No4

Sorry Jim, That's the formula for increasing indicated airspeed, or in other words cruising closer to Vne. Which of course means a reduced angle of attack, and a poor lift to drag ratio. You might want to check this link http://www.av8n.com/how/htm/power.html#sec-sketch-power-curve May I refer you to section 7.5.4 I think you will find that it is the power to weight ratio that controls top speed. Some interesting propeller driven figures ATR-72 4000hp -20000kg-5kg/hp=250ktas Bae Jetstream 2250hp-9000kg-4kg/hp=300ktas Fairchild Metro-1500hp-7000kg-4.6kg/hp=300ktas Beech King Air-1500hp-6500kg-4.3kg/hp=300ktas Beech Starship-1800hp-6500kg-3.6kg/hp=300ktas My Cozy TurboDiesel 2005'-300hp-1000kg-3kg/hp=300ktas and you can eat my Kero fumes if you don't believe it. By the way, it's pretty easy to take your engine when it's ready to the dyno shop and run a test on it. You could then get all tricky like the test pilots do, and weigh everything in the plane before and after the flight, record speeds, fuel flows, airspeeds. If you can't get to a dyno, the specific fuel consumption figures for most aero engines are available and measure the fuel flow. Your right about my figures aswell Jim, I put what I like to call a fudge factor in them. My prop will actualy be 80% efficient, Gravity will be only 9.81 times mass, and the specific fuel consumption will be 0.225 kg/kw/hr or better. That figure is for an old diesel truck engine. As far as reno goes, I think I said props lose efficiency after 300 knots. Beech king Air 1500hp-9 people- 300 knots 4 hours endurance Hawker Sea Fury 3000hp- one pilot-450 knots 30 minutes You also seem to doubt the figures Nat sends out, the Cafe foundation did a very thorough testing of it http://www.cafefoundation.org/aprs/Cozy%20IV%20APR.pdf looks pretty close to me. Cheers!

I apologise for my previous poorly worded post,and incorrect mph figure, I left mph on the motorway in England. It's all knots and kmh over here. I agree 180 bhp at 25,000 is unlikely with a TIO-380, but those are the figures Dust asked Marble to interpolate. When I said the Cozy was "out there" I mean't it is very light all ready, and I wouldn't know where to shave any off. I'm currently studying my ATPL Aerodynamics and Flight systems and came across some fascinating stuff. The basic equation I quoted is Horsepower = Thrust * True Airspeed I quoted it because a lot of people are speculating how fast will their Cozy go with such and such horsepower. This is the equation at the heart of a Flight Management Computer on a Boeing or an Airbus. If you work in weights, density's, and a cosine or sine here and there it will give you rate of climb, angle of climb, fuel burn, and lots of other exciting formulae. If you know your engine break horsepower and pass it through a propeller, which on average are 75% efficient, you get Thrust Horsepower = Break Horsepower * 0.75 If you have a set of figures for your Lift/Drag ratio at an Indicated Airspeed, and you know your weight, then you can calculate the drag. Lift must equal weight, and Thrust must equal drag for straight and level flight. So a weight of 2200lbs with a lift drag ratio of 10:1 must require 220lbs thrust. So if you know your horsepower, and divide it by your thrust, that will give you your true airspeed for flight planning. The numbers I quoted are from the Custom Planes magazine article that came attached to my set of plans from Nat. If I remember they are 2200lbs max take off, and 220mph cruise at 75% power, with an 0-380 180bhp motor. 180 bhp at 75% power is 135 bhp, which is 100 Thrust horsepower, which is 75 Thrust kilowatts, which is 75000 watts. A watt is a Newton metre per second. 220 mph = 100 metres per second 75000 / 100 = 750 Newtons thrust required = 75 kg = 165 lbs So if you are 1650 lbs heavy making 220 mph, using 75% power, you have a lift drag ratio of 10:1 Your best Lift Drag ratio will be at your best rate of climb, best glide Indicated Airspeed. So of course the lesser the drag the better, and the faster you will go with the same horsepower. That is all well and good, but remember you have to climb to some severe height to make 90 indicated equal 270 knots true. Whilst you've gone climbing to the flight levels the standard cozy is roaring away. If you've got a 270 knot fixed pitch prop it will climb like a dog. Ah so of course we want more horsepower, but that means a higher fuel burn, and higher engine weight. Ah and now we need to compress the thin air so we need turbo and superchargers, more weight and more fuel. So now we need more fuel to achieve the same endurance, which is now more weight still. We should probably get weather radar, nav systems, and TCAS now and the gear and brakes need upgrading, and we're starting to really need a constant speed prop. Then we need to work in weight and balance for C of G calculations, and of course can the structure handle the increased loadings. Now we don't really have a Cozy at all, and I wouldn't know where to start with the mathematical relationships between all of the above. That's taking things to an extreme, and I'm sure you could find many happy mediums in between. The further apart your Indicated Airspeed and True Airspeed the better. I have no doubt that a cozy with retracts will have less drag than fixed, and maybe not even more weight. But certainly more cost, worry, maintenance, and complexity. For what? You can go 100 miles further than standard on full tanks, you can beat the time by 1/2 an hour A to B. Remember Marble that drag is Indicated Airspeed, if you're going to try and bust Vne, then that's silly. The Cozy is slippery all ready. More horsepower? Why not? How fast do you want to go? It will cruise closer to Vne or higher and faster with altitude compensation. Props can't go much past 300 kts due to transonic flow on the blade tips. 300 knots = 150 metres per second * Thrust 750 Newtons =112500 watts = 112.5 Thrust kilowatts /.75 = 150 thrust hp /.75 = 200 brake hp and if thats 75% then full power is 265 hp. The props likely to be losing efficiency at that speed, so add a few hp. So that's 190 knots Indicated Airspeed = 300 knots True Airspeed @ FL260 @ 200 hp. 200 hp is 150 kw. The Volvo diesel uses 0.25 kg/kw/hr so it will use 38 kg an hour Jet A1, or about 50 litres per hour. If you want to go 300 knots at a lower altitude, you will have a higher Indicated Airspeed, The lift drag ratio will be worse, so you will need more hp. You can calculate the rate of climb, using sin angle of climb times weight added to thrust required for straight and level. I'd imagine it's not going to be worse than the already excellent 2500 feet per minute. Climb rate decreases with altitude, so give 20 minutes for the climb to FL250. You will want to descend at Vne if you are in a hurry, but adding some range again say 40 minutes. MTO Cozy = 2050 lbs = 930 kg Empty Standard Cozy = 1050 lbs = 477 kg Empty Modified Cozy ( 100 kg heavy)= 577 kg 2 people at 80 kg = 737 kg Baggage 40 kg = 777 kg Fuel load available = (930 - 777) = 153 kg 153 kg @ 38 kg/hr = 3.5 hours endurance + reserves range (2.5* 300) + (1 * 200) = 950 nautical miles average speed 270 knots That's as fast as you can go without losing prop efficiency, and so really having to pile on the horsepower. It is achievable with hp alone, so why make it hard and change everything else? $10,000 on retracts = + 15 knots $10,000 on csu = + 15 knots $10,000 on motor = + 100 knots With regard to the fixed pitch prop design. The blades will have an optimum advance per revolution. 2500 rpm = 42 revolutions per second 150 metres per second / 42 = 3.6 metres per revolution. I don't know how to build a prop, but for a certain blade length, a corresponding blade angle will give you that advance per revolution. Good luck working that out! All considered it's pretty hard to beat the original, well done Nat. It's a pleasure to chat planes with you guys

Check out these photos http://www.airliners.net/open.file?id=228443&WxsIERv=TG9ja2hlZWQgQy0xMzAuLi4gSGVyY3VsZXMgKEwtLi4uODIp&WdsYXMg=RnJhbmNlIC0gQWlyIEZvcmNl&QtODMg=RmFpcmZvcmQgKEZGRCAvIEVHVkEp&ERDLTkt=VUsgLSBFbmdsYW5k&ktODMp=SnVseSAyMDAw&BP=0&WNEb25u=UGhpbGlwcGUgTm9yZXQ%3D&xsIERvdWdsY=&MgTUQtODMgKE=&YXMgTUQtODMgKERD=MzA2MzA%3D&NEb25uZWxs=MjAwMi0wNC0xMQ%3D%3D&static=yes http://www.airliners.net/open.file?id=376950&WxsIERv=TG9ja2hlZWQgTWFydGluIEMtMTMwSi0zMCBIZXJjdWxlcyAoTC0zODIp&WdsYXMg=VUsgLSBBaXIgRm9yY2U%3D&QtODMg=WmVsdHdlZyAoTE9YWik%3D&ERDLTkt=QXVzdHJpYQ%3D%3D&ktODMp=SnVuZSAyNywgMjAwMw%3D%3D&BP=0&WNEb25u=U3ZlbiBEZSBCZXZlcmU%3D&xsIERvdWdsY=Wkg4NzY%3D&MgTUQtODMgKE=J1NwaW5uaW5nJyBhd2F5IGZyb20gdGhlIHJ1bndheS4uLiBsb29rIGF0IHRob3NlIHZvcnRpY2VzIQ%3D%3D&YXMgTUQtODMgKERD=MTI5NDQ%3D&NEb25uZWxs=MjAwMy0wNy0wMg%3D%3D&static=yes The prop describes what is called a helix through the air. A fine prop the the helix is a tight coil, coarse a fat coil. A plane with a fine prop will rev freely and climb like a mutha, a plane with a coarse pitch will bog in, take a longer take off roll, but eventualy howl past the fine pitcher. Advance per revolution of the aircraft is a function of the length of the blades and their angle of attack to the airflow. 180 hp times prop efficiency of 75% = 135 hp 135 hp is 100 kilowatts example weight of Cozy is 2000lbs = 910 kg = 9100 newtons I'm guessing the cruise lift/drag ratio to 10 to 1 Drag is therefore 9100/10 = 910 N = 200 lb A kilowatt is a thousand watts, and a watt is 1 newton metre per second 100,000 watts divided by 910 N is 110 metres per second 110 metres per second is 220 ish knots is 230 mph . Thats at 8000 feet and matches the official figures. Up higher you can get closer to your best rate of climb speed (best lift drag ratio), and it could be worth another 50 knots. Thats it, doesn't matter if you can make 40,000 feet you'll never go faster, unless you can reduce drag, and the only way to do that is maintain best rate of climb, but then you've to have bigger superchargers, or you could reduce weight, but all ready the Cozy's on the limit. 110 metres per second is 6600 metres per minute rpm of lycoming at FL250 altitude 75% setting is maybe 2500 rpm 6600 divided by 2500 is an advance per revolution of 2.64 metres. I initialy posted on this site touting cs props and retracts. After listening to Burt Rutan on designing the Voyager, I agree with the boss when he talks about weight and complexity. CS props are rudely expensive, require heavy maintenance , and add to weight. like wise retracts, the speeds the Cozy fly's at the decrease in drag might give a only a few more knots. After doing my homework I say listen to Burt, listen to Nat, listen to Nick, and Go the fixed pitch prop! The standard cozy hammers along with an O-360. Installing A TIO-360, or heavy calibre rotary will make the cozy a beast. Don't worry about going fast, you'll have one of the fastest light aircraft on the planet. Anyway, if you are into props, you might want to read this... http://www.centennialofflight.gov/essay/Theories_of_Flight/props/TH18.htm Cheers PS If you are contemplating the IVO prop you are technicaly what they call a "nutter" :D

Turbojets, nice! Brave person who go's full chat in one of those. I was speaking to a chap who's mad for pulse jets, reckons he's going to build cheap cruise missiles for the NZ air force. Very cheap to manufacture, very light, no moving parts, and the same fuel guzzling capabilities as a turbojet. http://www.aardvark.co.nz/pjet/ I've just seen a V10 Volkswagen Turbo Diesel, and i'm wondering how I'm going to get it to fit.

Yes Evan you are correct. Idle thrust at all speeds would be found if we were using rocket motors or jet engines. A prop connected to a turbine, for example a PT6 in a King Air is merely connected to a gearbox and a small turbine wheel, a separate turbine is connected to the compressors. This is why you will see turboprops attach strops to the props on the ground to prevent them windmilling. A prop connected directly to a reciprocating engine however will try to turn the pistons, and experience resistance through compression. Watch someone try to hand start a prop. An aircraft such as a DC-3 has 1830 cu in of compression, and if the prop is left at full course, the prop is unlikely to start windmilling at anything less than a gale. Thrust figures do not give the full picture of how fast an aircaft will travel. Excuse if I work in metric. To achieve 10 newtons of thrust you can accelerate 10 kg of air at 1 metre per second, or 1 kg of air at 10 metres per second. The first example will not be able to travel at greater speed than 1 m/s, the second not more than 10 m/s. Out of interest if you use the equation for kinetic energy 1/2 m v2, you can see that the first example uses 5 joules, and the second 50 (sorry I'm on a public computer and may have used the wrong units). To equate this to aircaft read helicopter, prop, high bypass turbo fan, low bypass turbofan , and ultimately pure jet, all have limiting speeds due to the amount of thrust they produce, and the rate at which the air is forced away from the aircraft. At Idle the engine ticks over at 800 rpm, and I doubt if it makes more than 20 hp. A fixed pitch prop will be 70% efficient at it's ideal design speed, so at idle a 150mph cruise prop will propably be somewhere around 40% efficient, 8 Thrust horsepower, or less. The prop will provide thrust at idle up to a walking pace which is usual in my experience, then go through a period of neutral thrust, and then if the plane is travelling any faster it will absorb energy through the prop into the compression of the cylinders. I can push a cherokee with one arm, and at a maximum equate it to lifting a 20 lb weight above my head. I think 20 lbs of residual thrust below 30 knots is all the residual thrust you will experience. Cutting the mix will remove a small amount of power, but if the prop stops spinning above 30 knots I believe you will be worse off. I have made those numbers up, to calculate it properly you would have to consider density, engine condition, prop pitch etc, etc, I draw again to the analogy of the automobile. 3 lanes of traffic approach a red light. In lane one you have a Kenworth shifting down through 14 gears, using the engine brake constantly keeping the revs high, and using the wheel brakes, similar to the constant speed prop, lane two the driver leaves his car in 3 rd gear and uses the brakes, similar to the fixed pitch prop, finaly the 3 rd car slips into neutral and coasts in on the brakes, a stationary prop. The point at which drivers 1 and 2 finaly depress the clutch and slip into neutral to stop crawling forward is equivalent to the point at which you may receive some benefit of cutting the mixture. But again if you need to do that you may be approaching a collision in which case I would also cut the masters, mags, turn off the fuel cock, fasten my safety belt, open the door to avoid it jamming, and concentrate on finding a soft spot to hit. Jim, I like your analogy of the C-130 to the Starfighter, and yes I fly dirty old 172's and Cherokee's. You are correct that I have never flown a greasy canard, yet hopefuly one day I will, I'm still working my way through Dust's book of good excuses. However I understand that canard's don't stall, just develop sink, so surely to achieve a similar descent you may use power off and a say a neutral canard position, or a slight amount of power with the stick slightly further back and a slightly higher angle of attack? If that is possible, wouldn't it be advantageous to approach like that and cut the power, as opposed to gliding in?

Jim, I apologise for calling ft-lb's torque, it's a unit I have not encountered before as work or energy. I have seen it used as a measure of torque. I don't really have a problem with you suggesting cutting the motor on the ground, but I think the main benefit to your friend is that it would have done less damage to the prop/ motor. As for encouraging people to make dead stick landings, I think you are wrong about the benefits. If I am worried about landing I will make a low pass in bad weather configuration, slightly to the right of the strip, make one more circuit, then come in with full flap as close to the stall as possible, with as much power as I can use, then cut the power when i cross the fence. At any point I can go around, If I get a gust of wind, a plane lines up on the runway, an animal, other traffic, or if I misjudge the approach . With a dead motor you are committed. I really don't think it is good advice to encourage people to do this.

A dead stick landing is encouraged in the case of a loss of power, as you will have a better gliding distance than if the prop is turning. The standard procedure for an engine failure with a constant speed prop is to go to lowest rpm, which gives the best glide speed. A prop on a plane will work like changing down in a truck to descend down a hill. The air drives the prop which turns the crank and absorbs horsepower through the cylinders. If you had two cars at 100 mph, both went to idle power, one remained in 5th gear, one to neutral, which would travel further? The car in neutral. It's only when you get down to 10 mph that braking action would be better in the car in neutral. Your velocity anecdote simply tells me that this plane was not airworthy, or that the pilot made a poor decision in aborting. I fly every day into very short strips in the mountains, and would never consider cutting the engine as an aid for a high performance landing. If you are in an aircraft with no/insufficient brakes and no/insufficient steering, and approaching an obstacle, yes I agree it's a good idea to kill the motor; but surely a good pilot with an airworthy plane should never get in that situation. Re. doing the maths, I very much doubt you are getting 100 lbs thrust with the throttle closed. Then you quote ft lbs which is a torque, but seem to be relating it to runway distance available and thrust, and then you say it is work, but that's horsepower, then you say it's energy, but that's calories. Again I have to say that I think that is bad advice to give people, and dangerous.

Turn off the motor? If you turn off the motor the prop will stop spinning "dead sticking "is the phrase I believe, and you will be worse off than having it windmill and creating drag. You will find it very difficult to go around. There is very good reason they teach you to land with mixture rich and full rpm on a csu prop. I'm sorry but I think that's very bad advice

Raytheon Beech are apparently breaking up all the Starships they can. A beautiful plane, but it lost them millions. http://www.ainonline.com/issues/07_03/07_03_bulkstarshipp1.html

200hp max @75%power=150hp*0.8(prop efficiency) = 120 Thrust HP at the prop. THP=Thrust * TAS(ft/sec)/550 180 mph= 264 ft/sec 120=(x * 264)/550 120=0.48x Thrust x = 250 lb's

At 300 knots the aircraft is traveling roughly at Mach 0.5. The propeller is also rotating to provide thrust, the tips must therefore be travelling through the air at something like their rotational velocity plus the aircraft speed. eg Mach 1 Parasite Drag increases with Indicated Airspeed, thus the plane must provide more power, or climb higher to travel faster. But then when climbing the True Airspeed will increase, increasing the Mach number. When objects start travelling above Mach 0.8, they start into supersonic flow. The speed of sound is somewhat like a wall. Lift will increase then suddenly decrease and then stabilise somewhere below it's original value. Drag inreases rapidly until supersonic, and then drops to a higher value than at 0.8M. So a supersonic prop will lose lift, gain drag, and become less efficient, therefore requiring a large increase in horsepower for a small increase in TAS. The sound of a big turboprop you hear is more the sonic boom from the props than the motor. Then of course there are engineering proplems in dealing with these forces and shock waves. A Spitfire was recorded at over 600 mph in a dive, when it's constant speed unit failed removing the prop and half of the engine from the aircraft. The Douglas Skyshark had a 5000bhp turboprop, and could manage 600mph straight and level. The only problem was the noise and resonance of the contra rotating props caused the crew to involuntarily vomit and pass out, and nick name it the "Thunderscreech". 0 - 300 knots = propeller 300 - 500 knots = high bypass turbofan 500 - 600 knots = low bypass turbofan 600 + = turbojet for some excellent aircraft sounds http://lsss.homestead.com/Aircraft_Pictures_and_Sounds.html cheers:D

Sorry Dust but that's rubbish. formula for kinetic energy or dynamic pressure if you like 1/2mass multiplied by velocity squared. 10kg * 1 m/s = 5 watts 1kg * 10 m/s = 50 watts The more air you can push back the better. Only if you were attempting speeds in excess of 300 knots would you then need to head for an unducted fan. An ATR 72 which is a 70 seater turboprop has two 2500bhp motors turning six bladed carbon fibre props of about 16 feet with curved tips which spin at 1000rpm. I agree 2700 is not a magic number, but slower is better, but that requires a longer blade and then ground clearance is a problem for a cozy.

Yes the Rutan Boomerang is right seat PIC actualy has each seat not parallel but slightly behind, creating a staggered effect, more space for everyone and more aerodynamic; tiny dials and very basic panel to save weight, the rest is run on a laptop. Good luck trying to engineer it though. Why not put all the instruments right in the middle, and fly from the right?

I'm a bit confused mplafleur, Are you part of Deltahawk or a prospective customer? Is it the Deltahawk that needs 18 amps and 130 volts? If so does that mean it is a mechanical injector pump using an electric motor? As for reliability etc there are plenty of diesels that would be ideal in a plane, just they are too heavy and underpowered. I've driven a landcruiser with water half way up the windscreen, pulled three trailers of cattle in 150 'heat, and chugged through two foot of snow at 7000 feet; all in turbo diesels and never a worry. I grew up with Volvo's and rate them as good reliable cars. The D5 has Mercedes, VW, BMW etc crying in their soup. The engine is mass produced, the block amongst other things also sits in the 300hp T5R, the injector pump is likewise mass produced by Bosch. Pretty soon people will start wrecking Volvo's with D5's in them so there will be plenty around, and at an affordable price. Sure I'll have to change the rings and timing chain every so often. To me that makes more sense than an experimental prototype engine from a company that may go under at any time. I've never seen a 2 stroke diesel, the concept looks good, but I think a 4 stroke diesel is a very good system. 2's are no more efficient than 4's, infact probably less so due to using the supercharger to scavenge the cylinder, just lighter, and ás a wise man once said "If it ain't broke don't try and fix it". Good Luck to Deltahawk with their motor.

Not really, check these guys out, but I don't think they are getting anywhere though... http://www.atpcoinc.com/Pages/New.html Isn't the guy from blue mountain avionics turbining his cozy?

Yes 2 blades, don't know but would bet on feather, size, don't know again but the 337 sits no higher than a 172.

Could you expand on Common rails "need a lot of juice", is this with reference to a mechanical pump? What system are you working on with 18 amps and 130 volts? Is a 2 stroke really any simpler?

Whats wrong with the cessna 337 prop? I've got an offer on one for $7500, somewhere stateside.

I don't think she'll have the minerals at 2700 rpm, but maybe I could use one of marbles'ducted fans? here's a link for the specs on a chipped version http://www.heicosportiv.de/images-produkte/bilder-produkte/s60-d5-190-ps.pdf With the exhaust gas recirculation removed, that should save some weight and give some hp, then with a good induction set up, intercooler and extractors, 200+hp sounds good to me. $25,000 sounds like a lot of money to gamble on the Deltahawk, and I don't like two strokes. Here's the original power curve...

165 kg dry. Plus reduction drive all the extras I'm hoping for 200 kg. http://www.swedespeed.com/features/tech/d5/index.shtml cheers

This is the Diesel I'm going to use... 230hp @ 4000rpm

What sort of CS prop are you going to use dust? I spoke to some Cessna people, and was quoted $7500 for an overhauled pusher CSU, I think with electric de-ice. I'm pretty sure it was designed for the TSIO 360. That's a lot of beer tokens, but the advantages of a constant speeder are very seductive.

Indicated Airspeed (IAS) is the measure of dynamic pressure. Static pressure is what is all around us, and decreases with altitude (altimeter). Dynamic pressure is the pressure achieved from motion through the air. Aircraft have a pitot tube/head, in which it measures static pressure( a hole facing downwards) and dynamic + static pressure ( a hole facing forwards). With the use of a bellows, with dynamic + static on one side and static on the other, the little gauge shows Indicated Airspeed, or dynamic pressure. Stall speeds, and best rate of climb etc are all IAS. IAS indicates how much lift you are getting. The pitot tube may not always be in an ideal place, so position error is accounted for and you get Calibrated Air Speed (CAS). Then at speeds exceeding 200 mph, air becomes compressable, and you need to compensate, giving you Equivalent Air Speed ( EAS). Then of course you have True Airspeed (TAS) which is EAS compensated for density (pressure + temperature). Ground Speed is TAS compensated for wind movement. So what does that mean? well if you climb at a constant Indicated airspeed, as you gain height the density decreases, therefore your True airspeed will increase. An U-2 spy plane at 82,000 feet has an indicated airspeed of 150 KIAS, but it is travelling through the air at 400 KTAS, and if it gets in the jet stream, it could have a ground speed of 600 Knots. Vne is measured in IAS, and above 220 mph indicated I would imagine to be quite dangerous. Yet as you increase altitude density decreases, so a TAS of well above 220 mph will be possible. The next limiting factor will be Mach number, because the speed of sound is dependent on temperature not density. An Air Racer at Reno achieves about Mach 0.68 average speed on a lap. Try this TAS calculator http://www.csgnetwork.com/tasinfocalc.html :D

Marble : Don't listen to John bro, Go for it! Although I think what you really need is a big tank of liquid oxygen and a couple of drums of jet fuel, I'm sure a smart chap like you will work out the nozzles and the turbopump etc. I think you can pick up an Osprey for it's weight in scrap. John : Don't put Marble off. When they remake "Those Magnificent Men in their Flying Machines", they're going to need some new footage for the start when the mad contraptions sh#t themselves on take off. I heard the Harrier has the dubious record of killing more of it's own pilots than enemy crews. I saw one at Middle Wallop when I was a wee nipper, hovering about, fantastic noise, but the thought of landing one at night, on a slippery deck pitching and rolling, no thanks. JakeC : Maybe you could help Marble set up some sort of launch ramp with a bit of C4 at the back to help him on his way? Dust : I understand about the slaves, ignorance is bliss. The trouble is that the unskilled labour will just sit around drinking beer talking rubbish all day, whilst I might get some sweat from the aero club crew.

200hp max @75%power=150hp*0.8(prop efficiency) = 120 Thrust HP THP=Thrust * TAS(ft/sec)/550 180 mph= 264 ft/sec 120=(x * 264)/550 120=0.48x Thrust x = 250 lb's You can obtain 2000 lbs of thrust from 280hp, but it would require a rotor diameter of 35 feet, so I don't know about going ballistic. I heard the line outside the USMC Osprey test pilot office is looking quite short, maybe you're the man for the job?