The KFC225 head in my Ovation does not have the YD button.  The King manual shows it is optional, as are the KS271C yaw servo and KRG331 rate gyro. 

My question: Is YD available and approved for M20R?

 

[carusoam]

Add on hardware is listed here...

https://www.bendixking.com/HWL/media/Pilot-Guides/006-18035-0000_1.pdf

I ran out of time in the day to find an STC list of planes that it can be mounted on....  Probably found in the installation manual.

See if JClemens may be knowledgable on this...

Best regards,

-a-

[Godfather]

Had an AP problem 5 or 6 years ago.  Turned out to be a bad wire but the 225 was sent to BK just to make sure it was working properly.  They tested it and said it was working 100% and returned it along with a bill for over 2 amu...  Point is you might find sending the unit back for a slight upgrade might be very expensive.

[LANCECASPER]

The only yaw damper I've seen in Mooneys are in 252's and Encores. In the Encore I had it. It served as a Rudder trim. The Rudder Trim I have in the Ovation serves the same purpose.

Edited March 21, 2016 by LANCECASPER

[Jerry 5TJ]

The M20R POH supplement for the KFC225 is found at

http://www.mooney.com/en/pdf/KFC225.pdf

it does say that the approval is for 3 axis (including yaw) control, however nowhere else is YD mentioned and the illustration of the panel mounted unit does not show the YD button.

The KFC225 Pilot's Guide does not list any STC information.  It does show the optional YD button and describes its use, unlike the POH supplement.

I looked at Ovation panel images shown on Controller and can't find one with the YD button.  So I assume no YD option was available to Ovation buyers circa 2000.

 

 

[carusoam]

The YD button is an add-on, separate device.

The only other place the YD gets mentioned (BK manual online) is the emergency section. The several ways to shut down the AP and disable the system.

There are other planes that really benefit from the YD.  Short body and V tail like planes.  The LB development probably took a pass on the opportunity to add the additional weight and paperwork.

Most of my O flights were in smooth air over 5k'.  I would wonder how well the YD actually works in convective type weather.  A measure of the computer's power, sensor and the speed of the servo motor.  The KFC225 is relatively young it is probably the best on the market.  It will probably dampen the waggy response, but it probably won't dampen the ride itself.  That would take a predictive sensor of some sort.

Similar to altitude hold.  The crazier the weather, the less well it works. 

The other thing to consider may be other vendors with newer digital APs.

See if there is any feedback over on BT.  (First time this advice may really make sense).

Best regards,

-a-

 

[Jerry 5TJ]

With the help of Honeywell at SnF  I did track down the fellow who knows the answer in Tech Support at Bendix King.

The official answer is - the YD feature of the KFC225 system was never certified on that airframe.  So no, the YD feature of the KFC225 is not available in Mooney M20R.

My P46T has the KFC200 system with integral YD and it does make a difference to the ride.  Yaw is more annoying and sickening than vertical bumps, it seems.  It is a checklist item to ensure YD off for take-off and landing as with YD engaged you can't move the rudder pedals easily.

[Jerry 5TJ]

I also visited S-Tec's booth at SNF.  They offer a stand-alone YD system.  Their YD can also serve as rudder trim which could be valuable on those Mooney models lacking yaw trim.  Ovations do have manually-controlled rudder trim.

"Is it available for the M20R?" I asked Genesys, who own the S-Tec line. Their tech support manager replied:

Our STC list does not currently cover a Yaw Damper installation with the M20R.  We have it available for the M20 series up to M20M so I am checking with our ODA administrator on why the M20R is not covered and if there is anything we can do to get a Yaw Damper installed.

 

 

[Marauder]

I also visited S-Tec's booth at SNF.  They offer a stand-alone YD system.  Their YD can also serve as rudder trim which could be valuable on those Mooney models lacking yaw trim.  Ovations do have manually-controlled rudder trim.

"Is it available for the M20R?" I asked Genesys, who own the S-Tec line. Their tech support manager replied:

Our STC list does not currently cover a Yaw Damper installation with the M20R.  We have it available for the M20 series up to M20M so I am checking with our ODA administrator on why the M20R is not covered and if there is anything we can do to get a Yaw Damper installed.

 

 

You forgot to mention the price Jerry.

When you told me, I was glad you knew CPR. Anyone know if Norm Smith's "Aero Trim" is still being sold? I know Norm is no longer with us but curious if his family kept selling it. I was never a believer until I saw I was indeed losing 2 knots at cruise.

[Jerry 5TJ]

21 minutes ago, Marauder said:

You forgot to mention the price Jerry.

I believe the booth reps said 7 AMU would cover their hardware.  

Norm Smith's Aero-Trim was only $695, according to the advertisement I found on-line.  Of course that's what it cost in the 1980s.  

aeroinfo.pdf

[Andy95W]

Aero-trim is now $895, it appears to still be available:

http://www.aerotriminc.com/id2.html

[Marauder]

Aero-trim is now $895, it appears to still be available:

http://www.aerotriminc.com/id2.html

Interesting. Sounds like either the family kept the STC or sold to someone who is selling them. I also see his self sealing stuff listed as well.

Norm was the ultimate Cheap Bast&$d. I will look into the kit. Thanks for finding it.

[Andy95W]

Did you ever meet him?  First time for me was around 1997 at a MAPA homecoming.

Ex-wife and I stopped in Opa Locka to see him after I'd bought all of his mods.  He paid for lunch for us.  He wanted everyone to know him as "The Mooney Miser", but he was very generous, and a great guy.