About to Order -- Questions

[flipfloplife]

All,

I've done a lot of lurking here. Thank you in advance for all I have learned already.

I have some questions before I order that may seem like random questions, apologies, they are the ones highlighted in my notebook that my own research hasn't satisfied.

Basic plan is a KF 7SS, Rotax power with enough guts for "out west" DA's (thinking ULS w/ big cylinders, on the fence about injection). I'm pretty on the fence about in IFA prop as well, not sure I'd get the performance boost to make it worth that kind of scratch. Initial and routine flying would be south florida and the bahamas -- then I'd like to trailer it and potentially amphib floats. Cabane Gear MShocks, Oratex, extended baggage, QB wing. I have never built a plane before, I don't have a ton of space.

Silly Question #1: Max fuselage width as it comes from the factory considering what door you can get it in? (yes, there may be a concrete saw at the end of my build log, but I have to get it started first, permit me to save the fun surprise part for later).

Silly Question #2: I read the specs, but unclear what length is w/o FWF on?

Silly Question #3: Max chord with and/or without flaperons attached (does it vary down the wing? it looks like its constant).

Silly Question #4: There seems to be a step somewhat early on in most builds where you put on a wing at a time "swung out" -- I have a bit of a narrow build space in mind -- what do you guys who have done tight spaces do with this one? Is this step something where you can roll it out in the driveway and do it, roll it back 5 hours later? Or is this a situation where I am not understanding the full pain of not being able to extend one wing at a time right there IN the build space?

Silly Question #5: I have read what guys have said about trailering -- it seems that universally draining the fuel is both desired and not that easy -- could I build in an easy drain to make this ... easy? Other thoughts on trailering out the gate, I think there is a grab handle on the tail, but should/could there be a small D-ring in the back/front for pulling in and out? (kind of like we do on boats)

Silly Question #6: Any reason to try and build to LSA instead of E-AB? I have read the rules and variety of postings on different forums, it seems it just gets me more confused. I have to keep a solid FAA medical for quite a while still, if I can't then I likely will have a plane for sale.... I care about re-sale but not to sacrifice either performance (IFA prop) or gross weight (no one has ever called me "svelte").

Not Silly Question #7: Fire away -- given described mission and proposed build, relatively tiny build space -- is there stuff you guys would have done out the gate differently? Stuff that I have laid out that seems dumb? (I am not bright). What would you guys be thinking about NOW if you were me?

Cheers,
FFL

[Dave S]

Scott,

Not all of us have a giant million dollar space to work with - probably few do and we work with what he have. The smallest construction space I am aware of locally is where a person built a Model IV in a small single car un-attached garage - got 'er done and the plane looks and flies very well. The big deal is to have the build close to, and better yet, at home so you can get to it. If the project is a drive to get to you won't work on it as much or as frequently.

We built in the attached garage (photos attached) and basement. Carefully measured the basement stairway to assure the wings would make it out OK and I could avoid the classical home builders conundrum. Be aware that with the wings folded they extend past the tail a bit.

Swinging the wings is not much of a problem. Many times in and out of the garage to work the wings at various steps. The door was a rather small 9X7 so it was necessary to fabricate a tail dolly to keep the prop low enough to get in once that was installed.

[Cherrybark]

Welcome Scott. As Dave said, have your build close to home if at all possible. Just stepped out to the garage to measure, in rough inches:

1. Max Fuselage Width is 43" - right behind the seat.

2. Fuselage Length w/o FWF is 180"

3. Wings are 163" long but you really want them mounted on a rotisserie which takes mine to 178"

4. Wing chord is a constant 42" w/o flapperons. Don't have them mounted so can't answer the second question.

Surely someone will double check my numbers?

I had the luxury of parking my wife's car outside and mounting both wings with bare inches to spare in a three car garage. This was at the stage where the spars are being drilled to rig the wings. It was nice to have plenty of time to work through the unfamiliar process of mounting of the wings, double checking the measurements, sleeping on it, and re-checking the next day before drilling. There is also a bit of fiddling to rig the jury struts. I ended up mounting the wings a second time to get the correct placement of the door compression strut and to trim the lift strut farings. That said, with some experienced help, you could probably rig the wings and put them away in a single day.

[ken nougaret]

In response to the question about fuel draining before folding: I trailer to the airport every flight. I have had as much as 3/4 thanks and don't believe I have spilled any trailering. I have my wings level on the trailer.

[flipfloplife]

Dave S -- ok, that's quite inspiring. You didn't have level ground, you had snow, and that is a tight shop space - but man your plane looks great! Sounds like you're saying that out and in was a fairly regular thing for you. From what I've read about trailering that 9x7' door was pretty tight w/ the wings on. I am going to have to work on that part. creatively.

Carl -- I'm on the road for work but those numbers are really really helpful! As soon as I get home I'm going to use them to do some figuring... I'm going to have to dig out your build thread if you have one about the Oratex (it appeals to me).

Ken -- Well that's good news for me! Do you trailer long distances and highway speeds in that configuration as well? I'm going to seek out something enclosed and a tails tand makes a lot of sense but I'm not sure how high the vertical stab can go w/o starting to push up the roof on an enclosed trailer ---- seems like a lot of guys are keeping the tail pretty low in the enclosed trailers?

Thanks for the thoughts so far -- they are going in my book and getting me closer to an executable plan.

[ken nougaret]

FFL,
You asked about a D-ring for pulling. I made this piece so as not to pull on the tail spring.

[GuppyWN]

If you build it the airplane WILL be EAB. Only the factory can produce a LSA. You’re thinking about the 1320 gross weight. You can certify it 1320 and utilize the LSA Pilots licensing rules.

[aviator79]

I built in a 1-car garage. It wasn't really too difficult IF you plan for it, and you have extra space somewhere to store things you aren't working on. I had a lot of parts, including a wing, hung from the walls and ceiling in a spare room inside my house throughout the build. If you go find my build log, you might find it helpful. There is a step when you install the #1 ribs where the wing must be on and extended overnight while the epoxy cures. In Florida, you can probably just do this outside. Up here in the mountains, there are only a couple months a year where it wouldn't get too cold at night for the epoxy to cure. I was able to work with the factory to have those ribs installed before when the rigged my wings in Idaho. It pays to read the manual very carefully to identify steps that might be difficult in a small space ahead of time so you can plan. It also pays to ask questions when you're placing your order.

Just to clear up LSA/E-AB Semantics: ANY airplane that meets the definition of an LSA under 14 CFR 1.1 is an LSA. If you build your airplane to meet the LSA definition, it will be an E-AB that is also an LSA and can be flown by a sport pilot.

A factory-built airplane will have an S-LSA airworthiness certificate. If you build your airplane, it will have an E-AB airworthiness certificate. But the type of airworthiness certificate is not what determines if it's an LSA, only the definition in 1.1 matters for that.

[efwd]

Something is still amiss here. The factory airplane may be built as a 1550# MGW. All of our S7 could be. In our builds they are E-AB. There is still the
E-LSA as well but I am not under the impression that this is an option with the Kitfox. That has to be supported by the factory I believe. I could be wrong so don't hold me to that. They may very well support it. For a Factory built plane with the 1550# MGW, what is it certificated as?

[aviator79]

Factory-built planes have a max gross of 1320 lbs. 1550 is not an option for an S-LSA (or an E-LSA). This is only so that it meets the LSA definition. There is no difference in the aircraft. For now, it's best not to make a confusing subject worse by throwing in the E-LSA rules. Eddie is right though, this would have to be something the factory offered or supported, which to my knowledge, they don't.

When you build an E-AB, you can set the Max Gross at 1550 (It's been tested to that), or you can set it at 1320 if you want it to be an LSA. There is no difference in the kit, the construction, or anything else. You don't have to make this decision until the day the DAR comes.

The next question that often comes up is whether you can reduce an airplane's 1550 max gross to 1320. The answer is yes BUT that won't make it an LSA. Part of the FAR 1.1 definition is that it must have met the requirements continuously since original certification. The minute an LSA is modified outside the LSA definition, it can never again be an LSA legally.

[jiott]

I believe an amateur built S7 registered at 1550# GW is E-AB but is not Light Sport and cannot be flown by a Sport Pilot. It gives you the freedom to install in-flight adjustable/constant speed props and other non-LSA items. An experimental is not "certified" even at 1550#.

[efwd]

Thanks, I was not aware the factory limits their builds to 1320#.

[rv9ralph]

Correct. It is a regulation thing, not an engineering thing.

Ralph

[flipfloplife]

Gents,

Ok -- the space will work. Any time I need to put a wing on it will kind of be a thing. But it's do-able.

Got it on the E-AB versus LSA, etc -- based on what you guys have said, at the end I'll end up with an E-AB non LSA, which is just fine with me, I will be certifying at 1550 and don't want to even blink at the idea of constant speed if i decide to go that direction.

So now my focus is going towards getting the order correct.

For instance from Aviator79 I learned that in my case it probably makes sense to see if the factory will go ahead and install my #1 ribs. (not an option on the order form... this one i'm sure is gold).

I also know that I don't need the covering kit (I'm pretty sold on Oratex).

What do folks think of the factory fairings? In my head it doesn't make much sense to put 26" bush wheels on ... AND fairings for the wing and stab? But I do realize that every bit helps. Thoughts on the factory fairing options? (I only get to do this order thing once...)

How does it work if you don't buy your Rotax from KF? There's a guy here in South Florida that has 912 core's and I might work with him to get something going that comes in over 100hp and isn't 30k. Am I still going to be wanting the FWF kit from Kitfox? Worry about that later?

How does delivery work? I see a lot of you guys head out to Idaho to pick your stuff up, that is a long way for me -- and that's like 5 days off both jobs, which negatively impacts finances. Thoughts?

Any specific order considerations for future floats? Hard to see in the website pics but there don't appear to be tie downs at the top of the wing struts?

I may be setting a record for most random questions in a single thread -- I know. But as I sit here with the order form there are a lot of 4 digit mistakes a guy could make. I'm sure it's gonna happen -- but I'd like to minimize it and capitalize on your expertise.

[jiott]

A few answers:
Yes you want the factory strut fairings; most of us would agree they add about 10 mph-that's a lot. The horizontal stab strut fairings are nice but not nearly as effective.
Many of us had the kit delivered, but you must use a service who knows what they are doing aircraftwise; I highly recommend Partain.
The standard kit comes with hard points for floats, and yes there is a tiedown loop at the top of the lift struts.

[rv9ralph]

Flip... you don't mind if I call you that do you?

Any how, when you call to place your order, John or Debra will walk you through the options. They want you to order the plane you want, they will not push you to add options that you don't want or need. In the process they will explain everything and answer any questions.

Ralph

[aviator79]

I agree with this. John will give you an honest opinion about each option without trying to sell you more than you want. Also be aware that there are many options available in the catalog that aren't on the common options on the order form. It's worth reading through the catalog and considering all the little bits you find there - it might save you on shipping later.

[efwd]

It is very wise of you to post questions because, as has been stated, the factory will not likely up sell you. There are many things the factory has available that are not in the catalog. Banjo fittings for the the fuel tank for example. If you have a Rotax engine that they have installed before, the FWF will likely be just fine. Little of the kit would be anything that you have. It will have radiator hose, oil lines and connectors, radiator and oil cooler for example. If I already had this kind of stuff on a motor I owned, I would still get the new stuff. As I understand it, hoses and the like need replacing after about five years anyhow, unless you buy Silicone as some have done. The Fiberglass stuff you will need as well.

[flipfloplife]

Some forums seem to go by name, some by handle -- my name is Scott -- I should probably fill out that profile thing a little better.

I called yesterday and spoke with Debra (i think) ---- super nice, super knowledgable and enthusiastic. It was quite refreshing to talk to someone who is enthused about their job. Nov 2020 is the next delivery slot and she mentioned the same things you guys did -- at some point I am going out there to fly w/ S&R -- and at that time I'll probably sit down w/ John or Debra and go through the minutiae. She too mentioned that there is a fair amount of stuff that "isn't on the website".

For the next guy that reads this -- current shipping from Idaho to south of Miami was quoted at $3800. I have to do the math but that may be break even or cheaper than doing it myself.

But in order to be smart enough at that meeting I'm going to keep combing through all the stuff on here. I clip out a fair amount of stuff to stick in my "digital notebook" on KF build. So for you guys posting pics and processes -- here's one guy who appreciates it.

10 mph is a LOT to gain from faired struts. Sold.

Engine stuff -- that makes sense Eddie -- I'm just thinking that there has to be a way to do a bit better on HP than a stock 912iS, even the 10-15 HP from a big bore kit is a significant increase. Still need to figure out if the price difference up to a 914 is worth it to me. "Whoaaa, that's too much horsepower" said no pilot, ever. However, as it turns out -- I have a while to think about that -- and a trip to S&R flying both the 912iS and the 914 may help answer the question as well.

Also as a point for the next guy doing research -- Aerotrek A220 is a competitor to the KF in a way (there is obvious ancestry there). I called that guy. He was nice, and knowledgable. It is sold only as a completed aircraft, mostly made in the Czeck Republic but has a reasonable rep for quality. That plane is sold as an SLSA, which I was told can be pretty easily taken to an ELSA status with a few pieces of paper. Now if you take a 16 hour Repairman course you can do your own maintenance and (i think) sign off your own condition inspection. You can also modify it as you please (which you can't if it's an SLSA). However -- you're still stuck flying it at 1320#. There is just no getting around that. Would it fly at the 1550# that a KF will? Likely. But now you're the jerk breaking the rules on purpose and it can be legitimately said, "*** were you thinking? The plane was not designed for that!". The (relatively) high usable payload is one of the key reasons I like the KF, the Aerotrek looks like a duck and sounds like a duck, but can't be loaded like a duck. An extra 200#'s is a lot. Also for reference, he is sold out until June 2020.

So all in all -- I'm going to put down a deposit in the next day or two to hold a Nov 2020 delivery. I'll also keep looking for a completed SS7, which I've been doing for quite a while --- seems like guys love 'em -- i get it. I may also try to pick up something to fly for the next 2 years while I'm waiting and then building -- sell it endgame to pay for engine when I get there on the KF. What was that fat little side x side cub? The J-4 or something? One of my kids is keen to fly and still thinks I'm cool -- maybe start teaching her a thing or two with something like that, or sometimes a Rans S-6/7 can be had less expensively ... (I have 31 tabs on barnstormers open right now...)

[aviator79]

When you get to S&R definitely fly both engines. However, be aware that the 912iS is mated to an Airmaster CS prop, while the 914 has a fixed-pitch prop, so you won't really get an apples-to-apples comparison. Here's what you'll find. The 914 plane will outclimb the 912iS plane significantly. But when you push over into cruise, you'll need to pull the throttle way back to keep the engine from overspeeding. The 912iS with the CS prop runs away from the 914-powered airplane in cruise. It's a good 15-20 mph faster, because it can make max continuous power all day long.

Here's my take: If most of your flying is below 5000' MSL, the 912iS with a CS prop is the sweet spot. Fuel injection, economy, price, mechanical simplicity, and perfectly adequate takeoff performance. I opted for the 914 because my field elevation is 7200', and we sit at the foot of several 10k-11k peaks. It was the right choice, but if I were closer to sea level, I'd have a 912iS. I do suffer from fuel-injection envy.

For those at high elevations reading this post, do consider that the amount of compression that the turbo needs to provide to get 40" MAP makes the intake air very hot. The Turbo controller will limit the airbox pressure setpoint when the airbox temperature gets too hot. I knew this, but failed to realize that in the summer months it will happen by the time I'm a couple hundred feet high every single day. At lower elevations, the boost reduction is rarely seen because the pressure ratio isn't as extreme. I did some thermodynamic calcs and found that on a standard day at my elevation, any ambient temperature above about 60 deg F will result in the TCU limiting boost. This is pretty consistent with my observation. So this winter I might fix my EFI-envy and add an intercooler at the same time. With a normally-aspirated engine, you don't have to think about any of this.

[rv9ralph]

A couple of thoughts on engine acquisition.

There are many sources for Rotax engines. After market rebuild/special builds don't always come with warranty.

Rotax engines from Kitfox have some specific things done especially for Kitfox installation. Two things specifically that I can think of is clocking the outlets from the water pump so they do not interfere with the engine mount. The other is the exhaust system, configured for the Kitfox Install. Oh, and with warranty.

Ralph

[jrevens]

...
Also as a point for the next guy doing research -- Aerotrek A220 is a competitor to the KF in a way (there is obvious ancestry there). I called that guy. He was nice, and knowledgable. It is sold only as a completed aircraft, mostly made in the Czeck Republic but has a reasonable rep for quality. That plane is sold as an SLSA, which I was told can be pretty easily taken to an ELSA status with a few pieces of paper. Now if you take a 16 hour Repairman course you can do your own maintenance and (i think) sign off your own condition inspection. You can also modify it as you please (which you can't if it's an SLSA). However -- you're still stuck flying it at 1320#. There is just no getting around that. Would it fly at the 1550# that a KF will? Likely. But now you're the jerk breaking the rules on purpose and it can be legitimately said, "*** were you thinking? The plane was not designed for that!". The (relatively) high usable payload is one of the key reasons I like the KF, the Aerotrek looks like a duck and sounds like a duck, but can't be loaded like a duck. An extra 200#'s is a lot. Also for reference, he is sold out until June 2020. ...


Hi Scott,
I'm not really very knowledgeable about the Aerotrek A220, and had always thought that it was some kind of foreign rip-off of the Kitfox design, but I've been told by their salesman that it is directly derived from the Avid Flyer. I don't know how truthful and accurate that actually is. I'm bringing this up because I'd like to know for sure and there are people on this forum who will hopefully correct any misconception on my part. As far as comparing one to a newer Kitfox that is designed for 1550#, I believe that it is more accurate to compare the Aerotrek to something like a Mod. IV Kitfox, both in design gross weight and size.

[Shadowrider]

A couple of thoughts on engine acquisition...Ralph

Just FYI you only have to reclock the water outlet if you buy the ring mount from kitfox. The rotax ring mount you don’t need to re clock water outlet.. Kitfox builds their own ring mount and can’t copy rotax exactly making the need to have to re-clock the water outlet.