I finished up the routing of the AC hoses down the right side of the fuselage. The hose going all the way to the tailcone dives down towards the floor and goes through the bottom most lightning hole to make sure it doesn’t interfere with the flap tube in the next bay aft. I placed a small piece of angle on the angle attached to the side skin, used nut plates to screw the 2 angles together and then utilized a nut plate to keep the hose from rubbing on the angle attached to the skin.
View of the metal piece riveted in all 4 corners of the lowest lighting hole with a bushing through the center for the hose to pass through.
The hose destined for the condenser scoop, goes across the flap tube area on it’s way across the tunnel and to the 1st bay under the left-most rear seat.
Hose continuing to the tailcone under the right rear seat.
I utilized Adel clamps anchored to the step to route the hose inward and keep it away from the bolt holding the step in place. It then makes its way aft to the tailcone.
Similar for the hose going from the condenser to the tailcone.
With the hoses done short of crimping on the ends, I started working on the evaporator shelf by using cardboard as a template.
I test fit the cardboard until it was trimmed correctly to sit between the longerons.
I then used the cardboard to mark up the fiberglass shelf and trimmed it, sanding a little bit to get a good fit. Shown here as well are the 3 holes matched drilled into the shelf brackets that get riveted to the longerons.
One other small task was to trim the upper cowl ramps and add a “wall” so that the baffle material could sit in-between the upper air ramp and this “wall” so it has something to push against.
I then mixed up some flox and bonded the “wall” in place with a small “D” shaped piece to provide support against the cowl wall. This was repeated for the other side.
One nice day, I decided to head outside and paint the interior panels. I ordered the lighter tan ones knowing that I was going to paint them a darker color. I think they came out nice!
I ran into a snag with continuing with the evaporator install so I worked on completing disassembling the panel. I removed the wiring harness and separated the metal sub frame of the panel from the carbon fiber.
I spent some time getting the metal subframe in place, followed by the carbon fiber panel with the avionics trays. This first test fit was mostly done to mark the sub panel where I’ll need to cut away and reinforce making room for the connectors on the back of the 650 etc.. Not a whole lot needs to be removed just a small rectangle near the bottom and really just for the connectors and so the wiring harness doesn’t get bent too much.
I’m probably being a little paranoid here, but I’ve decided to protect the wires coming out of the hall sensors up near the flywheel. These connections are needed to keep the engine running. I fear an alternator belt snapping and whipping around as it’s sort of hung up in the area for awhile cutting the wires. Of course, it would have to cut both wires for it to be a real issue, thus maybe I shouldn’t worry about this too much.. However, the solution really didn’t take too much time to implement. I bent up some 0.032″ metal to wrap around the sensor as shown below. One side has a narrower flange to accommodate the alternator tensioning arm.
Below you can see the hall sensor and the use of these small center locating punches that screw into a hole and mark the exact location to drill for the bolt.
Previously I had used this technique to locate the 2 holes for the SDS fuel pressure regulator on the firewall and forgot to write about it previously. I used a piece of scrap metal to drill and use as a template to drill the firewall.
I placed the unit down on the scrap metal and tapped it with a rubber mallet to mark the location location of the holes that needed to be drilled.
This technique worked perfectly and allowed me to drill holes for the regulator on the firewall that exactly matched the hole location on the regulator.
Back to the metal guard for the hall sensor… I punched the top side, drilled the hole, and once that hole was located, I installed the bolt and marked the location of the 2nd hole then drilled that and bolted it to the hall sensor mount. Below is a test fit of both bolts installed.
I re-used some aluminum fuel line to route the wires from the hall sensors through. I used an Adel clamp to secure it with the one of the bolts. drilled a hole through the baffle and installed a piece of angle on the aft part of the baffle for another adel clamp.
Below is the whole thing put together. Obviously the wires will ultimately be routed through the tube, but I need to remove the baffle and paint it at some point, so waiting to do that until after that is completed.
Also the DB-9 connectors on the end of the hall sensor wires are soldered on.. so another reason to delay putting them through the tube just yet.
My engine builder supplied a flywheel with the magnets for the SDS system already installed, but I needed to install the magnets in the dual pulley flywheel suppled by Airflow AC. I basically followed this blog linked on the SDS website. https://tasrv10.com/?p=2822.
Below is drilling the holes with the drill guide provided by Ross.
I wasn’t quite as lucky as the linked blog post and the hole sort of ate into part of the grove, but not completely.
I mixed up some 5 minute epoxy, as specified, and also applied red loctite onto one of the grub screws, which was inserted into the hole from the outside. The magnet was inserted into the hole from the outside. The grub screw was screwed down until the magnet was basically flush with the inner surface of the flywheel.
Once everything cured.. I decided to buy the Devcon Titanium putty recommended in the in the linked blog. It is expensive and you really need a very small amount compared to what is provided, but I didn’t want to skimp on this. I prepped the flywheel and applied the putty to each hole location as shown below.
I let the putty cure for approx. 3 hours and then sanded it using a combo of files and sandpaper. It was a bunch of work, but the end result is what is shown below.
One other thing left was to size up the air intake into the left size heat muff. I mocked this up with some skeet tubing I has lying around. It seemed like it would work, stealing some air from the left side intake,.
I cut a 2″ hole in the left snorkel.
I took a 2″ duct and flox’ed it in place over the hole that was drilled. Once cured, I re-test fit the skeet tube to the exhaust.
I then laid up some fiberglass cloth and some peel ply to glass over the flanges of the 2″ metal tube.
I was then able to get back to finishing up the condenser install of the Air conditioning. I utilized some scrap metal along with some construction paper to mark out the center lines of the connections on the aft side of the unit. I did decide to use some straight connectors that Airflow systems provided to put the connections in the first bay from the tunnel.
I used some cardboard to enlarge the holes and make sure the holes were in the right position prior to drilling into the bottom fuselage. Everything seemed to be correct.
I then took the metal template and screwed it into position and prepared to drill the holes to mark out where the hoses are to be placed.
Then I screwed the AC scoop into position and test fit the aft hoses that go up into the fuselage. Everything worked out well as shown below.
I installed some grommets into the holes to seal them as much as possible.
A view from the inside with the connections coming up through the fuselage skins.
Most of the FWF fuel and oil hoses are complete now minus some Adel clamps that still need to be added. I’ve tried to annotate the pictures as much as possible to help show what all the hoses are.
Below you can see the main fuel supply comes out of the firewall bulkhead fitting on the left (pilots) side and attaches to the SDS post filter. In this picture is also one of the two oil cooler lines that connects to the engine.
Below is the closeup of the post filter clamped to the engine mount.
The fuel supply comes out of the post filter and continues on to the fuel rail after it passes through the baffling. Also shown is the fuel pressure line that comes back to a sensor, the other oil cooler line, and the oil pressure line.
A better view of both lines coming out of the oil cooler.
The blue hose is the oil breather line connected to the Air/Oil separator. This configuration will keep oil off the belly of the airplane. I also added an adel clamp on the firewall to hold it midway.
Moving to the other side of the engine, we have the manifold pressure line coming from the sensor on the manifold block. You can also see here the fuel return line coming through the baffling as it makes its way back to the fuel pressure regulator.
One of the add-ons I decided on was a remote oil filter adapter. This will make oil changes much easier with the filter readily accessible and with the filter oriented vertical, all excess oil will be in the filter when you spin it off preventing a mess. This does, however, require 2 additional hoses to get back and forth to the engine as shown here.
Below you see the Borla pressure regulator for the SDS system mounted to the firewall and taking return fuel (top right) from the engine, and returning it to the firewall mounted bulkhead fitting below the heat box on the right (copilots) side. I still need to attach a manifold line to the center of the regulator.
Looking at the engine side and the fuel block on top of the case.. you can see the supply, return, and pressure lines as they make their way from the rear baffle to the block. There is a T fitting in the supply inlet to provide the pressure back to the sensor.
Each of the cylinder is fed out of the sides of the fuel block like the 3 cylinders shown below.
I also drilled a small hole in the oil filter adapter to attach safety wire to when safetying the oil filter itself.. not done here as the install is all temporary for now.
One of the other things I needed to finish up as creating an airfoil of sorts to back up the pin for the hidden oil door. I used some air-drying modeling clay to form the shape that I wanted.
I then laid up a few layers of fiberglass cloth over the clay and allowed it to cure overnight.
I finished it off with some micro and sanded it smooth.
Another task I needed to figure out was how to feed air into the left side heat muff. With the AC compressor installed on the engine there is no good way to use anything from the air inlet area like the stock setup does. The only options I saw were to feed it from the aft baffle (like the right side does), feed it from the left intake snorkel, pull from the right inlet area (but this is also tight with the alternator over there), or add NACA vents to the lower cowl.
I’ve decided on pulling from the left intake snorkel. This does steal some combustion air , but the Showplane’s setup is designed to only need air from one side to be sufficient. So I will add a 2″ SCAT tube between the locations shown with arrows below. Of course, I’m going to need to get a 180* setup for the #2 cylinder heat muff from Custom Aircraft parts instead of the normal 62.5* one I have now. This will have air come in from the outside of the exhaust and intake tubes to the engine and the outlet will be on the inside of those tubes feeding the left heat box.
A rough mock-up of where the 2″ SCAT tube will go. There seems to be sufficient space between the lower cowl and the engine to do this.
A rough approximation of where the inlet to the heat muff will be.
In talking to Clinton about this, he’s also been fighting some cracking in the exhaust on the left side. He had previously sent me a support setup for the exhaust to help with vibration, which I have, but haven’t done anything with it quite yet. He asked that I install my exhaust and check for any interference with the intake tubes and in the end, I’ll need to send my entire left side of the exhaust back to him for modification to help prevent cracking in the future.
While sending it back, I’m also going to have him “stud” the heat muffs on both sides (as shown below) to allow for some better heat transfer. I didn’t know about this option prior to ordering and it apparently helps get some more heat for the colder months. The stock Vetterman exhaust is known to have too much heat, but that’s not always the case with the Custom system.
Back when I installed my fuel lines, Tom from AS Flightlines ( http://www.aircraftspecialty.com) really only had one solution to the SDS fuel filters. On top of the fuel pump module using adel clamps. I really don’t like having these in the tunnel for maintenance reasons. It seems inevitable that some amount of fuel will spill out into the tunnel no matter how careful I am trying to catch it all as I take this all apart for yearly service. Additionally, I placed the access panels on the tunnel sidewalls a little further aft and not perfectly aligned to the whole assembly, so access to the forward-most fittings is a bit challenging. Taking the top of the tunnel off, while doable, is a royal pain seeing there are throttle cables, etc.. routed on top of that. I really have always viewed this solution as something I’m going to regret and will spend way more time than I really should on each condition inspection. Also I can envision lots of curse words being used. Below is a view of the original filter setup in the tunnel.
Since that time, Tom has come up with pre-filters in the wing roots, and moving the post filter firewall forward. Despite having some re-do.. I opted to take some time now to change and use this new configuration. Maintenance will be much easier and more accessible that way. If fuel does spill, it’ll be outside of the cabin. With just the fuel pump in the tunnel, there will be basically no reason to ever go in there very often at all, other than to remove the access panels and check on the pumps.
Of course that meant all new cabin hoses and some additional expense, but Tom actually helped out in this regard. I also went with some other arrangements that Tom has standardized on for routing, like having the supply come out on the left side of the firewall and return on the right. One thing that we did decide on was seeing we had to remake the hoses under my seats, was to re-use the hole I had already cut for one of the fuel lines. I cut this hole pretty close to the stock supply hose location and sided it just big enough to get a -6 hose swivel fitting through. Seeing both the stock and hole I drilled were too big for normal AN bulkhead fittings, I had to utilize the TCW fittings (https://www.tcwtech.com). Bob has come up with a washer with a neck/bushing on the inside that fits into the 1″ stock location so the fitting doesn’t fall through the hole. I also asked Bob if he could make me a custom one for the 25/32″ hole that I had already drilled. He made it the next day and had it off to me. I’d say I had a bit of shit luck with how these 2 washers fit basically perfectly. I really figured I was going to have to carve a half moon in one of them for clearance to the other.
I installed 2 new hoses under each seat for the supply and return.
Below you can see the routing to the side skins. In retrospect, I really wish I didn’t route my brake line in the middle row of the systems brackets.. It would minimize hose crossovers.. In the end the right-most hose in the picture below passes under the brake hose with some clearance. The left-most hose is angled enough with the 45* fitting that it also clears everything.
I then spent some time re-locating the pump module. I used the “standard” length hoses from Tom to place this. I also noticed that I needed to raise the module up 2″ from the 3/4″x3/4″ angle I had placed on the tunnel sidewalls already.
In order to raise the module up, I decided on using some square aluminum tubing. I could some 2″x2″x.125″ material on Aircraft Spruce and ended up cutting 2 pieces. I re-used one set of holes and nut plates I already had on the angle for the aft-most tube. I then added 2 new pieces of angle for the forward tube as shown below.
I was then able to bolt the pump module down with 4 bolts into the square tubing with nut plates and AN3 bolts. I added a couple of adel clamps to the longer return hose as it made its way back to the selector valve.
Tom also sent along my FWF package with integral firesleeved hoses.
I started on the fuel supply and routing it from the firewall to the post-filter to the fuel block on the top of the engine. This hose passes through the aft baffle with a grommet.
More FWF plumbing to come now that the cabin and pump are complete.
In prep for installing the baffle material, I used my go-to method of using construction paper to make templates for each piece prior to cutting the actual material. I targeted 2.5″ above the metal baffle material based on what others have done. I did a few test fits with the upper cowling on to make sure that length seemed like it would work. I tied to make the pieces overlap around the split points in the metal in case I ever need to take the whole assembly apart at a later time.
I then marked the templates with a line along the metal baffles to mark their position for reinstallation later on. I also marked out a line with enough edge distance for drilling 1/8″ holes to pop rivet the baffling material to later.
Once that was done, I removed the templates and cut out the material one piece at a time. I tried to cut such that the natural curve from the material roll would be in the direction I wanted the material to lay.
The method I found worked the best to punch holes in the baffle material was to first tape the template on the piece.
I then used the previously drawn line to place the template/piece assembly in place relative to the metal baffle making sure I had enough material for the overlap spots to the adjacent piece. I would use a drill to cut away the construction paper enough to mark the spot of the hole to be punched. I did the first 2 holes, then punched holes.. put the piece back into place with clecos and then drilled the remainder of the holes so I didn’t have to try to hold the assembly in position for the entire sequence.
I then used a punch to make the hole in the proper spot in the silicone baffle material.
Below are some pics of the final install. I did have to take some of the curl out of these pieces as they tended to curl inwards a little too much. I rolled each piece by hand in the opposite direction and sat some weight on the pieces to take some of the curl out. I also used some duct tape to hold adjacent pieces somewhat together. This will simulate the eventual RTV that will be used to hold everything together.
I then did something similar to the plans for the stock cowl to bridge the gap between the air intake tubes and the cowl. I used the metal strip material provided and curved it to match the round intake shape of the cowling. I then matched drilled 3 holes for #6 screws to hold this to the cowl. I cut some additional baffle material and used contact cement to adhere to the metal strips.
Below is a picture of the iniital test fit of this strip/baffle material fit. It seals up the small gap between the cowling and the intake tubes by resting on the inside of the air intake tube. I’ll likely trim this piece a little more for a better fit. Note also that I was sort of holding this in position to take a picture so the alignment is a little off, but you get the gist of what I am trying to accomplish here.
It’s really exiting to have the last major piece of the puzzle in hand.. There is still so much to finish up…, but it’s encouraging and helps me to keep grinding away towards completion.
To recap the configuration:
Triple Garmin 3GX touch screens
GTN650 IFR Navigator
Dual GSU25 ADAHRS
G5 Backup Attitude Indicator
GMC507 Autopilot Head
GMA245 Audio Panel
GEA24 EIS (Engine monitoring)
GTR20 Remote COM (COM2)
GTX45 Remote Transponder
SDS EFII Controller
Mountain High EDS-4ip 4 place oxygen controller.
GDL-51R Remote Sirius XM receiver
A picture of the panel propped up on my table.
Pictures of the left, center, and right sections closer up.
Aerosport Switch Pod housing lighting controls.
Lower center console housing the SDS EFII controller, defrost, and Air Conditioning controls.
Stick grips came in the package as well all wired up and ready for me to connect. I went with the Infinity HOS (Hands on Stick) Military style grips. Several controls are on the stick that might otherwise be on the panel. The idea here is to have both hands on the controls and throttle during critical phases of flight; not having to move them to activate flaps, for instance.
Here’s a rundown of the button assignment:
High hat in the center to control roll and pitch trim.
A switch on the thumb side to control the flaps. This is a momentary down to advance the flaps electronically to the next “notch” and a constant up position so the flaps are raised all the way up.
Opposite of the flap control, there is a Take off/Go Around button. This will sequence the autopilot/GPS to the missed approach segment when needed.
The Red button on the thumb side is a Auto pilot disconnect/control wheel steering button.
And finally a frequency flip-flop button. I didn’t really know what to add to this button, but decided on this.. Some people do ident, start button, or other functions. We’ll see how useful this ends up being in practice.. Guess if doing instrument approaches etc.. I may be setting up next frequencies in the standby area ahead of time enough to just have to hit a button with my pinkie to switch when needed.. We’ll see..
And finally some pictures of all the wiring between all the components. Along with several P-Plug connectors on either side of the panel for me to connect to all the other locations in the plane. Aerotronics mounts as many of the sub components right to the panel, as you can see. This alleviates me from having to mount them on my sub panel. Of course all the wiring harnesses are also already all done for me. Including runs out to the wings for AP servos and magnetometer, along with runs to the back for AP servos and trim servos back there. Lots and lots of wiring ahead..
And finally a picture of my panel from Aerotronics all powered up and tested prior to shipment.
During some down time with baffling tasks, I decided to tackle finishing off the oil door and its hidden hinge release method using a Bowden cable. I started by filling in the left side upper inlet with expanding foam to allow the baffling material in the area of the prop governor something to press against.
I then placed it on the plane and looked at the clearance to the governor arm. I sanded it down as a curve until I was happy with the clearance.
I then put the Bowden cable in place and got a rough idea of where the cable would penetrate the upper inlet ramp. I marked and drilled 2 holes on either side and then ran a 1/4″ drill bit through the foam to connect the 2 holes. I was then able to get the cable through.
I then laid up 4 layers of cloth over the Bowden cable, the exposed foam to close it out, and the upper inlet ramps to better adhere them to the cowl per the Showplane’s instructions.
After curing the view of the results.. The cable is now permanently adhered to the cowl. I also cut the metal cable housing to length and bent the inner pin at 90* to get your finger on it.
Then I took a quick video of how one opens the oil door. Closing is equally easy.. just hold the door down and push the pin back into position. I still do need to get some molding clay and make a small weathervane with a slot to house the cable end in the inlet area. This clay will be used as a mold to lay up fiberglass and allow it to cure.
In order to get the top cowling back on, the baffle needed to be trimmed. I saw two ways to do this, and I ended up sort of using both. I started by elevating the top cowl 6″ above the lower cowl. Care was taken to make sure it was aligned both fore, aft, left, and right to the bottom cowl. I just used some pieces of scrap wood and clamps that I had lying around on each corner on the outside of the cowl. I measured in multiple locations along the horizontal split to be sure I was satisfied before moving on.
I then made a tool out of a tongue depressor and an aluminum block I had. I taped a sharpie to the bottom of the block and adjusted the stick to get exactly 6″ from pen to top of the stick. I didn’t take any pictures, but the idea here is that you have enough room (with the 6″ elevation) to get your hands/arms inside to hold the stick at a 90 degree angle with the sharpie along the inside of the baffle. Holding the stick on the inside of the upper cowl, you move it aft tracing the contour of the top cowl onto the baffle which will serve as a trim line.
I then trimmed to that line. That basically got me to flush. One could certainly add some extra to the length of the stick to get the the gap you’d like to achieve. Instead, once the initial trim was done, I utilized the 2nd method of paper clips all along the baffles. You barely stick them on and then place the top cowl into position. They slide downward and give you an exact indication of how much gap you have at that location to the top cowl.
Below you can see the results of the first attempt. You’re shooting for somewhere between 12/32″ and 16/32″ gap per the plans. At each paperclip location, I wrote the number of 32’nds needed to get to 12/32″ by measuring how high each paperclip was above the edge of the baffle.
Those measurements basically were used to draw a new trim line.
I ended up doing this for a couple of cycles until I was completely satisfied with the gap all the way around. Making smaller adjustments in specific areas as I went. Below isn’t the best picture, but it was the results of the baffle trimming with a gap to the top cowl.
I fabricated the clips and drilled them into position per the plans. I’m holding off riveting most of this stuff until later.
Now that the baffles were trimmed, I decided it was time to affix the top cowl inlet ramps. I placed them into position with clecos and some scrap metal strip to hold them in place at the front.
I then test fit the cowl and had to trim the outer side baffles more to account for the curvature. I did get somewhat lucky due to my cowl being so far forward based on my prop/spinner setup compared to most. The ramps didn’t require trimming at the prop governor to at least test fit. I did end up trimming around to give some more clearance, which I’ll foam in later to provide a good backing for baffle material.
Once I was happy with their location, I epoxied them into place. Later I will layup some cloth, but for now just epoxy to hold them in position. I also did a single layer of cloth and some peel ply on the inlet circle just to hold that area into position.
I then laid up 3-4 layers of cloth for the underside of the circular inlet.. Placed that into position and let it cure. I sanded down the outside area and added micro. Once that was cured, I sanded to a smooth finish.
With the upper ramps completed enough for now, I moved on to customizing the center baffles. I started with the right side, seeing it’s the easier side without compressor interference to deal with. I cut the stock baffle leaving just enough flange to rivet a new piece that would angle toward the inboard side of the inlet. I first made a template from construction paper and got it as close as I could. I transferred to metal and worked on trimming to get a good gap to the upper inlet ramps.
I then spent some iterations trimming this custom piece to match the curvature of the upper inlet ramp with some gap for baffle material. Below are the results.
To hold the inboard side in place I fabricated up some 3/4″ x 0.125″ Angle. Seeing there was a slight bend in the baffle I just created near the inlet, I marked a cut to match that bend in the angle. I marked and cut out a “V”
Below is the end result after match drilling and cleco’ing the baffle to the angle.
I utilized 3 screws to tie the aft piece of metal holding the carbon fiber ramp to the front pieces, including the piece of metal that runs under the carbon fiber ramp. I trimmed the excess away on the inboard side of any carbon fiber and metal plate so it didn’t protrude past the angle.
I then did a similar thing using a template on the left side. I decided to use one piece of metal to wrap around the governor and bend around the AC compressor belt to box it out of the inlet area.
Once I was satisfied with the paper template, I transferred it onto metal, cut it out, and made the needed bends as shown below.
I then worked to fabricate another short piece of angle with a notch cut out for AC belt clearance to hold the inboard side in place. I drilled 2 holes for #6 screws to attach to the stock baffle that I had cut off and left a bit of a flange for connecting my custom piece to.
During various periods of downtime waiting for epoxy to cure or waiting on parts to come in.. I continued some work on the Air Conditioning Scoop that houses the Condenser on the belly. The first step was to mark the center line front and back as well as a line around the perimeter for the screw holes to line up to.
I then placed a string between the center point at the firewall and the center point at the tail to line up the centerlines marked on the scoop. A single hole was drilled for a cleco to hold the scoop in place fore and aft.
I then drilled approx 32 holes around the perimeter per the instructions making sure to not drill into any underlying structure. The corners are where you have to be really careful as they approach the rivet lines for the ribs.
As most of these holes are blind and there is no access from the inside, I had to install rivnuts to accept #8 screws. I practiced on some scrap that I had prior to doing it for real so I could get a feel for the tool and how rivnuts work in general.
Below you can see the rivnut squeezed down and onto the metal on the inside holding it in place.
I enlarged all of the #40 holes that were drilled to the proper size (#2) for the rivnut installation. The holes on the scoop were countersunk to accept #8 flat head screws with a tinnerman washer.
Below is a picture of me using the tool to set the rivnuts into their holes with a small amount of red loctite on the barrel of the rivnut.
Each rivnut has a “key” feature on the inner face of it to help prevent it from ever rotating. A notch had to be added to each hole to accommodate this feature of the rivnut. An example is shown below. I used a flat file to do this..
Seeing I had previously removed the seat pans and baggage area floors on the right side, I oped to use nut plates instead of rivnuts in this area. Also any holes in the tunnel utilized nut plates as well. Given access, using nut plates will always fare better than rivnuts, which could potentially spin in the future and make it impossible to get the screw loosened or tightened without drilling it out.
One of the thing about the scoop, is it didn’t sit very flush to the bottom of the fuselage skin.. so I applied packing tape to the bottom skin in the area and then applied a generous amount of micro around the flange and screwed the scoop into place to cure and fill in the gaps etc.. between the scoop and the skin.
Once cured, I took the scoop off and sanded around the perimeter of the flange. (shown below prior to sanding.
The next step is to put the condenser coil in place and work on a template to drill holes into the bottom skin for the hose connections inside of the plane.