Control Cables

[KS170A]

OK, so I ordered and received a complete set of control cables for my 170A. Through some other threads, I noted with curiosity how some rudder cables may be longer than they were when they left the factory, to the extent that some people have extra holes drilled in the links attaching the cables to the rudder horn. I compared my FAA-PMA'd cables to the ones I pulled out, and the PMA'd one was nearly an inch longer! Through an offline discussion with another member, this was about the same length discrepancy. My curiosity is that the 170A IPC, figure 49, lists the cables as PN NAS314-27-2247. Speculation on my part, but I'd think the -2247 would indicate 224.7 inches long. However, the factory spec according to the 170A control cables installation drawing lists the cable numbers as 0510105-1, which is 224.88 inches. 0.12" might be able to be adjusted with the turnbuckles, but 1" is too much.

Rudder Cables.jpg

Additionally, the lower flap cable, p/n 05010105-5, is spec'd at 125.62. I measured the new PMA'd part, and it is about that long. BUT, the old cable (that was of proper functioning length, is nearly 6 inches shorter!

Flap Cables.jpg

Has anyone else had this problem?

[Bruce Fenstermacher]

Josh I'm wondering if you've discussed this with the manufacturer of the cables for their input to the length discrepancy of their PMA'd part to the specifications?

[minton]

FYI: The flap cables of which you refer (4ea.) are all of different lengths. I would suspect that the one you have concerns over might have been labled wrong from the manufacturer. Be sure to replace them into the proper location or you will never be able to re-rig them.
As an asside: They are a bugger to remove and replace.

[KS170A]

FYI: The flap cables of which you refer (4ea.) are all of different lengths. I would suspect that the one you have concerns over might have been labled wrong from the manufacturer. Be sure to replace them into the proper location or you will never be able to re-rig them.
As an asside: They are a bugger to remove and replace.

Actually, the 170A (which I have) only has 3 cables. One from the flap lever to aft of the cargo area, up to the top of the cabin, then it connects to two equal-length cables to the hinged flaps. I believe the B models have the 4 cables.

170A flaps.jpg

If I get a chance during working hour I will certainly call the manufacturer.

[KS170A]

Flap cable mystery solved. The 170A IPC, figure 45, page 83, indicates the lower flap cable p/n is 0510105-5. Actually, it should be a -14, which happens to be exactly six inches shorter than the -5. The flap cable is reference (round-a-bout way) in the seaplane option listing, figure 61, page 109, indicates the stainless steel version -114 (add 100 to the galvanized steel version to get the stainless). I discussed this with the PMA manufacturer, and they will send me the correct cable (and hopefully revise their kit). For the rest of us, pencil in -14 instead of -5 in figure 45.

[Bruce Fenstermacher]

Josh did you ask about the discrepancy in length of the rudder cable?

[KS170A]

Upon further review, and an assistant helping with measurements, I came to the conclusion that all the new cables were at least the same length as, if not very slightly shorter. I'm returning the -5 lower flap cable and one of the rudder cables for damage. I'm going to replace all the pulleys as well, so I'm expecting positive results once I get the correct sized flap cable.

[170 Scott]

I just had the same problem with the replacement lower flap cable being too long. So, I thought I'd pass along what I learned.
I have a 1950 Cessna 170A, s/n 19519.
I ordered, from McFarlane, the p/n (MC)0510105-5 as our Cessna manual shows, and got a cable 5-6 inches longer than the original. While on the phone with McFarlane, they found a note in their specs and forwarded it to me:

"The seaplane option may be identified by confirming the installation of reinforcers to the bulkhead located at the end of the cabin compartment. Advise the customer to compare his aircraft to the parts catalog at the figure that shows the seaplane installation. The aircraft's equipment list and other factory data or logbook entries may also confirm installation of the seaplane option.

There has been some confusion regarding the length of the MC0510105-5 cable. The cable is used on Cessna Model 170 and 170A aircraft in the flap control system. The cable is attached to the flap lever and runs aft then up to a "wiffle tree" where the direct flap cables are attached.

We have verified with Cessna that the length of the McFarlane -5 cable is correct @125.56. Customers who have stated that our cable is to long request a cable 119.62-inches in length. This length is correct for a -114 cable. The -114 cable is correct if the aircraft has the factory seaplane option installed. We have also verified that the length of the -114 at 119.62-inches."

My aircraft didn't come with the seaplane kit (I have the original packing list from 1950), and the logs don't show anything about it ever being installed either. Nor do I have the reinforcers mentioned. So, the fix was to order the -114, and unfortunately, since they think it's for a seaplane, they don't offer it in galvanized. The stainless steel -114 is $161 vs. the galvanized -5 at $61.

Maybe Cessna installed the flap portion of the seaplane kit on a range of airplanes due to lack of standard parts? Either way, I suggested McFarlane add a note to to their catalog to measure the lower flap cable before ordering to avoid this hassle.

I'd like to know what the difference is, in the flap system, between the standard airplane and one with the seaplane option install, if anyone knows. Also, I'd be curious if the s/n's of others that have had this problem are near mine.
Thanks,
Scott

[KS170A]

I just had the same problem with the replacement lower flap cable being too long. So, I thought I'd pass along what I learned.
I have a 1950 Cessna 170A, s/n 19519.
I ordered, from McFarlane, the p/n (MC)0510105-5 as our Cessna manual shows, and got a cable 5-6 inches longer than the original. While on the phone with McFarlane, they found a note in their specs and forwarded it to me:

"The seaplane option may be identified by confirming the installation of reinforcers to the bulkhead located at the end of the cabin compartment. Advise the customer to compare his aircraft to the parts catalog at the figure that shows the seaplane installation. The aircraft's equipment list and other factory data or logbook entries may also confirm installation of the seaplane option.

There has been some confusion regarding the length of the MC0510105-5 cable. The cable is used on Cessna Model 170 and 170A aircraft in the flap control system. The cable is attached to the flap lever and runs aft then up to a "wiffle tree" where the direct flap cables are attached.

We have verified with Cessna that the length of the McFarlane -5 cable is correct @125.56. Customers who have stated that our cable is to long request a cable 119.62-inches in length. This length is correct for a -114 cable. The -114 cable is correct if the aircraft has the factory seaplane option installed. We have also verified that the length of the -114 at 119.62-inches."

My aircraft didn't come with the seaplane kit (I have the original packing list from 1950), and the logs don't show anything about it ever being installed either. Nor do I have the reinforcers mentioned. So, the fix was to order the -114, and unfortunately, since they think it's for a seaplane, they don't offer it in galvanized. The stainless steel -114 is $161 vs. the galvanized -5 at $61.

Maybe Cessna installed the flap portion of the seaplane kit on a range of airplanes due to lack of standard parts? Either way, I suggested McFarlane add a note to to their catalog to measure the lower flap cable before ordering to avoid this hassle.

I'd like to know what the difference is, in the flap system, between the standard airplane and one with the seaplane option install, if anyone knows. Also, I'd be curious if the s/n's of others that have had this problem are near mine.
Thanks,
Scott

Scott,
Sounds like you had the exact same problem I had, and McFarlane did nothing to rectify the problem I pointed out to them. At the time, I worked at Cessna and had access to the ORIGINAL blueprint drawings. During my investigation, I noted that the CESSNA 170A Parts Catalog contained an ERROR (imagine that!), stating the galvanized cable should be the -5. What the Cessna technical publications department failed to incorporate in the IPC was the very small note on the drawing that took me several days of staring at to find stating the serial effectivity of the -5 and the -14 cables. Here's the deal: Drawing number 0510103, "170 Control Cable Installation," is the effective drawing for 170 & 170A control cables. In area 5 of that drawing, it calls out cable p/n 0510105-5, 1 req'd, ser (serial effectivity range) 18003 thru 18728. Revision note "D" added this: "0510105-14 Flap Cable, 1 req'd, SER 18729 & on." I would love to share this drawing with the Club, but the drawings all had "Cessna Aircraft Company Proprietary Information" emblazoned on them...slight legal challenge! Thankfully, there are times my memory serves me really well... ...such as being able to quote drawing notes years after viewing them...

I am not intimately familiar with the PMA process, but I suspect that McFarlane simply looked at the IPC (which was WRONG) and obtained their approvals based on manufacturer's published (incorrect) information. I spoke to an engineer at McFarlane in 2010, quoted them the above information, etc. Well, we see how far that got!

To rectify my problem, they sent me a -114 cable, which I installed on my airplane PERFECTLY. As far as flight control cables are concerned, the ONLY difference between the seaplane and land plane versions are galvanized steel cables for the land plane and stainless steel for the seaplanes. No dimensional differences. You need the -114 (or -14, which they'll probably tell you they have no data on).

Bruce...I wonder if this is something that the Association can encourage McFarlane to correct? One person every few years apparently isn't enough.

[minton]

I would think a new thread dealing with "Errors" might be of more use to the club as moving these large businesses to correct errors is akin to changing the IRS rules