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What's Under Your Floor?

Snoho3

Well Known Member
Getting ready to close up my -9A floor. Both baggage and seat pans. I have installed the steps, both LH and RH. But there is seemingly a lot of empty space there, and I wonder if I should be planning any other installations in that space? Not quite sure what they might be, but thought I'd ask. Sound proofing/insulation? I am planning a Skyview system, A/P and electric trim. Will I need to run any wires through there? Maybe for the flap motor?

It would be nice to have to close up the floor only once...

Thanks in advance for any inputs.

Lars
 
Looked like useable space to me...:)

ELT under a removable panel on one side.

Dynon ADSB box under the removable floorboard on the other side.

This keeps the ADSB coax short to the nearby second antenna and it helps that only 4 #22 wires need to cross the main spar... helpful in a -6 but would not be an issue in a -7 or -9.
 
I didn't have enough room in my single tunnel pass-through for all of the wires to the back. I've got a tail position light, Dynon ADAHRS, ACK ELT, electric trim, pitch servo and a GPS receiver behind the baggage wall. I've got a network hub in the back and I run the 4 wire network cable from the pitch servo back to it and I run the extra 3 wires from the pitch servo up front. I also ran a pair of wires for a baggage light back behind the wall and up. End result is a lot of wires. I ended up with another wire bundle run up under the right side floor. My floors are all removable, but I still got all of my wire runs in place prior to screwing down the baggage floor.
 
Not what you were looking for, but when I started working on my wiring after moving from Colorado to Idaho, I found where I had hid a bunch of silver coins and bars. I would sure have been puzzled when I went to weigh my plane!

Im my 9A, I have a FP Catto prop and light battery. I am already light up front and don't want anything behind the seats that doesn't need to be there so I have options on what to pack when traveling.
 
We have the same ish fuse, I did removable rear floors, mounted on the underside R side is Dynon transponder and ADSB box on L, made a .060 plate to mount and fasten on top of center tunnel is the ELT. one big loom under there also to go to rear deck, trim, ADHRS, tail lights. Note, if you have steps, you may want to make the floors removable for possible future step repair?
 
Might want a tiny drain hole in an appropriate place. More than one RV has collected water under the floor.
 
A PC680 fits perfectly between the ribs under the baggage area floor on an RV7/9. In Subaru days I had one on each side back there. I still have Whelen flasher power supply back there. Now considering Dynon remote transponder as it will be very close to it's antenna and simplify wiring. I have been happy with my decision to make the floors removable.
 
You can run most of the wires for lights, AP servos and such down the center tunnel which stays accessible. I did put a conduit on each side, which is advisable for running extra wires and lines through. The only thing I have under the baggage floor is the bolts and blocks that hold the step weldments. After my steps cracked, I had to pull up the floor pans and get in there. Not a fun job. I would leave that space empty. Adding nutplates for access under the floors is difficult and unnecessary weight/complexity. Building a hatch or access hole is also probably unnecessary.
 
Thanks folks - follow up question...

I have already installed nutplates so the floors are removable. Yes, that was a royal pain. But it just seems there is a lot of empty space there, hence my original question.

I like the idea of running some conduit through there because I suspect I will have a lot of wires. And it is very light. But here is my question - how does a wire bundle using this extra conduit transition to forward of the main spar? Over? Around? Through? In other words how should I most efficiently orient/route the conduit?

And I have ordered an ELT that I plan to install under the baggage floor. It has a 5 year battery, so I will probably have to replace it once or twice before this bird actually flies.

Lars
 
I have already installed nutplates so the floors are removable. Yes, that was a royal pain. But it just seems there is a lot of empty space there, hence my original question.

I like the idea of running some conduit through there because I suspect I will have a lot of wires. And it is very light. But here is my question - how does a wire bundle using this extra conduit transition to forward of the main spar? Over? Around? Through? In other words how should I most efficiently orient/route the conduit?

And I have ordered an ELT that I plan to install under the baggage floor. It has a 5 year battery, so I will probably have to replace it once or twice before this bird actually flies.

Lars
Assuming that the battery comment was a joke, on the -7 you can add a wire path through the spar carry-through just inboard of where the actual wing spar stops inside the fuselage (centered vertically in the web). Might be worth a call to Van's to see if you can do the same with the -9 spar.

Charlie
 
.........And I have ordered an ELT that I plan to install under the baggage floor. It has a 5 year battery, so I will probably have to replace it once or twice before this bird actually flies. Lars

You'll be inspecting the ELT yearly: From FAR 91.207(d):

(d) Each emergency locator transmitter required by paragraph (a) of this section must be inspected within 12 calendar months after the last inspection for--
(1) Proper installation;
(2) Battery corrosion;
(3) Operation of the controls and crash sensor; and
(4) The presence of a sufficient signal radiated from its antenna.


You might want to reconsider your mounting location.
 
My ELT is under the rear fairing, it is a nice location and fairly easy to get at during the conditional inspection. Whelen box under the baggage compartment floor, smaller inspection cover. My entire floor is done with nutplates just like yours. If you run the conduit to the back of your plane, try to do it in one piece front to back. Place a string inside for pulling wire. Good luck.

Jim Fogarty
RV-9A flying
 
You'll be inspecting the ELT yearly: From FAR 91.207(d):

(d) Each emergency locator transmitter required by paragraph (a) of this section must be inspected within 12 calendar months after the last inspection for--
(1) Proper installation;
(2) Battery corrosion;
(3) Operation of the controls and crash sensor; and
(4) The presence of a sufficient signal radiated from its antenna.


You might want to reconsider your mounting location.

Yes, it needs access. I still think under the floorboards is agood location

I mounted mine upside down on a thicker separately removable panel with some cross stiffeners between the longitudinal bulkheads.

The mounting should be stiff to prevent false activation...:)
 
I was planning to copy the approach from other builders with a small door in the baggage floor and mount the ELT in there.

There is the point of letting the antenna cable go through a bulkhead. It is not recommended by the manufacturer due to high likelihood of cable being cut after impact.

Anyone have any issues with that (during airworthiness inspection) ?
 
A picture says it all

Look at this picture, taken while installing my ADS-B stuff.

SPCzSbSfVtyYdBq26


If the picture does not show up go here:
https://get.google.com/albumarchive.../AF1QipM2Ls8TJYQpFdsyk2iqfSGMmUus3IzeXe_oWwRZ

I'm glad I added these doors while building.
 
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I was planning to copy the approach from other builders with a small door in the baggage floor and mount the ELT in there.

There is the point of letting the antenna cable go through a bulkhead. It is not recommended by the manufacturer due to high likelihood of cable being cut after impact.

Anyone have any issues with that (during airworthiness inspection) ?

I threaded the antenna through a Vans flex conduit, making sure the conduit wasn't stretched as it went aft and pushing some extra co-ax into the conduit.

That ELT co-ax should not be neatly and tightly harnessed like all of your other wiring...:)
 
What Gil said. I left a lot of slack in the ELT coax, and secured the excess coil with loops of Velcro so it could pay out if necessary in a crash. It goes through a bulkhead, but I used a snap bushing about two sizes larger than necessary.
 
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