Arbiter

Since this is cockpit related.. One of the things I am grappling with is how to connect the two control sticks... They are not on the same level, so I have come up with a few alternatives I can think of. I welcome any other thoughts on this too! 1. Universal joint. This would use a system like the drive shafts on trucks. I believe I can get the angle right so that the movement is free, but I would have to worry about two joints and the pins that connect them. 2. Just angle 1 solid tube. This would be supported by 3-4 bearings along its axis and would allow the sticks to roll together. I think this would probably be a lighter solution, and the pull-up push down motion would just have an obtuse angle with the axis. I don't forsee any trouble with this, but I haven't tested it in the CAD system or in my Mock up. 3. Chain and Sprocket. I think this would be fairly easy to execute. Just put the sprockets on the middle bulk-head attaching the tubes with a chain. This would give me 2 Axes parallel to the centerline of the plane. However, I see this as the option with the most weight and moving parts. Also, how do you control the pull and push motions. The chain could also bind up under high G loading with deflection of the structure. Any thoughts to my control stick ramblings? Thanks! -Chris

TMann, Yeah, unfortunately it seems that way. I still haven't seen anyone point me to a website or business number I can call, request an IO-540 for 26-30K.... Anyways.... This post is meant to be about my cockpit layout and design. I am glad to get feedback on engines, since this is another area of research I am still trying to understand (Ask me about jet engines and I can answer most questions, but pistons are another story ). If you have remarks about engines please PM me or start a new thread and point me to it in the enigne section. Thank you very much for the feedback so far, keep it coming! -Chris

Hi ErlendM, I got a similar pricing answer from them directly as well. TMann, do you remember where you got your 30K figure? Thanks! Any comments on the cockpit layout? -Chris

I'm certainly going to look at Mistral at Oshkosh (I think they're going anyway) along with the other engine manufacturers. I am definitely leaning more towards the widely accepted Lycosaurs, but I am open to the rotarys. I DO NOT want to do a conversion from a Mazda, but from what I saw of Mistral it looked good. We'll see I guess . Thanks for the advice, any more on the cockpit layout though? -Chris

Edge, For the mission I am asking the plane to do, at the gross-weight I am at, my design calculations are telling me I need roughly 230 HP to do the job.... I don't know about you, but I certainly don't have unlimited resources. Everywhere I have looked the price for a 540 is much higher than what you are quoting. I believe what you are saying, but that's not my experience. The approach of being price concious is not ameteur. You think Boeing just sits up there and says get me an engine that has the thrust I need even though it costs $3Mn more than I have the budget for? No. They trade those costs just as they do Aerodynamic parameters... I have been doing the research and calculations for months now, and I believe my numbers based on my assumptions are solid. For the performance I want, 230 HP will do it. If my mission changes (This is called a "Trade Study") I believe I can alter my fuel weight requirements so that it will get me to the HP requirements I desire for cost reasons. Given your input though about cost for a 540, maybe I do not need to worry so much about it, and therefore becomes a less powerful player in the trade-off studies. Where do I go to see prices like the ones you're talking about? Wherever I've gone on the net, IO-540's start at ~40K new. Point me to a site or some hard resource that tells me different. I've met Chris, and he's a great guy, and his plane is really sweet! He's also probably more connected than I am and found a great deal. Anyway, I am babbling about my engine selection on an instrument panel discussion. Please, let's turn this back to my Cockpit design and layout. I will be sure to post my preliminary sizing conclusions another time. -Chris

Lynn, I am not planning on getting too much lighter myself! What I am referring to is if someone else flies the plane that is lighter than me (170 Lbs or so) . As far as HP goes, I am mainly driven to a lower horsepower because of fuel consumption, and the fact that when you go from 215-230 HP to 300 you add 20K to the engine. An IO-540, at prices I've been looking at start at about 40K for a new or "zero-timed" engine. An IO-375 will run you 23-26K at Aerosport power brand spankin new. That's a huge incentive to remain within the horsepower range, don't you think? I don't disagree that the more HP the better for performance, but I am hoping to finish the project for less than 100K when all is said and done! To answer your alternate powerplant question: At this time I am not pursuing it. I've thought about it long and hard and I just would like a Lycoming/Continental behind me. The one fancy/complex thing I will be doing is making a shaft between the propeller and the engine. This will require one of those damper assemblies used on the Mini-imp to dampen out the oscillations on the shaft from the engine strokes. This is nothing new, it's just not that conventional. The reasoning for this configuration is so that I won't have to retract the forward gear because of CG issues, and that the engine will be mounted to the rear bulk-head that supports the wing. There will be 3-4 main heavy lifting bulkheads: 1 Between Pilot/Passenger, 1 Aft of passenger supporting fwd spar and possibly main gear, 1 supporting rear spar and engine mounts (This will be the fire wall). A fourth towards the rear will transfer loads from the tail and reinforce the thrust bearing in the tail-cone. This is just me thinking out loud at the moment. I am not sure this is the final primary structural arrangement, but it's what I am thinking at this point. Thanks! -Chris

Lynn, Great points, all of them! I felt making a dummy in CAD wouldn't get me anywhere near what I need for understanding the form, fit, and feel of the cockpit. If you look at panel 3 I believe I point to extra panel space that will be used for Nav/Comm if necessary. There is a remote transponder unit I found earlier that didn't seem too expensive that I will be using. I do think I will be able to fit everything in. I may build the panel out towards the pilot on the side walls for switches, Nav Comm etc... I will definitely take to heart the point you made about map cubbies. After what you said I agree with you and won't put something there! As far as HP required is concerned I am currently in the 230 HP range. I am hoping to optimize my mission (Right now I have a loiter phase at a low L/D that is causing more fuel to be necessary) so I can get to around 215 HP. We'll see as more detailed design is done. One of the other reasons I am designing a higher performance airplane with heavy occupants is that the performance will be better as the weight of the occupants goes down. I will be starting the website within about 6 months where people can see the documentation of the design and hopefully learn about what it takes to do something like this thoroughly! Take care, and keep the comments coming! -Chris

Keith, Great idea!!!! I've been thinking about it! I think it would be a low wing, but it could definitely fit the wing underneath the passenger. This would leave the engine, propeller and drive shaft to balance out the pilot mainly CG wise. This would help with structural synergy as well since the landing gear will likely go into the wing, and I could put the main supports into the bulk-head back behind the Pax. There are only two things that give me pause to doing this. First is downward visibility for the passenger. I want them to not have to stare down at the wing if possible. Second, I was initially planning on placing the baggage compartment below the passenger. However, I have been contemplating a compromise! How about putting the passenger's butt essentially at 25% chord. They wouldn't be able to look down un-obstructed. However, this makes the CG shift very minor with varying pax weight, and the passenger will be able to see downward when they look slightly forward. Also, the baggage compartment, though smaller, would still be below the passenger. Great suggestion! -Chris

Hi EracerFL, I see your point about wanting to make the canopy rails more level! What I can probably do with the rails is make the side-walls level. Having about 15-20 degrees over-nose viewing is typical of military trainers so I am hoping to keep that. Since the aircraft will mainly be flown in VFR conditions, the IFR nature of the panel is more for emergency use if you happen to get cornered into a cloud or bad weather now and then. I plan to use my airplane in good weather most of the time. If it came down to panel space being taken up, I would reduce the center screen size to the 7 inch and I would have plenty of space I think. Does this make sense? I go back to the core of my design with this one: Excellent visibility for both occupants (One reason I chose tandem seating, so the view left and right is the same for both occupants) while providing speed and utility. Thanks for the comments! Keep em coming! -Chris

Hi Rich, I agree! I am a big guy to begin with! One thing I did was have the Fuselage seats designed 22 inches wide. I have wide hips already and I still have room to both sides. I did make the arm rests big for that very reason though, so that if I need to I can thin them out again! I don't think I will need to do that though since the seat is already 22 in wide . I am planning to pad the arm rests amply as well. I am starting to think about putting a Map Cubby behind and to the left of the pilot's shoulder. There will also need to be an initial ingress/Egress handle somewhere! Thanks for the suggestion, keep them coming! -Chris

It's a really special joystick for the throttle quadrant. It will act as a fluid dispensation system when not acting as a throttle . Seriously, I just put it there to mark the approximate location of the throttle quadrant. There will be the throttle/mixture and possibly a pitch adjustment lever in that location. The idea will be to minimize the strain of the pilot's hand at the lower end of the throttle as much as possible. This is because if you have more dexterity and control of the throttle during a landing, you will be more precise. I remember when I was flying piper warriors I was always unhappy with the way the throttle was located. It was especially difficult to cut the throttle slowly and evenly during flare out, and I had to jerk the throttle around, making landing less smooth. I hope to change that with my design. -Chris

Bruce, Thanks for the comment! I am hoping the canopy line will turn out to be angled straight at the bottom! At the moment I am planning on 2 canopies, one attached to the roll bar for the pilot, the other to the rear bulk head for the passenger. This may change if the canopies get too large, and I may go to a side folding like the Cozy or Long EZ. -Chris

Hi Folks, I wanted to solicit some feedback on my project so far. Let me tell you a little bit about it first: 1. This is an entirely new Design. I am starting from scratch at the preliminary sizing level. I am not sure if it will be a conventional configuration or a Canard. I am leaning towards conventional, but have not made the down-select yet. 2. This aircraft as it stands now is 2-place tandem made from primarily composites with 1000lb useful load (2 place @ 325 Lb each + Bags and Fuel for 700+ nm Trips). This puts it at about 3200 Lb Gross Wt fully loaded. This is an aircraft for larger people. The thought with 325 Lbs is the airplane could be re-configured and widened eventually for 4 "regular" 170 Lb individuals (Decrease in the already ample baggage load to make up the difference in weight). 3. One simple design Philosophy. Visibility with speed and utility. Based on aircraft I've sat in I have almost always been dissapointed with the visibility, especially the passenger. I hope to solve this with my design while maintaining high cruise speed (150 Kts) and ample range. Now that I have given you a quick background on Project Endeavour, I have a full-scale cockpit Mock-up in the works. Below are some pictures I would like feedback on. One thing to keep in mind is that none of the dimensions with the exception of the 22" seat width and the minimum 36" cockpit width have been fixed. Enjoy, and I look forward to the feedback you have! Panel 1: This picture shows the over-all cockpit architecture. Notice the stadium seating arrangement. This is much like the BAE Hawk and Apache Helicopter. At this point the pilot is still sitting in the bottom seat, but I have been debating whether or not to place the pilot in the back... Either way, visibility will be un-obstructed. In the middle where the front seat-back is located will be a roll-bar. It is likely this will form a brace for the canopy and will be placed such that the rear passenger has a relatively un-obstructed view. The seat pans are 15 degrees up from horizontal, and the seat backs are 120 Degrees. There is a horizontal portion behind each seat I am planning on bolting the restraint systems to, though this may not be necessary and would save precious space if the shelf could be eliminated. Note: The second deck will have an instrument panel of similar size, but will likely have one single display. Panel 2: Shows a view looking down from the second deck (Though this is not necessarily what the passenger would be able to see). The dimensions show where the 22" seat width and the 36" total width are. I have an old Apache style military grip (Planning to use infinities with the hat switches on my actual sticks) approximately where the side-stick will be located. The cup represents the throttle quadrant (Sweet lever huh ). When I measured the angle the instrument panel makes with the horizon from my eye level I should land somewhere between 18 and 20+ degrees nose down (Depending on seat cushion thickness). This will give great forward visibility if some other design constraint doesn't knock the nose out too far! Panel 3: This is where I hope to get the most feedback. I am looking to build this aircraft within the next 10-15 Years ( This is not a hard time-line, afterall, this is a hobby) so projecting what avionics will be available is hard, to say the least. However, I believe Dynon is here to stay, and they are going modular, which is what I like. I am planning on having an auto-pilot and electric trim, and a completely glass cockpit capable of IFR. My panel philosophy is this: -Maintaining control whilst pushing buttons is a must. Therefore, all buttons that may need to be pushed in most regular flight conditions, and those critical in the most common emergencies will be located such that I can use my throttle hand to operate them while fully seated. -My main display will show and artificial horizon, Vertical speed, altitude, and airspeed. Com info, and a heading tape at the top would also be sweet but I am not sure if Dynon has this yet. If not, possibly an HSI at the bottom. The second display on the right will be dedicated to navigation and will serve as a back-up to the primary and vice versa if necessary. Also at the same level will be the engine monitor on the left. -The left hand side will be where most of the switches and buttons are located. I am currently planning on using those cool Aveo Technology button stacks. The gear lever will be likely placed near the left side as well. -The right side will be where the circuit breakers and Anunciators are. I will probably put the breakers on the side wall in front of the control stick since that will be easier to get to while seated with my back against the seat. I am looking for ideas on how to reduce pilot work-load. I am planning on trying to utilize the stick mounted buttons as much as possibe (Electric trim, Comm, Xponder, Etc...) Speaking of transponders: I am hoping that more companies will offer remote mounted GPS receivers, Transponders, and Nav Comms, because I want all that info displayed on the Dynons eventually without the equipment taking up extra panel space. I think this will be a direction industry will take. If not, then the panel space will dwindle accordingly. NOTE: Speaking of sidewalls... There are none at this point. I will be adding them as I develop the shape of the canopy. They will probably stick up at most 6 inches from the panel interface... Panel 4: This panel just shows the side view more closely. The panel is approximately 38.5 inches from the middle bulkhead. Thank you for looking at my long post. I hope to invite some good discussion about my panel layout and the mock up! I'd be happy to answer any questions that I can at this point about my project! Thank you! -Chris Zupp

On this topic, I am working my own design, and I am planning to use retractable main gear. I want to use Oleo struts, and I have had a lot of trouble finding where to order one or get one built custom.... Has anyone had any experience and know where to get an Oleo Strut custom made or at least a place that offers the struts that can be ordered stock? Thanks! -Chris

Pro/E has a good deal on Wildfire 4.0. It's about $250 and it's called WF 4.0 Personal Edition. Can't use the license for anything professional and it saves in a different format than the professional version, but it's fully functional and intuitive. From what I understand (And I am not an expert about this) is that programs like Rhino/Amapi/Maya/3D Studio Max are great for modeling, but I would not call them CAD programs... From my limited experience they lack the capability to technically define a surface very well. What I mean by this is I don't think they are good at defining engineering stuff on drawings. They may be great at producing surfaces and solids, but I don't know if they offer mechanical analysis of tolerances, solid dimensioning/sectioning, area, moment, and material property definition etc... Again, it's been a while, but if you want a true CAD program I'd go with Pro/E, Solid Works, Catia (Boeing uses this), Unigraphics. Pro E I know starts at around $6K for the base package which does not include all the bells and whistles for the professional versions, and I think they are one of the least expensive. I am in the process of designing my own airplane from the ground up (Not Long EZ derivative or anything like that) and I am using Pro/E. I want to use finite element software to do the composite analysis, and Either Star-CCM+ or ANSYS CFX for computational fluid dynamics, but each of these is $50K PER YEAR to run plus maintenance fees ($9K). It's definitely not cheap, I know I am not going to have access to these systems unless I can work a good deal, but it'd be worth it if I could . Anywho, good luck collecting CAD stuff. Hope this helps, and people can make sense of my blabbering . -Chris

Hey Seb, If you want to professional version of Raymer's code it's $15K. Same for AAA. Now you are correct about student editions, they are much cheaper. However, I am not a student and have not had much luck in the way of negotiating the not-for-profit pitch to the AAA guys. I haven't looked into the other systems as I am following Roskam's design series of books. This series is pretty comprehensive for preliminary design, and their staff has been responsive. Though I cannot afford the code, Roskam does provide good clarity in his books. At this time I haven't found anything that I haven't been able to code up in Microsoft Excel. In my mind the only thing the codes would provide me is assurance that all of my design parameters are consistent, but that can be taken care of using Excel too, it just takes some creativity . Anywho, thanks for pointing out the other programs! I will be definitely using Xfoil and the similar suite of codes as necessary, but for the most part it will be my own spreadsheets. Thanks! -Chris

Hi Seb, I do use Aircraft Design: A Conceptual Approach. I'll also be looking at his simplified homebuilt design book. I do not use his program because it is $15K last I saw. I am following the Roskam Design Series (AAA Software is their program, also $15K) which is programmable in spreadsheets without much difficulty. The most difficult part at this point is documenting everything properly, at least that's the part that has taken the most time. I am almost done with preliminary sizing. If there is interest on this site (Though I am making a conventional pusher design) I will post some of my documentation for review. I am not planning to do this for profit so I do not mind. Take care! -Chris

Hey Colin, Congratulations on beginning a new and exciting design project! I wish you the best of luck as I too am working on a new airplane design. Mine is a conventional configuration, not a canard, but that's another discussion! I am looking forward to seeing how the project turns out! Do you have any preliminary sizing data you would share with us? Do you have any parasite drag or wetted area predictions? What set of design books are you looking to use? I am following Roskam's books for preliminary design (With Dan Raymer's as back-ups) for my main texts.... I'd recommend Bruhn for structures, and he does a good treatment of sandwich structures from what I can tell. It will be great to see how things turn out! Good luck, and keep the chin up through it. It's the long road to be sure, but it's full of learning and fun along the way! -Chris

Hi Chris! Thank you for the information! The turbo will definitely heat up!... If it's an exhaust type, the turbo uses exhaust gasses to power the turbine and thus the inlet impeller. You definitely don't get something for nothing, and the additional heat load will have to be accounted for! I am not sure 180 HP will be enough, the aircrafts MTOW is around 2700 lbs, predicted, which is around Velocity size. Velocities use IO-540's with a bit more hp than 180 I believe... However, if I drop my cruise sizing point to 8,000 ft, then I can get down to about 210 hp required for 160 kts. The issue I am running into is my Weight/Power ratio is already 15.5, which is higher than most home-builts. So, as an engineer, I have to skeptical that I will be able to go toe-to-toe with Lancairs and Velocities in cruise speed with LOWER horsepower . One of the issues I found that you run into is some websites specify only the speed, and not the % power! Lancair for example says 215 mph as the cruise speed. But when I asked them, they said with the IO-390, the speed would really be 207 mph at 75% power.... Not much of a difference, but they may be quoting 85% power. So, bottom line is, there's a lot to think about, and overall, what is really important, 160 kts cruise @ 75% power, or the $20K price difference?!? I think the price difference will win out, unless I can find a turbo-ed TIO-360 for $30K or so... We'll see. Thank you for your input and putting up with my ramblings . -Chris

Wayne, Thank you very much! I am starting to lean much more towards a turbocharged IO-360 installation in my design. The difference in preliminary sizing is 30-40 Hp... The trick is now going to be finding an engine TIO-360 source that is like $30K for re-built or ideally factory new. I will talk to the two folks suggested in this forum. Thank you all for your replies so far! More are always welcome too. Has anyone successfully turbocharged a non-turbo-ed IO-360 or other lycoming? I'd greatly enjoy a discussion about those experiences! Thanks! -Chris

Neil, Thank you VERY much for the link! I noticed he doesn't seem to do turbocharging though. Have you heard of anyone who has had that done by him, or a site like his that sells turbo-ed engines? Thanks very much for the reply! -Chris

Hey Folks, It's been a while since I've posted.... Been working on a project of my own. Coming down to some initial sizing decisions around the engine. The issue I have is I need ~180-220 hp to meet my cruise constraint on the design. The aircraft will cruise @ 12,000 ft, and 150-160 Kts. As we all know, a normally aspirated engine's Horsepower dies down with altitude. I have given some thought to turbocharging, which would get me the required horsepower at altitude I need to maintain the cruise speed I want with my given power loading. The issue I am running into is Lycoming's Thunderbold TIO-360 starts at $60K.... The IO-360 @ ~$34K..... Is there any way to SAFELY convert the IO-360 to (T)IO-360 for cheaper than the $26K they want for the upgrade? I called them and was told the turbo itself was $15K, which I find hard to believe (Maybe I am wrong, but car turbos are like $3K for a big one). In addition, they also said the pistons are a bit different and they added oil squirters, presumably to allow the generation of that horsepower at altitude... I am looking for your thoughts on this, and if anyone has heard of a conversion like this and about how much to expect to pay... For $60K I'd rather go with a bigger engine normally aspirated.... Anywho, thanks for the input up front. -Chris Z

No Problemo! Thanks! -Chris

Thanks! My heart hath be skipping a few beats hehe j/k! -Chris

Hey folks, Anyone else having issues accessing A/C Spruce's website? I tried to call them but only got a busy signal... Is anyone else having these issues, and if so, does anyone know what the deal is? They aren't going out of business or something are they? Thanks! -Chris