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Going off reservation with changes,,,,,

grubbat

Well Known Member
Current and future builders,
One of the most distracting and sometimes paralyzing things a builder can do is go off reservation and make changes. Sad but true. It usually starts by reading something here on VAF or seeing something at Oshkosh and wanting to incorporate it into your build. Every change I have done during the course of my build has cost me time and sometimes money. At some point, you have to freeze the design and finish the dog-gone thing, at least that's what I've been telling myself. Guys like Horton and others come up with some of the best stuff but those great ideas have added years to my build (little exaggeration here if I may).

If you ever make the mistake by calling a fellow builder who is flying their creation, you will be sorry because they will provide so much hands on experience you will be remaking stuff before nightfall. At some point you will be presented with so many must do changes, it will cause temporary builders paralysis. I know, I've been there. I talked with a fellow RV yesterday and today I need therapy.

So, my advice is stay the course. No changes. None. Especially no structural changes because the designer owns the design. Want to install a tinted high dollar canopy? Nope. Want to change the wingtips to the new top secret RV-9 high speed high efficient mooney style tips? No way. Want to put oversize tires on your deal? Denied. Want to improve the fire rating of the firewall and floor design. Sorry. Want to improve the structure to provide more margins? Can't do it. Want bigger fuel tanks? Say it ain't so. Want a custom exterior color? Sure, any color as long as it's high visibility white. Want to use Silka? No way Hosea. Want titanium gear legs? No your not Trump. Want to put a RV-4 wing on an RV-6? Sorry, that's impossible (don't shoot me Smokey Ray). Want to put a 6-cyl on a -6? Time for therapy. An auto engine? Are you crazy??

I could go on and on but I hope you get the point. No changes. Simple and effective and the best use of your time. Thank you for your time and best wishes for your standard run of the mill RV build. You will thank me later.

Please excuse me while I attempt shoehorn this -14 horizontal on my rear of my -9. Shouldn't take that long..............

Cj
 
Well said

What about:

Park brake, crotch strap, pmags, fuel injection, smoke system, grove goodies, antisplat this n that, backup batt, dual alternators, IFR, multiple screens, multiple nav/coms, tie down rings, anodized parts, plenums, cam locks, lights, dimmers, fancy vents, fancy interiors, sunshades (ok those are necessary), lemo plugs, heated seats, rudder trims, pedal extensions, braided hoses, primer, engine primer, and on and on... :eek::eek::eek:

All adds time and cost. Maybe I'll get it right on the second one and just "keep it light" and simple
 
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Build the plane you want to build. Mine is 98% stock (so far) -- it does have some riblets and an Andair fuel system, and I think I substituted some -4 rivets where the plans called for some -3.5's...
 
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In all seriousness, it depends on your goals. My -6A has several things which are custom and that took longer, but it was worth the time then and I'd do the same mods again. Hidden oil door latch, custom composite instrument panel, custom wingtip lighting, and more.

If you want something custom, go for it! But do think twice before doing anything structural.
 
Old Pilots

Hi Craig,

Just a personal perspective (opinion):

I would agree that the “no mod” rule is an excellent guideline; particularly with regard to flying as soon as possible. I would also say that many RV builders have made excellent, safe (and safer) modifications to their RVs, but, yes, usually at the expense of building time. Like several others, I would agree that structural modifications should not be pursued as a rule. Also, aerodynamic modifications are extremely risky without professional analysis and testing.

On the other hand, that does not mean that RVs cannot be improved by careful, competent designers and builders who thoroughly analyze and test everything they are doing. Van successfully modified the Stits Playboy. Many of the people on this forum are capable of doing the same. Also, as a result of experimental aviation, there is a strong, mostly well-vetted, experimental aircraft service and modification supply business. Many of these businesses advertise here on VAF and are quite successful and well-appreciated.

From my perspective, I have seen many RV maintenance access, human factors, and systems modifications which make a lot of sense. I have pursued some of these modifications myself. This is, after all, experimental aviation. This is where general aviation progress is made; mostly for the good, but I would agree sometimes for the bad which is occasionally the price of any new endeavor. It’s a personal time and risk decision. We should feel fortunate that we, like the Wright Brothers and Van himself, have the freedom to design, build, and even modify our own airplanes (. . . while occasionally taking forever to do it!).

Now to your main point: I think you are absolutely right about the greatly increased building time associated with modifications. From my own experience, I would say there is no such thing as one modification. One modification seems to require somewhere between five and ten other related modifications to safely accommodate the original modification. In other words: Mods lead to more mods. Mods lead to more time. Mods lead to old pilots building old projects and, eventually, flying young airplanes!

Thanks For Your Post and Respectfully,
 
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I have a solution.

Cj, it sounds like you need to go and buy a Part 23 certified airplane. The FAA will ensure you don't even get to choose your paint color.
 
Nice note CJ. And all those roubles saved could be burned later. Life is short go fly! :D





I like wjb comment


3163433.jpg
 
My mods was the reason I didn't just go buy one already built! They were all time consuming and some were worth it and some were not. So far, I'm happy with most of them but have not used the parking brake much!:D
 
Guys like Horton and others come up with some of the best stuff but those great ideas have added years to my build (little exaggeration here if I may).

Don't blame me. I agree with you. That said....if you like to build, extra time doesn't matter very much.

You might be amused to hear that I had most of my current RV-8 together as a very stock airplane with a canopy kit...then business tanked in 2008. I couldn't take any cash out of my business for the final push, and I wasn't going to borrow any. So, I launched into things like firewall tests and the whole low drag cooling experiment, because I had plenty of time, and they didn't require much money.

Look Ma, a fully fitted stock cowl ;)

 
Don't blame me. I agree with you. That said....if you like to build, extra time doesn't matter very much.

You might be amused to hear that I had most of my current RV-8 together as a very stock airplane with a canopy kit...then business tanked in 2008. I couldn't take any cash out of my business for the final push, and I wasn't going to borrow any. So, I launched into things like firewall tests and the whole low drag cooling experiment, because I had plenty of time, and they didn't require much money.

Look Ma, a fully fitted stock cowl ;)


...and here we just thought you where obsessed. Your experimenting and research has prompted a lot of good discussions.
 
Sure it would have been done sooner if I hadn't made any of the mods along the way - but it would have been done even faster if I just wrote a check for one. The problem with that is that I wanted it MY WAY, and that meant building it with a few mods. Yes it takes more time, and more money, but if it's the only realistic option to get it the way you want it, and you can afford the dollars and hours, then that is the path you take.

In my case I have a 172 to fly while working on the 9A, so it wasn't like I was grounded until it was finished. YMMV.
 
Funny!

Cj,

That is funny, and so true. Yes mods and custom touches are nice and fun. But in the end, a RV Flys just about like all other RVs of the same - #
I have several different missions and had to solve the problem with extra airplanes.
My RV8 the Borrowed Horse, is pretty stock. There are several things I would like to change,,, but it is too much trouble to take the airplane and turn it back into a project.
If ???,?, If, I had that light weight battery on the firewall,,, I would have to move the Voltage regulator, drill out the floorboards, and move the starter solonid, and, and! I could get rid of that Gascolator, and install the filters I bought. But, BUT! Oh! I bought those Pulsar AEROLEDs ,,,,uho the foot print is a little different, I hate to have to repaint the wing tips..
It would not fly any different, just be down for a time.
Just get it flying,,, but do do the wheel pants ,, and finish all the fiberglass
There are some RV builders that have had three different panels. In their flying airplanes,,those folks are workers.!
 
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I am always the only IFR capable airplane at the IAC aerobatic competition events that I enter. Everyone else is day, VFR only. They won't even put a heat muff in some airplanes and they remove the portable GPS during competition to save weight. I wonder if my -8 would do better aerobatics if I removed the heater, the lights, the IFR panel, the custom paint, the autopilot, the parking break, the smoke system, the seat heaters...

When the contest gets shortened because of weather and they all sit and wait for a break in the weather to beat feet for home... I'm filed and on my way in the comfort of a heated cockpit, on autopilot busting through the weather, landing safe at home after dark.

Nope, I'm not ditching any of the extras. Except maybe the parking brake. I never have used that thing.
 
Ha! Great post, Cj!

I think there's a difference between making "design improvements" for the sake of improving an already great design, and making mods because you enjoy the challenge and creative process of crafting something different. The former will probably lead to frustration and extra money spent, but the latter can just be something fun to do (and perhaps also lead to frustration, but in a different way).
 
Different Strokes Dude!

For some of us, it's as much (or more) about the build as it is about the flying.

I do absolutely agree though, that mods cost time (sometimes lots of time) and usually money. Just need to have your eyes wide open about that.
 
Thank you for your time and best wishes for your standard run of the mill RV build. You will thank me later.
Cj

I understand what you are trying to convey. However here is the flip side, If Van never replaced the wings on his Stits aircraft, we would not be here. That was not per plans or design.

My take; build what I want, not what others say I should build.
 
I understand what you are trying to convey. However here is the flip side, If Van never replaced the wings on his Stits aircraft, we would not be here. That was not per plans or design.

My take; build what I want, not what others say I should build.

A big +1. Well said.

Charlie
 
I hear you on your comments.

I made some changes but nothing like you are thinking about. The end results were outstanding and I can't think of anything that I would different.
 
The OP must not be an engineer! :D

Figuring out a better mousetrap is part of the fun of building. I agree that sticking to the structural plans is a good idea, but there are still lots of places to improve that don't take much time to implement.

Now to figure out the best way to fix my cracked step...
 
I wanted to build an airplane because I wanted to know more about airplanes......and I could buy it 1 piece at a time. The building process is a Great learning process, it's also an exercise in patience and persistence.

Following the plans step by step is one of the best parts about building an RV and will yield a Great airplane. But even the plans taper off in the Finishing Kit stage and leave more to the builder to design and figure out on their own.

It is easy to get sidetracked with things, I have an awesome toolbox door in the baggage floor of my RV that took me 25 hours to build that I've never used and is covered by carpet.

I also made the decision to fly now and install radios later, it was more work in the long run but gave me a year of great flying after a 9 year project and allowed me to buy more pieces after saving for another year.

I couldn't be happier with the flexibility, education and recreation the experimental category gives me.
 
The beauty of this whole thing is that each person gets to decide what, and if, they make any mods when they build. I just wanted to point out the obvious... if people hadn't started dreaming, scheming, and making things a bit different, we'd never see any improvements. We'd all still be flying behind steam gauges (not that there's anything wrong with that!). If you want a simple, basic stock design, go for it. If you want all the stuff the OP mentioned and more, knock yourself out. This is experimental aviation, after all.

My own project has taken me a lot longer than I thought it would. But it's not so much because of the few mods I've done. Like Crabandy and Dan Horton and I'm sure many others, money became an issue. I was really hurt by the economy in 2008, and then the passing of my son. So I've had more time anyway, not of my choosing. But I'm going to get there. Soon now. And I'm thrilled with the few mods I've incorporated. It makes for a better airplane, and they didn't cost that much. So I'll keep my seat heaters, thank you, my short center console, the much-improved canopy latch for my tip-up, my Anti-splat nose wheel bearing mod, tapered pin, and especially, the SikaFlex job on my canopy. There ARE better ways of doing some things. Cheers, everyone! :)
 
One thing that you guys are missing is that you can modify the plane after it is flying. Yes there are some things that are easier to do as you build but a lot can be done in the off flying season. I can tell you that making a fast plane go faster through modifications is, to me, much more satisfying then the initial flight.
Build a basic VFR plane with a bare bones simple panel with a long term plan to add equipment as your flying skills and needs dictate. Modifications are fun; make it a goal to change or update something at each annual.
My current plane still has a mock primer camouflage paint scheme. It is so nice not to worry about expensive paint, to repair scratches with a spray bomb, to make airframe modifications with no worry about matching paint. I get more compliments from the tower regarding my paint scheme then I ever got with a shiny paint!
 
One thing that you guys are missing is that you can modify the plane after it is flying. Yes there are some things that are easier to do as you build but a lot can be done in the off flying season. I can tell you that making a fast plane go faster through modifications is, to me, much more satisfying then the initial flight.
Build a basic VFR plane with a bare bones simple panel with a long term plan to add equipment as your flying skills and needs dictate. Modifications are fun; make it a goal to change or update something at each annual.
My current plane still has a mock primer camouflage paint scheme. It is so nice not to worry about expensive paint, to repair scratches with a spray bomb, to make airframe modifications with no worry about matching paint. I get more compliments from the tower regarding my paint scheme then I ever got with a shiny paint!

Exactly! After 8 years I just needed to do what it too to get flying and cut out extras and plans deviations to push through the last year. I flew on one of the last days of my annual month of December (winter in Ks Bbbrrrrr) and started a 3 month annual and avionics install. This year I sent my prop in and used that as an excuse to work on the cooling system, I'm planning a trip in March so I best get cracking!
 
My second build was an HR-II, which is a highly modified RV-4. I then modified it with an F1 canopy and other parts including structural mods. Then I designed 8 custom avionics modules and custom interior bits.

Lucky for me I already had a flying 9a in the hangar so I could take my time... And it took a long time!
 
...
Nope, I'm not ditching any of the extras. Except maybe the parking brake. I never have used that thing.

You've never flown into Kernville, CA (L05) solo, have you? It's kind of embarrassing when you have call the waitress on Unicom and ask her to come out and chock your airplane while you get out, to prevent it from ending up in the weeds downhill from the ramp...


...Yes there are some things that are easier to do as you build but a lot can be done in the off flying season. ...

Flying has a season? I thought there might be when I moved to Michigan, but we had 10 inches of snow the Saturday before Thanksgiving, and by 9:30 Sunday morning our privately owned and maintained public-use airport was plowed and ready for use.
 
I see the OP as more of a warning to prospective builders or those who may not realize that ANY little modification adds time, usually much more that estimated. Some more than others. If you want to fly quickly, skip it.

As for me, I've made some mods here and there but as I'm closing in the finish line my current motto is GET IT IN THE AIR! No more improvements / changes / additions. I figure there's many things I can go back and tweak or change later if I want.

Some people love the challenge of customization and that's awesome! I'm just ready to fly this thing. :) Plus I've got my work cut out for me trying to repair some recently discovered mistakes made by the builder who started the project (post to follow shortly).

MK
 
My current plane still has a mock primer camouflage paint scheme. It is so nice not to worry about expensive paint, to repair scratches with a spray bomb, to make airframe modifications with no worry about matching paint. I get more compliments from the tower regarding my paint scheme then I ever got with a shiny paint!
My still-unpainted-after-3-years-of-flying plane would love to see a picture, Tom!
 
Flying has a season? I thought there might be when I moved to Michigan, but we had 10 inches of snow the Saturday before Thanksgiving, and by 9:30 Sunday morning our privately owned and maintained public-use airport was plowed and ready for use.

Yeah, but this Mississippian wouldn't have had the gonads to leave the house after weather cold enough and long enough for 10" of snow. That'd definitely not be flying season for me. Besides, isn't winter why there are a lot more scratch-built planes from above the Willie Dixon line?

Charlie
 
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