13.99 – ADS-B in antenna

This entry is part 65 of 66 in the series 13 - Electrical / Instruments

For ADS-B in, I’m going somewhat old-school.  While I could have gone with an installed ADS-B receiver and displayed the output on the Grand Rapids EFIS, I don’t like that approach.  I like having weather on a device other than my PFD.  And displaying it on the co-pilot EFIS would have it too far away for my taste.

Currently, I use an iPad with Foreflight for charts, approach plates, weather and traffic.  A Stratus II provides ADS-B weather and traffic. And I like it that way.

But I’ve been unhappy with the reception performance of the Stratus internal antenna. They sell an external antenna, but it’s $70 and probably would only be marginally better.

I exchanged some email with Jim Weir of RST Engineering (his manual is what I’ve used when building antennas). He gave me the spec’s for building an external antenna for the Stratus II.  Basically, it’s two 3″ legs. The real shocker was the connector that is used to connect to the Stratus.  It’s an unusual, tiny-ass connector and the best price that I could find was $17! (normally, coax connectors are around $1-4)

Once it came in, I donned the magnifying headset and terminated the RG-174 cable to the unbelievably expensive Hirose connector. Then I decided to run a little test.  Before installing the foil antenna and connecting the coax to it, I separated the shield from the center conductor and used duct tape to attach it to the side of the fuselage just aft of the instrument panel.

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I went up and checked the reception status and this is what I saw using the internal antenna:

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Receiving from four towers and one was showing a 51% error rate.  This is actually pretty good compared to what I normally see. Then I connected my new, test antenna. Unfortunately, I didn’t get a screenshot, but it was showing 5 towers and all had 0% error rate!

So now I’m debating whether to go to the trouble of building the the foil antenna and just sticking this one behind the panel.

12.99 – Oil temperature and heat challenges

This entry is part 47 of 48 in the series 12 - Engine / Propeller

I’ve been having an ongoing issue with oil temperature from day one. But unlike most builders, my problem is the oil temps are too low.  Around 150 is about as high as it gets during flight.  For a long time I didn’t notice it because I was only keyed in on if it got too hot.  So it didn’t register that it was running too cold. The Continental operations manual says between 160 and 180 is normal in cruise oil temp.

Another problem is my idea of using a servo to control the damper to block the outside air from the nose oil cooler and recirculate cabin air through the oil cooler failed miserably. The problem is that the NACA duct for the nose oil cooler is useless.  Because the surface of the fuselage at the nose is angled in, the oncoming air goes directly into the oil cooler.  The NACA duct does not reduce the pressure or speed of the air.  As a result, the servo can not overcome the force of the air and remains retracted. So on our recent trip from Chicago, the “heater” was putting out about 40F air into the cabin.

I could try a stronger servo, but because of how the damper attaches to the pivot, I’m worried that it will break the damper off the pivot.

These two problems are somewhat related.

I thought that maybe the vernatherm (thermostat which controls whether oil goes to the cooler) for the nose oil cooler was stuck and was always allowing oil to go through the oil cooler. To test this I blocked the air inlet for the nose oil cooler. That helped some. But it only went up about 10 degrees. But it also allowed the damper to move which permitted cabin air to run through the nose oil cooler.

So I decided that the easy fix was to build a winterizing kit. This would be an easily installed (or removed) cover for the nose oil cooler. Since the nose oil cooler is only for cabin heat and the engine mounted oil cooler is more than capable of keeping the oil cool, closing off the nose NACA duct isn’t a problem.

Here’s the Mark 1, Johnston Velocity Winterizing Kit.

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If needed, I can close off the holes in the baffle to further reduce outside air.

Installed (I’ve started prepping it for paint so there’s some filler on it).

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When I did a test flight with the Mark 1 JVWK, this was temperature of the air coming out of the heat duct.

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That takes care of the cabin heat issue.

For the low oil temps, I should replace the vernatherm that controls the oil to the nose oil cooler, but I can’t see a part number on it and replacing it requires removing the oil filter, oil filter adapter plate and maybe disconnecting the oil lines. At some point, I’ll get the part number and swap that out, but for now I’ll start with the engine oil cooler vernatherm.

I picked up a new vernatherm (used, actually) and tested it.  This is done by putting it in oil on the cooktop, heating it while verifying that it opens at correct temperature. The vernatherm in the engine is stamped “77C” which converts to 170F.  It tested correctly.

Getting to it is not the easiest thing in the world.  It’s located almost directly above the engine mount.  But an hour later, the replacement was in and I was doing an engine run-up leak check. Inspection of the area showed no leaks. So I replaced the cowling and cranked up the engine for a test flight.

This graph is from a flight about on month ago.  The OAT was 60F, altitude of the flight was 4,500′ and the engine was running at 25″ MAP and 2,500RPM.

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Max oil temp was around 150 at the beginning of the flight and it drops down to 140 in cruise.

This flight is after the new vernatherm was installed. The only difference was this flight was at 3,500′ instead of 4,500′.

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Max temp in cruise was 171.  Yay!  RIght in the middle of the allowable range. I’ll test the old vernatherm soon and see how it behaves.

5.6 Improving door fit

This entry is part 16 of 16 in the series 05 - Doors / Windows

During the last trip, I had a lot of time (10 hours) to determine that there were leaks around the doors. I didn’t think these leaks would make a huge difference but since painting the plane is around the corner, I makes sense to do it now.

I identified two places around each door where I could detect some air movement. It was the same locations on both doors.  The first was on the forward edge about six inches up from the bottom. The second location was at the very top of the rear edge.

When I looked at those locations, it was pretty obvious what was going on.

Here’s the forward opening on the pilot side door.

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The flange isn’t straight (this is where the two fuselage halves are joined).  Since the weatherstripping is following the flange, that is creating a gap between the weatherstripping and the door.

Top rear of the door opening.

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Same issue as the forward edge but over a larger area.

There are two possible fixes:

1) Increase the thickness of the door at these points.

2) Increase the thickness of the flange on the fuselage side.

Now method 1 is just plain wrong. In addition to that, it would make the door heavier.  Although not by much… But still heavier.

So I pulled the weatherstripping off in the affected areas and mixed up some epoxy with cab-o-sil and micro. Applied it, sanded it so I had the proper dimension and reapplied the weatherstripping.

Here’s the forward edge of the co-pilot door.

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There was one other thing that I had to address.

The outside of the upper, forward edge of the door was sitting proud of the fuselage. Not much. Maybe a strong 16th of an inch.  If the leading edge was below the fuselage, I would probably leave it be. But with it sticking out into the airflow, I thought that in addition to drag, it was probably generating some noise as well.

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Scott recommended using polyester resin for this type of fill. The advantage is that you can paint directly over it.

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I masked the area with tape, mixed up the resin, added some micro and cabo to thicken it, and then applied it. I did one more fill to get just right and then some glazing putty (polyester as well) to finish up.

Now the doors are perfectly fair with the fuselage. During this time, I was also making some changes to the nose oil cooler/heating and made a quick flight to test those changes.

The difference was surprising!  Before there was always a lot of wind noise and some whistling.  I assumed it was from the openings for the main landing gear.  Once I installed the vanity panel, that seemed to help a little. But on this flight, it was significantly quieter!  (And faster. Everything you do makes the plane faster. Soon I’ll be indicating 300knots… in the climb!)

99 – First Trip

This entry is part 9 of 9 in the series 99 - Non-Build Topic

The Southeast Triangle

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Up to now, I’ve only made a small handful of short trips.  Three down to Sebastian to fix a fuel leak, move the hydraulic dump valve and to talk with Scott Swing about painting the plane and Justin about interior. The only other trip was to head up to Smyrna, TN so that my old A&P/IA could show me any tricks on doing the inspection on the Continental IO550. All of these have been only about two hours away and Ann has only been on one of those trips (to talk with Justin about the interior).

Since Ann had a business trip that was going to have her away on her birthday and I didn’t have anything planned, we decided to do our first long trip. Panama City, FL to Dallas, TX (couple days of business meetings) to Chicago, IL (fun for the weekend) to Nashville, TN (one business meeting) and then back to Panama City.

I spent some time making sure everything on the plane was ready and on Monday we got up early to be at the airport and in the air by about 8:00 so we would be in Dallas by noon.  That right there is significant.  If we were still in the Cessna, it would have been a tad bit different.

In the Cessna, we would be looking at about 4:45 in the air. That means two stops.  Not for fuel but to accommodate Ann’s “two hour rule”. She didn’t like worrying about not drinking too much liquids and having to deal with unplanned stops. So she created the “two hour rule”. Occasionally, she allow an exception if it’s only 10 or 15 minutes more, but otherwise, it’s a hard rule. And it’s a good one. Life is much easier when you’re not thirsty most of the day and you get to wander around small airports.

Another (new) thing we experienced is the significantly smaller baggage volume available in the Velocity as opposed to the Cessna. The Cessna 182 is like a flying Ford Explorer.  There’s TONS of space inside.  Between the baggage compartment and the back seat, you can fit massive amounts of stuff in that plane.  And with the 182, the general rule is: If you can fit it in, the plane can carry it. Meaning it’s almost impossible to overload a 182 unless you’re carrying lead.

The Velocity is more like a Porshe 911.  Yeah, it’s got 4 seats and baggage compartment, but there’s no comparison to an SUV.  It was made more challenging in that Ann had about three days of business during this eight day trip. So we were jamming stuff in the baggage area, back seats, floor, etc. It was pretty messy looking.

For this first day of the trip, we would only be making one stop. I chose Vicksburg, MS because they have cheap fuel and it’s about halfway. We took off around 7:45 and climbed up to 6,000′. Where we encountered a 15-20 knot headwind that would be with all the way to Dallas. After stopping in Vicksburg, I added 20 gallons of fuel and wandered around while Ann took some phone calls. Then it was back up for a short 1:40 hop into McKinney National Airport.

And what a nice airport it is. Big honkin’ airport with one of those big fancy FBO’s where they pull your rental car right up to the plane after you park. Which I discovered is a little different when you’re rockin’ a Velocity.  The line guys get a little confused when they are marshalling you into a parking spot. So I ended up stopping a bit short and we pulled it in the rest of the way. After unloading the plane, Ann went to take care of the rental car paperwork while I stayed with the plane for about 20 minutes answering questions.  ATP has a flight training operation there so it seemed like every student walking by wanted to look and ask questions.

After a couple of days in Dallas (actually Plano), we were off to Chicago to spend the weekend with a very good friend, hang out in the hot tub, and partake in great food and some adult beverages. Ann of course went shopping… I did too, but my shopping was at Berland’s House of Tools.  In Panama City, if you want high quality or specialty tools, online is the only option. :-(

There was a front moving through on the day of the trip. Clear skies but howling winds. Fortunately, they were blowing out of the south which would give us a 40 knot tailwind and be straight down the runway at every airport.

So we blasted off of McKinney at 8am.  Got vectored around Dallas for a while and we were then at 5,000′ making about 240 knots over the ground for our first stop in Lebanon, MO. Approach and landing was… interesting.  Once below about 4,000′ it got bumpy.  So I used a modified Millin Approach.  Andy Millin has a fixed gear Velocity and if he needs to get down fast, he slows down, deploys the speedbrake, pulls the power to idle and holds about 90 knots and gets a 3,000 foot per minute descent. I don’t have a speedbrake, but I do have landing gear that’s pretty draggy. So I was able to go from smooth air to landing pretty quick and limit the time in the bouncy stuff.

That was a timed stop as Ann had a one hour call that she had to take so we planned our departure to arrive at the appointed time. After the call and taking on 20 gallons of fuel, we were off to Chicago.  After takeoff I trimmed for Vy and got above the bumps in about 2 minutes.

About 100 miles out, I got the usual (and expected) “we have an amendment to your routing, advise when ready to copy.”  Like always, it was just a minor detour (you can see it on the map) so no big deal.  As we began our descent, Chicago approach asked if I could “maintain that speed”. I responded affirmative.  He then told me he had a Piper also heading to Dupage and that if I could keep up the speed, he could get me in before the Piper and not have to slow down. Okay. Usually I’m the slower one so it’s nice to not be that plane for a change. Then it got a bit more unusual (at least to a long time Cessna driver). Typically, Chicago approach is busy and they don’t have a lot of time for idle chitchat. But the controller then asked what speed I was indicating. I responded “187 indicated and 205 true.” He then asked what my fuel burn was. I replied “12.6 gallons per hour”.  He came back with “You can’t beat that.”  Nope. You certainly can’t.

After landing, I dropped Ann off at the Taj Mahal (what the locals call the main terminal at Dupage) so she could get the rental car and then I taxied over to the east side of the field to Travel Express.  Back when I first got the Cessna, I rented it out at Dupage with Cougar Aviation. Travel Express was one of the other outfits on the field. They were much bigger and did charters using turbo prop and jets.  One of the instructors I used while getting my instrument rating is a check pilot there and he was kind enough to help me arrange to have the Velocity put in their big hangar.  That was a huge relief since it’s not exactly water tight yet, it’s freakin’ cold up there now and I haven’t even thought about dealing with pre-heat.

After a nice long weekend, we made the drive down to the airport from Barrington, loaded up the plane and were airborne just after 7am for the 2 hour flight. Ann had a meeting near Nashville at 11am so the plan was to get there with enough time to get the rental car, and drive to the location. I had called Lynn, my old A&P/IA and since he was going to be around that morning, I would taxi over to where he was on the east side of the field and we would go to lunch.

The original plan was to spend the night in Smyrna since Ann didn’t think she would be ready to leave until 3pm. I haven’t flown the Velocity at night yet so I didn’t want to deal with that issue just yet. but she called after Lynn and I got back from lunch and said if she got back by around 2pm, would be be able to get home tonight.  In the Velocity?  Heck yeah!  It’s a damn time machine!

So we lifted off from Smyrna, TN at 2:30pm and we were driving out of the airport at 4:30pm.

Total distance traveled: 2,000 nm
Total time enroute:  9.8 hours
Which works out to 204 MPH for the trip!

Now two of the three legs had tailwinds.  And one of those were epic tailwinds.

But still, not bad. Not bad at all.

I’m glad we did this trip when we did and before paint and interior. Because we discovered a couple things.

1) That my nose oil cooler NACA diverter doesn’t work… at all. The Chicago-Nashville trip was COLD!

2) We have to come up with some in flight storage solutions.

Experimental is the name of the game.

9.99 Fuel Imbalance

This entry is part 18 of 18 in the series 09 - Fuel System

One of the things that I’ve noticed on the cross-country flights I’ve made is that the right tank has been running lower than the left tank. Sometimes as much as 10 gallons.

Now in the Cessna, that type of behavior is almost always the result of a misaligned fuel vent for the tank.  But the Velocity doesn’t have fuel vents for each tank.  It has one vent for the entire fuel system.   The other thing that causes it is a bad seal or gasket on the fuel cap.  Since the top of the wing is in a low pressure area, any leaks at the fuel cap will cause the tank to depressurize slightly and draw fuel from the other tank.  The final possible cause of fuel imbalance is if the airplane flies with one wing low.

So I checked the level of the plane in flight.  Perfectly level.

Next, I taped over the fuel cap on the left tank. No change.

Then I started looking more closely at the symptom.  On the ground, the tanks are pretty equal. During the initial climb, they’re equal.  It’s not until I get to level cruise that they start to diverge.  So I graphed out the fuel tank levels with the airspeed. Sure enough, the faster I go, the greater the imbalance.  This is a huge finger pointing at a bad seal around the fuel cap. But I checked that by taping over the cap!

At this point I’m questioning my sanity.

So I started looking at the data again (this is where full flight and engine data monitoring comes in real handy).

Here’s the graph of a flight down to Sebastian and back.

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Notice the fuel levels are within a couple gallons of each other on the ground but as the airspeed increases, the levels diverge (the spikes where they level out is where I was slipping the plane to see if I could balance them out).

But then I noticed something. The left tank level is a relatively smooth line while the right tank level varies about 2 gallons (the sample rate is one second). So now I’m wondering why the left tank varies .1-.2 gallons per second while the right tank is changing 10 times as much.

I called the owner of the company that makes the fuel probes and controller module (who is also one of the owners of Grand Rapids). He said that the controller module averages the readings over about 5 seconds and transmits them engine monitor.  So there’s really no way that the readings should be changing that quickly. He sent me a replacement controller… Which meant that I had to calibrate it. :-(

After installing and calibrating, I made a test flight.  Fuel levels were never more than 2 gallons apart.  And the graph line looks just like the left tank.

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So I never had a fuel imbalance problem.  I had an instrumentation problem.

Oh well.

9.7 Fuel Shutoff Valves

This entry is part 17 of 18 in the series 09 - Fuel System

Back January of 2015 about 6 months before first flight, I picked up some gas valves from Home Depot and installed them between the strake tanks and the sump tank. I was a bit uncertain about the setup because… it just didn’t feel right.

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A couple of days after I put these in, I was talking with Scott at the builders center and he mentioned that someone had put in similar valves and that apparently they didn’t agree with avgas and began leaking.  He suggested checking and making sure the valves were compatible with liquid gas as well as gaseous gas.

I tried but couldn’t verify compatibility so I pulled them out.

Fast forward to Sun-n-Fun 2016.  Walking around the B&B Aircraft Supply tent I ran across these.

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They are used in a helicopter, spring loaded in the open position and really small. At $50 each, they aren’t cheap, but they are aviation grade so there’s no question they’ll standup to avgas.

Because the valve is spring loaded, all it takes is the slightest bump and the valve will spring open. So I got some aluminum C channel and make a safety lock to hold them closed.  There’s even a safety wire hole to make sure they stay in place.

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This week, I borrowed some fuel jugs and defueled enough gas to install the valves. Because the downstream end is a bulkhead fitting, it would have been nice to install them in the gear bulkhead, but it is way too thick for that. So I settled with having the B-nut fitting snugly in the hole in the bulkhead.

Here’s the right side fuel line with shutoff valve installed.

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6.3.2 Seat rails and hardpoints

This entry is part 42 of 42 in the series 06 - Fuselage

Back when I was preparing for the visit from the DAR to perform the airworthiness inspection, I discovered that getting into the back of the plane was a huge PITA. This was due to the fact that my wife and I both have rather long legs which requires the bottom of the seat rails be mounted a bit further back than normal and that the seat rails only have about 7″ of travel.

To resolve this, I tried a couple of different approaches:

  1. I checked a few auto salvage yards looking for seat rails that had more travel.  While I found a couple candidates that had more travel, it either wasn’t enough to be worth the trouble or they would be too tall (headroom is an issue as well).
  2. Go with a dual action seat mount.  If you’ve even gotten in an 80’s era Ford Bronco or Chevy Trailblazer, you know what I mean.  The seat slides forward and then it pivots at the front and the whole seat folds forward. But that would have raised the seat high enough that only a small child would fit in the front seat.

I eventually found an aftermarket seat rail that had 10″ of travel. The Sparco 00493.  I found them at a few different shops online.  Since it would be easiest to access the back of the plane from the passenger side, I decided to do this on the copilot seat only.

Once I had the seat rails, I had the old rails removed and the new ones welded on. Then I removed the old hardpoints and installed new ones. I also moved the seat just a bit more forward.

The end result was easier access to the back of the plane. Easier, but still not enough for my liking.  And… my wife found it more difficult to enter the front seat.  With the seat all the way back, she could barely get her legs in the plane.

Oh well, I’ll have to keep looking for a solution.

Which came from fellow builder Reiff Lorenz.  He came up with (what I call) quick release seat mounts.

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Instead of bolting the seat rail to the hardpoint in the floor, you attach four shouldered studs to the bottom of the seat rail.

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Then you place the seat on the new mounts, slide it forward and insert locking pins into the four mounts.

Once all the hardware arrived, I (once again) removed the existing hardpoints. Next I made new hardpoints with four tapped holes in each hardpoint. When it was time to locate the positions for the hardpoints, I checked the measurements so Ann would be able to get in and out of the front seat and then made the cutouts the the floor, epoxied the hardpoints in place and covered them with 2xBID.

Then I just had to cut open the holes for the drilled and tapped holes and screw down the new seat mounts. I decided to orient mine so that the seat is slid forward and the locking pins are placed behind the studs.  My logic is that there will be more force exerted in the forward direction than rearward. Although given the span of the locking pins, I doubt it makes much difference. Here you can see the new seat mounts screwed into the hardpoints.  And you can see where I had to patch where the old hardpoints were.

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Then for the moment of truth. The seat was in and secured in about 30 seconds!

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Here’s a closeup of the front, outboard mount with locking pin installed.

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After a couple of months with these, I decided that if I used these on the pilot seat as well, the seat behind me might actually be usable.  As it is now, even with my seat all the way forward, there is simply no way for a person to get to the back seat.

So I ordered another seat rail (did I mention they slide much easier than the factory seat rails?) and mounting blocks from Reiff. Once all that arrived, I had a new challenge. If I install these like I did for the copilot side, the seat would be about 1′ higher.  And I’ve got maybe 2″ of headroom.  And that’s with no interior installed.  So I was going to have to get creative.

I decided to embed the outboard hardpoints directly into the floor (same as the standard hardpoints). By doing it this way, I would only be raising the seat about a half inch.

The next challenge was how to cover the mounts. Unlike flat hardpoints, these have a “pedestal” the protrudes up. So what I did was to cover the flat sides with 4 layers of UNI. Two layers going straight, front to rear and two layers that angle inwards.  Then 2xBID over the whole thing.

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So now when it’s time to do any work in the back, I can have both seats out in about 60 seconds. :-)

To be honest, I’m thinking real hard about doing this with the rear seats as well. Up until now, the only time I’ve had the rear seats in is for the airworthiness inspection.  So it’s been relatively easy to do any work around the firewall. I can see how these would be really nice for maintenance or for those trips where I know there won’t be anyone riding back there and I want just a little extra room.

6.2.2 Safety Harness Replacement

This entry is part 41 of 42 in the series 06 - Fuselage

I got the hardpoints installed for the new safety harnesses.

The inertia reel is mounted directly below the Door Post Extension (DPE).  That’s the steel loop that the shoulder harness goes through. In addition to making sure the webbing exits the reel straight up to the DPE, the reel also has to be perfectly vertical front-to-rear and left-to-right. So when installing that hardpoint I had to make sure the face was plumb.

The hardpoint for the DPE was done by cutting a slot in the back of the carbon B-Pillar and inserting the 3/8″, drilled and tapped hardpoint and using structural adhesive to bond it in place.  Then I made a plug and covered the slot.

For the lapbelt hardpoints, I deviated from plans.  With the original harness, I placed the lap belt hardpoints according to plans. Which has the outboard hardpoint right below the rear corner of the door. I get the reason for this location.  1) The belt will be out of the door opening for accessing the rear seats and 2) it would allow the layups covering the hardpoint to be bonded to the carbon fiber B-Pillar which is very strong.

But I noticed an issue with that location. When the seat is moved forward to where you would have it during flight, the lap belt is more aft than down.  Now my pilot seat is very low. but I noticed that it’s not much better on the co-pilot seat.  In the TC aircraft that I’ve flown, the lap belts are anchored farther forward.  What this means is that while they would be effective stopping forward movement, they are almost completely ineffective stopping upward movement (like you would experience during turbulence).  Another issue is that it would allow submarining in the event of a forward stop.  Meaning that you could slide under the lap belt.  This is why they always tell you to place the lap belt “low and tight across your lap.”

Here’s a picture from about 5 years ago to illustrate the situation.

Before (red line is the path of the old lap belt)

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I did some reading and found there is an optimal angle for the lap belt. So I moved the hardpoints forward of the rear door pin. This will provide improved vertical and forward security.

After

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Finally, I had sleeves installed on the belt mounted against the keel which will hold the buckle up when no in use.  No more fishing around on the floor for the buckle.

Here’s the copilot side harness (seat is all the way back).

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6.2.2 Safety Harness Replacement

This entry is part 40 of 42 in the series 06 - Fuselage

One of the challenges/frustrations with building an airplane is that you sometimes have to make decisions about things that you don’t have all the information on.

With the safety harness, I deviated from plans in that I wanted a 4-point harness with inertia reels for the shoulder harness.  I made this decision because one or the first things I did when I got the Cessna 182-RG was to install these. They are great!  First, because the shoulder harness is on an inertia reel, you can lean forward to reach things that would otherwise be out of reach. Second, having two straps (one over each shoulder) provides much better restraint than the auto style one strap over the shoulder, diagonal harness.

So I started talking with Steve Pekrul and Seatbelt Planet and ended up with a really nice harness system for the front.

But in actual use, it’s not that nice. I mounted the retractor reels on the overhead beam behind the front seat. The webbing has to exit the reel at particular angle and everything lined up. But Because the top of the seatbacks are the proper height (they are actually above my head), the harness has to come over the headrest and then down to the shoulders. So it’s rubbing the back of your head the whole time. And because the point where the two shoulder straps meet is so close, the two straps are always rubbing on the side of your neck. I could have created a slot in the back of the seat and fed the strap through. But the seats are already covered. And it would have messed up the geometry of the strap leaving the reel.

So I decided to investigate the harness that Velocity uses. I found out that their 3-point harness is made by Beam’s which is who made mine. Then I got in touch with my friend Bob who has them in his twin to find out what his thoughts where. His report was mostly positive except that he said the inertia reels don’t always lock in turbulence and while it’s not a problem for the shoulder harness, it is for the lap belt. That isn’t a problem with the 4-point since the lap belts are manually adjusted.

Time for most investigating.

I called up Steve at Seatbelt Planet again. He remembered me because I guess he doesn’t get that many people buying safety harnesses for experimental aircraft. :-)

I explained what I was looking for is a 3-point harness that will reliably lock in turbulence.

It turns out that Seatbelt Planet was started by one of the people that started Beam’s.  And that they produce some of the components that Beam’s uses in their harnesses.

Steve made some suggestions.  Like using a manual lap belt and a retractor for the shoulder.  But that’s a bit of a kludge.  What we ended up settling on was something called the “Tri-Lock” retractor with a 3-point setup.  The Tri-Lock works like this: In normal mode, it uses an ELR (Emergency Locking Retractor) which locks when you pull too fast or if the mechanism senses an upset.  This is done by means of a small ball in the retractor that if it gets displaced the reel locks.  Because of this the retractor has to be mounted perfectly vertical.  It sounds like this will lock pretty reliably.

But the neat part is when you put it in ratchet mode.  When you pull the harness all the way out, it will retract, but not extend. So if you think there’s turbulence ahead, you can lock it down as tight as you want.

The downside is that if you want it back in ELR mode, you have to unbuckle it completely and let it retract all the way to the rest position. But that would only take one second at the most so I guess that once you’re through the turbulence, you can reset it.

Here’s a video that shows how it works.

Beam’s Tri-Lock

The harnesses came in a couple days ago so I’ll start working on getting the new hardpoints in once I’m done with my very first annual.

The other reason for the new harness is that Ann explained that the harness color that I bought didn’t go with the interior color palette that she is using. 😉

13.99 – Current Sensor Repair

This entry is part 64 of 66 in the series 13 - Electrical / Instruments

I’ve been getting some wonky current readings lately. Numbers that are just too low… sometimes. I knew the charging system was working, it was just the current reading from the EIS/EFIS.

Checked everything that I could think of but couldn’t find a culprit.

I called Grand Rapids and Eric had me check some things out. Everything checked.  Then he said “grab the wires at the sensor and give them a tug.”  Say what???  But I did it and they pulled free of the sensor with very little effort.

Turns out that GRT had a guy making these sensors and the way he would attach the wires to the pins was to lay the wire next to the pin, slide some heat shrink tubing over it and heat it up. They thought that they had tracked down all the sensors that were incorrectly assembled but it looks like mine slipped by.

They sent me two replacements but I thought that I could solder the wires on the primary alternator output easier than I could replace it so I gave it a go.

IMG_20160604_103000873

Fired up the engine and EIS/EFIS were showing good readings.  When I get some time,  I’ll swap out the sensor on the secondary alternator B lead.