No4

Being a spotter Marble, that is in fact classified as dihedral. Sweep is the angle of the wing to the airflow. Cherokee, Cessna, Cozy canard no sweep, 747 main wing 30' sweep, and is a Mach speed problem. Dihedral is used for lateral stability in the main wing of many aircraft. If one wing becomes lower than the other, the resultant lift force causes a sideslip which results in the lower wing producing more lift and righting itself. The opposite is anhedral, a down slope in the wing, which is more common in high wing types like the big Antonov 125 cargo rig. I'm sure you could be right that it is to allow clean airflow to the wing, as much as for stability.

DOH! http://www.alexisparkinn.com/aviation_videos.htm

Absolutely nothing to do with canards, but I would just like to share this with anyone that might enjoy seeing a V12 Merlin approaching an unawares TV presenter at 300 mph at about 5 feet. It's very good quality digital video, very slow to download, but definitely worth it!!!! Video - Oh My God! (make sure there are no kids in the room). Also Tex's barrell roll in the 707, and a very sad end to a B-52 attempting low level aero's.

Hi Chris, The standard small block Chevy, sits in a 2 tonne heavy car such as a Camaro and is capable of launching it 100 mph in say, 20 seconds. Any auto engine is constantly accelerating and decellerating throughout it's rev range in urban traffic, and then expected to work just as well cruising along at 70 mph. An aircraft engine can be given a severe beating in a trainer or military operation. But a Cozy for instance, on a long range X-country could be set for take off power, then 75% cruise power, then the descent and landing power. Most engines which run continously at 75% power will never exceed their temperature or torque limitations. From my experience of driving long distance trucks and operating machinery such as generators, as long as the filters and lubricants we're maintained there was never a problem. I suggest the de-rating concept as used in turboprop and turbofan/jet engines. Some are designed to produce 1200hp, but the operator sets maximum power at 1000hp, resulting in a 6000 hour period between ovehaul. Firstly chose a strong engine which is capable of more horsepower than you require, and one that is commonly modified. For example the small block Chevy. But it could be a Subaru, Mazda, Nissan, Ford etc. Using the 400 cu in aluminium block and heads, chose a racing crank, rods, pistons, and camshaft. Heat treat the engine, and use the finest gaskets, filters and seals. Make the cooling , electrical, ignition systems immaculate for the worst case scenario. With a turbocharger this engine could maintain over 500 hp at 20,000 feet. The engine will be rated to rev to 7500 rpm, so set your rev limiter for 5500 rpm, If it is rated to 15 psi boost, set your boost to 10 psi. Thus this engine designed to haul a NASCAR around Daytona at 200mph, at 50% of its maximum power, will be hauling your Cozy around at 200mph. It should never come close to exceeding it's torque, temperature, or pressure limitations. Of course you could set an override switch or a gate in the throttle to give you the full noise if you got in trouble and urgently required power. The big jets have a TOGA button (Take off go around) which deselects cruise power and allows full thrust if the throttles are opened. A full blown race engine will cost you a mint, but a good strong 300hp motor would be less expensive than a new or rebuilt Lyco/Conti. Did you know 99% of lawyers give the others a bad name? Only kidding.. Cheers

Fair question M, Any manouevre not exceeding the G loading should be possible. Inverted flight in any aircraft requires modification to the oil and fuel system. Stall manouevres would be unwise, for if the main wing is stalled, with the canard and nose high, the C of G now rearwards would result in a "deep stall". This will lead to a massive sinkrate and a possible irrecoverable attitude. Hello trees.... You are correct all aircraft can barrel roll, the 707 performed two barrel rolls over a Seattle yacht regatta when a prototype. Tex the chief test pilot (also chief test pilot of the X-1) was called in for an interview without coffee with the Boeing bosses and explained "Well Sir, you see it's a 1G manouevre". I know an ex-RNZAF flight engineer who was witness to a barrel roll in a Hercules at night. No one in the back woke up.

I'm guessing a hot exhaust/ pulsing exhaust/ vibration could be a problem in any turbo/supercharged engine. I believe there are chevy engines with aluminium blocks and heads which weigh as little as 300 lbs, capable of well over 400hp. Turbocharging is more fuel efficient than supercharging, but supercharging has it's advantages. Listed below are companies dealing in Ford/GM aero conversions http://www.beltedair.com/products.htm http://www.team-38.com/ http://northwest-aero.com/ JONES CUSTOM AIRCRAFT SERVICES PO Box 157 Laurelton, PA 17835 717-922-4877 sjonesfly@aol.com LIGHTNING ENGINES 4099 Brick Church Pike Whites Creek, TN 37189 615-865-1802 615-865-9164 (Fax Aviation Enterprises State: TN Tel: 615/865-1802 Fax: 615/865-9164

I agree entirely with cncdoc, imho piper or cessna gear wouldn't work / not worth it, but certainly possible. As for gear up's, well that's airmanship. Nearly all commercial aircraft are retractable gear, and failing to lower gear is not a common cause of accidents. Older Pipers and Cessna twins occasionaly experience partial gear failures, and the reccommended action is to land gear up to prevent the uncontrolable condition of one wing's leg up and the other down and locked. The Arrow has a horn which sounds if 20' flap is selected, or if the throttle is closed without gear down and locked. Below 100 knots the gear automaticaly deploys. So I would have to be attempting to land with power on and only 10' flap at above 100 knots and have forgotten my downwind, base, finals, and short finals checks for three greens. Unlikely. The last thing heard on the flight recorder of a South American 737 was "whoop whoop PULL UP TERRAIN!" in a recorded Seattle accent, followed by "SHUDDUP GRINGO!" from the Captain, followed by a loud bang and then silence. Largeprime, The only thing I can think of is a turbo and a gas mask, any good?

Links for Vortex Generators http://www.nar-associates.com/technical-flying/vortex/Vgs_stall_wide.pdf http://www.nar-associates.com/technical-flying/vortex/Vgs_cruise_wide.pdf http://www.smartcockpit.com/operations/Vortex%20Generators.PDF and links for winglets http://www.boeing.com/commercial/aeromagazine/aero_17/winglet_story.html http://www.mandhsoaring.com/articles/WL-Soaring.pdf

The link below takes you to the photo page of Thielert, for their water cooled Centurion 1.7 diesel. The photo's are too big to attach. http://info.thielert.com/centurion/main/photoarchive.php This link below shows the radiator and ducting of the 1.7 unit that has replaced an 0-320/360 in a Cessna 172. http://info.thielert.com/fotoarchive/45.jpg I imagine a Rotary would require as much or even more cooling than a 140 hp diesel. There are lots more photos including the intercooler set up, for three different aircraft types. cheers

This is what they put on the nose gear of 737's when operating into rough strips in Canada, to prevent stone damage to engines and airframe.

Marc, I'm in a similar position to yourself, sitting on a Pacific island doing my homework on how to build a Cozy. I can't say from experience, but I have learn't this. Burt Rutan, who designed the plane the Cozy is an enlarged version of, is a real minimalist. He says "If you can pick it up, drop it, and it falls to ground, then it's too heavy to go in one of my planes." He's obviously exagerating, but you get the point. If you look at the gauges in the Boomerang, there are 5 from memory, and each one is as big as your watch face. Nat Puffer has done an excellent job of designing a wider version of Burts lightweight EZ. I'm sure you could change some parts and materials, but you'd have to be confident with your structural analyses. Regarding the Titanium, I have here an article about the SR-71 Blackbird. In its design and manufacture Kelly Johnson, and the Skunk Works team at Lockheed broke new ground using titanium. Cadmium, as you say, which plates some tools is incompatible with Ti, and will cause failures, they had to make special tools, normal screws and bolts corroded aswell. The chlorine in tap water corrodes Ti, they had to wash the beast in distilled water. They had to make special drill bits and use a special lubricant for the holes, and any welding was carried out in a nitrogen chamber. Even marker pens were banned from the workshop, because of the Flourine they contained was causing corrosion. Sounds a bit risky eh? Best of Luck with the planning.

Jim, Would it be the ram air causing the rise in thrust? Anyway, wrong website for that. I'm not a jet driver yet but hope to be in the next couple of years. Yes you are looking at the wrong page in the CAFE report. Page 8 is a chart of TRUE airspeed. Drag is relative to INDICATED airspeed. If you look at the table on page 9, 8 lines down in the table headed Cruise Flight Data. CAS 155mph, 12,000 feet, TAS 186 mph, 6.5 gph, 28.6 mpg, range 1338 It is highlighted to help you find it That's the lowest indicated airspeed tested at 12,000 feet, and it returns the best range. Marc, Good work with the number crunching, personaly I thought it was a very good post.

There's not a lot I've seen on the net about turbonormalised aero engines, but I did find this. Turbonormalisation http://www.nar-associates.com/technical-flying/turbo/turbo.pdf The main site with lots of fascinating stuff http://www.nar-associates.com/technical-flying/technical_flying.html It refers to the Bonanza, but is appropriate for Dust's engine, you turbo rotary guys and hopefuly some day soon my Cozy uber diesel as well.

Sorry to pick holes again Jim, You are correct except for a sentence in the middle. "...thrust increased with airspeed, and drag did too (but a lot faster)...." To quote A.C. Kermode's "Mechanics of Flight" Whereas the thrust of a proppeller falls off as forward speed increases, the thrust of a jet is nearly constant at all speeds (at the same rpm). Whereas the fuel consumption in a reciprocating engine is approximately proportional to the power developed, the fuel consumption in jet propulsion is approximately proportional to the thrust. So dividing the drag by the air speed gives one an airspeed drag ratio. The lowest number ratio will be the best range cruise indicated airspeed, which will be higher than the min drag speed. The effects of altitude cause the True airspeed to increase, so the efficiency will be greatly increased, and range will be increased. Thus to get range jets must fly high. Your description of the graphs, and best endurance speed is spot on. ...edited to add, jeez Marc we've got a synchronised posting thing happening here with regard to the diesel, it being turbocharged, if you were to consider oxygen and high altitude cruise, you would have the same improvement in range, AND get there a lot faster because the true airpeed would be higher for a corresponding indicated airspeed and drag. The winds up there are also stronger, which gives you the option of climbing high to catch the big tailwind, or staying low to avoid the worst of the headwind .... I found this great site that covers all of what we discussed, and lots more; it refers to the Beech Bonanza, but is just as relative for the Cozy. http://www.nar-associates.com/technical-flying/technical_flying.html

....Edited to say Marc got there first whilst I was typing... Have to disagree with you very slightly there Jim, but in all you are very much correct. From the engines view point, flying for max range you would want to use full throttle (not choked), weak mixture, highest boost permissable for the mixture, and lowest rpm consistent with the charging of the generator and avoidance of detonation. Without a CSU and supercharger the job is much easier. From the airframes view point, the angle of attack that gives the best lift/drag ratio will give you best range, (the best glide speed,which will be very close to the maximum excess power available speed at sea level, which is best rate of climb). For a given weight this will give you an indicated airspeed for best range, regardless of height. The altitude you choose will be decided by the engine and propeller efficiency, as long as you maintain the best glide indicated airspeed. However that is in nil wind conditions, and you are correct regarding the speeding up / slowing down. The half rule of thumb I heard was to add half the headwind/ subtract half the tail wind, but I believe mathematicaly it is not quite correct and the equation is a bit of a monster. In a strong tailwind you would utimately want to fly at min power speed, ie max endurance.

Well Dust if you fit the prop on, and give it the whoomer (that's full power to you), you've got a firebreathing 220 hp monster trying to rip the test bed off it's moorings, if not properly secured she'll be through the hanger wall and ploughing across the apron with people running for cover! Or if you do manage to secure it well enough, you'll have a mini cyclone blowing @#$% all over the place. The clubs are fat and heavy, and the shape of it produces neutral thrust, just lots of drag, which absorbs all the horsepower.

Marc, You are correct regarding glide speed and rate of climb. Incorrect of me to say more lift, yes higher lift coefficient, but definitely more drag at high and low AofA. regarding Cl My book converts the kilos to Newtons, which would pretty much put you one decimal point out by my reckoning. I make the wing areas to be 7 and 9 m2. Which brings us to around 0.2 .

Dust, Regarding the turbo problem, I've been told that you have to plan your descents very well to prevent cooling problems. The engine will run hot, with a lot of heat trapped in the turbo and exhaust manifold. If you suddenly cut from 75% (less than 31", more like 27" I guess) power at 15,000 feet travelling at over 200 mph, the front cylinders will freeze, whilst the rear ones will cook. Bang bang hello trees. I'm told the trick is cowl flaps open at the end of the cruise to commence cooling, cowl flaps closed and a slow reduction in power and speed to commence the descent, and then a smooth trip down . As you approach the circuit you have to warm the engine back up, otherwise full power in the go around might be catastrophic. The Cozy is pretty slippery! So it might take some thinking out. Very excited down here in NZ to find out how the beast will go when she is ready. Have you got yourself a pressure suit? Don't want to get the bends up there at Fl 250. I was reading about a guy in a small GA turbo plane forget which) who was up at 30,000 feet. All the Airline Captains passing were saying " What the hell are you doing up here!".

Easy Gents! Cheers Shender, no offense meant. No Marble I think we have about got it. You are right that the Lanc is more slippery, and smaller. I agree the naked eye is a very good judge of aerodynamics. I've looked at lift coefficients for ages, and never really understood what they realy meant until last night, using an actual example. I went through an aero book I have that explains it very well. In the back of it is a long section of aerofoil data. At every angle of attack an aerofoil has a coefficient of lift, and one of drag, and thus a lift to drag ratio. At the optimum AofA (usualy 4') the lift/drag ratio is furthest apart.(Best rate of Climb speed) At a higher AofA there is more lift, and more drag (think of a Cessna 172 full power, nose up 40 mph) At a lower or even negative AofA the lift reduces until it becomes less than the drag.(approaching VNE) Think of the difference between a Spitfire wing and a Piper Cup's wing, different aerofoils, different airspeeds. Of an equal span the Cub would lift more weight, but would stop working before the Spitfires has even got started. The Lancair has lower lift and drag coefficients, which means it needs a higher CAS to achieve the same angle of attack. The cozy is designed for slower operation, has more lift, more drag and reaches its optimum AofA at around 120 CAS, at this speed the Lancair will have a higher angle of attack, and a poor lift/drag ratio. As we reach 200 mph the Cozy's AofA is reducing to 0', and it's lift to drag ratio is decreasing, whilst the Lancair is still at maybe 2' and it's lift to drag ratio is at it's optimum. Thus an aerofoil designed for higher speeds will have poor slow speed performance, and an aerofoil designed for low speeds will require an enormous amount of power to increase speeds at 0' AofA. The Lancair has a faster wing, and thus is more efficient at high CAS. The design coefficients are 0.2 for the Lanc, and 0.5 for the Cozy, which agrees with my theory. Marc, I worked out the Cl for both types and got 0.2 and 0.18, whereas you got 0.05. Could you run me through how you calculated that?

Right on Largeprime, Not an argument as to the $$$$ of modifications, we were comparing airframe aerodynamics. Why bother to rubbish the thread if you don't care? Some of us have been working pretty hard on this one. From my workings 0 - 150CAS Cozy is more efficient 150 - 180CAS becoming neck and neck 180CAS - Lancair pulls ahead

I agree pretty much entirely with that Marc, The Cozy is a larger aircraft, 18% wider and with 33% more wing area, which at 300 lbs off max weight, is slightly out performed by a smaller aircraft at max weight, at speeds above 180 mph. (If we agree that RG is worth 20mph, and the csu helps fuel efficiency). So the Cozy's Lift to Drag ratio must be worse at around 200 IAS. Meaning a higher coefficient of drag. However, the best rate of climb speed for the cozy is 20 mph less than the L320; The minimum sink rate is 20 fpm less for the Cozy, and their glide ratios are 1.5 in the favour of the L320, yet they coarsend the prop, whilst setting the Cozy to idle. I'm willing to go out on a limb and say with identical prop, same same numbers. Furthermore the Cozy achieved almost the same climb performance with a fixed pitch prop as did the Lancair with a CSU. The Cozy vne is 50 mph below the Lancair. At 100 mph, the L320 uses as much fuel as the Cozy with fixed gear and a prop out of its speed range. Looking at the chart again, I see the best MPG for the Cozy is 28.6(155 CAS), and the best for the Lancair is 30 MPG (190 CAS). This for me explains the design lift coefficients, which of course do not remain constant with AofA and CAS. I'm not sure how you calculate your lift coefficients, Marc, but I get 0.2 (L320) and 0.18(Cozy) at 200mph and 8000 feet. Using the design coefficients, I get 130 CAS best speed for the Cozy(Va is 138 CAS) and 180 CAS for the Lancair (Va is 165 CAS). So, one larger aircraft designed for operation between 150 and 200 mph is better( more efficient) at doing that, and the other, smaller, designed for slightly higher speeds is better ( more efficient) at doing that. I'm off to NAAFI for a cup of tea

"<... l320 lift coefficient is 0.2, the cozy's is 0.5 ...> Just how was that arrived at? " Page 11, both CAFE reports "Anyway, I'm losing track of what the squabble is actually about" Trying to compare airframes, discounting gear and csu, refering to CAFE reports. So far we can say RG is worth 15 to 30 mph on the Cozy, bringing the performance pretty close. "But nevertheless, we who can't quantify much of anything at all are now trying to parse all of the factors that go into the CAFE result, guessing at some, ignoring others and (predictably enough) getting hopelessly tangled up in our underwear. It would be nice if someone would explain exactly what any of this means in the cosmic scheme of things" Speak for yourself Jim, if you are not interested or have anything constructive to say then don't bother to post.Personaly I've found it a very interesting and educational experience to analyse these reports. I think we have done a pretty fair job so far, sorry if you are disappointed. <... What I am trying to understand is how a canard pusher, which should be 10-20% MORE efficient, is 10-15% LESS ...> I would be inclined to revisit the premise. Where is that carved in stone? In some particular aspects it may very well be, but overall I suspect it probably is not." Using the CAFE figures at 8.5 gph "If the Lancair is 14% faster, all we have to do is increase power by about 50% and we'll go just as fast. Of course fuel economy might suffer a tad." Don't agree with that I'm afraid, as I think we have established. I agree the prop at the front is more efficient , but on the cozy's side it has undisturbed flow over the canard, fuselage and wing. Anybody found the matches? Sure is dark down here.

Lift co efficients are straight out of the CAFE reports. Which the thread was started to compare,as is the 222mph versus 195mph at 8.5 gph; weights were considered the same, horsepower the same. The cozys drag co efficient must be higher than the L320, but it appears the lift/drag ratios are similar. Parasite drag is not to do with the wings, it refers to pitot tubes, props, aerials, and undercarriage. Form drag or profile drag is that of the frontal area of the aircraft, and skin friction drag refers to the surface area. Induced drag being that created by lift. The Cozy has more wing area, yet is shorter by nearly five feet. Skin friction drag may even be less, it depends on the total surface area. I think Marc, if you re read your last paragraph you have summed up the dilemma for all aircraft designers, you want the wing as wide and narrow and thin as possible, yet at the same time as short, deep and as long as possible. By the way, I didn't say that was all their was to aerofoil design. Still standing by my assertion of very comparable performances at 8.5gph.

"If you don't understand aerodynamics, at least pay attention to what the facts show" Not sure who you think you are and where you get off Marc. It's not in a canard but my experience of retracts and csu is 25 knots true which is 29 mph improvement. Infinity who make the gear claim 25 mph. We were comparing the airframes, and trying to ascertain the improvements in performance from retracts and csu, to then compare the airframes. Even you agree on 20 mph, which takes us, with reference to the CAFE report to 215 mph and 25 mpg. Not a million miles from 222 mph and 27 mpg is it? If per chance you might be wrong, and I, perish the thought, am correct, then we have 225 mph and 27 mpg. Bingo Largeprime. Pretty similar performance in my book. The cozy is 4.5 feet wider, or 18% the l320 chord is 48" tapering to 29", the cozy 93 tapering to 21 wing area is 76sqft for the l320 and 101.4 sqft on the cozy, or +33% the thickness ratios are similar the loading is between 1 and 3 lbs more per sqft on the l320 The power to weight ratios are almost identical. Quoting Marc "And this is a big difference. Going by your numbers, the COZY MKIV has 33% more wing than the Lancair 320/360 (Don't just call it a Lancair - there are many models of Lancair). That's a HUGE difference - there will be 33% more wing profile drag, and depending upon the drag polars of the respective airfoils, the fact that the Lancair will be flying at a higher Lift Coefficient (at the same speed) means that it might even have less induced drag." l320 lift coefficient is 0.2, the cozy's is 0.5. A 33% increase in wing area does not mean a 33% increase in profile drag. Profile drag is the wetted area presented to the airflow, nothing to do with surface area. 1 *10 and 10 *1 have the same area 1/10th frontal area. The Cozy is wider by 18%, yet it's wings end narrower and thinner, so you cannot guess the increase in Form drag, or the induced drag. CSU vs Fixed Pitch for economy, performance, engine longevity; no contest. Back to the 24 hr ration pack and ready for the artillery....

So wheel pants make 12 mph difference, but removing them altogether from the airflow couldn't make 27 mph difference. Interesting logic. I've sat in a Lyco plane with the pic explaining to me that 75% power at 8000 feet was 2900 rpm. I just sat there fingers crossed waiting for the bang clunk clunk noises. Much rather have a csu.