BAF - Things to Consider

My goal is to build a simple and reliable (ok, who doesn't want that in an airplane?) day and night VFR craft. With that in mind, my RV-9 will not be loaded down with unnecessary instruments and radios. Remember, the first and only aircraft I have ever owned was a 1941 T-Craft, BC12/65 with no electrical system. Just the thought of having a radio that doesn't require batteries seems odd to me.

Anyway, when building the wing Van's tells you to drill in the spar web to accommodate their pitot tube, if you plan on using a heated pitot tube or one from Dynon, do NOT drill this hole as you will only have to fill it in later.

December 9, 2004

F Bucking bars are one of the simplest, yet most import tools you will collect. The tool on the left is a standard bucking bar that I'm sure every builder of metal airplanes has. The two bucking bars on the right were given to me by a neighbor who is a maintenance director for one of the major airlines. They are made from tungsten and weigh almost as much as the bigger, cast iron bar. 1 lb, 13 oz for the cast iron bar and 1 lb, 3 oz for the rectangular tungsten bar. The smaller bars are so much more convent than the bigger cast iron bars and fit in small places. I sure wish I had a set of these when I started on the Horizontal Stabilizer!

I highly recommend you get a set of these, if you are going to do any type of riveting! Unfortunately, I have been unable to find a source for tungsten bar stock so I can't help you locate a bar or two.

Riveting (Added 4/2/08)

I usually don't like to link to other web sites as links change and/or go away but if you haven't checked out Dan Checkoway's web site, www.rvproject.com, you must do so. On his site he has an entire page dedicated to riveting. This should be required reading prior picking up a rivet gun. The following is a shameless cut and paste job from that page and is posted here for quick reference:

Suggested Operating Pressures

As I mentioned, I use different operating air pressures at the rivet gun for various different sizes of rivets and material. I put this table of information together based on my experience. Keep in mind that I use an Avery 3X rivet gun, and that your results may vary (some builders opt for a 2X gun, which may behave very differently). Also, you can vary the duration of driving the rivet to compensate for pressure in many cases. For example, instead of cranking the psi up, you can drive the rivet for a longer period of time. Anyway, here are the "baseline" settings I use for reference:

AN426 Rivets:

Rivet Type	Air Pressure	Duration
AN426AD3-3 to 3-4	34 psi	1 second
AN426AD3-4.5 to 3-5	37 psi	1 ½ seconds
AN426AD3-6 plus	40 psi	1 ½ seconds
AN426AD4-4 to 4-5	45 psi	1 second
AN426AD4-6 to 4-9	50 psi	1 ½ to 2 seconds

AN470 Rivets:

Rivet Type	Air Pressure	Duration
AN470AD4-4 to 4-5	60 psi	1 second
AN470AD4-6 to 4-7	60 psi	1 ½ seconds
AN470AD4-8 to 4-9	75 psi	1 ½ seconds
AN470AD4-9 plus	80 psi	1 ½ to 2 seconds

Prop it up! (updated 8/2/05)

What prop should I use? Metal, wood, composite, or a combination? Two or three blades? All of these questions need to be answered by the builder, in this case, me. Each type of blade construction have both benefits and drawbacks. I like flying with wood props because they transmit less vibration to the airframe but they require more maintenance than metal props. Mostly they have to be re-torqued every so often. This isn't a big deal but is something you need to be aware of. Some people like wood props because in the event of a prop strike, you won't be rebuilding your engine. Metal props are good in the rain, don't need to be re-torqued, are usually more efficient at turning engine power/fuel/noise into thrust. There are more reasons to select one type of prop over another, if you want to know more, a Google search will give you more info than you can digest, along with a lot of folklore. Since my -9 will be powered by an O-290, I won't even go into a diatribe regarding constant speed props.

I managed to get in touch with gentleman from Canada who completed an O-290 powered RV-9A. He was flying with a 70" by 70" Colin Walker wood prop and was turning 155 mph indicated / 170 mph true. He spoke very highly of the engine/prop/airframe combination and was surprised more -9/-9A builders weren't considering that option in the US and Canada. (Apparently that is the engine of choice in Europe.)

Originally I thought I would use a Colin Walker prop but I couldn't locate him and heard a rumor he is no longer making props. If this is not true, please email me. After doing some research, talking to people and seeing one or two in person I have decided to have a Catto prop custom made for my -9. Craig Catto believes a 68" diameter by 66" pitch two bladed prop will get me to that magic 175 mph cruise speed without giving up too much climb performance. I can deal with 175 mph from a 135 hp engine and its resulting fuel burn.

December 19, 2004 - Work Space

Think about your workshop before you start. Van's mentions this on his web site, take it to heart. I started on my -9 in my basement workshop. It was good as a shop goes, dry and roomy. I went through the trouble of ringing the shop with electrical outlets, with every other one on a different circuit so I wouldn't have to worry about blowing a fuse then I hung up a bunch of shop lights and still wish I had put more and need to move some of the ones I installed to eliminate the shadows cast on some of my bench tools. Maybe someday I'll get to that last task.

After spending a year and a half working in the basement without any insulation and the only environmental control being an over worked dehumidifier I finally decided to insulate the place. Where I live in NC, it can be below freezing in the winter and in the upper 90's with the humidity in the upper 90's during the summer. Not really conducive to spending a lot of time there. Having grown up in Mid-Michigan, the cold didn't bother me at all but the heat and humidity was unbearable. My wonderful wife and part time bucking partner grew up in Texas and Oklahoma and just doesn't deal well with the cold so I knew if I was going to get her in the basement for year two I need to insulate the place so my space heaters would have a chance to keep her fingers working.

My house was built on a hill so 1/2 the basement walls were cinder block and the other half is 2x4 construction with the studs being on 12" centers because they had support a two story house. This meant that I had to buy 24" wide R-13 fiberglass insulation and cut each baton to fit and then drywall. Not a difficult task (two days to complete and yes, I have hung drywall before, so there was no learning curve for me.) but one that required moving tools, equipment, and airplane parts. I highly recommend taking care to make your shop comfortable before you start. Heck, I found that when my shop radio died, I didn't spend as much time working down there so I replaced the home stereo and moved the old one down to the basement, now both the wife and I are happy.

Oh, the results of the newly insulated basement, Nora will come downstairs, pull up a book and read while I chip away on the -9. Best of all, she is right there, if I need her to hold anything or buck a rivet. What a woman!

Riveting Help

At some time you are going to need help driving rivets and your usual riveting partner won't be available. I had always thought it was more difficult to teach someone to drive rivets than to buck them. BOY was I ever wrong. It has been my experience that the person with the bucking bar is more important than the person with the gun. I teach each new rivet driver to put the rivet in, put a small piece of tape over it, place the gun on the rivet, hold the rivet set in place with their free hand so it doesn't move then gently squeeze the trigger.

Trying to teach someone to keep a bucking bar on a rivet without pushing the rivet out while holding the bucking bar in the correct place has prove to be rather difficult.

That is my $.02 on the subject, others might have had different experiences.

January 4, 2005 - Wing Jig

E I received an email asking how I managed to keep the vertical posts in alignment while I worked on the wings. This picture shows my solution. The bracket was screwed on to the bottom of my vertical 2x4 posts.

When screwing the posts together, I checked the end grain and made sure they were back to back, that way the post wouldn't warp. The end of the 2x4's should look something like this [)))][(((]. The fear of the posts warping was also the reason I didn't use a 4x4 as specified by the instructions. Initially I was going to use two "feet" on each post but after installing one and lowering the foot, the posts wouldn't move, even after someone ran into them. (I'm so happy to have those things out of the middle of my basement!)

After installing the posts and making sure they were perfectly vertical the next trick is to get the horizontal arms at exactly the same height. I accomplished this by using a long section of clear vinyl tubing about the size of a garden hose. I filled the tubing with water and worked all the bubbles out. I then duck taped one end of the hose to each vertical post. The water will seek it's own height and when it did, I measured up (or was it down?) from that "head" and marked where the horizontal arms should go. It then was a simple task to attach the arms using a standard carpenter's level to make sure they were "square".

January 23, 2005 - Drawing Table

Last weekend I was paid a visit by one of EAA 309's Technical Counselors. If you have one available to you, take advantage of his or her expertise. It is well worth it, more so when the FAA DAR asks to see the TC forms and you have to explain that you don't have any.

F When building, you will need a place to put all those wonderful drawings. The TC told me he hung his drawings on the wall around his shop. That way he could look at more than one of them at a time. I built this drafting table to hold mine but whatever you do, you will need someplace to hold them for viewing. You can find the plans for the table on John Petersen's site: http://www.petersenart.com/drafting_table/.

E Ok, you've decided to build an aluminum airplane. You've searched the net on corrosion protection and are wondering what other people are doing. I do not guarantee that my method is the best. I believe the best is epoxy priming but I'm lazy and cleaning the spray gun every time I prim a part sounds like a pain. What I did was alumniprep'ed, alodined, then finally sprayed the parts with cans of Self Etching Primer. It seems to work but check back with me in 20 years and I'll tell you how it is holding up. To make life easier on my index finger, I bought the pistol grip you see in the picture from Home Depot.

January 29, 2005 - Marking Edge Distances

F This evening while fitting the four "J" cannel to the aft fuselage I realized I had to mark a line down the length of each "J" cannel. Now you have to mark these "J" cannels for the wing as well and Avery's sells a neat little tool to hold a Sharpie but I'm too cheap to spend the money on their tool an besides, I wanted to mark the cannels this evening and not wait for the order to arrive. Looking around the shop for a chunk of wood that I could cut and drill I noticed these funny little straps with a small flange bent up on one end in my scrap bucket and a light bulb light up over my head. I can take one of those, measure in the appropriate distance, drill a hole for the tip of a sharpie and then bend the thing up to hold the other end in place. This picture is what I made and it works great. You don't have to bend the flange at a funny angle like mine. As I said earlier, this strap came out of my junk pile and I can't even remember what it came from. Why didn't I think of this earlier?

February 20, 2005 - Builder's Log Book

E Log books are such a pain to maintain and I'm such a bad writer that I thought I would put my computer skills to use for maintaining my log book.

E Excel is such a great tool! Here is what my log pages look like. Excel even has a "Hyper Link" feature that lets you link a cell to a picture. While looking at my log in Excel I can click on the link and the picture will pop up.

E There is a tab on the worksheet that will produce the HTML code to print and label the pictures for my builders log once you copy and paste the code to a text editor and open it in your web browser.

This is a sample of the spreadsheet I created. If you are going to use this, you will need to modify it to match the directory structure on your computer. Please don't call or email me with Excel questions. I am very good with this tool but trying to walk someone through a computer issue via email is a challenge.

Here is a sample of the HTML code I used to print the images. Save the file on your drive and open it using the text editor. You will need to leave the header section in place and paste the picture producing text (first three columns from the "Image Printing" tab on the spreadsheet) in to it, save the thing, and then open it IE or whatever web browser you are using.

February 24, 2005 - Dimpling Tables

Before you start using a C-Frame tool to dimple your skins you will want to build something to hold the skins level with the flat part of your dimple dies. Without this you run the risk of damaging the skins if they are not perpendicular to the center of the die.

F This was my first attempt at a solution. Needless to say, it didn't work out very well and was a real pain when working with the bigger skins. Someone suggested I use two tables, one on either side of the C-Frame. I sure wish I could remember who suggested that as I would like to thank him.

F The tables I built use particleboard and some 2x4's I had laying around. The 2x4's had to be ripped lengthwise so the tables would be at the correct height. One of the advantages to this setup is you can push the tables off the edge of your work surface so you can get to those pesky HS skins

F Another advantage is you can slide the C-Frame back and forth while the skin remains in one place. My preferred method is to put the male die on top and hold it in place while I hit it with a hammer.

F Here is what happens if you don't hold the die in the hole and the skin moves just before the hammer falls. This skin was replaced. Don't get discouraged, I figure when the weight of my ruined parts equals 1/4 the empty weight of the airplane I'll be ready for the first flight.

April 10, 2005 - Clamps

E Every project, be it a boat, plane, car, or drafting table requires the use of some type of clamp.

I have a number of different size C clamps, bar clamps, cleco clamps, Vise-grip clamps, and Duct Tape. Yes, you read that correctly, Duct Tape. When using C clamps protect the aluminum with either pieces of wood or duct tape.

There have been a number of times when something needed to be held in place and my arms just weren't long enough to hold it in place and there was nothing to clamp it to. The trick it to line up the part correctly and then hold it in place with Duct Tape. Since the tape can't hold the part very tightly I usually just mark it with spinning drill bit, remove the part and finish drilling it on the bench then reinstall it using clecos.

Don't forget you can make your own clamp with some scrap wood and sheet rock screws. I can't tell you how many parts I have held in place using this method.

April 14, 2005 - Drilling Control Push Tubes

F At some point you are going to need to drill rivet holes in push tubes used to active the ailerons and elevators. I drilled my first set by hand and although they are airworthy I just don't like the way they came out. This is a sample I drilled using the drill guide. Notice how nicely spaced the holes are.

F This picture illustrates how to get good results with the Drill Rite drill guide. I clamped the tube in a "V" block then set the edge distance to the hole using a cleco clamp. (Note, the cleco clamp is not clamping the tube in place.) The Drill Rite is clamped on the tube using the wing nuts provided and the holes are drilled with a hand drill. It can't get much easier than that!

The Drill Rite arrived but did not include a bushing for 1/8" drill bits. A short call to the Eastern Technology Corporation in East Hartford, CT had one in my mail box in less than a week. The owner of the company helped a friend build an RV-4 a few years ago and is well aware of the tool market for homebuilder's and was more than willing to help me out. In fact, it sounds like the jig may start shipping with the 1/8" drill bushing just for us RV builders.

US Industrial Tool Company sells the guide for $48 and they are listed under "Precision Drill Guide", part number TP974.

April 17, 2005 - Removing plastic from large pieces

E It took me awhile to figure out how to get the plastic off some of the larger skins. The best method I have found is to roll it up on section of 1.5 - 2" diameter PVC pipe.

May 30, 2005 - Long reach dimpling tool

F Dummy me forgot to drill and dimple the holes in the aft side skins where the rudder cable sheathing is held in place before I riveted it all together. The solution was to take some aluminum angle and make a long reach dimple press. I will use a clamp or similar tool to squeeze the thing together. Note the through depth. This will reach over the "J" stringers and in a trial fit, looks like it will work out fine.

July 15, 2005 - Knee/back/head pad

E This tip didn't even dawn on me until I went over to help out a friend with his RV-9A. He had a problem at an airport other than his home base so we both packed up the tools we thought we would need and in doing so I grabbed an old foam backpacker's mattress that I have been using in my shop. Probably the best one going is the Z-Rest from Therm-a-Rest. They cost $34.95 from CAMPMOR. I like this one because you can fold it up to fit the area you are working in, such as the cockpit.

It is much easier the knees to kneel on one of these than to kneel on concrete or aluminum.

July 15, 2005 - Long reach scribe

Ok, if I didn't make so many darn mistakes I would be flying by now. Then again, making mistakes allows me the freedom to figure out creative solutions. This time I didn't drill the main spar flange side caps earlier and I had drilled one hole in the flange to hold the forward end of the armrest in place. The problem I now had was how do I match drill the hole from the outside of the cap and into the existing hole without elongating it? Worse yet, the hole was about a foot down the inside of the spar flange cap.

F What I did was take a long piece of scrap aluminum and bend a flange along its length to give it some strength. Of course it had to be thin enough to fit down the hole created when you put the spar cap on. I then pulled the tip off of a Sharpie and drilled a hole the size of the base of the Sharpie tip in one end of my newly flanged scrap aluminum strip.

F The tip was then placed in the aluminum strip and taped in place so it wouldn't fall out. The next thing to do was reach down the spar flange with the "new tool" and mark the hole on the spar flange cap from the inside. Once I removed the cap the hole was clearly marked and was easy to drill.

July 17, 2005 - Aircraft Grade Pooper Scooper

Well, it is aircraft grade when you considered I used my newly acquired metal fabricating skills to make it. The first picture is the stock scooper. A good unit and one you can operate single handed, which is a bonus when you are using your other hand to hold back 51 lbs of Torque AKA the poop producing Bull Dog puppy and need to fling the freshly scooped poop into the woods.

E Here is the stock unit with the jaws held open, an action shot, if you will. Not a bad design but the plastic tends to break. One scoop lasted 10 months and its replacement lasted one day. Thus the need for the modification.

E A quick trip to the Aviation section at Home Depot turned up some U-channel pooper grade aluminum stock and pop rivets. The rest, as they say, is history.

July 30, 2005 - Roll Around Fuselage Stand

With the fuselage sitting up on sawhorses it was a bit too high to work on comfortably. Since I hadn't drilled the firewall for the engine mount it wasn't possible to attach rotisserie type engine stand yet and I wanted to be able to climb in the fuselage as I worked, be able to move the thing around the shop, and raise and lower the tail as needed to level the thing. The following three pictures are what I came up with.

F This picture if of the "table". It was made of some scrap 3/4" plywood and 2x4's I had laying around. The long horizontal 2x4's are from the wing jig and run back to the tail cradle. The entire thing is on wheels so it can be moved around the shop as needed.

F Because I'm lazy and figured I would never get the tail to sit at the correct height I bought a 2" ratcheting tie down strap to raise and lower the tail.

F To keep the hooks from pulling out of the simple little brackets I made for them I took a strip of aluminum and screwed it through the hook eyelet. Note the bracing used to keep the cradle from moving inward and forward. It does move around a bit but I don't have to worry about it falling like I did when it was supported by two sawhorses.

F A fellow builder asked for the dimensions of the stand and since I just put the -9 on its gear taking a 1/2 decent picture of it was easy enough to do. The height of the table does not include the full castering wheels. The black and white stuff on the table are rubber tool box liner to keep from scratching the skins. If you go this route, get some rubber furniture cups to put under the wheels to keep it from rolling around your shop.

September 25, 2005 - How to accurately measure the tail and wings

While fitting the horizontal stabilizer you will need to measure from a common point on both tips to a common point on the fuselage. Using a string seams like the natural choice but that can and will stretch. I have heard of people using safety wire, which sounds good but there is a better way.

Drill a #40 hole in the center of your tape measure at the 3" mark. Cleco the tap measure to a hole in the HS and then measure to a common point on the fuselage. This works better than the string method because you can pull the tape tight to get an accurate measure.

September 25, 2005 - Fuel Valves

F The valve on the left is from Van's, the valve on the right is from Andair. It is obvious that quality of the Andair valve exceeds that of the one Van's includes with the kit. Originally I had planed on using the Van's valve as the other is rather expensive. Then I spoke to gentleman who had built two RV's and out of the blue he asked me which valve I was using. His experience with the Van's valve was enough to convince me to buy the Andair unit. His comments were along the lines of, "The Van's valve will fail after 100 hours. You can replace it with another Van's valve every 100 hours or re-plumb your plane to accept the Andiar valve, which is a task on a completed plane." He strongly encouraged me to buy and install the Andair valve now, while my RV was under construction. When I returned home I pulled the Van's valve out of the bag, looked at it, played with it, and then ordered the Andair.

October 9, 2005 - Reamers

There are a good number of parts that receive AN3 & AN4 bolts. Some of these parts are pre drilled and some are not. The problem with using a drill bit to size a hole is that they will give you a triangular hole which is not very good if the bolt you are going to put through it is critical. One way to solve this problem is to drill the hole undersized and then use a reamer to enlarge to the proper size. One thing to consider is that reamers will not straighten a crooked hole, they will only size it properly while following the existing hole.

The three reamer sizes I have used to date are 1/4", 5/16", & 9/16". If I find I need another size, I will update this page.

January 10, 2006 - Serial Numbers

Throughout the building of your aircraft you will install a number of items that have serial numbers. I strongly suggest you create a spreadsheet to track all of these. It would be a major pain in the butt to have to pull an instrument out of your panel to check a serial number IF an AD is issued against them only to find out your instrument was not included in the AD.

March 26, 2006 - Instrument Wire Runs

A fellow RV builder recommended installing plate nuts (K1000-8) on the bottom of the ribs that support the instrument panel. These will facilitate using Adel clamps to hold wires running back and forth behind the panel and forward to the fire wall. Each rib has five plate nuts. The first is one inch behind the instrument panel, the second is one inch in front of the sub panel, the third is one inch behind the sub panel, the fourth is six inches further forward, and the fourth is one inch aft of the fire wall which also works out to be six inches forward of the fourth plate nut. This may be over kill but it will sure make installing all of those wires easier.

April 22, 2006 - Van's Toolbox

On April 22nd. EAA 309 held a workshop for prospective builders. Although the class was not centered on building RV's, Van's was kind enough to contribute a number of their pre-punched toolbox kits for us to use. After the class was over, Bill Wilson figured out how Van's determined the size of the box.

June 15, 2006 - Drilling out flush and Pop Rivets

My steps for drilling out flush rivets.

1. Center punch the rivet. There should be a dimple there but not always. Besides, it doesn't hurt to make the dimple bigger.

2. Start drilling.

3. Remove the drill and look at the hole, if it is off center, "push" it over with the drill.

4. Once the hole is about as deep as the dimple, take an old drill bit of the same size, turn it around and put the shaft in the hole. Bend the drill bit over and the rivet head should pop off. Hint, use an old drill bit because you can bend #40 bit very easily. (Same goes for setting the drill down, be careful not to set it down bit first. If you do, you will bend the bit.)

5. Drill the remainder of the rivet out.

By the time you get to the fuselage you should be able to drill out an entire wing panel w/o buggering up any holes.

Pop or Pull rivets:

1. Find a nail the size of the hole in the rivet.

2. Grind off the point.

3. Put the modified nail in the hole and hit it lightly with a hammer. (This will drive out the "pin". If you don’t drive the “pin” out the drill bit will wonder off center when it hits it as it is harder than the aluminum rivet.)

4. Drill out the rivet using the appropriate drill bit. (If the rivet starts to spin, try a little JB weld on it to keep it from moving. Just a little, because you will have to remove the rivet head later.)

August 18, 2006 - POH & Condition Inspection

Note: These documents are a DRAFT. At the time I made them available my RV-9 had not been weighed, thus you will note some discrepancies in the W&B section. If you elect to use these documents, edit them to match the numbers for your airframe.

E Before your first flight you will be required to write up a POH (Pilot Operating Handbook). Here is a DRAFT of the POH I have assembled from various sources. This document is based on the RV-9 I am building and no other aircraft. All the numbers are in MPH, not knots. I would like to thank the person who came up with the original format but I do not know who that is.

E A year after the first flight a condition inspection (AKA Annual) must be performed on your airplane. The attached document is a DRAFT of the items that will be checked during the inspection of N941WR. The attached list is specific to this aircraft and the equipment installed, ignition system, etc. and no other.

October 14, 2006 - Installing Adel Clamps

F If you haven't installed an Adel clamp, you are in for one of the home builder's greatest challenges. That is, unless you follow this simple little tip. I discovered this in a moment of brilliance. I suspect others are doing this but I had never heard of it before and it worked out great. Use some safety wire to draw the Adel clamp closed, making it a snap to install the bolt, washer and nut. Just remember to remove the wire before tightening the nut.

I sure wish I had thought of this sooner.

January 16, 2009 - Inexpensive Engine Pre-Heater

E It came time for me to create a simple and cheap engine pre-heater. While this isn't an original idea, I just simply worked with the items I had laying around. An inexpensive ceramic heater ($21) from Wal-Mart, some scrap aluminum (In this case it was a damaged elevator skin left over from my initial build.), and a dryer vent hose ($10 ) from the aviation isle at Lowe's.

After removing the screen from the heater, it was used as a template to trace out the shape, including the tabs on the scrap aluminum. That piece was then cut to fit the opening in the heater. A four inch circle was cut out, including tabs to attach the dryer hose. To secure everything, aluminum heat duct tape will be used.

It can't much simpler than that.

January 22, 2009 - Firewall mounted oil cooler

F The night before we were scheduled to depart for SnF 08 a friend was struggling with high oil temps. After doing much research he felt the solution was to install a 4" SCAT tube from the baffle down to the oil cooler. He had purchased a 4" flange which he was going to rivet to the baffle, after enlarging the hole but the big question was, "How are we going to attach that hose to the oil cooler?" The solution was simple, fiberglass, clay, and Styrofoam. Two rectangular pieces of blue Dow Styrofoam were cut to match the oil cooler, which was bolted to the firewall. Clay was then used to form the transition from the Styrofoam to the hose. As the clay was built up and around the engine mount, the 4" flange, which was not yet riveted in place, was pressed into the clay and the inside filled with even more clay. Any clay on the outside of the flange was removed and the transition was smoothed over. (This was done to form a perfect 4" circle for the SCAT tubing.) Once it looked like everything would fit, the clay and Styrofoam mold was taken home and three layers of fiberglass was laid over it. The next morning it was put in place and the angle aluminum braces were match drilled to it and riveted in place using pull-rivets. The hole in the baffle was enlarge, the 4" flange riveted in place, and the SCAT tube installed. Problem solved.

June 18, 2009 - Ratchet Strap Tie Downs

E A discussion on the VAF Forums raised a concern I have always had regarding the use of ratchet straps as tie downs. The issue I had was that to keep the hooks in place, you really need to ratchet the plane down to the ground. Even then, a good wind might bounce it enough to take the hooks off the tie down ring. Two seconds with a hacksaw had the hooks removed and a carabiner in its place. Note in the picture I have a both a Petzl climber's beaner and a cheap gear beaner. Use climber carabiners, not the cheap ones you can buy at any hardware store. The cheap ones I have are good for 150 lbs, which is better than the 40 lbs I usually see them stamped with. The Petzel is rated at 24 kilonewtons with the wheel closed. More than strong enough to hold my plane in place.