Flying Stats for 2021

Happy New Year! A quick blog post to recap my 2021 flying activities. I almost made it to triple digits in 2021, but ended up with only 98.9 hours of flying time in the RV-9A. This has been the least amount of annual flying since I completed the airplane. Last year I just barely cracked 100 hours, and I had a feeling that this year was going to turn out similar.


The global COVID-19 pandemic continued to put a bit of a damper on the flying. However, I did manage to take a couple of longer trips. Oshkosh Airventure 2021 was the big trip this year, and I wrote all about it here. The only other overnight trips were up to the Northern California area, first with my daughter Alicia for a weekend fly-in at Georgetown where we camped on her birthday weekend, and then with my wife up to Sonoma for some wine tasting and sight seeing. I did some lunch flights, but they were just to the usual local places like Hemet, Corona, Montgomery and the EAA Chapter 14 meetings at Brown Field. Alicia and I went to the Bakersfield EAA Chapter 71 lunch fly in and we also were able to have lunch at Harris Ranch on the way back from Georgetown.

Probably the biggest impact on my flying this year was just the time commitment spent being a full-time student again. I finally got a spot in the Miramar College Aviation Maintenance Technician program. I started in the Spring semester and got through all of the General courses, then in the Fall semester I took the next block of classes. It is still difficult to get spots in the classes, but hopefully I can get added to all of the Spring 2022 classes I need. One year down, one and a half to go!

As far as the airplane maintenance goes, I didn’t really have much work to do on the RV-9A beyond the annual inspection and oil changes. I did a modification to the front cylinder baffle that cured my temperature imbalance on the left side CHT’s. The scratched up wing tip got repainted at Corona Air Paint. I have some electronic upgrades planned, but the IFR panel has still not been completed. I did buy the upgraded Vertical Power VP-X Pro, and some new FlyLED’s position and strobe lights. I hope to get those installed here between semesters.

No more scratches on the wing tip!

I did a couple of pre-buy inspections this summer. One was on another RV-9A and the other one was an RV-14A. Both sales went through and I caught quite a few little issues that were easily fixable. I did a pre-buy on an RV-7 kit that was partially built (tail/wings only). I also did some more tank repair jobs on an RV-4, RV-9A and RV-10. I also fixed some RV-10 door latch sensors.

I visited 10 new airports. At the end of 2021 the airplane had 947.4 hours on the Hobbs meter. My total flying time in my logbook is 1087.6 hours (690.2 hours of cross country time, and 42.2 night).

My goals (again) for 2022 are to continue with the A&P courses, get the airplane IFR capable, get myself Instrument rated, and get that Commercial certificate. Let’s hope that the COVID-19 pandemic finally goes away and we can once again start to move about more freely.

Adding a Flop Tube to an RV-4 Fuel Tank

I just finished up a quick little job installing a flop tube in an RV-4 fuel tank. What is a flop tube? It is a flexible fuel pickup line that “flops” around when you fly inverted. It can pick up fuel from the top side of the fuel tank when you are upside down. It is primarily used when you are doing aerobatics. It is an approved modification to the standard fuel pick up design. Van’s Aircraft has some information available on the RV-4 plans and also sells the material.

Plans showing the flop tube installation.

I flew up to Compton to meet with the owner and see what we could do to open up his fuel tank and get the flop tube installed. He had already taken the fuel tank off the wing, and had removed the access panel on the side of the tank where the fuel sender lives. The standard tank has the fuel sender in the first bay of the wing tank mounted on the inboard rib. The flop tube would interfere with the fuel sender, so the sender has to move to the second bay and be installed on the back baffle of the tank.

The flop tube would normally sit and pickup fuel from where the standard tank fuel outlet sits down in the lowest point of the tank. The standard fuel outlet gets plugged, and the flop tube moves the fuel outlet to near the leading edge of the tank. This requires some changes to the fuel tubing that leads into the fuselage and the fuel selector. We had to drill a new hole at the front of the tank for the new AN 833-6D bulkhead elbow fitting.

Looking inside the tank where the new flop tube connects to the elbow fitting which is being held by the anti-rotation bracket. Tubing on the left is the fuel vent line.

Another modification is to add a small hinged flap over the hole that allows fuel to move between the bays. This helps keep the fuel in the first bay when you are doing aerobatic maneuvers. I had prefabricated this from material I had on hand. There are also some “anti-hangup guards” that need to be installed inside the bay to keep the flop tube from accidentally getting stuck behind the internal stiffeners.

Hinged door on the bottom left. Cover plate and guard strip in the center keep the flop tube from getting hung up on the internal stiffener on the bottom of the tank.

I took a bunch of tools with me, but as usually happens, when you get working on the project you will find that you need something that is left back in my hangar. We were able to get the holes drilled in the tank, but the day was getting short, and I needed to be back in Ramona before sunset. The forecasted weather was going to have potential fog rolling back in the evening, and it was getting very hazy. If the visibility got below 3 miles, I would be stuck. The RV-4 fuel tank was small enough to fit inside my RV-9A on the passenger side. I took off the passenger seat back and we were able to get the tank situated so I could fly back home with it.

During the week, I got busy working on installing the little flap cover and guard strips. I had to use pull rivets on these items because there is no way inside the tank to buck a standard rivet. Another item needed for the installation is an anti-rotation bracket to hold the new elbow solidly in place and keep the flop tube from coming loose. Van’s has anti-rotation brackets available and I had some spares on hand, so instead of trying to fabricate something from scratch I had to figure out if it would fit. The prefabbed anti-rotation bracket looked like it would just clear the tank attach angle that sits on the outer part of the tank. This involved using a mirror on a stick to get a good view inside the tank. I drilled some mounting holes on the side of the tank and got it in place with some clecos. I used some pull rivets to secure it in place on the innermost rib of the tank. These are special sealed end pull rivets that are correct for use on fuel tanks. As I installed the flop tube, elbow and bracket, I smeared tank sealant on everything.

New AN elbow fitting in front of the tank attach bracket, and the clecos holding the anti-rotation bracket.

The fuel sender relocation was pretty easy. Again, I had to use some tiny flush pull rivets for the nutplates that are used for the screws that secure the fuel sender to the back baffle. We put a new fuel sending unit in the tank, even though the old one was still working. I changed out the old Phillips head screws with some socket head screws when I put the sender and the side plate back on.

New hole for the fuel sender in the second bay of the fuel tank. Nutplates get installed here with tiny flush mounted pull rivets.

I flew back up to Compton on Sunday to deliver the modified tank, and to help get the tank installed back on the wing. The owner had already gotten a new longer aluminum fuel tube ready. We just had to get the tank on, bend and cut the new tubing to the right length, and then flare the end to fit on the tank. This actually took quite a bit of time, since there isn’t a whole bunch of room for the tubing where it goes around the forward tank attach brackets. We massaged the tubing in place and finally got it all aligned and tightened down. The tank needed to be leak checked, and I didn’t have the fuel cap for it when it was at my hangar. He was able to get it checked later with the Van’s leak tester kit. The sealant also needs to firm up for a couple of days before he can fill it with fuel and slosh it around to make sure all of the debris is out. The last thing needed is also to extend the wire that goes over to the relocated fuel sender.

The other anti-hangup guard is mounted on the access plate.
Just enough room for the new fuel line to get around the tank attach brackets and get connected to the new fuel pickup location.

This was a fun job and I got it done in about 8 hours of labor. We had all of the other parts and materials ready, so we didn’t have to wait to get any shipments.

A&P School Semester #2

Has it been 3 months since I did a new blog entry? Yes. Yes, it has…

I managed to get registered for all of the A&P classes I needed this semester. As a student who already has a college degree (or two), I’m basically at the back of the line for getting into these community college classes. I was on the wait list for every class, but was able to get added to the following 9 classes:

  • Aircraft Wood, Fabric, Finishing and Composite Structures (lecture and lab)
  • Aircraft Assembly, Rigging and Inspections (lecture and lab)
  • Powerplant Ignition Systems (lecture and lab)
  • Induction and Fuel Metering (lecture and lab)
  • Aircraft Fire Protection and Digital Logic (online)

I’m basically at school from 4:30pm to 11:00pm 4 days a week, with Wednesdays off. So far I’ve really been enjoying these classes over the General topic ones I took last semester. It is great to be able to focus on a particular subject in the curriculum. The online class is easy and is only 1 unit, so the amount of time spent in it is about 1-2 hours per week with watching videos, discussion forums, and quizzes.

The Assembly, Rigging and Inspections class has been pretty basic stuff. How to make sure the aircraft you are working has everything rigged correctly (including helicopters), along with how to do inspections. The class is taught by one of the adjuncts who works on big jets for a purple box package delivery company. He doesn’t do little airplanes with pistons. It’s a completely different perspective on what work life would be working at the airlines. He has a lot of good stories and advice.

Swaging cables in the rigging lab.

The Wood, Fabric, Finishes and Composites class has quite a bit of material to cover and the lab/lecture is the longest of the classes. I’ve never done any fabric or wood stuff, so this is all new to me. The lab projects for this class have been really fun and challenging. We had to buy some materials for this class (PolyFiber System and West System epoxy). We learned how to cover an aircraft with the PolyFiber System. We did a small airfoil project which involved cutting, gluing and heat shrinking the fabric, then lacing the ribs with waxed cord, covering the lacing with tapes and putting on some inspection covers and a drain hole cover. This involved several weeks of work before we could spray on the silver UV protection cover coats. As of this week, we are just finishing up a composite airfoil project where we built templates from aluminum sheet metal, used a hot-wire to cut some polystyrene foam to shape, then laid up layers of unidirectional and bidirectional fiberglass over the surface. We have also done a couple of other projects like registration markings, stitching repairs on fabric, seat belt inspections, and plastic repairs.

PolyFiber fabric glued on the frame before shrinking with the iron.
Nice and tight after some ironing.
Lacing stitched on the center rib, UV protection sprayed on and ready for a finish coat of paint.
Underside of project with an inspection port and tiny drain hole cover up in the top left corner (lowest point in the wing).
Using a hot wire cutter to slice out an airfoil shape from a foam block.
Composite airfoil project foam cutout template held in with T pins and hot wired to shape.

The Induction and Fuel Metering class has mostly focused on carburetors. We have disassembled, inspected and reassembled float carbs and pressure carbs. The lectures have been on induction systems like turbos and superchargers.

The Ignition Systems class is a bit shorter than the others. We first learned all about magnetos, and we did a project where we disassembled, inspected and reassembled a magneto, internally set the timing, and then put it on a test stand to see if it would make sparks (it did). We also used a magneto timing box to externally time magnetos on some of the engines in the lab. We performed a harness inspection on some spark plug wires and we should finish up the semester with spark plugs and turbine igniters.

I keep pretty busy during the week just reading all of the materials, studying for tests, and doing the report writing portions of the classes. I haven’t done a whole lot of flying this fall. I have gone up to Long Beach to help work on Marc’s RV-10, and I did a couple of flights to Corona to get supplies from Aircraft Spruce for my classes (and get my scratched up wing tip repainted). The rest of my flying has just been quick local flights here and there to keep the oil warmed up on my engine. I was hoping to be able to take advantage of the great weather we have in fall to fly somewhere for a little vacation, but I really haven’t had the time to plan anything.

I’ve got an upgrade to my RV-9A’s lighting (FlyLED position and strobes) in the works, but I haven’t had the time to get it started. I soldered up all of the electronics and bench tested the lights, but I need to upgrade my power circuitry to handle them. The Vertical Power VP-X Sport in the airplane is all out of circuits, so I’m going to swap it out for the VP-X Pro which has 8 more circuits. This will also finally get the airplane ready for the IFR instrumentation additions. I have a couple of other quick fuel tank related jobs scheduled for some other RV’s that are going to keep me busy over the Fall semester break at Thanksgiving.

FlyLED’s control board project.

The third semester class schedule is now out, and I’m ready to enroll for Spring 2022 classes. In talking with my cohorts, it looks like they mostly are getting their class registration appointments already done this week (early November). My registration appointment isn’t until 11/29! This pretty much guarantees I’ll be on the wait list again. Hopefully, I should be able to get in the classes I need to keep on track.

Baffle Modifications

I guess after 900 hours of flying, the airplane should be very well sorted out and working great, but there is always room for some improvements. On my flight out and back to Oshkosh for Airventure 2021, I had a lot of time to stare at my engine’s cylinder head temperature readings (CHT’s). I regularly fly Lean of Peak (LOP) and the cylinder temps are pretty happy there. The right bank of cylinders (#1 and #3) are usually within 20 degrees of each other, and a similar story with the left bank (#2 and #4). However, the left bank usually runs hotter than the right bank. My #2 cylinder (front left) is always the hottest when climbing and cruising. It can be at 360F while at the same time the #1 cylinder (front right) can be running at 310F. In cruise #1 is usually the coolest. When I adjust the mixture to get to LOP, all of the CHT’s peak pretty close to one another, so the fuel flow from each of the injectors seems well balanced and is not the problem. I haven’t had any intake leaks, so the obvious issue seems to be down to the amount of airflow the cylinders are getting for cooling.

During my Phase 1 flying I started cutting down the air dams on the front baffles to try and find the right balance between temps on the right and left sides of the engine. I chopped down the air dam in front of cylinder #2 the most, but it hasn’t been working to cool the cylinder as well as I’d like it to.

The way the cooling fins are cast on Lycoming cylinders, there isn’t much fin depth on one side of the cylinder. In the center of the engine between pairs of cylinders this isn’t a problem, since this thin side is paired up with the other side that has much more fin depth. This allows the cooling air to flow down and around the cylinders. The two problem areas are where the thin fin depth sides butt up against the metal baffling on the front of cylinder #2 and at the rear of cylinder #3. Many builders will add a small duct on cylinder #3 to aid in cooling of that cylinder (you can Google references online to the “Braly Mod”).

Depth of fins in the cast cylinder head is 1/16″.

I recently did a pre-buy inspection of another RV-9A and the builder had done some similar modifications to his front baffle on cylinder #2. This similarly increases the airflow and cooling. He claimed that his change completely cured the hot temps on cylinder #2. This modification is pretty simple, so I decided to give it a try on my airplane.

I had my cowling off after the Oshkosh trip to do an oil change, so I started looking into what it would take to make this baffle modification.

The first step is to remove the baffling around cylinder #2. Fortunately, the way the baffle pieces are designed, removing it just involves unscrewing and unbolting a few fasteners from the engine case and cylinders. The hardest part is just figuring out how to get the unfastened portion off and out. It is a bit of a puzzle to unlock the baffle from the engine.

Baffle section around #2 removed from the engine.

I started by making some markings on the baffle where openings will need to be cut. I elected to keep most of the lower baffle material intact, and just do some small cuts. I can always enlarge them later if needed.

Initial markings and cuts on the front baffle. The part of the cylinder with the minimum fin depth is right where the top of the baffle touches the cylinder.
This is what it looks like underneath wth the view of baffle with hole cut out for more airflow around the fins.

After the cuts were made, and smoothed out with some filing I made a small template out of paper for the new ducting. I went through my stack of scrap aluminum pieces and found some suitable sheet of the the same thickness as the original baffle material. I cut out the rough shape on the band saw and then used some sheet metal bending tools to get the duct piece roughed out into the basic shape. After many iterations of fitting, grinding and bending, the duct was ready to match drill and mount on the original baffle.

New ducting fabricated from scrap aluminum sheet material.

I took some time to really clean up the baffle, sand down some rough areas and then gave it a good wiping down with acetone prior to painting the new and old pieces.

New duct temporarily in place on lower baffle.

The next day I got out the rivets and attached the new duct to the baffle, and reinstalled the already cut down air dam. I figured that I would keep the air dam as is, so I can only have one variable to work with in my post-modification testing.

Air dam back in place and held in with clecos.

Reinstallation was easy. I put new lockwashers under the various screws that hold the baffle segment on the engine, and ran some high temp RTV around the edges of the baffling to reseal everything.

Inside view of lower baffle with new duct and opening.
Riveted in place and painted.
All you can see of the modification from the front and top side is a narrow slot to allow more airflow to the bottom side of the cylinder cooling fins.

I let the paint and RTV set up for a day. The next day I went for a quick test flight. I took off and did a long climb at best climb speed (Vy is 83 knots) from take off to 5000 feet. This would normally get cylinder #2 pretty hot. I usually lower the nose and climb at 110-115 knots to manage the temps on #2. I was really glad to see that the modification seemed to be working. The balance between #2 and #4 on the left bank was only a couple of degrees, instead of 20+. I lowered the nose, leaned out the engine and did some flight at cruise speeds. Again, the temps were almost the same front to back and side to side. I finished off the testing with some slow flight and did a long straight in final approach to the airport for landing. The #2 cylinder temp was lower and much more balanced front to back. I’ll have to do more flight testing, but this certainly looks promising. The flight was in the morning and the air temperature was not as hot as it has been for some of my recent afternoon flights where the CHT on #2 had gotten up above 400F. Keeping the CHT’s down below 400F during climbs can be challenging in the summertime when the outside air temps are pushing triple digits.

Airventure Oshkosh 2021

After a year off, the worlds biggest aviation event in Oshkosh, Wisconsin is back for 2021. I had made my plans over June to attend. I got my NOTAM and wristband delivered in advance, and a hotel booked to stay Saturday night on the way out there. The days before leaving were mostly spent getting items packed, snacks/beer purchased, and weather forecasts watched.

The airplane had a fresh oil change at my annual inspection last month, so it was ready to go. I gathered up all of my camping stuff and weighed everything. I had just under 100 pounds to load, but since I was going alone, the overall weight wasn’t going to be a problem. I still had about 200+ pounds of weight left after packing everything in.

I had been watching the weather over the week prior and it wasn’t going to be easy to get east over Arizona and New Mexico. A big monsoonal system had set up over the Southwest area and it wasn’t moving or dissipating. Thunderstorms are not something to mess with.

The default Plan A would be to get up early on Saturday morning, fly to St. Johns, AZ for fuel, and then cross the southern end of the Rockies over in New Mexico, get lunch in the Texas panhandle and fly up over Oklahoma and Kansas into Iowa for the night.

Plan B was to try and jump start Plan A by getting out to Arizona on Friday so we could get an earlier start from there to get across New Mexico. Plan A and B were both scratched off fairly easily given the heavy thunderstorms that seemed to set up over the area all week.

Plan C was to aim further north towards Utah and Wyoming and cross the Rockies along Interstate 80. The forecast looked best for Plan C, but there was still a risk of some lingering storms in the southwest along the Arizona and Utah border.

My friend Ethan was also going to Oshkosh in his RV-10, so we had been chatting daily about these flight planning options. He was going to try and get to Prescott, AZ, but the weather was horrible there on Friday. Instead he took off Friday for Kanab, Utah. I elected to stick with leaving Saturday morning, but head in the same direction.

The new airport at Grand Canyon West is right on the rim.

I was up early on Saturday and took off before sunrise headed to Kanab. The weather was a bit hazy, and there were just a few clouds along the way. I flew over the west end of the Grand Canyon and just got a few small rain drops over the Bullhead City area. Sunny skies in Kanab as I got fuel.

Getting refueled in Kanab, Utah

By the time I got to Kanab, Ethan had already taken off. Another pair of RV’s from Ramona (Ken in his RV-7 and Jim in his RV-9A) had left less than an hour after me. We also had been coordinating our flight plans in the weeks prior. Flying at 9,500 feet over the Utah backcountry most of the way, we surprisingly had decent cell phone coverage and had been texting back and forth as we flew.

My next stop was going to be Rawlins, Wyoming for lunch, but as we got up towards that area the heat and density altitude was looking like it was going to be an issue. Ethan headed farther east to Torrington, Wyoming for fuel, and I went just a bit further to Scottsbluff, Nebraska. The airport at Scottsbluff has a restaurant on the field, so I had lunch there. As I was getting ready to leave, Ken and Jim arrived. Ken landed and his tire went flat. I had brought a spare tube, so he took it. We were able to get the airplane lifted up enough to get the wheel removed so he could fix the flat. I still had 3 hours to go in order to get to Iowa for the night, so I took off. Ken and Jim stayed the night in Scottsbluff. I got to Ankeny, Iowa around 8pm, walked to the hotel and met up with Ethan to go get some dinner.

Our route out to Oshkosh.

The next morning we met up in the hotel lobby and got a ride back to the airport. We headed out in trail to the Oshkosh Fisk arrival. This year the procedure was modified a bit to have several new waypoints to feed the normal Ripon waypoint into Oshkosh. Ethan and I were communicating on the air-to-air frequency. We were able to hear the Oshkosh ATIS at about 95 miles out. The ATIS said to use Endeavor Bridge as the first waypoint in the arrival. As we listened to Fisk arrival frequency, the FAA controllers there were of course (like previous years) doing something completely different. The controllers were telling people to line up even farther out at Portage. This confused a lot of pilots who were repeatedly asking them what was “Portage”, and why it wasn’t in the NOTAM. I knew that Portage was a small town with an airport just south of Endeavor Bridge. The arrival stream was now really long and spread out (a good thing), but since ATIS was saying one thing and the controllers another, it did make a bit of a mess. We were told to hold at Portage (again, nothing in the NOTAM about what this meant), and when they released this hold everyone started heading to the Endeavor Bridge waypoint. We got in line somewhere in between the two waypoints and I was following a pair of high wing aircraft by about a mile. Ethan was right behind me a half mile back. We had to putt along slowly at 90 knots and 1000′ above the ground for about 30 miles until we got to Ripon and Fisk. It was good to hear the Fisk controllers calling out the N numbers of airplanes that were trying to short cut this long line. Big brother is watching!

The arrival traffic coming into Oshkosh was well sorted out before Ripon.

We both got slotted over to land on Runway 36L and the yellow dot. I made a smooth landing, but the controllers were constantly telling us to quickly get off the runway over to the grass. I let down my nosewheel and got a big shimmy going that was disconcerting. Once I slowed and was in the grass it went away. Ethan was right behind and we taxied to Homebuilt Camping and were parked next to each other. I got a couple of texts from friends who were watching our progress. Our landings were captured on the EAA Live YouTube feed. (scroll to about the 9 minute mark to see me arrive and 9:35 for Ethan).

We made it! Parked in HBC at Oshkosh.

I set up camp, got the airplane tied down, registered and then wandered around for a while. The big beer tasting event at Homebuilt camping was later that evening. After we had our fill of beer I met up with Ken and Jim and we got some food at the SOS Bros. tent just outside the main gate. It was pretty hot and humid that day and I didn’t get much sleep. Ear plugs are recommended for the loud music at SOS Bros.

I got up Monday morning and spent most of the day walking around. I happened upon the Van’s presentation and heard about the new RV-15. They weren’t saying much other than high wing bush plane. I ran into lots of friends as I walked around all of the Exhibit halls. I took in the big jets on Boeing Plaza. They had a flying eye hospital plane there, along with a German Luftwaffe Airbus A400 cargo plane, and a US Air Force C-17. I sat in on a gas welding forum, but I wasn’t really dressed appropriately to actually play with the torch. I headed back to the camp site to sit in the shade and drink a cold beverage. It was really hot at over 90 degrees and the high humidity was not something I’m used to. Around 5pm we went over to the RV Social beer event, and eventually back to get some food up the road at SOS Bros.

It was another warm and humid evening in the tent and I left my rain fly unzipped to try and get a bit of breeze to cool off. At 1am they broadcasted a weather Alert over the PA system. I zipped up my rain fly as it had started raining and then the wind came in very strong. Around 4am, another band of storms swept in and it started raining pretty hard. My poor old tent got drenched. I managed to keep dry, but lots of water was starting to enter from the floor of the tent. I eventually got up and went to go get some pancakes at the EAA Chapters breakfast area over by Camp Scholler. As I was there, the rain started to dissipate and by the time I got back to the tent, it was starting to get sunny. I spent a bit of time drying everything out, and I wiped off the rain from my airplane. My camping neighbor had a big shade structure that toppled over in the wind and it scratched up the paint on my wing tip. He was gracious and it will be touched up eventually. Thankfully, no damage to anything critical.

Ouch! Big scratch in the paint on the wing tip.

My plan for Tuesday was to get all the way to the south end and work my way back up to show center. I got on the tram and went from the Vintage area to the South 40, then walked back up to the Ultralight area. I took all of the various tram lines back around to the Homebuilt pavilion and got ready for the Rivetbangers dinner at the Black Otter Supper Club. I had to get back over to the North 40 and take the bus to the Super 8 gate where I met up with my ride. There were about 30 people at the event this year and it is always a fun time with some great people. I elected not to get the 32oz Prime Rib, and instead settled on the “small” Ribeye steak ( just over 1 pound).

Wednesday I got up early and watched the sunrise. The Homebuilder HQ has a free donut meet and greet event, so I walked down there. The topic of the day was the weather forecasted for that evening. A huge storm was headed to Oshkosh with possible tornadoes and 1″ hail, not to mention inches of rain. There were lots of people leaving the homebuilt camping area. Ethan and I talked about our options. I really wanted to stay through Friday, but I didn’t really have anything crucial to be there for later in the week. My plan for Wednesday was to wander around the Warbirds for a bit and do some more forums. It also looked like they would be cancelling the Wednesday evening airshow.

Not wanting to see my airplane get damaged (beyond the wingtip scratched paint), and having to suffer more rain with my old tent, it was best to just call it done for the week and head back home. I packed up everything, went back to Homebuilt HQ and got my unused camping nights refunded. I got my VFR departure brief, looked over the weather and tried to come up with a plan for my return trek. The weather directly west was cloudy and rainy, but it looked clear to the south. I got in the airplane, got escorted to the flight line and was told it might be 30 minutes of taxiing until I could take off. Fortunately, I got to short cut the departure line and in 5 minutes I was off and heading south. I’m not sure how that happened, but I just followed the directions of the people holding the orange sticks. I headed to Quad Cities (Moline), Illinois for some cheap fuel. I had to get down under a broken layer of clouds and flew along the Mississippi River straight in for an easy landing. My plan for the day was to get close to the Rockies, spend the night and depart the next morning to get across the mountains and home. My niece and her husband live in Centennial, Colorado so I texted them and then was on my way. One fuel stop in Nebraska and I then landed for the night at Centennial Airport. I got picked up and we went out for a nice Mexican dinner.

Good thing to have left early. This storm looked nasty. Yellow circle is KOSH and the storm is headed in that direction.

I got dropped off early in the morning back at Centennial. I needed to get gas, so I started up and taxied over a short way to the self-serve fuel pump. After filling up, I couldn’t get the airplane to start! The engine was too warmed up for a cold start, and not hot enough for a hot start, so I ended up with a flooded engine. I almost drained the battery trying to start it. I decided to walk away for a bit to let it cool down. I walked back to the FBO lounge for a bathroom break, and by the time I got back to the airplane it had cooled off enough to get it started using the cold start procedure. Oh the joys of ancient aircraft engine technology, manual mixture controls, boost pumps and fuel vapor lock. After I finally got the engine going, the airport did a runway change, so I ended up taxiing all the way to the other end of the airport for take off. There were jets galore here and I was about fifth in line to depart. My poor engine was already really hot as I climbed out of there towards the Rockies.

The path home was more or less made up as I went along. I flew towards the mountains and it was clear skies and smooth air, so I kept heading southwest over the Rockies. I climbed up to 13,500′ and put on the oxygen. I ended up landing in Aztec, NM for a quick gas stop, then all the way across Arizona dodging the building thunderstorms. Surprisingly, the air was pretty smooth, and I was able to see a clear path between the big areas of rain. I had the most turbulence of the trip just getting back over the local mountains into San Diego.

Map of the return trip.
Flight tracks for the last leg from Denver to home. Some big thunderstorms were over Flagstaff and Prescott, so I went around them.

The trip out and back was a total of 24.9 hours on the airplane. It is pretty amazing to fly over half way across the country in a couple of days in a little airplane I built in my garage. These are very capable little machines. Having moving maps with synthetic terrain mapping, GPS, autopilot, weather and traffic information with sophisticated engine and fuel management information all readily available make it an excellent cross country traveler.

I was bummed about having to leave early for the bad weather, but it was probably best to get out of Oshkosh before the big storm. Thankfully the hail and tornadoes didn’t hit the Airventure grounds. They did get 2″ of rain and it was very windy. The little town of Ripon just west of Oshkosh did get some heavy storm damage. It was a good, but short trip and I’ll definitely be there again next year. An abbreviated Oshkosh Airventure is better than none!

My photo album from the trip is here. Lots of pictures and captions.

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Annual Condition Inspection 2021

My airplane’s condition inspection is due again. For some unknown reason, I always seem to pick the hottest week of the year to work on it. This has been 7 years of flying and the airplane has 881 hours total time.

Day 1

I had lent a couple of my tools to another RV owner so he could get his condition inspection done the week prior. I did a quick flight over to his hangar at Gillespie Field and then got started with removing the cowling so I could get the oil drained while the engine was hot. As I was removing the lower cowling, a bolt from the baffles fell out. I also immediately saw that another of my exhaust hangers had cracked. I grabbed a new lock washer for the bolt, and thankfully, I had a spare exhaust hanger to install as the oil drained out. I got on the new filter and pulled the oil screen on the bottom of the oil pan. The oil screen had a bit of carbon debris in it, but nothing there was metallic or magnetic. This time I was smart and I used a plastic bottle that I cut up as a drip catcher for the oil screen. I removed all of the lower spark plugs and cleaned out the threads in the cylinders. The lower plugs always have lots of lead build up. The top plugs are always clean. I packaged up my oil sample to send off for analysis. The old oil filter got cut opened and examined for any metal. Didn’t find anything metallic, but just some small flakes of carbon like the oil screen had.

Dropped the cowling and this screw fell out on the floor.
Found a cracked exhaust hanger.
Replacement exhaust hanger next to the broken one.

Day 2

I had hoped to get the compression checked while the engine was hot, but no one was around yesterday afternoon to assist. I ended up doing the compression check today by myself. I’ve done it solo before, and it isn’t too hard, but it is much easier and safer to have another person hold the prop when you pressurize the cylinders. Compressions were all in the 70’s, so that is good. I then took out the top spark plugs and cleaned up all of the spark plug adapters and ran the thread chaser in all of them, and the cylinders. I brought the laptop, so I was able to borescope all of the cylinders and take screen shots. The valves all looked good.

This year I purchased new fuel and oil pressure senders. The fuel pressure sender I had was recalled and Dynon put out a Service Bulletin to replace it. The oil pressure sender was still working fine, but I decided that I might as well upgrade it also to the new specification. This involved splicing into the wiring to add a +5V and Ground line for the new sender. I had bought some solder sleeves, so I used those to tee off the existing power and ground wires. I spent the rest of the day getting the new spark plugs installed and checking all of the engine lines, nuts/bolts, controls, and serviced the air filter. The K&N air filter was replaced last year and looked very clean, so I just hit it with a bit of air filter oil without doing the full clean/wash process.

New pressure senders (with the wires attached) to replace the old units.

I took off the prop spinner, inspected everything on the prop, and re-torqued the bolts. I had a small nick on the back of the prop, so I smoothed it out and mixed up some epoxy with cab-o-sil to fill it.

Day 3

This morning I made a quick stop at the grocery store to get some water, tea, sodas to replenish my hangar’s refrigerator. The high temp today was 100F and it was humid. I have to have some hydration as I sweat away in the hangar! I got to work with the vixen file on the prop to shave off the excess epoxy. Some light sanding and then a layer of flat black paint finished the prop off.

Next up was to check the P-mag timing, ohm out the spark plug wires and do a thorough engine cleaning. To finish off the engine section of the inspection I cleaned off the cowling and gave it a ceramic coating. The ceramic coating is something new I’m trying on the airplane. Hopefully, it will make the smashed bugs easy to clean off. I also replaced the rubber seals on the lower cowling entry. The painter oversprayed purple paint on these when the airplane was painted. The paint has really stiffened these up and they were starting to rub up against and wear into the lower baffle ramps.

I took out the seats and took off the back baggage bulkheads to begin my inspection of the aft fuselage area. I lubricated all of the elevator control rods with LPS-2 spray lube, along with the flap linkages. Lots of little things to inspect here, like the seat belt anchors, ELT connections, AP pitch servo, ADAHRS units and the static lines.

I tested the flaps, trim, interior lights, position lights and strobes. I did notice that my left strobes didn’t disable properly when I turned them off and had the position lights on. The right and tail light strobes did turn off. The disabling circuit is just switched to ground, and the switch is common to all 3 lights, so it must be in the LED light circuitry itself. This is not the first time I’ve had issues with these cheap lights from (now defunct) Ztron Labs. Maybe it is time to replace these. The FlyLED’s I put on Josh’s RV-9A were super bright and affordable.

Day 4

Spent my morning taking the dog to the vet for a quick checkup. Got to the airport around noon. Not as hot out today, so that was nice.

I started off by taking out the seat pans. Lots and lots of screws. Once I had those off, I extracted the auxiliary fuel pump and fuel filter. The fuel filter just had a few little bits of fuzzy stuff inside that needed to be cleaned out.

I set my iPhone alarm to go off at the top of the hour and I did the Emergency Locator Transponder checks in the 5 minutes after the hour that they are allowed to be turned on for testing. The rear fuselage is ready to be closed up, but I needed the extra leg room that having the baggage area bulkhead out provides when I lie down to get under the panel. With the fuel pump out, I had access to the main wiring runs. I needed to run 3 wires out to my new heated pitot tube. I started by getting a wire fishing tool into the wing from the access panel on the underside. Then I was able to pull the 3 wires into the wing. Next step was to route those wires up behind the panel. The heated pitot power wire gets added to the Vertical Power VP-X box. The Ground wire simply goes to my ground block on the firewall, and the status wire then goes into the Engine Management System box. It’s not fun to wedge yourself under the panel, and invariably I’ll get situated then find myself needing a tool that I can’t reach. I left for the day with most of the wire in place, but nothing hooked up. I am using waxed lacing cord for the wire bundles, so I have to cut off the old ones and add new ones to secure the new wires. Tedious work, but it looks nicer than using plastic tie wraps.

Day 5

I spent most of the day under the panel finishing up the lacing and getting the 3 wires for the heated pitot connected. I got the corrugated plastic covering back in place over the wires and then put back the center tunnel cover and fuel pump in place. The access under the panel is so tight!

Once the wiring was in place, I got out the laptop and the VP-X crossover ethernet cable to reprogram the unit. I enabled the new 15A circuit and set it up to use one of my existing switches on the panel (the autopilot switch). I moved the autopilot switch over to the APRS tracking switch, and then made the APRS “Always On” (no more need for the switch). I always fly with the APRS tracking on, so it really doesn’t need to be switched from the panel. I can always go into the VP-X menu on the Dynon Skyview and disable it if needed. The Pitot Heat Status widget was added to the EMS pages and I verified that everything worked and that the pitot gets hot when turned on. I used my Dymo label maker to relabel the two switches on the panel.

I had considered buying the various IFR instruments to redo the panel during this inspection, but I’m going to wait until after Oshkosh to see if anything new is coming before I spend the money. After doing some more planning, I think that I will definitely upgrade my VP-X Sport to the Pro model and this will get me the additional circuits I need to hook up the Garmin GPS navigator, the back up Attitude Indicator, the remote Magnetometer, the Autopilot/Autotrim unit and update my Nav/Strobes to the FlyLED’s.

Moving to the VP-X Pro means I really only need the one additional J8 connector. I found several places that sell these Molex 150XL backshells online, but they are all backordered and out of stock. Buying a complete VP-X Pro wiring harness is an option but it is expensive and way more than I need. Vertical Power will lend builders a special crimp tool for the pins. Seems like a lot of hassle for 8 wires and pins extra on the Pro model. The professional grade crimper can be bought for a mere $425!

Day 6

I took the next day off to help my wife clean out her classrooms for the summer. Also had to run a few personal errands. I was also pretty tired and sore from yesterday’s under the panel work. And it was pretty hot and humid here.

I started my next day’s work session opening up the tail fairing and inspecting all of the bolts there, and lubricating the elevator linkages. I made sure all of the rod end bolts were secured with tight jam nuts. I cleaned and inspected all of the tail surfaces and then applied some ceramic coating on the empennage.

I gave my cordless screwdriver a workout and took off all of the access panels and tips off of the wings. I played around with the left strobe connector and the problem with the strobe disabling on that side disappeared. I’m also looking at potentially adding a GPS antenna for the IFR GPS navigator in the right wing tip. I bent up a little bracket out of sheet metal and made sure it would fit on the end rib of the wing. The bracket needs to be level in flight, so I built a little offset in it to handle the dihedral of the wing. I’m not going to actually install this until I get the unit.

I got some photos of the aileron bracket rivets on the wing rear spar. Van’s has a service bulletin to check these annually. No cracks! I checked and lubed all of the aileron bellcrank control rod bearings.

I finished up the day getting the wheel pants and gear leg fairings all removed so that I can look at the brakes and wheels tomorrow.

I noticed some tiny cracking or crazing in the paint where the wheel pant is mounted. Just on the right side wheel pant.
The center strap over the wheel nut was missing a screw on this side, which would have allowed the wheel pant to vibrate. New screw and lockwasher installed.

Day 7

I got to the airport and started to work on the wheels and brakes. I got out my jacks and got the airplane up off the ground. The brakes on the left side looked down to the minimum, so I removed the wheel and caliper. I had bought a set of pads in advance so changing them should have been a quick job. I was setting up my pneumatic squeezer to set the brake pad rivets when I accidentally caught the end of my finger in the squeezer. My finger was smashed pretty badly. Thankfully, the dies were set to be mostly wide open. after tending to first aid and getting the bleeding somewhat under control, I took off for home. Brakes can wait for a day or two while my finger heals.

Definitely need new brake pads.

Day 8

My finger was feeling much better today. Still hurting, but not throbbing. I got over to the airport in the late afternoon and managed to finish off the new brake pad installation. I got the wheel bearings regreased and the wheels back on. I checked the nose wheel and verified the breakout force. I started cleaning up the hangar and put away lots of my tools and supplies. I should be able to finish up everything tomorrow.

My squished fingertip.

Day 9

Another late afternoon start, but not much left to do. I put on the gear leg fairings, and set out cleaning the wings top and bottom. After that I continued with applying the ceramic coating on the wings. I pulled the airplane out of the hangar and got it started, then checked the fuel/oil pressure readings with the new senders. The fuel pressure used to be 23-33 psi (engine mechanical pump and electric boost pump readings are within 10 psi of each other), now I’m seeing 33-43 psi. Same relative range but the new sender seems to be calibrated higher? I think the old readings were more correct since the mechanical pump should be producing around 25 psi of fuel pressure. I wasn’t able to do a static RPM run, since my brake pads aren’t bedded yet. Not much stopping power until they get snubbed for a few cycles.

After the engine run I checked for any leaks, and found nothing so I finished installing the cowlings. Then I started up again and did an up and back taxi run and stomped on the brakes several times. The instructions for the brake pad bedding say to do this procedure at least twice and to let the brakes cool for at least 10-15 minutes between runs. It was really overcast today, and as I was taxiing, drops of rain started. I decided to just put the airplane back in the hangar and I’ll finish off the brake pad bedding for tomorrow. I want to be able to do a full static run up prior to flight, and right now the brakes are starting to slip at just 1500 RPM.

Day 10

I got all of the legal paperwork completed in my log books to return the airplane for flight. I posted a query on Vans Air Force about the pressure sensors and got back a potential solution. There are two Kavlico V2 items in the menu. I had inadvertently selected the wrong one. I did a quick engine run after switching the sensor selection and it now looks normal again. I ran the airplane up and down the taxiway and did another set of hard stops. I did a full engine run up to see the static RPM, and then parked back at my hangar to get the wheel pants reinstalled. After they were back on I did a quick flight around the airport and made sure everything was running fine. No issues! I’m ready to be back in the air.

Back to School

I never imagined that I’d become a full time student again. I’ve been trying to figure out how to get my Airframe and Powerplant (A&P) Mechanic license so I can continue to expand my skills and be able to work on certificated aircraft. The local Community College at Miramar has classes, but it seemed like every semester I was unable to get a spot. I tried back in Fall 2019, when they had both day and night courses, but was not able to even get on the waitlist. In Spring 2020, I tried again, but I was about number 20 on the waitlist. I decided to at least take an Aviation class and I was able to get into the Instrument Pilot Ground School. We had in person classes until mid-March when everything went online due to COVID-19. The class was fun, and I was ready to start on my Instrument Rating, but with the pandemic, getting dual instruction in a tiny airplane seemed like a bad idea. In Fall 2020, again I was unable to get a spot in the A&P classes. All of the classes had gone to remote learning, and instead I took the Commercial Pilot Ground School class. We did all of the classes online using YouTube videos for lecture and lots of FAA safety classes for assignments, along with the usual weekly quizzes. When enrollment opened up for Spring 2021, I tried once again for the A&P classes. There are 4 classes that are the prerequisites for all of the subsequent curriculum. Yet again, I was unable to get into the classes, but was now only 12th on the waitlist. I had been in contact with the instructor and he said to just keep trying. They had eliminated the day classes due to budget cuts, and were down to only the night classes. The available spaces were now even tighter, not to mention with COVID-19, they had a hard cap of 20 students in the class. I was pretty sure I wasn’t ever going to get into these classes!

On the Friday evening before classes started for Spring semester on February 1, I got an email from the instructor telling me that I had a spot! Totally unexpected, but I was ready to jump at the opportunity, so on the following Monday evening I was back in the classroom. I was able to also get into the other 3 classes that are needed for the subsequent classes. The classes are Monday through Thursday nights from 4:30pm to 10:45pm. Half of the evening is lecture, and the other half is lab. The classes are in person, so we get screened as we enter the building, we have to wear masks, and have to stay socially distanced in the classroom and lab.

These first 4 classes cover most of the General A&P curriculum. A lot of it is familiar to me after building and maintaining my own airplane. I have learned quite a bit of information and every day in class is interesting, so the time goes by quickly. We have quizzes and exams online, and also have some written assignments. Miramar College also has a hangar down at Montgomery Field, and we have done a few nights down there looking at their collection of aircraft while learning about fuel systems.

Right now I’m on Spring Break, so I’ve finished up the first set of “Blocks” that they have divided up the course into. We have done some basic mathematics, technical drawings, fuel lines, basic use of tools and safety wiring in the lab classes. The lectures have covered things like basic airplane terminology, structures, controls, hardware, atmosphere, pressures, measuring devices, and helicopters. The course sticks pretty close to the FAA requirements for the exams. Nothing so far has been very difficult, but the reading is tedious (all of the curriculum is standard government FAA publications).

The entire program takes 5 semesters, so I’m planning on finishing up in Spring 2023. Then I can get my approval from the FAA to take the written A&P test, the oral tests and the practical tests. It is quite a bit of work, but then I’ll be able to officially work on certificated aircraft from little propeller Cessna’s to jumbo jet Boeing’s. My objective is to stay in the General Aviation sector and be able to do Condition Inspections on Experimental Amateur Built airplanes. Maybe I’ll even get involved in some restoration work. In the mean time, I’ll continue to do some repair work on EAB airplanes in my spare time (which has been significantly reduced with all of the class work).

One final note, our flying adventure stories will be hopefully coming back soon. I got my first vaccination dose this week! My wife and daughters have all been fully vaccinated. My son has had his first shot also. Looking forward to getting out and about more this year.

Another Fuel Tank Repair Job

Marc has an RV-10 that he flies. It had a couple of areas on top of the wing tanks that would weep fuel when it was topped off with gas. He took off the left tank and brought it down to my hangar. He had a heck of a time getting this tank off. One of the bolts where the tank attaches to the wing spar would just spin. He ended up having to drill out the head of that bolt to get the tank detached! It turns out that the bolt threads and/or the nutplate on the Z-bracket was completely stripped. I ended up drilling out the nutplate and putting a new one on. Even with the nutplate removed I couldn’t get that stupid bolt unscrewed. Marc also was unable to get the fuel sender wire detached. Who ever put it on certainly overtorqued the connection. He inadvertently twisted the screw there too much and it spun internally which twisted off the wire inside.

Lots of leakage on the lower side of the tank. The leaky fuel outlet tube fitting was found to be installed with teflon tape, which is a big no-no on aircraft!
This bolt head had to be drilled out. The nutplate was completely stripped and the bolt would just spin in place.
The fuel sender wire was over torqued and when they tried to loosen it, the entire connection spun and twisted the internal wires until they broke off.

The person he bought the RV-10 from had tried to fix some of the leakiness by spreading some epoxy based fuel tank sealant along the aft baffle edge. Mostly on the outside, but they also poured some inside the tank! Unfortunately, the type of sealant that was used was incorrect for an aluminum tank. It is normally used on composite tanks to keep the fuel from penetrating fiberglass and foam (think glass airplanes like Lancairs). I started to work chipping off the epoxy sealant from along the aft baffle, and there were blue stains from the fuel along the entire lower baffle. Thankfully, this stuff really didn’t stick that well to the aluminum and it would just flake off. Once I got the big 5″ holes cut into the aft baffle, I found the issue with these leaky Quickbuild tanks. The majority of the sealing on the inside was OK, but along that lower aft baffle they had put down the bead of sealant too far forward and when the baffle was inserted it never got close enough to the bead to seal it up.

This epoxy type sealant doesn’t adhere well enough to the aluminum tank. I could just flake it off and underneath was a long line of blue fuel staining.
Each fuel bay on the lower aft baffle flange had staining underneath the epoxy sealant.
More of the epoxy sealant was poured into the inside of the tank. This stuff was quite a bit more difficult to chip out.

It took several days to get the proseal inside cleaned up. As I was inside the tank I noticed that the Van’s Quickbuild contractor (a company in the Phillipines) had even left one of the factory paper part number stickers on one of the ribs!

See the white paper parts number sticker on the rib? Yikes! if that clogged up your fuel system it could cause the engine to stop.

I resealed all of the bays inside and put on the tank repair plates to cover the 5″ holes on the aft baffle. Lastly, I installed a new fuel sender. The job took a couple of weeks longer than it should have, but it was right around the holidays, and our order for parts from Van’s was back logged for a week. The day our order shipped the entire parts department at Van’s got shut down for 15 days for a COVID-19 quarantine issue.

Finishing up the last fuel bay and getting the baffle all sealed up.

I ended up driving up to Marc’s hangar in Long Beach to deliver the first tank. It was nice to get to actually go drive somewhere! I’ve been stuck mostly at home this last year.

Marc reinstalled the tank and was back flying for a short while before he started tackling the other tank. The right tank wasn’t as bad as the left one. This side had some weepy rivets on the top again, but the rest of the tank seemed pretty solidly built. I started with the Polygone sealant remover along the aft baffle mostly to just get it cleaned up enough for me to be able to get all of the rivet lines sealed up. I only drilled out the inboard bay for access and I left the fuel sender in place. The weepy rivet on the top of this tank was caused by just a tiny gap in the pro-seal around one rivet. I used more Polygone to fully clean up around the weepy rivets.

The underside of this tank had a significant number of paint blisters. This issue has been seen by many other Quickbuild tanks. None of these rivet blisters had any sign of fuel leaking. It appears to be just some sort of strange outgassing from the sealant or rivets that causes the paint to blister. I decided to leave these alone, since from what I could tell with looking internally on both of these tanks, there was sufficient pro-seal inside to prevent leaks on the stiffeners along the lower skins.

The paint blisters were numerous on the other tank’s lower skin. Nothing was leaking, but these are likely caused by poor preparation of the surface prior to painting.

Inside near the fuel drain was quite a bit of debris and what looked to be some rusty water stains. I was able to clean all of this with some acetone and a toothbrush. After the cleanup, I got the weeping rivets completely covered in new sealant. The weather was really cold the week that I did the resealing, so the sealant took much longer to really set up. Marc came down and picked up the tank.

More photos with captions are here.

Flying Stats for 2020

This should be a rather short blog post. 2020 presented some challenges to flying. My flying this year just broke 100 hours (by a tenth of an hour). Yes, just 100.1 of Hobbs time.

The year began with a nice New Year’s day flight out to Lake Havasu, AZ for lunch with the SoCal and Arizona RV folks. I also did several introductory formation flights and that was progressing nicely until the pandemic put a stop to socialization.

I enrolled in the Instrument ground school class at Miramar College. Part of the class was a Lab where we flew Redbird simulators, however the FAA won’t allow the school to sign off any flight time. I had hoped to get started on my Instrument Rating, along with updating the panel in my airplane for IFR use. Then COVID came along and classes went virtual, lab class was cancelled, and I wasn’t going to be sitting next to an instructor any time soon.

I had some issues with my main EFIS screen not wanting to display anything. The airplane was grounded for almost a month due to sending that screen out for fixing, then it coming back and still not working, and then finally getting a new unit that works. This prompted me to get and install a second screen. I also managed to install a backup ADAHRS unit in preparation for IFR flight. The COM radio also got updated.

We managed to take a nice weekend trip up to Paso Robles for my wife’s birthday in January. I did a couple of “lunch” flights, but they were all either takeout or outdoor dining. Some of these airport restaurants were rather lacking in their policies for masks and social distancing.

Alicia and I beat the heat a couple of times during summer and we did some hiking around Catalina and Oceano. Alex and I did a flight out to Santa Barbara and got to walk the pier in Goleta and have some take out food from the cafe on the beach. Marissa wanted to camp somewhere so we did an overnight at Payson, AZ. This trip to Payson was my furthest trip away for the entire year. No Oshkosh in 2020, so no big summer trek across the country.

This fall I completed the Commercial Pilot ground school class at Miramar College online. I still need to take both the Instrument and Commercial written exams, along with all of the necessary flight instruction. Hopefully, 2021 will accommodate some flight instruction.

On the repair work, I did quite a bit of stuff including wing tips, brakes, tanks, fiberglass, lights, and avionics. I have several repair jobs lined up for 2021, so I’m sure I will be keeping busy at the airport. I’ve been trying to get into the Aviation Technician classes at Miramar, but so far I haven’t been able to enroll due to shortages of slots for the classes.

My logbook stands at 988.6 hours of flight time, and the RV-9A now has 848.5 hours. The low price of avgas this year helped drop my hourly fuel costs down to $23.14 per hour!

Goals for 2021? Get the IFR panel update done. Start Instrument and Commercial Pilot training. Hopefully, we can take some overdue trips to see friends and family.

Fuel Tank Repair Job

I got a request from another RV-9A owner to see if I could fix his leaking fuel tank. The tank has been weeping fuel for a while. The leaking fuel was along the aft fuel tank baffle, which is a common area for leaks. The aft baffle is the final piece put in place when you build the fuel tanks. There is no way to access the inside of the tank with the aft baffle in place, so if you skimp on the sealant, or do a poor job getting the sealant spread where it needs to be, you will increase the chances for leakage. You have to get enough of the tank sealant on the baffle so that when it is put into place, it creates a leak-proof seal.

He took the tank off his airplane and drove it down to my hangar in Ramona. He also provided a Tank Repair Kit from Van’s. The repair kit is a pre-punched disc of aluminum along with some special closed end pop rivets. To get inside the tank, you need to drill out a 5″ hole in the aft baffle. Once the hole is created, this gives you access to reseal the tank from the inside. After the sealant is redone, you cap off the large access holes with the aluminum disc, along with more sealant under the edges. I ended up ordering 5 more of the Tank Repair Kit’s so that we could access each bay in the fuel tank. I had to take off the fuel sender and access plate. It was bonded on with sealant, so it took some persuasion with a thin putty knife to get it to part with the tank rib.

I got to work cleaning off all of the old sealant where it was leaking. When the fuel starts to leak, it makes the underlying sealant very gooey. There is a product called Poly-Gone which is a gel you can use to remove the sealant. I proceeded to brush this on and then wait a while for it to start dissolving the sealant. After it starts to weaken and dissolve the sealant you can use a nylon scrub brush to work your way through to the aluminum of the tank. This was definitely the hardest part of the job. The old sealant was slapped on fairly heavy in some places, but in others it was barely used. Looking inside the tank along the back baffle, there was hardly any squeeze out of the sealant when it was originally installed.

The blue dye found in 100LL avgas leaves a tell-tale sign when there is a leak. Each of these rivet heads should have been encapsulated in tank sealant.
The leaking fuel stained the paint on the bottom of the fuel tank.

I got the tanks all cleaned up on the outside, and did a bit of clean up on the inside, too. I thoroughly cleaned and scuffed the areas that were going to get resealed. The original builder of the tanks simply did not do a very good job of applying the sealant. Van’s Aircraft recently did a long YouTube video of the tank building process. This gave me some great tips and techniques on using the sealant for the repair.

The fuel access panel on the side of the tank holds the fuel pickup tube. The access plate was sealed in place, along with using a cork gasket. The gasket can seep fuel, so most builders don’t use the cork gasket and instead just use sealant directly on the plate. Note that the blue nut on the fuel pickup line is not secured by an anti-rotation bracket, or safety wired.
The access hole on the side of the fuel tank after prying off the fuel sender access plate. Looking inside the tank, you can see hardly any sealant along the edges of the inside of the tank along the aft baffle.

I spent several hours applying the new sealant along the aft baffle from the inside. It definitely requires some patience, and good lighting along with a mirror to be able to see what you are doing in each of the tank bays. I did the resealing over a couple of days. It helps to let the sealant, which is extremely sticky, set up and harden between sessions.

New access holes have been drilled in each bay of the fuel tank. At this point I was almost done removing the sealant along the bottom row of rivets.

The next phase in the repair is to get the big access holes covered with the tank repair discs. I scuffed and cleaned these plates and got them in place with several clecos after smearing on more sealant around the edges. The plates get pop riveted on with some special blind rivets that are fully sealed at the end. You dip the end of the blind rivet into some sealant, place them in the holes around the plate and then use the pneumatic puller to set the rivets.

The sealant gets spread around the edges of the new covers for the access holes, then they get clecoed in place for final riveting with special pop-rivets that have a sealed end that goes inside the tank.

The fuel sender access panel is on the side of the tank and this is where the fuel level float mechanism is installed. It also has the fuel pickup tube attached. Van’s has put out a Service Bulletin on the fuel pickup tube. The tube can possibly rotate and unscrew itself. Van’s has designed an improved bracket for dealing with this issue. This tank did not have that upgraded bracket installed, so I ordered a set. The other acceptable option is to simply drill a hole in the nut that secures the tubing and then add some safety wire.

The final step in the repair was to get the fuel sender Service Bulletin done, install a new fuel sender and seal up the last access panel. The fuel sender and access panel are screwed in place so that you can service the fuel sender. I bought some socket head screws from Aircraft Spruce to use instead of the standard Phillips head screws. There is limited space on the side of the tank since it is next to the fuselage. Using the socket head screws allows you to get an Allen wrench in there to unscrew the fuel sender and access panel much easier than trying to use a stubby screwdriver. This way you don’t have to remove the tank from the wing if you ever need to replace the fuel level sender.

Repair and resealing almost done. The pop rivets on the access covers get encapsulated along with the rows of rivets on the aft baffle.
The Service Bulletin for the new anti-rotation brackets on the fuel pickup line is in place. This bracket prevents the blue nut on the fuel line from unscrewing.

I let all of the sealant set up for a couple of days. With the colder temps here in December, the sealant takes longer to really cure and set up. I plugged up the vent, fuel cap, and pressurized the tank to check for any leaks. I sprayed all of the edges on the aft baffle down with soapy water and didn’t see any bubbles forming along the formerly leaking edges of the tank.

I made arrangements with the owner for me to deliver the tank back up to his hangar in Santa Monica. The tank was way too large to fit in my RV-9A, so I had to drive. Another RV owner at Santa Monica wanted some help with his RV-12 electrical wiring, so I managed to get that done too.

More photos from this job, along with captions are located here.