Roost Air Lounge => Aviation related topics => Topic started by: Frank N. O. on February 18, 2006, 02:41:30 PM
Title: Would this plane-concept work/be legal?
Post by: Frank N. O. on February 18, 2006, 02:41:30 PM
I've mentioned my special idea a few times now and I thought that with your experience here I might get some questions answered so I can get a little closer to finishing the design details on it. My plane is special in several areas compared to normal GA planes, exterior, interior and maybe also propulsion. Since the idea I had for propulsion is still intested in flying as opposed to driving then I'll ask about it first.
Propulsion in an aircraft is crucial in many ways and I've thought of how to make the best possible, both in terms of speed, manouvrering and fuel-economy and minimum polution. One concept I've gotten is pretty wild but here goes: Serial Turbo-Electric Hybrid. One gasturbine engine integrated behind the cockpit only working as a generator chargin a smaller pack of batteries that then via a computer (to maximize acceleration without using more power than can be used, and for synchronizing the engines to eliminate torque turning the plane) drives two parallel low-speed electric motors driving a set of ducted scimitar fans each. Electric motors have a ton of torque and can be made to go at low speed thus hopefully making them more silent and the torque will enable high-power fan-shapes for high thrust as well as enable direct drive instead of the need for a reduction gearbox to eliminate un-needed extra parts and service. Another thought is that the hybrid setup would mean that if the turbine had to switch off then maybe I'd have a minute or two of batterypower and thereby thrust left to perform manouvres to get out of a possibly bad area besides the idea that this setup would maximize fuel-efficiency and minimize noise with the turbine placed in the body with intake and exhuast over the fueselage it would be very silent for both me and the people underneath.
Btw to quickly explain how the plane is shaped then it's based partially on a fighter with a 2-seat side-by-side cockpit with a F-16-style two-piece canope in the nose of the plane, with partially forward-swept wings starting just behind the cockpit, placed in the middle, height-wise, to hopefully minimize the need for rudder to make the plane bank direclty on the centerline, where the drivefans are place also. The main idea with the wings were to give full visibility both up and down and I forward swept them slightly to try and keep the wing-lift on the good side of the cog but of course that's hard to plan without knowledge of propulsion system weight etc. I had an idea of having the plane fuselage have lifting body proporties also since it only had two seats and two seperate fan-pods in the back. Another idea was to borrow the tail from the Black Widow II with a seperated V-Tail however only have them as elevators and use a split aileron as seperate rudders that could thereby also double as speed-brakes like on the Rutan LongEZ. The split surfaces are inspired from Bugatti's old fantastic race-plane that had a similar system developed for manouvrering. The inner part of the main wings would be designed like I understand the big Lancair is, to stall first so the outer wings can make the plane stable and manouvreable even in the stall, at least that's how I think they did it, they never explained what made the plane stable but I guessed since I know most planes have at least two different aerofoil shapes in the main wings. The plane would also have the ballistic airframe parachute or whatever it's correct name is. The projected performance is no more than a Mooney Bravo in terms of top speed, I'm pretty sure that'll be fast enough for me. Spoilers are also planned btw, for the inner wings specifically.
The third part of course is the cockpit that would be inspired in shape and seating position like a car but since I haven't figured out if the hybrid propulsion setup would work then I can't come closer to making a mock-up of the panel since there are a lot of switches that may or may not need to be placed. But the controls would be a side-mounted wide single throttle with a button for the thrust-reverse and a panel-mounted yoke.
So, how crazy am I? It's all planned to try and make the plane as effcient and safe as possible, while designed to be used strictly by me and not intended for general production.
Frank
Title: Re: Would this plane-concept work/be legal?
Post by: Inept on February 18, 2006, 06:36:53 PM
interesting concept. How much will your electric motors weigh... it sounds like a silly question, but I've looked into electric powerplants and found them impractical because of their immense(sp?) weight.
Secondly, what formulas and calculations do you use to calculate the airfoil design, lift/drag coefficients, lift requirements for the aircraft, required engine performance, etc? I've not been able to figure those out, but I've also not been trained as an engineer.
Title: Re: Would this plane-concept work/be legal?
Post by: fireflyr on February 18, 2006, 09:28:24 PM
Holy cow Frank, You are ambitious aren't you? Anything that flies sounds like fun but I'm one of those people who has no interest in inventing anything. I like it when those fan things either push me or pull me fast enough for the wing things to catch enough air to lift me high enough to go someplace neat, and the faster it goes, the better I like it. Your ideas sound fascinating, maybe you'll go on to make history with new concepts in aviation. There is always room for a better idea! Jim
Title: Re: Would this plane-concept work/be legal?
Post by: Gulfstream Driver on February 19, 2006, 06:29:24 AM
I love this idea. I do have a couple of concerns, mainly with the wing. The nice thing about a forward swept wing is its maneuverability. It'll do a snap roll without the pilot even thinking about it. Unfortunately, that also means it's extremely unstable and will stall at the tips first. I think it would be possible to design an outboard section with more lift than normal, possibly with slots, but it is something to consider. Since you don't have too much forward sweep, you may or may not need a computer to keep the wings level. I'll try to find a good website on wing design and aerodynamics.
Also, weight would be an issue, I think. Will the gas-turbine engine and the batteries be light enough and hold enough juice? Something to consider.
Will it use props or jets? I realize there will be electric motors, but what will actually pull the thing through the air? I'm also confused about the elevator/rudder concept.
Please don't take this as criticism. And, I'm no engineer, so these are just a few tidbits I picked up in aerodynamics in school. Good luck and good designing!
Title: Re: Would this plane-concept work/be legal?
Post by: Frank N. O. on February 20, 2006, 01:02:04 AM
Thanks for the replies :) Sorry for my late reply though, I've had a bad few days sleep.
I'm not an engineer, although I did start a 3 1/2 year course before I got sick when the loss of my dad really set in, although that was for electronic engineering. I have however a natural sense of noticing and logically analyzing what I see and vehicles have always interested me greatly.
I sadly have no info on how heavy the things would be however I know there's an electric motor weighing 67 kg that can give 500Nm of torque so I thought that might work, plus the gasturbine would be a small one that's also capable of using multiple types of fuel to make it easy to fuel although it had to be ultra-clean burning for low emissions and high effiency but that was part of the reason for the whole hybrid setup since any combustion engine has a set rpm where it's the most effective at burning fuel.
The forward wing-sweep was in case I needed to move the wing-lift point further forward in relation to the cog without having the wing underneath the cockpit ruining the downward visibility, to make sure it wouldn't tip nose-up when stalling, I read that in a book somewhere that the cog and wing-lift position decides this, of course people, fuel and luggage will move the cog I know. However the gasturbine would be behind the cabin and the engines and fans further aft so maybe the forward wingsweep isn't needed to correctly place the lift point vs the cog. But thanks for pointing out the stall characteristic of forward-swept wings, I appreciate it :)
To clarify the propulsion system I'll try again. There is a small gasturbine engine in the fuselage that only drives a electricity generator. That generator keeps a smaller set of batteries topped off. Those batteries drive two electric motors that each drive 1 or two counter-rotating ducted fans that provide the actual propulsion. The idea about having two engines is to be able to use smaller fans and to have counter-rotating fans and electronic control of the motors should cancel any torque on the plane, plus the fans should be directly on the centerline further making the plane easier to fly. using ducted fans was also to further increase the effciency of the system both to help performance and fuel-use.
The electronics would just be for the powerplant itself, monitoring and controlling the gasturbine to keep the batteries topped-up, to make sure that no more power was applied that could be used for acceleration for the electric motors when giving full throttle and to make sure the two engines run at exactly the same speed to cancel torque so rudder-correction wouldn't be needed for that. The aerodynamic controls however would be fully manual like a normal GA plane, I don't see any need for fly-by-wire for a plane that size since others don't and with the wing-position (height wise) and torque-canceling centerline-placed propulsion then such a system shouldn't be needed anyway.
Btw, it's not totally grabbed out from thin air though. One thing about hybrid propulsion systems is the need for batteries that are capable of charging and discharging at a high rate and NEC recently announced a new cheap battery-type that could do just that, although they planned on making back-up power-systems for PC with it first. The batteries were also claimed to be very small and light and made by rather simple materials.
I hope this answers all questions there were I could anwer, if not then ask again.
Frank
Title: Re: Would this plane-concept work/be legal?
Post by: Gulfstream Driver on February 20, 2006, 06:22:07 AM
If you're worried about CG placement in relation to center of lift, you could move the wings all the way to the back and put a canard on it...Just a thought.
No matter what, you will need some way to control yaw. If I read correctly, it sounds like you're trying to get rid of the rudder. Even if your engines don't produce a yawing motion, you still get adverse yaw when you turn and will need some way to land in a cross wind.
Title: Re: Would this plane-concept work/be legal?
Post by: Frank N. O. on February 20, 2006, 06:53:07 AM
I have thought of a canard design but some said it wasn't very good due to the difference in lift, I think something concerning that a canard plane has lift from both surfaces meaning flaps can't be made easily whereas conventiontal planes use a downforce elevator. My concept does have a rudder though, it would be a split-function of the aileron's that work sperately like the LongEZ so you can activate both for speed-brake function. I chose this since the V-tail might make the rudder roll the plane and since the wing and propulsion positions were all made to reduce/remove asymetric forces on the plane then that would be a dumb decission.
I do admit that part of the design was to make the plane look different too, however for me there's no contest, function has the priority over form in case you can't have both.
A canard design to my knowlegde gives several other problems btw, stall characteristics for instance, and you can't have spoilers on them, but maybe the spoiler could be on the lifting body section instead so the plane could decend quickly if needed for a landing. But would it still be possible to create the plane to be manouvreable in a stall like the conventional winged Lancair? There might be benefits to the canard of course, a shorter distance for the elevator controls to go and better downward visibility. However with canards you can't have a V-tail naturally which means that it probably needs a vertical stabilizer to be aerodynamically stable and that means possibly higher drag than the V-tail configuration, although I have heard that the old Beech V-Tail had the same top-speed as the sibling model with the conventional tail so if it has any benefits except visual that I don't know.
Frank
Title: Re: Would this plane-concept work/be legal?
Post by: Roland on February 20, 2006, 08:09:36 AM
I’m very concerned about the propulsion system in this concept. My problem here is weight. The e-motors will be very heavy as well as all the batteries necessary to fulfil the concept. Using a gas-turbine to keep the charging of the batteries on top level doesn’t make things easier.
Think about the loss of efficiency of the energy available (here within the Jet-A1 fuel) over the whole “power-train” to your fan-blades. According to the law of entropy (loss of energy) within the thermodynamic laws this concept of propulsion will have a tremendous loss.
But just start to calculate. What rate of thrust you will need for the plane to take off (not to fly!)? So then you know the energy needed. Next you calculate the source of energy transformation, i.e. from fuel to thrust.
See, the helicopter became so widely used only after installation of gas-turbines. Why? Well, gas-turbine engines can transform energy stored in fuel far better into thrust then piston engines can due to the better engine-weight/power-output ratio.
I think your aircraft will not fly due to weight problems. Batteries, especially Nickel-Cadmium, are bloody heavy.
Title: Re: Would this plane-concept work/be legal?
Post by: Sleek-Jet on February 20, 2006, 04:15:48 PM
Battery weight would be a consideration. Even "small" battery packs would probably end up weighing as much as the bare airframe. But it might not be a bad idea to start working on now... "room temperature" super conductors are already in use in the utility industry (I believe Switzerland has built a transmission line using them in the last few years), so I would guess that industrial uses for them aren't that far off... say a decade or so. ???
If you had super conducting motors driving the fans, you wouldn't need nearly as large a battery pack.
Title: Re: Would this plane-concept work/be legal?
Post by: Gulfstream Driver on February 21, 2006, 12:18:34 AM
The nickname for the Bonanza is the V-tailed Doctor Killer...The problem with the V-tail is that you don't have both a rudder and an elevator. Combining the two reduces the effectiveness of both. They look awesome, but they're dangerous.
Title: Re: Would this plane-concept work/be legal?
Post by: fireflyr on February 21, 2006, 05:39:29 AM
I heard once that if it wasn't for Bonanzas there would be more doctors and that if it wasn't for doctors there would be more Bonanzas --Kind of a self canceling equation don't you think?
Title: Re: Would this plane-concept work/be legal?
Post by: Ted_Stryker on February 21, 2006, 04:49:19 PM
The nickname for the Bonanza is the V-tailed Doctor Killer...The problem with the V-tail is that you don't have both a rudder and an elevator. Combining the two reduces the effectiveness of both. They look awesome, but they're dangerous.
Very true! Also, when they originally were manufactured, Beachcraft printed incorrect airspeed data in the Bonanza POH, and the empennage wasn't strong enough. With the V-tail configuration (rudder-vators) a harmonic caused by high speed airflow between the surfaces would cause a twisting motion. The tails of the planes would, therefore, if flown near the middle of the yellow arc on the airspeed guage (originally), rip right off the plane! Beachcraft never admitted fault, but they did, quietly, revise their Bonanza manual on the plane, and two ways of fixing the issue were introduced. A tail reinforcment kit, or, later, an actual conventional tail replacement could be retrofit (a small cottage industry in such Bonanza conversions sprang up in fact).
The idea behind the plane's unique (at the time) design, was to help increase speed by getting rid of one more airfoil surface to reduce parasitic drag. It does work for that aspect of flying, though the airfoil surfaces ideally should have been slightly larger. The F-117A Stealth fighter takes advantage of this same concept very sucessfully.
Just an fyi. :)
(I found some errors in my post and corrected them.... that's what I get for typing while brain is flying faster than fingers can keep up with ;) )
Title: Re: Would this plane-concept work/be legal?
Post by: Sleek-Jet on February 21, 2006, 06:28:13 PM
I wouldn't go as far as calling a V-tail Bonanza dangerous... no more so than any other high performance single engine airplane. Not to say that there arean't flaws in the design, but it is an elegant solution to parisitic drag problems. They do suffer from marginal directional stability in turbulance (that's why they are called the Wiggle Wagons...), and it should also be noted that the convetional tail Bonanza wallows around in the bumps as well.
What didn't help things, is the control surfaces are very particular to static balance. If an "elevon" had been worked on or painted and not re ballanced, they had a habit of coming off in flight, usually followed by the rest of the tail. That's not a design problem, that's a maintenance/owner problem.
But what it boils down to... is why are you operating any airplane into the yellow arc routinely in the first place??? Cessna 210's have a habbit of shedding parts when operated into the yellow and the add a little turbulence. But nobody goes around saying how many lawyers have died in Centurions. (It has been my experiance, the doctors fly Beechcraft, lawyers fly Cessna... ::))
Title: Re: Would this plane-concept work/be legal?
Post by: Gulfstream Driver on February 21, 2006, 07:21:02 PM
I wouldn't go as far as calling a V-tail Bonanza dangerous... no more so than any other high performance single engine airplane.
Good point. I guess the main problem was people with a lot of money buying an airplane and then not getting enough training. Cirrus is having the same problem right now.
Title: Re: Would this plane-concept work/be legal?
Post by: Frank N. O. on February 21, 2006, 10:19:32 PM
Wow a lot of great posts :)
The idea for the hybrid was both optimum fuel-use even though this is a lot easier in an airplane vs. a car since they don't accelerate nearly as often, but also to try and clean up the cockpit of half a dozen levers per engine but maybe I should re-think and use the gasturbine to drive the ducted fans instead, but to have just one set of controls mean I can only have one engine and wouldn't that make it a problem to have twin fans? It would need to be co-axial correct? And how much power-loss would that be besides the reduction-gear? Furthermore, does ducted fans still have adjustable pictch or only conventional props? FYI I planned on using showels of some kind to provide reverse-thrust and I'd planned on having a transverse hand-grip handle for the throttle with the switch for reverse-thrust on a thumbswitch of something similar to be able to land fast with all needed controls within reach for increased safety.
The split V-Tail was inspired from the Black Widow II but I also though of what I've read about stall-problems with different tail-positions causing the elevator to be in the turbulence and therefore loose effectiveness and with a angled section then there should be at least part of the wing in clean airflow, bus as I said, I'm just an enthusiast that have picked up stuff here and there and not an engineer sadly.
One more question btw, how come even so-called wide cabin GA planes like the Commander 112/114/115 are still a lot smaller on the inside than even a european minicar, specifcally in width/shoulderroom? One place even said the Commander is slow because of it's big wide cabin give it a big drag.
Frank
Title: Re: Would this plane-concept work/be legal?
Post by: fireflyr on February 24, 2006, 01:40:52 AM
Frank, it's all about drag, Think, wide cabin, more surface, more drag! Jim
Title: Re: Would this plane-concept work/be legal?
Post by: Frank N. O. on February 24, 2006, 02:25:48 AM
I can understand that, but how can adults fit in the cabin? Try to sqeeze some healthy sized (not overweight) americans into a Peugeot 206 and they're most likely going to complain about it being cramped, but the cabin of it is much bigger than even a Commander let alone a Cessna or Piper GA single according to drawings and measurements I've seen.
Frank
Title: Re: Would this plane-concept work/be legal?
Post by: Sleek-Jet on February 24, 2006, 02:45:29 AM
I'm not familiar with the Puegot you're talking about... but the average light airplane cabin is about the size of an American compact car... with one big difference... cabin height. You sit up in most GA airplanes (Mooneys and Bellancas excepted). People don't need as much room when they sit up, rather than reclined as in most cars. Also, most of the front seats are on sliders, so you can stager them to achieve more shoulder room.
I've flown Cessna's with some rather large people sitting next to me, and room has never been to much of a problem.
Title: Re: Would this plane-concept work/be legal?
Post by: Frank N. O. on February 24, 2006, 03:31:18 AM
Be lucky you don't know a 206, soft brakes that wear fast, rough running engine despite computercontrol and bad feedback on the power-steering (former car: 1989 Ford Orion aka sedan-version of the european Ford Escort, aka Ford Verona in south-america).
The 206 is 165cm (65.0 inches) wide in the normal version (the GTI has slightly flared arches) and the inside cabin width over the armrest at the front-seats is about 140cm I think I measured it at. According to a drawing I found then a Commander 114's ditto measurement is 46.5 inches or around 118cm, and from what I remember then I found out the Commander is wider than most other singles.
Frank
Title: Re: Would this plane-concept work/be legal?
Post by: Gulfstream Driver on February 24, 2006, 04:00:18 AM
I've flown Cessna's with some rather large people sitting next to me, and room has never been to much of a problem.
Must not have been a 152...
Title: Re: Would this plane-concept work/be legal?
Post by: fireflyr on February 24, 2006, 10:29:44 AM
Actually Frank, I agree with you. I'm 6'3" 225 lbs and I've been squeezed in a lot of GA cockpits. Been offered flights in a Mooney Mite and a Baby Ace but couldn't get in the darn things because of the legroom.
I had a 330 lb student in a 152 (instructors, do the W&B on that one) for comfort I had to keep my left arm behind him--he spun out of a REALLY poor steep turn and I was rather busy for a moment trying to get throttled off and recover before it went flat, scared me a bit!
But the fact remains, smaller cabins make for smaller airplanes which make for less parasite drag and we ain't gonna see much relief in the training airplane department.
I also wanted to own a bug eyed Austin Healy Sprite back in the 60s but couldn't because I couldn't fit---Hell, I've got a 54 Jag XK120 now that I have to drive in my stocking feet cause there's no leg room so the problem is not confined to aircraft.
Jim
Title: Re: Would this plane-concept work/be legal?
Post by: Sleek-Jet on February 24, 2006, 02:36:17 PM
I'm 6'3" 225 lbs and I've been squeezed in a lot of GA cockpits. Been offered flights in a Mooney Mite and a Baby Ace but couldn't get in the darn things because of the legroom.
I had a 330 lb student in a 152 (instructors, do the W&B on that one) for comfort I had to keep my left arm behind him--he spun out of a REALLY poor steep turn and I was rather busy for a moment trying to get throttled off and recover before it went flat, scared me a bit!
Haven't done a W&B on a 152 in a while, but isn't the useful load like 600 lbs? How much gas did you take along? :)
We used to have a 152 for training. Before I started with Eagle 1, they had a larger student that wanted to take a check ride in it. The DE on the fiel weighs about 250. They had to keep coming back to get gas.
Title: Re: Would this plane-concept work/be legal?
Post by: fireflyr on February 25, 2006, 02:37:39 AM
AW, we had full tanks (the only time I got too much gas is if I'm on fire)
It ain't pretty--W&B out the aft end
Title: Re: Would this plane-concept work/be legal?
Post by: Gulfstream Driver on February 25, 2006, 03:31:25 AM
That's impressive. How much runway did you use?
Title: Re: Would this plane-concept work/be legal?
Post by: fireflyr on February 26, 2006, 07:25:22 AM
Can't recall but how much but performance was OK. We were flying off Cloverdale which is about 2,400. If I had it to do over, I'd refuse to fly with him but I was pretty hungry in those days and hungry sometimes makes for stupid.
Title: Re: Would this plane-concept work/be legal?
Post by: Ted_Stryker on February 26, 2006, 10:19:15 PM
I did my primary flight training in C-152 II's through Parks Air College (before St. Louis University took them over). Between me, and my instructor, we were most definitely W&B challenged! I remember some long takeoff runs, but fortunately I was flying out of KSUS and KCPS, both of which have nice long runways, and the elevations here run between 400 and 500 MSL on average. Even so, on a hot summer's day, we took up quite a bit of runway!
I saw one of the old birds I used to fly still out there at what is now SLU-Parks at KCPS! When I looked into the cockpit on that one, it had changed very little, except for the mode C transponder (they didn't require mode C or mode S back in those days). I couldn't believe how small it looks now. I remember thinking... I spent 56 hours in THIS to get my license?!! On my long solo X-Country, it was hot, and turbulent, and I had to stay below 3000 for part of my final leg, right over the Mississipi River. I got bounced around pretty good from all the radiation heating causing convection in the atmosphere down low. After I got down, I felt like I'd been flying a riding lawnmower with wings!
Despite all that, it was one of the best memories I have of flying. It was a challenge, and fun, and a huge step in my flying career.
I still prefer the greater weight and size of a C-172 though.... of course, if you have a hot date to fly with... a C-152 can bring that "extra closeness" only a tiny plane like that can ensure ;)
Title: Re: Would this plane-concept work/be legal?
Post by: Gulfstream Driver on February 27, 2006, 01:26:35 AM
I think Cessna required poor door seals for all 152's. There was one day last winter when my student and I had to come back early because we got cold. If it got below 0, the instructors really didn't want to fly.
Title: Re: Would this plane-concept work/be legal?
Post by: Ted_Stryker on February 27, 2006, 03:29:38 PM
I think Cessna required poor door seals for all 152's. There was one day last winter when my student and I had to come back early because we got cold. If it got below 0, the instructors really didn't want to fly.
I will say one thing in defense of our trusty C-152's.... it's small enough where one can use the doors as turning mechanisms in an emergency situation! I actually trained in using them for steering as a last resort. With my short arms, I couldn't do it in a C-172, but in a C-152, no problem! :)
Title: Re: Would this plane-concept work/be legal?
Post by: Gulfstream Driver on February 28, 2006, 12:48:47 AM
Neat. I've never heard of that, but it makes sense.
Title: Re: Would this plane-concept work/be legal?
Post by: Frank N. O. on February 28, 2006, 02:50:54 AM
With regards of drag then couldn't one make the cabin lower by not having the folding gear under the cabin, and having a lower instrumentpanel so you sit more like a sporty car? I for one would rather sit reclined (a'la F16 for instance) in a wide cabin where I had shoulder room than sit twisted with room for a 10-gallon hat.
I couldn't help but picture you two crammed into the tight cabin with you trying to catch it with one arm locked behind him, I know it was serious but since it went ok I hope it's ok to laugh at the visual of you trying to work with almost no space, of course I'm not laughing at the crash-risk! Btw, pardon the question, what does DE and W/B mean? W/B = Weight and Balance, used for fuel-calculations for the trip?
I've never heard of anyone using doors for steering, but I did read a review from a real pilot for a FS-add-on C152 where he said it could be steered using just rudder like the real thing since it was so light and slow.
How big/heavy is a 177 vs 152, 172 and 182 btw? As the story goes the Cardinal was supposed to replace the Skyhawk, originally it was designated 172J if I remember correctly, and it was supposed to be more powerful and advanced with a new tail, un-braced wing etc. Speaking of wings, is the 177 wing weaker than the other Cessnas?
Frank
Title: Re: Would this plane-concept work/be legal?
Post by: Gulfstream Driver on February 28, 2006, 05:26:04 AM
Yes, technically, you could recline the seats to reduce ceiling height, but you have so many things to consider. Is the spar going through the cabin, over, under? If it goes through, where do you position the seats? In the Columbia, the front seats are on top of the spar. Most retractable gear end up in the wings (the mains, anyway). If I remember right, the normal distance between the main gear is about 1/3 the wingspan. Of course, you could always have fixed gear...Makes the plane lighter, but you have added drag.
DE is short for Designated Examiner. The FAA choses certain flight instructors to test applicants for certificates and ratings.
W/B is Weight and Balance. You're right, it is used for fuel calculations, but it's also used for determining if you're under the max gross weight and within the center of gravity envelope of the airplane and in calculating performance. Pretty much everything your airplane does is affected by weight.
The Cardinal is a little bigger than the 172. Basically Cessna's answer to Piper's Arrow. It's got a 200 horse engine and (I believe) a higher gross weight. The 182 is bigger yet and high performance (more than 200 horse). The Cardinal wing should be the same strength as the 172. It'll take 3.8 g's just like the 172.
Title: Re: Would this plane-concept work/be legal?
Post by: Sleek-Jet on February 28, 2006, 06:49:52 PM
The orginal 177 cardinal (the one that went into production, not the "concept" airplane) was designed as a replacemant for the 172. The wing was essentially a lightened 210 wing. However, because of the different wing planform and the fact that the airplane turned out heavier than expected, it was an anemic performer on only 150 horse power. In fact, the 172 would out perform it in most flight regimes. After a couple years, Cessna started putting 180 hp engines in the 177 and it wasn't to bad of an airplane. Later still came the 200 hp Retractable Gear (RG) version.
Also, the 177 was the only Cessna with a stabilator (ala Pipers) and there was a problem with stabilator stalls during the landing flare on the first models. This was solved by adding a slot along the leading edge of the stabilator and limiting up travel as well...
In the end, I think Cessna discovered that it was marketing it's version of a Piper Cherokee to Cessna pilots, and the airplane wasn't nearly as popular as what it was slated to replace. So, the 172 is still here...
Little bit-o-trivia... Cessna actually built and flew a 187, based on the 177 design, but with a slightly large fuselage and 230 hp engine designed to replace the 182... it proved not to perform any better than what it was designed to replace and never went into production.
Like GD stated, the 177 wing was certified to the same strength limits as the 172... so they are just as safe in any normal flight envelope.
Title: Re: Would this plane-concept work/be legal?
Post by: fireflyr on February 28, 2006, 10:45:00 PM
Frank,
What Sleek Jet and Gulfstream said is exactly right and probably put more concisely than what I might have replied with, I only wish to add one thing.
The W&B concern I had with the large student and myself in a 152 when it stalled was that with the center of gravity located so far aft, the aircraft could have gone into a flat spin if not recovered to normal flight soon enough. A flat spin is one in which the airplane is rotating with the fuselage in a horizontal position, more or less nose level, caused by excess weight in the rear acting on centrifugal force to keep the airplane stabilized in that position. The problem there is that you need to push the nose down to break the stall before you can stop the spin with rudder and if you can't do that, it will rotate merrily all the way to the ground which will, of course, stop the spin, albeit somewhat abruptly, in what is known in aviation parlance as a "crash", an undesirable consequence. When this happens it is referred to as "screwing the pooch". You have to visualize a bunch of other pilots standing round a smoking hole in the ground saying things like "BOY, that idiot really screwed the pooch" and since most pilots are ego maniacs, to be spoken of in such derisive terms is also undesirable.
Jim
Title: Re: Would this plane-concept work/be legal?
Post by: Ted_Stryker on March 01, 2006, 04:46:16 PM
With regards of drag then couldn't one make the cabin lower by not having the folding gear under the cabin, and having a lower instrumentpanel so you sit more like a sporty car? I for one would rather sit reclined (a'la F16 for instance) in a wide cabin where I had shoulder room than sit twisted with room for a 10-gallon hat.
I couldn't help but picture you two crammed into the tight cabin with you trying to catch it with one arm locked behind him, I know it was serious but since it went ok I hope it's ok to laugh at the visual of you trying to work with almost no space, of course I'm not laughing at the crash-risk! Btw, pardon the question, what does DE and W/B mean? W/B = Weight and Balance, used for fuel-calculations for the trip?
I've never heard of anyone using doors for steering, but I did read a review from a real pilot for a FS-add-on C152 where he said it could be steered using just rudder like the real thing since it was so light and slow.
How big/heavy is a 177 vs 152, 172 and 182 btw? As the story goes the Cardinal was supposed to replace the Skyhawk, originally it was designated 172J if I remember correctly, and it was supposed to be more powerful and advanced with a new tail, un-braced wing etc. Speaking of wings, is the 177 wing weaker than the other Cessnas?
Frank
As the other points about the 177, 182, 172, have been addressed quite well, my only other thing to add here is that yes, you can do a rudder-only turn in a C-152. In fact, it helped me out one day when I had a bad load of fuel and had to make a turn back to the airport after the engine started to go on me when I was only 300 ft AGL on a long solo at Lee C. Fine Memorial airport here in Missouri. You know all the AD's they have out now that make us deal with all those extra sump points? Guess what? If I had had that on the C-152 I was training in back then, I would have found that water in the tanks on pre-flight inspection! Instead, after liftoff, it jostled the water that was in the tank and got it to the fuel line. I couldn't have detected it ahead of time without the "wing shake - wait 20 minutes - sump" procedure that was put into effect about two months after my incident. For all I know, it was my incident that caused all those extra sumps and the new procedure that came about... ugh! Well... to make a long story short, the engine RPM was beginning to drop, and I was getting rough running after I was at about 300 FT AGL. I had a tree covered mountainous region all around, with a lake straight ahead where people were powerboating. My only choices were, 1) Try to make it back to the airport, 2) land into the trees and probably die but not take anyone else with me, or 3) ditch in the lake and probably drown as the plane sank, and possibly take some poor powerboater with me. I opted for #1. I used rudder-only, to avoid as much loss of lift in the turns as possible, trimmed, and then made it to the numbers just as the engine was about to completely fail. I made it off the runway to the ramp area. Turns out they had just refueled the fuel truck they had used to fuel my plane, and they had not sumped the truck properly (if at all).
Now, I always get fuel before I preflight if I need it, and sump last. That way if there is any water in suspension, or in other areas of the wing, it has time to settle out and be sumpable.
So, the short and sweet of it is, not only can you steer with the doors on a C-152, so can you steer/turn with rudder only. I trained in both techniques as part of my initial training. Both techniques work quite well :)
Title: Re: Would this plane-concept work/be legal?
Post by: Sleek-Jet on March 01, 2006, 05:01:38 PM
You can steer/turn with the rudder in any airplane.
Title: Re: Would this plane-concept work/be legal?
Post by: fireflyr on March 01, 2006, 10:08:57 PM
Good way to practice spin enties also-----be careful with airspeed if you're gonna be doin' that!!! :o
Title: Re: Would this plane-concept work/be legal?
Post by: Frank N. O. on March 04, 2006, 02:50:14 AM
Sleek, I thought generally it was hard to do in larger planes which is why you use banking instead?
Thanks for the info on the 177, so overall it's still a nice plane after it's updates :) I wonder if it's possible to update the engine with a fuel-injected one from a later model 182 perhaps. And speaking of 182 and 177 I've actually thought about a 187 on several occasions but I'm surprised to hear a prototype was made. Does anyone have any pictures of it? I tried searching but couldn't find anything, even if one picture caption said a person and his Cessna 187 but it was identical to a 182 so it was probably an error.
Fadec, I saw that on the A Helicopter Is Born show with that english vet. Is it some kind of dual redundancy electronic engine control system?
Thank you for the replies :) Frank
Title: Re: Would this plane-concept work/be legal?
Post by: fireflyr on March 04, 2006, 03:35:27 AM
Full Authority Digital Engine Control is the much touted new power control system that I was hoping someone out there had flown and would report on. It is a system that uses a single lever, through computers, to control mixture and RPM relative to the power setting selected. Has anyone flown one yet---I would be interested in hearing your impression of it?
Title: Re: Would this plane-concept work/be legal?
Post by: Gulfstream Driver on March 06, 2006, 06:37:15 AM
Sleek, I thought generally it was hard to do in larger planes which is why you use banking instead?
It's more efficient to bank through a turn. The rudder is generally used to remain coordinated throughout the turn. However, the rudder is also used for uncoordinated flight whenever it's needed (slips, etc.) and I usually use it to level the wings in normal cruise flight rather than adjusting the ailerons. It's a lot less fatiguing to fly hands-off as much as you can.
Title: Re: Would this plane-concept work/be legal?
Post by: Inept on March 07, 2006, 04:33:45 AM
Has anyone flown or have any opinions on centerline thrust, push-pull twins? In a push-pull, does the tail engine need to be a standard engine, or one that rotates the shaft the other way, or does it matter, since it can be geared to work whichever way it needs to (at a loss of power, of course)?
Title: Re: Would this plane-concept work/be legal?
Post by: fireflyr on March 07, 2006, 10:07:04 AM
Has anyone flown or have any opinions on centerline thrust, push-pull twins? In a push-pull, does the tail engine need to be a standard engine, or one that rotates the shaft the other way, or does it matter, since it can be geared to work whichever way it needs to (at a loss of power, of course)?
I've flown Skymasters the last four years on government contracts and have accrued about 750 hours in them. The engines are identical but since the rear engine is pointed backwards in a pusher configuration it counter-rotates thereby eliminating any torque or P-factor. The turbocharged engines in mine put out 225 HP and in our pressurized model, they are boosted to 235 HP which is a lot for a 360 ci 6 cylinder and makes them rather heat sensitive, especially the rear one.
Overall, the push-pull concept is a good one and eliminates the critical engine problem inherent in most twins. Unfortunately, the 337 series has a high accident rate BECAUSE it's so easy to fly single engine and the reason for that is many pilots become complacent about practicing engine out procedures. They tend to forget that in the average light twin, when you lose 50% of your power you also lose about 85% of your performance, that equation stays the same regardless of where the engines are mounted so you need to practice single engine procedures on a regular basis. The turbo'd Skymaster has a single engine ceiling of 13,500 with the rear one feathered and 15'000 with the front engine caged (or about that--I need to check the manual) which illustrates the efficiency of a pusher configuration. Most accidents occur when an engine is lost on takeoff and the pilot does not adhere to airspeed discipline. For example, if either engine quits at or below rotation you WILL retard both throttles and continue straight ahead on the runway regardless of how little distance is remaining. Many accidents happen in this airplane because pilots don't recognize a failed engine immediately and try to fly away with a severe performance impairment. Sounds stupid but it has happened a lot.
In addition, the Skymasters are noisy inside and have a small payload when carrying full fuel. The government uses them because of a contract requirement calling for high wing multi engine aircraft.
To sum it all up, I fly one because I'm paid to do it---If I were buying an airplane for my own use it would not be a Skymaster! Jim
Title: Re: Would this plane-concept work/be legal?
Post by: Frank N. O. on March 08, 2006, 06:19:13 AM
Dornier made such a plane during WW2 for Germany too, it was said to be very fast, and looks quite stunning but it didn't make it in big service I believe. A former payware version was recently released for MS FS2004 if anyone's interested in that.
I'd prefer counter rotating co-axial props but I guess the trasnmission system is a bit complicated but it has been done, also for WW2 fighters like a Corsair and Spitfire I think, special versions only though. Btw, speaking of turboprop's, would it be possible to convert a Commander or Cardinal to turboprop configuration if a small engine with the same power even exists that is? And how does a small turboprop engine compare with a fuel-injected piston-engine with the same power output? (circa 200-250hp)
Frank
Title: Re: Would this plane-concept work/be legal?
Post by: Sleek-Jet on March 08, 2006, 02:38:42 PM
Dornier made such a plane during WW2 for Germany too, it was said to be very fast, and looks quite stunning but it didn't make it in big service I believe. A former payware version was recently released for MS FS2004 if anyone's interested in that.
I'd prefer counter rotating co-axial props but I guess the trasnmission system is a bit complicated but it has been done, also for WW2 fighters like a Corsair and Spitfire I think, special versions only though. Btw, speaking of turboprop's, would it be possible to convert a Commander or Cardinal to turboprop configuration if a small engine with the same power even exists that is? And how does a small turboprop engine compare with a fuel-injected piston-engine with the same power output? (circa 200-250hp)
Frank
The big deal with small turbines is the cost.... there are a few small gas turbines out in the homebuilt market, but not many of them (if any) have flown. But, back to the cost, a gas tubine is about 4 times the cost of a comparable piston engine. Also, another thing to keep in mind, gas turbines use alot of fuel at lower altitudes (where you would most likely fly something like a cardinal or commander), so your range ends up shortened quite a bit.
There are a few STC conversions using the RR 250 (i.e. Allison) turbo shaft engine. But, those are for the Cessna 206/210 and Bonanza airframes. A company called Soloy does most of them.
Title: Re: Would this plane-concept work/be legal?
Post by: Frank N. O. on March 11, 2006, 05:19:23 AM
Strange, I've heard gasturbines are the most efficient combustion engines there are, so why do they lose to the pistoin engine at low altitde? Another reason for the idea is also that besides not needing a manual mixture to adjust then a gt can run on several different types of fuel and that might be practical in the near future.
Frank
Title: Re: Would this plane-concept work/be legal?
Post by: Frank N. O. on April 19, 2006, 10:51:46 PM
I tried to find some pictures of the Cessna 187 and while I didn't find that I did find more info and a describtion on this page: http://www.wingsoverkansas.com/features/article.asp?id=461 It says it was designated 343 and had a T-tail, but still no picture of it. Does anyone think it's still in existance or have they smashed it decades ago?
Frank
Title: Re: Would this plane-concept work/be legal?
Post by: Gulfstream Driver on April 19, 2006, 11:07:32 PM
I'm having a hard time picturing a t-tail Cessna. :)
As to your previous post, Frank, GT engines automatically mix air and fuel. The more air you have, the more fuel you need, so at low altitude, a piston engine will use less gas than a turbine.
Most turbine engines I've heard of run on jet fuel. I know that diesel and kerosene can sometimes be used as replacements, but I've not heard of any other options. Have you heard something different?
Title: Re: Would this plane-concept work/be legal?
Post by: Frank N. O. on April 19, 2006, 11:21:31 PM
Yeah I can't picture it either, but I'd really like to see a photo of it, and actually another site listed that both tail-versions were tried and it gave the reg-number of the plane. And it also said the 177RG prototype was designated 1008 I think it was. Funny thing, several sites lists a Cessna 187 but shows a 182 model, maybe there was a local designation in some countries? Maybe a Reims variant, or that other license company that made Cessnas?
Gasturbines in general can run on anything that can be burned. The Chrysler was tested on cognac and Chanel Number 5 perfume. I was also thinking that a diesel-engine might be a good alternative to the GT engine for a more conventional parallel twin engine version of my concept, especially if fitted with particle filters that would both be a good, simple and clean engine and the diesel's torque must be well-suited for planes although it seems like it would need a reducation-drive judging from the 1.7 Thielert engine's RPM range being the same as in a car, up to 4000 rpm. The lack of an ignition system and intake valve like a gasoline engine could also be good (ignition for reduced engine-failure hopefully and the lack of an intake valve is a problem on part throttle for efficiency in a gasoline car-engine but really hard to replace but BMW is doing it via one heck of a complicated system with hydralic valves and such).
I'd like to know if the self-ignition function still works correctly at various temperatures but maybe the turbocharging/normalizing eliminates that possible problem.
About the tail then I plan on asking about the various tailpositions in terms of stability esp. in terms of stall and such.
Thanks for the replies :) Frank
Title: Re: Would this plane-concept work/be legal?
Post by: Gulfstream Driver on April 19, 2006, 11:51:28 PM
I've never flown a diesel engine before, but I would bet it would work out a lot better than a gas-turbine.
Ask away. :) Not a bad way to get some free dual.
Title: Re: Would this plane-concept work/be legal?
Post by: Frank N. O. on April 20, 2006, 01:27:41 AM
Ok, exactly what does "dual" mean here? I first thought it meant flyingtime as a student with a instructor in the next seat but that can't apply in a forum, or can it? My first notion was it was referring to a 2 engine plane but I strictly know that as a "twin" so that was dismissed on the spot.
Frank
Title: Re: Would this plane-concept work/be legal?
Post by: Ted_Stryker on April 20, 2006, 01:35:32 AM
Ok, exactly what does "dual" mean here? I first thought it meant flyingtime as a student with a instructor in the next seat but that can't apply in a forum, or can it? My first notion was it was referring to a 2 engine plane but I strictly know that as a "twin" so that was dismissed on the spot.
Frank
Dual time is the time logged with an instructor where you are not acting as PIC. Until you hold a rating for the category and class of aircraft you are flying, you can't act as PIC of that aircraft, so any instructional time is logged as "dual" time. You can log both "dual" and PIC at the same time too, if you are rated in the airplane and getting instruction, such as for a biennial flight review check, etc.
Hope this helps clear it up. :)
Title: Re: Would this plane-concept work/be legal?
Post by: Gulfstream Driver on April 20, 2006, 03:10:57 AM
Or when you're getting ground instruction. It's not always logged, but you usually have to pay for it. ;)
Title: Re: Would this plane-concept work/be legal?
Post by: Sleek-Jet on April 25, 2006, 01:38:06 AM
I'm having a hard time picturing a t-tail Cessna. :)
As to your previous post, Frank, GT engines automatically mix air and fuel. The more air you have, the more fuel you need, so at low altitude, a piston engine will use less gas than a turbine.
Most turbine engines I've heard of run on jet fuel. I know that diesel and kerosene can sometimes be used as replacements, but I've not heard of any other options. Have you heard something different?
Most gas turbines will run just about any petrolium product. Some are even certified to run 100LL gasoline, there are power charts in the manuals and such, since gasoline would burn hotter than kerosene (Jet fuel), and also shortened inspection times and what not, depending on how often you were to run it that way.
The operator of the FBO where I learned to fly tells of Shell oil running a Sabre 40 in the early 60's in the New Mexico/Arizona/Colorado area during the oil boom. None of the airports at that time had Jet-A on tap (remember, business jets were brand new, and King Air's and such were still a couple years away). They ran 100 octane through it. He said the tail was white from all the baked on lead.
Title: Re: Would this plane-concept work/be legal?
Post by: Frank N. O. on April 27, 2006, 10:28:34 AM
That's actually an important aspect I didn't think about, different combustion characteristics. Thanks for the interesting info and the history lesson |:)\
Frank
Title: Re: Would this plane-concept work/be legal?
Post by: spacer on June 03, 2006, 06:24:13 AM
I wouldn't suggest actually burning anything not acceptable by the engine manufacturer, however, unless you are willing to be a test pilot. Different fuels have different burn and flow characteristics, and if you aren't well versed in the engine type you're working with, I'd avoid alternate fuels entirely. This is where you need to be an engineer, unless you happen to have a turbine on a stand which you're willing to sacrifice. Though we covered turbines in my A&P classes, nearly all my work in the field was in recips, so I'm no expert. It seems that 100LL would bring the turbine inlet temp way up, way fast, and there may be problems with mixture as well. That being said, I'm sure some of the military or even other engines are designed with this in mind, but that would be beyond me without a little research. ...and my better half is giving me those eyes... you know... THOSE eyes... 8) research later...
Title: Re: Would this plane-concept work/be legal?
Post by: Roland on June 04, 2006, 08:34:27 PM
I love that statement and support it to the full extend. With simple words a complex problem is described.
Thilert (Diesel engines for the Diamond DA 40/42)found it not so easy to run a diesel engine on kerosene. Did cost a fortune to get things right and honestly it will cost another.
If you run an gas turbine engine on 100LL you’re limited to a certain time to do so. Its not only the temperature that maters but the dirt you will find on the turbine blades due to the additives within the fuel. Sulphur will kill the turbine blades.
Title: Re: Would this plane-concept work/be legal?
Post by: SteepTurn on June 04, 2006, 10:40:32 PM
Holy cow Frank, You are ambitious aren't you? Anything that flies sounds like fun but I'm one of those people who has no interest in inventing anything. I like it when those fan things either push me or pull me fast enough for the wing things to catch enough air to lift me high enough to go someplace neat, and the faster it goes, the better I like it. Your ideas sound fascinating, maybe you'll go on to make history with new concepts in aviation. There is always room for a better idea! Jim
ROFL!!!! good points!!
Title: Re: Would this plane-concept work/be legal?
Post by: SteepTurn on June 07, 2006, 10:32:08 AM
