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170A Flap cable run grommet?

Posted: Wed Oct 17, 2012 12:40 am
by Bruce Fenstermacher
Anyone with an A model have a grommet in the hole around the flap cable where it passes through the fuselage under the rear wing fairing?

Can't find one in the A model IPC but I might have missed it.

I've got one on one side and not the other. Looks like a stock item. Looks like it might be a good idea. Unless you look close and see the cable is cutting a slot in it and the cable wouldn't hit if it weren't there.

Re: 170A Flap cable run grommet?

Posted: Wed Oct 17, 2012 10:52 pm
by hilltop170
Del Lehman put felt seals around my flap cables in that location to deter water running into the cabin. I don't know if he added grommets or not but would bet he did. I can't see any reason not to add grommets, they would not hurt anything.

Re: 170A Flap cable run grommet?

Posted: Thu Oct 18, 2012 12:43 am
by Bruce Fenstermacher
Great minds think alike. We have several feet of the felt from the recent window installation and I thought it would be perfect over those holes. I can't see how the grommet, the thick one I have anyway, helps anything. The cable passes through at a big angle so there is still at least a 3/4" hole. The cable is rubbing a grove the grommet and it the grommet wasn't there I don't thing the cable would touch the hole sides. At least it doesn't on the side with no grommet.

Re: 170A Flap cable run grommet?

Posted: Thu Oct 18, 2012 2:59 pm
by hilltop170
Bruce-
If the cable doesn't touch anything and has good clearance thru the extend/retract cycle then I agree, the grommet isn't needed.

Re: 170A Flap cable run grommet?

Posted: Thu Oct 18, 2012 9:01 pm
by FredMa
The problem is the A model flap cable is not under tension. In flight when flaps are lowered you are pulling against the aerodynamic forces that are trying to keep the flap at neutral. That does put some tension on the cable but on the ground the flaps can be blown or pushed down. This causes the cable to become completely loose and it can flop around. I will have to look at my plane next chance I get to see exactly what you are talking about but if the cable is coming in contact with the aluminum skin, it should be fixed even if it is only occuring when the cables are loose.

Re: 170A Flap cable run grommet?

Posted: Thu Oct 18, 2012 9:45 pm
by ghostflyer
The 170A flap has a lock system in each rear wing root. When the flaps are retracted this lock system stops the flaps moving when on the ground. This wing area where the rear wing fillet is attached to the fuselarge is a corrosion area and should be inspected on a regular basis. I have fitted a rubber grommet where the cable exits the fuselarge. This area is then heavily sprayed with LPS 3 on a regular basis to stop corrosion and give a little lublication to the locking mechanism.

Re: 170A Flap cable run grommet?

Posted: Thu Oct 18, 2012 10:56 pm
by Bruce Fenstermacher
The cable did not touch the skin but would touch the grommet. The grommet was not cut so it had to be installed with the cable. I removed it till I figure out why someone put it there.

Re: 170A Flap cable run grommet?

Posted: Thu Oct 18, 2012 11:15 pm
by FredMa
Bruce, you said you have one on one side and not the other, right? i am talking about the side that doesn't have a grommet. As for the locks, mine does not have them installed. I am sure that many others don't have them as well.

Re: 170A Flap cable run grommet?

Posted: Fri Oct 19, 2012 1:36 am
by Bruce Fenstermacher
The plane had one grommet. It was not slit so it was installed then the cable installed through it. Don't know why because neither side hits with out the grommet.

Re: 170A Flap cable run grommet?

Posted: Fri Oct 19, 2012 1:18 pm
by GAHorn
FredMa wrote:...As for the locks, mine does not have them installed. I am sure that many others don't have them as well.
Check again: See item 6 in this illustration of the right flap (item 10 on the left flap illustration)

Many are simply worn and need dressing -up the "hook"....or replacement. They are intended to prevent the flaps from "banging" when tied-down in a breeze or when helicopters are nearby (maybe why Bruce keeps his operational.) :lol:

Some operators park their A-models (and straight-170s) with the flaps fully-deployed to prevent damage to flaps that will not lock up.
170 A Flap Pawl.JPG