Looking for Flap Cables

[Paul462]

African 337,

Do you happen to know how many hours were on the plane, and if the flap cables have ever been removed for inspection (if so, how many hours ago?). What year and model 337 was it?

[African 337]

Hi Paul,

It is a 1969 Model C337D. Total time around 9000 hrs. Used to be N86439 if anyone out there knew it in USA! No idea on previous history of the cables. The problem is mainly a design one as the cable makes a sharp corner right my the long nipple and this is all around the back out of sight so only if your engineer uses a torch and missor and knows where to check will he see anything but in truth you'd be best to unmount that end of the cables and have the carefully inspected. We were lucky. Could easily have all ended in tears.

[WebMaster]

I'm pretty certain there is a Cessna SB on these. The sharp bend around a smallish pulley is the culprit. The procedure for checking them is simple.

Take a rag, and wipe the cable. If it snags anywhere, you have a broken strand. If you have a broken strand on the outside, you undoubtedly have many on the inside. Waste no time, replace the cables. Both of them.

As others have pointed out, this should be part of the annual inspection that your IA performs.

The only way you can check these cables is to remove them at the bell crank. A flashlight and mirror doesn't usually show the frayed cable. I've attached a picture of where they fray. Hope this helps.

[Paul462]

African 337,

Thanks! We have similar aircraft - we're flying a T337C. You are correct in that the only way to inspect the cables is to remove them. There are two per side which hold the flaps DOWN - these, of course, are the critical ones. There is also one cable per side to hold the flaps UP - these are much less of an airworthiness concern where a cable breaks in flight.

Once the four important DOWN cables have been removed for inspection, one might as well replace them. The cable and end connectors can be easily had, and then the only thing one needs is an A&P with a big swedger, and voila! four new fabricated cables for not much money.

I've heard of one operator of several 337s in Australia who does this routinely every year with his fleet of 337s.

[edasmus]

I agree as well. Removal is the only way to inspect these cables. A visual inspection tells only a small portion of the story. It is better than nothing but probably not adequate.

Ed

[brian]

Thanks for this great info everyone. N2125X is just going in for annual and I will likely ask them to remove the flap cables for inspection based on this. Curious as to what the cost was for replacement cables?
Brian

[edasmus]

As best I can tell, I spent $1,200.00 for all the cables and 10 hours of labor to do the job. Labor was another $770.00. So about $2000.00 for the entire job in September of 2009.

Ed