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RV-8 fastback retrofit

Jeff,
Got your PM- not able to upload photos in mail, so attached here. How I was able to cure fiberglass in the hanger during the winter.
Sam
 

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Well, there are RV's on floats and with retractable gear and radial engines. Retrofitting a Fastback onto a flying -8 isn't the craziest mod out there. I'm building an -8 with the Showplanes Fastback mod and I have no regrets. It's not really hard. Instead of wrestling with the steel frame for a slider canopy, you wrestle with assembling and bonding a fiberglass canopy frame. The canopy rails will have to be altered to go from slide to tip over. Obviously the aft turtledeck changes and the leading edge of the VS gets cut away to mate that new profile. That will require new fairings back there. If you want to get into instrument panel mods, you can do away with those fixed side panels and have a removable panel that goes canopy rail to canopy rail. Kinda cool.

What's the impetus?
 
Needed to be removed: turtle deck skin all the way to the tail, the upper section of all three turtle deck bulkheads, modifying the bottom of your vertical stabilizer and tail intersection fairing, removing your installed canopy side rails, windshield and windshield roll bar, boot cowl skin that intersects with the new tip over canopy and and front glareshield. Then you’ll need to install all the parts you just removed with the new replacements parts, including welding the new roll over bar to your existing front seatback support. That’s all before starting the fiberglass parts for the fastback canopy.
Don‘t get me wrong, I love the Showplanes Fastback mod - I built one, and it’s beautiful. But I built it as an original part of my RV8 build. I think retrofitting the Showplanes mod on an existing flying RV8 will be at least twice as much work, and require very good attention to detail to make it all fit right. Anything is doable, but make sure you know what you are getting yourself in to.
 
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Things come off the airplane amazingly quickly - checking my photos, in three days everything was removed and prep'd: turtle deck, bulkhead tops, canopy deck, windscreen, rollbar, top forward fuselage skin cut. After that it's like installing a showplanes fastback during the original build. My painter told me it was the nicest fiberglass finishing he'd ever seen. The best reason to not do it is: you won't be flying for a year. Unless you really want a fastback, there is no good reason to do it. Also be really sure of your skills and determination, there is no going back, only forward.
 
I think this would be a big undertaking, but if you do decide to go ahead with this, I would love to know the "before" vs "after" aircraft weight.
 
The thought of retrofitting a fastback mod to a flying RV-8 came from a couple different angles during some hangar talk. Maybe it's education and recreation. Maybe it's a badly cracked slider aft canopy section that needs much work anyway. Maybe somebody just always wanted a fastback.

In any case, while thinking through this, I considered the idea of going the fastback slider configuration and leaving the existing windscreen/rollbar/boot cowl/fairing in place, and integrate only the back half of the fastback mod, aka Tom Clark's slider fastback.

My search yielded no good results so I posted the question here. Coincidentally, I stumbled upon a slider fastback at Sun n Fun (an initial build however). The builder has done a superb job building and the look is right. Great looking lines and appealing to the eye in the side view. There was a good number of stock kit parts in the build, both "stock" from Van's and "stock" from ShowPlanes. I was surprised at how much of the standard canopy frame was used.

So the discussion was really about getting the fastback mod onto a flying airplane in the least painful way. Thus far it appears uncharted territory.
 
clam said:
The thought of retrofitting a fastback mod to a flying RV-8 came from a couple different angles during some hangar talk. Maybe it's education and recreation. Maybe it's a badly cracked slider aft canopy section that needs much work anyway. Maybe somebody just always wanted a fastback.

In any case, while thinking through this, I considered the idea of going the fastback slider configuration and leaving the existing windscreen/rollbar/boot cowl/fairing in place, and integrate only the back half of the fastback mod, aka Tom Clark's slider fastback.

My search yielded no good results so I posted the question here. Coincidentally, I stumbled upon a slider fastback at Sun n Fun (an initial build however). The builder has done a superb job building and the look is right. Great looking lines and appealing to the eye in the side view. There was a good number of stock kit parts in the build, both "stock" from Van's and "stock" from ShowPlanes. I was surprised at how much of the standard canopy frame was used.

So the discussion was really about getting the fastback mod onto a flying airplane in the least painful way. Thus far it appears uncharted territory.
Click to expand...
 
clam said:
The thought of retrofitting a fastback mod to a flying RV-8 came from a couple different angles during some hangar talk. Maybe it's education and recreation. Maybe it's a badly cracked slider aft canopy section that needs much work anyway. Maybe somebody just always wanted a fastback.

In any case, while thinking through this, I considered the idea of going the fastback slider configuration and leaving the existing windscreen/rollbar/boot cowl/fairing in place, and integrate only the back half of the fastback mod, aka Tom Clark's slider fastback.

My search yielded no good results so I posted the question here. Coincidentally, I stumbled upon a slider fastback at Sun n Fun (an initial build however). The builder has done a superb job building and the look is right. Great looking lines and appealing to the eye in the side view. There was a good number of stock kit parts in the build, both "stock" from Van's and "stock" from ShowPlanes. I was surprised at how much of the standard canopy frame was used.

So the discussion was really about getting the fastback mod onto a flying airplane in the least painful way. Thus far it appears uncharted territory.
Click to expand...
My question is..... How much aircraft sheet metal work experience do you have? If you no or little experience, this mod would probably be way over your head. I say this, because unless you know what you are doing, once you remove that turtle-deck, you can introduce all sorts of errors if the mod is not done correctly. To my mind, you would probably need to build a fuselage jig and install the plane in it prior to removing the turtle-deck skin. Otherwise, you may very well end up with a fuselage which is no longer straight. The mod can be done, but NOT by a rookie.
 
chaskuss said:
My question is..... How much aircraft sheet metal work experience do you have? If you no or little experience, this mod would probably be way over your head. I say this, because unless you know what you are doing, once you remove that turtle-deck, you can introduce all sorts of errors if the mod is not done correctly. To my mind, you would probably need to build a fuselage jig and install the plane in it prior to removing the turtle-deck skin. Otherwise, you may very well end up with a fuselage which is no longer straight. The mod can be done, but NOT by a rookie.
Click to expand...
Lots of maybe’s and probably’s in there. My original question remains. Since you asked, I built my airplane. You state “the mod can be done” … so tell us how.
 
chaskuss said:
My question is..... How much aircraft sheet metal work experience do you have? If you no or little experience, this mod would probably be way over your head. I say this, because unless you know what you are doing, once you remove that turtle-deck, you can introduce all sorts of errors if the mod is not done correctly. To my mind, you would probably need to build a fuselage jig and install the plane in it prior to removing the turtle-deck skin. Otherwise, you may very well end up with a fuselage which is no longer straight. The mod can be done, but NOT by a rookie.
Click to expand...
Fuselage jig? I didn’t need a fuselage jig when I built my fastback. Did you use one when you built your fastback?

The fuselage is very sturdy without the turtle deck and canopy installed. I would remove the wings for a fastback retro fit just so it’s easier to move around the fuselage. The skill required is no different than building your plane the first time.
 
clam said:
Lots of maybe’s and probably’s in there. My original question remains. Since you asked, I built my airplane. You state “the mod can be done” … so tell us how.
Click to expand...
The showplanes kit comes with directions on how to install onto a finished 8 complete with lots of pics. I think you can download all of the install documentation from their website for free.
 
Building the fastback on an existing fuselage is standard RV build stuff, so anyone with an airframes worth of experience shouldn’t have problems.

Drilling out rivets to remove the existing turtledeck requires being very good at removing rivets without enlarging the holes.…. a different skill than building from new parts, but still doable with practice, the right tools, good technique, and enough patience.
 
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