Posted by dannparks on Friday, July 15, 2011 @ 02:03 PM:
Does anyone have any photos or a diagram of how the pitot hose run through the cockpit to the instrument panel in a RF4D? Where does it enter the cockpit and how does it get to the panel?
Thanks.
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Posted by Jorgen on Friday, July 15, 2011 @ 07:27 PM:
Ahh yes,
I think we're in for a series of pictures from cameras stuck into various RF 4 orifices. That's great, we will all get pretty versed in various details of Fournier anatomy eventually I think. I'll see if I can get a few shots this weekend.
May the 4's be with you/ Jörgen
Posted by Bob Brock on Saturday, July 16, 2011 @ 10:19 AM:
While pulling the wing (on the dolly) out of my hanger, the entire pitot hose came out of the wing so I am trying to get a new one back into the correct position before I paint the wing. If anyone has any ideas they would be most welcome. My plan is to open a small section on the wing to install outrigger wing brackets and at the same time, try thread a line from the center opening to the pitot tube opening that is way out there on the wing. I'll keep you posted of any progress.
Posted by Jorgen on Saturday, July 16, 2011 @ 02:52 PM:
OK Dann, here ya go.
I had some Murphy influence today- the camera battery suddenly went dead- probably someone has learned how to turn it on but not off, Hmm Sofi? Consequently it's pictures from the phone, so quality is maybe not so good. Anyway, first picture shows how the pitot line sneaks into the cockpit from the left wing, I didn't remove the panel to have a closer look but I guess the tube enters through a hole in the fuselage sidewall after running in the D-box of the wing leading edge:
The pitot tube then runs along the cockpit floor aside the rudderpedal (note the wear on the center of the pedal, I have stopped flying with my SPD cleat bicycleshoes now) and up along a support/bulkhead:
After that it runs aft along the stringer along the fuel tank (the grayish blob on the right) and joins the other cables to form the usual serpents nest on the back of the panel:
This is all on RF 4 D "SE-XST" there might of course be alternative solutions. Most things on "XST" looks alright to me and I have great respect for the work done by Mike Woolard in the UK who did the latest restore/rewiring of the panel.
Bob, you have my sympathies but I am positive you will find a good solutions for that little challenging problem.
Today I had an hour of simulated ETA-soaring (a 90 foot span glider): 2200 rpm, soaring up on the windward side of clouds, absolutely spectacular. Loosing that altitude is as you know another pleasure. With our significant fuel prices a 1,5 gallon, one hour flying is another pleasure.
May the 4's be with you/ Jörgen
[Edit by Jorgen on Saturday, July 16, 2011 @ 03:03 PM]
Posted by dannparks on Saturday, July 16, 2011 @ 06:11 PM:
Thanks, Jorgen.
I didn't realize what that hole in the fuselage was for and I covered it up with fabric. Thanks for pointing it out. It all make sense now.
[Edit by dannparks on Saturday, July 16, 2011 @ 06:16 PM]
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Posted by eugenio on Friday, July 22, 2011 @ 04:09 PM:
The pitot line runs into the spar, if you ran it out you can put in a new one with the aid of a straight steel rod to center the holes in the spar's bulkheads. It's not easy, but is possible, I could do it on a RF3 (the wing is nearly the same) with the wing installed on the fuselage.
Eugenio
Posted by Bob Brock on Thursday, July 28, 2011 @ 07:18 PM:
If I understand what you are saying regarding the pitot tube and plastic tubing (the pitot tube on the wing (bent metal tube into a base place with 4 screws), the tube goes into the spar somewhere near that opening and down inside the spar box to a point where it exits the spar and enters the fuselage. My plastic line had a 90 degree sharp bend in it (don't know if it is needed or became that way).... also, would it be a good idea to replace the plastic tubing? Where does the straight steel rod go... through the bottom D box plywood) and into the spar, or from the center of the wing into the spar about at the level of the main 14mm attachment bolts? Thanks... Bob Brock
Posted by Markku on Friday, July 29, 2011 @ 06:37 AM:
At least in my plane the plastic tube to pitot tube is located inside the D-box, not inside the spar, that arrangement is also shown in the drawings.
Posted by Bob Brock on Friday, July 29, 2011 @ 10:36 AM:
Markku: Thanks for the drawing, it makes it much easier to understand... it looks like they put in the tube before they did the D box. Boy this is going to be fun to plumb. You may hear some screams coming from Oregon! Let you all know if I find a solution short of a chain saw.
Posted by Donald on Friday, July 29, 2011 @ 11:35 AM:
Bob, is your wing on the fuselage yet? If not then I think Eugenio gave you the answer.
Looking at Jorgen's photograph where the pitot line enters the cockpit suggests that the path runs low through the D box. If the wing is separate from the fuselage I'd guess you could take advantage of the dihedral and feed a long rod into the hole from underneath the starboard wing. If you can and if you can get it out to where the pitot head mounts then you ought to be able to fish the end to either pull in the pitot tubing directly or to tie on a draw string which you can pull back through the wing. But where to get a sufficiently long and thin rod?
Some years ago I had to do a similar job on the boom of a sailing boat. From my local building supplies store I got several 1 meter lengths of aluminium tube, probably about 6mm diameter, and some aluminium rod. I threaded the internal ends of the tube and the rod which I cut into short lengths. I screwed the rods half way in to each tube section and used loctite to hold. As each section goes into the boom/wing, screw on the next section. Just like small scale drain rods. As a refinement you could make up a soft nosed 'bullet' to screw into the lead end to help it guide itself in and not snag.
Posted by Jorgen on Friday, July 29, 2011 @ 03:56 PM:
And a further refinement could be to make the soft nosed bullet off-centered so you can rotate it through tight spots. I don't remember how the D-box ribs looks, are there holes near the bottom?
It's so easy to sit in a recliner and figure out how to overcome someone else's problem, eeh Bob?
. The junction with the pitot tube (the L shaped metal tube) is done with a piece of silicone hose. The nylon line run up to the space that remains between the wing root and the fuselage (below the fairing) where you can put a quick connector for ease of assembly the line after the wing is assembled.