DIY - Rudder Cable Replacement

[Moonshine]

Doing the cables right now
1300 hrs time in service, first 1200 in a flight school
Guess how many of the cables show any kind of wear?
None. They are all perfect.
Very, very pissed.

[Colin]

the need to throw perfectly new cables in the garbage.

I give mine to a shorter plane so they can cut off the ends and use them.

[Chris B]

My “new” ride turns five in July, so I was planning to have Glenn make the cable swap while she is already on the rack for the annual inspection. However, Glenn’s recommendation was to defer this work as long as possible in the hope that RealSoonNow™ it will not be necessary. Not announcing anything, just saying…

The only Diamond aircraft that Glenn has seen with worn cables are in high-hour (>2-3k) flight schools. In addition to high hours, they probably were not diligent about keeping the tubes lubricated. Crucially, on the rare occasions that the wires needed replacement, so did the S-tubes.

The origin of this requirement is rooted in the nature of the certification process. Under the normal (but intense) pressure to launch the aircraft (just imagine the final “punch-list”!), it was simply easier and faster to agree to a worst-case replacement schedule than deal with a more nuanced recommendation. All it would take is for someone to formally note that one cannot visually inspect the cables, but there is no simple way to un-ring that bell…

Chris

[Rick]

My “new” ride turns five in July, so I was planning to have Glenn make the cable swap while she is already on the rack for the annual inspection. However, Glenn’s recommendation was to defer this work as long as possible in the hope that RealSoonNow™ it will not be necessary. Not announcing anything, just saying…

I have heard such rumors, too, within the past few months, so we will remain hopeful...

The only Diamond aircraft that Glenn has seen with worn cables are in high-hour (>2-3k) flight schools. In addition to high hours, they probably were not diligent about keeping the tubes lubricated. Crucially, on the rare occasions that the wires needed replacement, so did the S-tubes.

Those flight school birds also probably saw a lot of rudder pedal adjustments, maybe almost every flight, which didn't help the cable wear in the S-tubes, either!

[hkavasch]

I heart from Diamond, that the time for rudder cable replacements will be over soon... The NG Models and maybe some of the later TDI's use a different type of stainless cables that can run "on condition" and does not need to be replaced every 5 years.

That was about time.... my buddy flies a bonanza... his cables are 40 years old and never had to be replaced...

[CFIDave]

I'm in the middle of my 2nd "owner-assisted annual" on our DA40, and this time we're in the middle of the dreaded rudder cable replacement process now that the plane just turned 5 years old. I did succeed in getting all of the seats out of the plane, including the rears (see photo).

So far the hardest part seems to be maneuvering the large crimping tool into the interior. We succeeded in replacing the 4 rear cables today -- tomorrow we tackle the front 4 cables attached to the rudder pedals.

I expect we're going to have to test-fly the aircraft and re-adjust the cable turnbuckles under the back seat in order to ensure the plane flies straight with feet on the floor. Fortunately the newer DA40s have access panels built into the rear seat pan, so I should be able to avoid removing the rear seats a 2nd time.

[CFIDave]

Finished up the rudder cable replacement, got the plane all put back together, and test flew the plane in the dark last night. The good news is that the plane still flies with no obvious yaw and the "ball" is still centered in straight and level flight (it also helps that our plane's nose gear fairing is usually straight) with feet off the rudder pedals. We spent quite a bit of time adjusting the turnbuckles while visually inspecting that the rudder was straight.

A big thanks to Rick for his instructions and photos that kicked off this thread. His cable length measurements in particular were extremely helpful. I'm amazed that he was able to do the work by himself, since it absolutely took 2 of us to install (and crimp the sleeves on the ends of) the new cables.

Here's a photo of the old cables (all 8 of them, cut into pieces) -- which of course were in ABSOLUTELY PRISTINE CONDITION before they were cut and removed. What a waste of time, effort, and money! Now that the DA42 rudder cables no longer must be replaced every 5 years, it's ridiculous that DA40 owners have to put up with this. C'mon Diamond, fix this!!!

[Gary]

Finished up the rudder cable replacement, got the plane all put back together, and test flew the plane in the dark last night. The good news is that the plane still flies with no obvious yaw and the "ball" is still centered in straight and level flight (it also helps that our plane's nose gear fairing is usually straight) with feet off the rudder pedals. We spent quite a bit of time adjusting the turnbuckles while visually inspecting that the rudder was straight.

A big thanks to Rick for his instructions and photos that kicked off this thread. His cable length measurements in particular were extremely helpful. I'm amazed that he was able to do the work by himself, since it absolutely took 2 of us to install (and crimp the sleeves on the ends of) the new cables.

Here's a photo of the old cables (all 8 of them, cut into pieces) -- which of course were in ABSOLUTELY PRISTINE CONDITION before they were cut and removed. What a waste of time, effort, and money! Now that the DA42 rudder cables no longer must be replaced every 5 years, it's ridiculous that DA40 owners have to put up with this. C'mon Diamond, fix this!!!

The requirement to replace these cables at this ridiculously short interval places DA40 pilots at risk due to possible inadvertent damage to other structures or errors during replacement of the cables.

[Gasser]

I've already had mine replaced once and am really crossing my fingers that this requirement goes away or is greatly extended. It's a shame looking at all those really thick perfect cables laying on the ground.

[David B]

I'm a big believer in the old adage that the squeaky wheel gets the grease. That being said, I have been on Diamonds case over this issue, and a few others, since I purchased my DA40 4 years ago. Each owner may be doing this, but if not, I strongly recommend ALL of us call, write, or e-mail Diamond about this issue and let them know that we, as customers, demand that they get this time issue changed. There is more than enough evidence to support the fact that we should not be changing out new cables with new cables. So far I've been pleased with how they respond to customer concerns, but this and the fuel hose issue need to be addressed immediately.