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Non standard rudder return spring system

Posted: Wed Apr 10, 2019 7:43 pm
by alanbaker
Hi everyone! New member here, first post. I bought my 170 to learn to fly tailwheel and to have fun building time. I'm in the process of getting checked out now.

My instructor was reporting some poor ground handling and so I did some investigating as to why that might be. I landed on the rudder return springs. I took off the inspection panel underneath them to see if there were any problems and I found that the right side spring was missing and the left side spring was just hanging from the arm on the rudder control.

Crazy right? The rudder does return to an off center position so I kept digging and found on the right side pedals that there is a non standard return spring system installed. I'll include pictures. Is this system an approved system? I can't find any mentions of it in the log books but this aircraft has been maintained by the same AMT for 25 years and he recently won the FAA AMT of the year so I have some confidence in the maintenance history of the aircraft.

What do you guys make of this? Thanks for all the info! I would not have gotten this far if it wasn't for this forum!

Alan

Re: Non standard rudder return spring system

Posted: Wed Apr 10, 2019 8:41 pm
by Bruce Fenstermacher
I know of no other approved return spring system other than the stock springs.

Re: Non standard rudder return spring system

Posted: Thu Apr 11, 2019 12:50 am
by ghostflyer
I would not fly that aircraft until it has been reverted back to as it came out of the factory . Have it done by a reputable shop. No wonder you were having ground handling issues. Plus if you had a accident the insurance company would wipe you like a dirty rag . The FAA would have a field day . Its a serious nonconforming modification.

Re: Non standard rudder return spring system

Posted: Thu Apr 11, 2019 1:42 am
by alanbaker
Thank you Bruce and ghostflyer! I ordered the springs yesterday after I found them missing and broke. I just wanted to verify that this was a farmer John fix rather than some STCd alternative I was not aware of. Don't worry guys, I will have it returned to stock before I fly it again! Thank you for confirming my suspicions!

Alan

Re: Non standard rudder return spring system

Posted: Thu Apr 11, 2019 8:42 am
by c170b53
Hey Alan welcome...nice splash on your first post. What’s you machine? Any pics?

Re: Non standard rudder return spring system

Posted: Thu Apr 11, 2019 12:06 pm
by IA DPE
Yes, we want to see pics of the WHOLE airplane, too :lol:

Re: Non standard rudder return spring system

Posted: Thu Apr 11, 2019 12:27 pm
by Bruce Fenstermacher
Alan, there are lots of good "Farmer John" fixes. There are two problems with most of them. There is no documentation which means there is no way to know if the modification is in good mechanical order. Your aircrafts mod apparently is not in good mechanical order or you wouldn't have noticed an issue. And second, as mentioned and is part of the documentation process, there was no appropriate approval sought to make the modification.

Installing these spring is a real joy. Specially for the first timer. I started a thread a while ago documenting a process I came up with to make the process easier. You can find it here:

http://www.cessna170.org/forums/viewtop ... pring+tool

Lots of good pictures and drawings and my home made simple tools to help you get this done.

Re: Non standard rudder return spring system

Posted: Thu Apr 11, 2019 1:50 pm
by 170C
Welcome aboard Alan! Look forward to seeing a post about putting the new rudder springs on your new 170 and some photos of your plane, inside and out.
Where are you located Alan?

Frank

Re: Non standard rudder return spring system

Posted: Thu Apr 11, 2019 2:03 pm
by brian.olson
Welcome, Alan, and congratulations on the purchase of your 170!

Re: Non standard rudder return spring system

Posted: Thu Apr 11, 2019 10:47 pm
by DaveF
Welcome, and thanks for the post!

Replacing the springs isn’t bad if you follow the recommendation (in the thread Bruce linked) to release the rudder cables from the rudder horn. That gives you the slack needed to hook the springs.

Welcome aboard!

Re: Non standard rudder return spring system

Posted: Thu Apr 11, 2019 11:50 pm
by ghostflyer
Returning this aircraft to standard configuration could be a bigger job than just replacing the old springs . The modification has to be removed also and what damage to structure has been done by the addition of the illegal modification. The area around the rudder pedals should be closely inspected for distortion and cracking and wear . I would be having the rudder system completely rigged checked especially the distance the rudder pedals are from the fire wall . This area is often missed during a 100hrly . It wouldn’t hurt to do a complete rudder inspection also. While you are relaxing and lying around on the floor of the aircraft and having a look around this area check your hydraulic master cylinders for level also.
Gosh!! Owing a aircraft is soooo much fun.

Re: Non standard rudder return spring system

Posted: Fri Apr 12, 2019 1:21 am
by alanbaker
WOW thanks for the warm welcome guys! Hopefully returning the return system back to original isn't too big of an issue! I will try to remember to take pictures as I work with an A&P to get everything buttoned back up! I contacted the A&P who has maintained it for the last 25 years and he had no idea. Probably what I would say too.....

Anyways, I'll get it straightened up!

Here she is! N4286V serial number 18700. looking forward to meeting you guys at some of the local fly-ins! I am in Oregon, anyone else local?

-Alan
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Re: Non standard rudder return spring system

Posted: Fri Apr 12, 2019 2:23 am
by GAHorn
Alan,..WELCOME also!

My predecessor Tom Hall created the Rigging Instructions for the 170 series. You will want to download a copy here in our Mx Library: http://www.cessna170.org/forums/viewtop ... =41&t=8196

Re: Non standard rudder return spring system

Posted: Fri Apr 12, 2019 4:09 am
by alanbaker
Thanks gahorn! I got lucky that the previous owner was also a member and have me a ton of documentation to go with the aircraft including that manual that uses member contributions to go through each system, such a brilliant use of community knowledge! I was impressed before I even logged in!

-Alan

Re: Non standard rudder return spring system

Posted: Fri Apr 12, 2019 5:23 pm
by GAHorn
alanbaker wrote:Thanks gahorn! I got lucky that the previous owner was also a member and have me a ton of documentation to go with the aircraft including that manual that uses member contributions to go through each system, such a brilliant use of community knowledge! I was impressed before I even logged in!

-Alan
Beware of the SRAM manual that is out of print. It was created before anyone paid attention to regulations and has a lot of backyard-hot-rod solution mentality. It's a fine book to have... just beware.