Looking for Flap Cables

Paul462 · #1 09-11-09, 07:56 PM

I really like Herb's siglines - some of them are deceptively shallow, yet obviously deep - for the most part (some of them).

edasmus · #2 09-23-09, 10:07 AM

I have nothing major to report on the flap cables from the other wing. They looked just like the first set. There was nothing obvious from the outside and we did not bother to take the time to cut them open figuring the worst case would be a few broken strands like the first set.

I do have a photo of the first set that I will post here shortly but I left the camera somewhere else and will not have it back until this weekend. I have never posted a photo so if anyone has any advice I am all ears. I can say that I have seen pictures on this forum of other people's flap cables and some of them were very alarming looking to me. The cables that were removed from my airplane did not display wear patterns that looked anything nearly as bad as some of the scary pictures that were posted on this forum. My wear patterns were not nearly as advanced as some of the other photos but mine were in the same location as those photos revealed.

Thanks Ed

edasmus · #3 09-26-09, 09:45 PM

Here is the photo my flap cables.....

African 337 · #4 11-06-11, 01:02 PM

This thread interested me.

GUYS PLEASE DO CHECK THESE CABLES!

One of these snappped in exactly that spot at the tight corner it makes next to the pulley, invisible to usual inspections. I wasn't flying myself. The cable snapped while the pilot was turning onto finals from a left hand circuit. the RH flaps immediately popped up and Left side remained set on full. You can imagine a fairly good roll rate commenced to the Right. Luckily the plane started banked to the left, pilot guessed the problem, reached straight for the flap control and selcted up. Luckily the Left flaps retracted. result was a safe landing (with 5 scheduled traffic passengers on board).

I checked the one the other side which also had many broken strands and we replaced both.

Unfortunately we don't operate in the sort of environment where we file official service difficulty reports!

jchronic · #5 11-06-11, 07:20 PM

I will heartily second that recommedation: Check your flap cables at the next annual, if not before!! We just finished an extensive 100-hour inspection on2697S under the expert supervison of Aeromx (who comes on here occasionally). As a result of info he and I picked up at the final CPA 337 seminar in Santa Maria earlier this year, we wanted to specifically inspect this seldom looked at area. What we found was bad; one cable frayed and the other with completely broken strands.

Needless to say, they were replaced at the cost of a week or so of additional down time and a lot of hard work by Aeromx, but it was a find I was glad we made. And an SDR report is being made to the FAA. Maybe Tim (Aeromx will get on here with more info; he has some pics of the frayed/broken cables.

Joe

Paul462 · #6 11-07-11, 07:45 AM

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 · #7 11-07-11, 11:50 AM

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.

Aeromx · #8 11-12-11, 03:43 PM

Quote:

Originally Posted by jchronic

I will heartily second that recommedation: Check your flap cables at the next annual, if not before!! We just finished an extensive 100-hour inspection on2697S under the expert supervison of Aeromx (who comes on here occasionally). As a result of info he and I picked up at the final CPA 337 seminar in Santa Maria earlier this year, we wanted to specifically inspect this seldom looked at area. What we found was bad; one cable frayed and the other with completely broken strands.

Needless to say, they were replaced at the cost of a week or so of additional down time and a lot of hard work by Aeromx, but it was a find I was glad we made. And an SDR report is being made to the FAA. Maybe Tim (Aeromx will get on here with more info; he has some pics of the frayed/broken cables.

Joe

Pics of JChronic's 1969 337D Inboard Flap Cable damage (x2) as found at 100hr/Annual Inspection - See attached.

As has already been noted by others you CANNOT see the affected areas of these cables with REMOVING them from the bellcrank. You MUST remove them for proper inspection. We replaced all 6 flap cables with new stainless cables and re-rigged the entire system per the service manual. The cables were tough to find but managed to find 5 out of the 6 we needed from 5 different sources. Had to have the last cable made/fabricated by Beechhurst Industries in NY (Ph: 718-468-1565). They can make most flight control cables under a Mil-Spec part number thereby eliminating the need for an STC or field approval....log entry only needed. The cost of the fabricated cable from Beechhusrt was the same as if I could purchase it from Cessna or other sources if it was available.

Let me know if anybody has any questions or needs any help.

- Tim/Aeromx

edasmus · #9 11-12-11, 04:37 PM

Great job!

Excellent photo's.

Ed