Lets make a helicopter
I have some reservations about the use of an APU. Firstly they are not generally designed for very long running lives - in most aircraft they are shut down once the mains are running. Secondly, they operate at very high speeds - generally not far under 100,000 RPM. The noise and gearing implications of that are problematic. I certainly remember doing some work on the Saab Gripen where my perception was that the APU generated 4+ times as much noise as the two main engines at idle - certainly you couldn't be within about 50 yards of the aircraft whilst the APU was running without ear defenders, whilst you could be stood next to it (albeit in some discomfort) without whilst the two mains were running.
The Aero Adventure engine is rated at 65,000 RPM which is still very high, but at-least a factor of two below, and one assumed more amenable to soundproofing.
G
The Aero Adventure engine is rated at 65,000 RPM which is still very high, but at-least a factor of two below, and one assumed more amenable to soundproofing.
G
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Lets make a helicopter
WANTED air cooled motorcycle engine suitable for convertion to diesel and dry sump. 3000rpm max. all replies to bug please, plus price and availability.Also required. Epycyclic gearbox to fit the above when mounted vertically , 6 to1 reduction on the top output shaft and 1 to1 on the side output shaft please. Will collect immediately.
The engine you want is almost certainly a Wankel.
However, Norton who were producing them until the mid 1990s got rid of all those projects sadly. Similarly Midwest who were trying to develop similar engines at Gloucester then somewhere in Germany are no more either.
However, a brief trawl around the web found this firm who might just do exactly what you want, although a search on "Mazda rotary" throws up several more.
G
However, Norton who were producing them until the mid 1990s got rid of all those projects sadly. Similarly Midwest who were trying to develop similar engines at Gloucester then somewhere in Germany are no more either.
However, a brief trawl around the web found this firm who might just do exactly what you want, although a search on "Mazda rotary" throws up several more.
G
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Bug, you make me think...
A french moto manufacturer did a diesel model.. but long time ago, and i think all this is gone in dust..
What about the Daimler Smart 2 troke 3 cyl diesel engine ? an aviation version was made by a german UL manufacturer, I don't recall the name ..
A french moto manufacturer did a diesel model.. but long time ago, and i think all this is gone in dust..
What about the Daimler Smart 2 troke 3 cyl diesel engine ? an aviation version was made by a german UL manufacturer, I don't recall the name ..
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IMHO
Genghis,
As you say, the Rotax engines may be one of the better engines for very light rotorcraft, but it has a problem that goes beyond the actual engines.
The installation manual of Rotax engines state "This engine shall not be used on rotor wing aircraft (helicopters, gyrocopters, etc.) or any similar craft"
B.J. Schramm and Rotax were not on talking terms because of Schramm's desire to use Rotax engines in his Helicycles. The CH-7 Kompress uses a Rotax 914 but the helicopter is sold without the engine. This is a detriment for any helicopter that intends to have large sales and eventually become a certified craft.
Zeeoo,
" Dave, look at the dragonfly rotor and tell me it doesn't look like something you saw.. does it seem complicated ?"
Yes, it looks familiar
. Superficially, it also appears to looks like the Scorpion and the Rotorway hubs. CRAN has asked for " Benign reaction to low-g flight " This implies a rotor that is somewhat beyond the primitive teetering rotor.
There are numerous one and two seat helicopters out there. All could be 'tweaked' into being something slightly better. None of them will take Rotorcraft to a higher plateau.
Consider the oxymoron of 'low price and superior features". This is not a question of which comes first - the chicken or the egg? It is simply and loudly;- "build a better mousetrap and the people will come to buy"
I strongly believe that;
1) Low price will ONLY come about when the helicopter is mass-produced. (think Henry Ford)
2) Mass production will ONLY come about when a helicopter has shown superior features.
It's the rotor, it's the rotor, it's the rotor. ---> It's the hub, it's the blade, it's the configuration and its the flight-controls.
As you say, the Rotax engines may be one of the better engines for very light rotorcraft, but it has a problem that goes beyond the actual engines.
The installation manual of Rotax engines state "This engine shall not be used on rotor wing aircraft (helicopters, gyrocopters, etc.) or any similar craft"
B.J. Schramm and Rotax were not on talking terms because of Schramm's desire to use Rotax engines in his Helicycles. The CH-7 Kompress uses a Rotax 914 but the helicopter is sold without the engine. This is a detriment for any helicopter that intends to have large sales and eventually become a certified craft.
Zeeoo,
" Dave, look at the dragonfly rotor and tell me it doesn't look like something you saw.. does it seem complicated ?"
Yes, it looks familiar
. Superficially, it also appears to looks like the Scorpion and the Rotorway hubs. CRAN has asked for " Benign reaction to low-g flight " This implies a rotor that is somewhat beyond the primitive teetering rotor. There are numerous one and two seat helicopters out there. All could be 'tweaked' into being something slightly better. None of them will take Rotorcraft to a higher plateau.
Consider the oxymoron of 'low price and superior features". This is not a question of which comes first - the chicken or the egg? It is simply and loudly;- "build a better mousetrap and the people will come to buy"
I strongly believe that;
1) Low price will ONLY come about when the helicopter is mass-produced. (think Henry Ford)
2) Mass production will ONLY come about when a helicopter has shown superior features.
It's the rotor, it's the rotor, it's the rotor. ---> It's the hub, it's the blade, it's the configuration and its the flight-controls.
G,
That engine from Aero Adventure looks very much like a modified APU to me. Not withstanding the relatively high power output, I'd lay money that the core originates from such a unit.
The Atkins rotary is a Mazda RX wankel, converted for aircraft use. Probably the best expert on these engines is the chap that designed and built my BMW EFI unit for me, Tracy Crook (see http://www.rotaryaviation.com/).
There's no obvious reason as to why a 12A or 13B Mazda can't be mounted vertically, the rotors are oiled via oil in the fuel and the rotor shaft and gear lubrication should be able to be modified. Tracy has flown an awful lot of hours on his RV using one of these Mazda engines, and is the sort of helpful chap who would advise on other applications, I'm sure.
VP
That engine from Aero Adventure looks very much like a modified APU to me. Not withstanding the relatively high power output, I'd lay money that the core originates from such a unit.
The Atkins rotary is a Mazda RX wankel, converted for aircraft use. Probably the best expert on these engines is the chap that designed and built my BMW EFI unit for me, Tracy Crook (see http://www.rotaryaviation.com/).
There's no obvious reason as to why a 12A or 13B Mazda can't be mounted vertically, the rotors are oiled via oil in the fuel and the rotor shaft and gear lubrication should be able to be modified. Tracy has flown an awful lot of hours on his RV using one of these Mazda engines, and is the sort of helpful chap who would advise on other applications, I'm sure.
VP
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Faster, cheaper, better. Pick two.
Im surprized that rotaries only got a passing mention here.
This is what I have been looking at for my project, they seem perfect for aviation.
A NA 12a is good for about 120hp, and a 13b about 150. With mods good for much more.
The best thing about a rotor is that once running, they tend to keep going. Even with the failure of a rotor they still produce about 40% power.
Im surprized that rotaries only got a passing mention here.
This is what I have been looking at for my project, they seem perfect for aviation.
A NA 12a is good for about 120hp, and a 13b about 150. With mods good for much more.
The best thing about a rotor is that once running, they tend to keep going. Even with the failure of a rotor they still produce about 40% power.
Jellycopter,
Everybody wants their helicopter to be turbine powered! If only it could be done for the required cost...
The APU derivatives have a number of disadvantages, the most importance of which is that they have a specific fuel consumption of around 1.2 lb/hp-hr that means they burn almost three times as much fuel as a modern piston engine (almost four times as much as a diesel). Therefore an R-22 equipped with such an engine would burn 27-30 US Gal/hr of fuel per hour. Hence there is a huge fuel-weight penalty. This problem is a result of the fact that these machines tend to use low-pressure cycles, with pressure ratios in the region of 3:1 which is far too low to be efficient without a recuperator. In addition, the engines are really rather heavy, in turbine terms. That is really not an avenue you would wish to waste money on i'm afraid. Though plenty have...
Genghis,
The seaplanes.com engine is an interesting one, I have been following it for three years or so and they don't appear to have done much. I believe they sourced the engine from Argentina:
http://savoiapower.8k.com/labala.html
[The picture shown was the original one used on the seaplane website]
The interesting thing here is that the pressure ratio is higher at 5 and so the engine can achieve more reasonable fuel consumption (albeit only at high power settings) of approximately 0.53 lb/hp-hr, which is not bad by contemporary standards. (The RR C250 varies between 0.6 - 0.72 lb/hp-hr)
But as Genghis says we know little of the quality of the engineering or the reliability of the machine...but it only weighs 17kg for 230 hp!
Bugdevheli, I’m aware of a project by the Royal Military College of Science (Cranfield, Shrivenham Campus) that modified a Kawasaki engine to run on JP4 & JP8 in order to satisfy the military single fuel policy, this engine is know in production and may be a good starting point - if only from a technology and approach standpoint.
http://www.drive.cranfield.ac.uk/cfm...motorbike1.cfm
Spaced et al:
Have you spoken to my neighbours regarding Wankel engines?
http://www.uavenginesltd.co.uk/index.php?id=393
Incidentally, I still have the same concerns about such engines; longevity and reliability when operating at high power settings for extended periods...be careful chaps.
Dave,
Of course ultimate low cost is never going to be achieved until rotorcraft are mass produced ~ but that will never happen. They are simply not the right vehicle, either in traditional or novel formats to be used for mass transit. They use far too much fuel, make far too much noise, will always offer too many opportunities for people to harm themselves and others. In addition, a large volume of such aircraft would require an enormous control infrastructure to provide collision avoidance and routing. [I’m aware of free-flight etc, but it’s a long, long way off.] This would take away all of the benefits of point-to-point VTOL. In addition, mass-production or not, we need to focus on operating cost rather than purchase cost because for commercial helicopters it the operating cost that is the real problem that prevents the helicopters market growing, not the purchase price.
One other point; if people really wanted a three-bladed rotor then I have no problem with that as long as we collectively accept that it will cost more! Dave, in response to your comments regarding low-g flight, I feel that for a fair-weather flying kit helicopter, sufficiently beniegn low-g behaviour could be achieved by configuring the aircraft in such a way as to reduce the role-rate in low-g flight - put the tail rotor in the right place! i.e. similar to Jet Ranger.
CRAN
Everybody wants their helicopter to be turbine powered! If only it could be done for the required cost...
The APU derivatives have a number of disadvantages, the most importance of which is that they have a specific fuel consumption of around 1.2 lb/hp-hr that means they burn almost three times as much fuel as a modern piston engine (almost four times as much as a diesel). Therefore an R-22 equipped with such an engine would burn 27-30 US Gal/hr of fuel per hour. Hence there is a huge fuel-weight penalty. This problem is a result of the fact that these machines tend to use low-pressure cycles, with pressure ratios in the region of 3:1 which is far too low to be efficient without a recuperator. In addition, the engines are really rather heavy, in turbine terms. That is really not an avenue you would wish to waste money on i'm afraid. Though plenty have...
Genghis,
The seaplanes.com engine is an interesting one, I have been following it for three years or so and they don't appear to have done much. I believe they sourced the engine from Argentina:
http://savoiapower.8k.com/labala.html
[The picture shown was the original one used on the seaplane website]
The interesting thing here is that the pressure ratio is higher at 5 and so the engine can achieve more reasonable fuel consumption (albeit only at high power settings) of approximately 0.53 lb/hp-hr, which is not bad by contemporary standards. (The RR C250 varies between 0.6 - 0.72 lb/hp-hr)
But as Genghis says we know little of the quality of the engineering or the reliability of the machine...but it only weighs 17kg for 230 hp!
Bugdevheli, I’m aware of a project by the Royal Military College of Science (Cranfield, Shrivenham Campus) that modified a Kawasaki engine to run on JP4 & JP8 in order to satisfy the military single fuel policy, this engine is know in production and may be a good starting point - if only from a technology and approach standpoint.
http://www.drive.cranfield.ac.uk/cfm...motorbike1.cfm
Spaced et al:
Have you spoken to my neighbours regarding Wankel engines?
http://www.uavenginesltd.co.uk/index.php?id=393
Incidentally, I still have the same concerns about such engines; longevity and reliability when operating at high power settings for extended periods...be careful chaps.
Dave,
Of course ultimate low cost is never going to be achieved until rotorcraft are mass produced ~ but that will never happen. They are simply not the right vehicle, either in traditional or novel formats to be used for mass transit. They use far too much fuel, make far too much noise, will always offer too many opportunities for people to harm themselves and others. In addition, a large volume of such aircraft would require an enormous control infrastructure to provide collision avoidance and routing. [I’m aware of free-flight etc, but it’s a long, long way off.] This would take away all of the benefits of point-to-point VTOL. In addition, mass-production or not, we need to focus on operating cost rather than purchase cost because for commercial helicopters it the operating cost that is the real problem that prevents the helicopters market growing, not the purchase price.
One other point; if people really wanted a three-bladed rotor then I have no problem with that as long as we collectively accept that it will cost more! Dave, in response to your comments regarding low-g flight, I feel that for a fair-weather flying kit helicopter, sufficiently beniegn low-g behaviour could be achieved by configuring the aircraft in such a way as to reduce the role-rate in low-g flight - put the tail rotor in the right place! i.e. similar to Jet Ranger.
CRAN
Last edited by CRAN; 22nd Nov 2004 at 12:05.
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CRAN,
The points you bring up have merit. This is particularly true if the objective of this project is that of producing 'just another helicopter'. If the objective is to produce a product that stands out from the pack, then this product must have one or more superior features.
The engine is anybody's guess. One idea that we have previously discussed is the installation of two smaller engines for reliability.
The fuselage, IMHO, must be carbon composite construction, with imbedded Kevlar in the shell around the occupants. The strength of carbon composite is far superior to metal construction because the plies can be laid up to suit the structural loads. The price of carbon cloth is continually coming down.
Empty weight is the albatross of the helicopter. Consider the advantages of weight reduction due to the use of composite construction. Consider a 70-kg saving in the fuselage weight of a 700-kg craft. This is a reduction of 10%. Simplistically, it now means that all of the other components can now be 10% weaker and thereby 10% lighter. This reduction of the weight of the 'other components' now means that ........ Basically, it is a recursive diminishing reduction of the craft's empty weight.
Lastly and most importantly, the rotor. You have mentioned the efficiency of the 2-blade rotor and you say; " sufficiently beniegn low-g behaviour could be achieved by configuring the aircraft in such a way as to reduce the role-rate in low-g flight - put the tail rotor in the right place! i.e. similar to Jet Ranger." Perhaps this may be valid.
Alternatively, here is a new and crazy idea from the Department of Demented Designs;
Take the Robinson's 3-hinge teetering rotor. Add a simple linkage so the coning hinges cone in unison. Link the coning angle to a hub spring. The smaller the coning angle <--> the stronger the moment of the hub spring, and visa-versa. The objective is better control over a lightly loaded rotor while not increasing the 2-P vibration during forward flight.
Just food for thought.
The points you bring up have merit. This is particularly true if the objective of this project is that of producing 'just another helicopter'. If the objective is to produce a product that stands out from the pack, then this product must have one or more superior features.
The engine is anybody's guess. One idea that we have previously discussed is the installation of two smaller engines for reliability.
The fuselage, IMHO, must be carbon composite construction, with imbedded Kevlar in the shell around the occupants. The strength of carbon composite is far superior to metal construction because the plies can be laid up to suit the structural loads. The price of carbon cloth is continually coming down.
Empty weight is the albatross of the helicopter. Consider the advantages of weight reduction due to the use of composite construction. Consider a 70-kg saving in the fuselage weight of a 700-kg craft. This is a reduction of 10%. Simplistically, it now means that all of the other components can now be 10% weaker and thereby 10% lighter. This reduction of the weight of the 'other components' now means that ........ Basically, it is a recursive diminishing reduction of the craft's empty weight.
Lastly and most importantly, the rotor. You have mentioned the efficiency of the 2-blade rotor and you say; " sufficiently beniegn low-g behaviour could be achieved by configuring the aircraft in such a way as to reduce the role-rate in low-g flight - put the tail rotor in the right place! i.e. similar to Jet Ranger." Perhaps this may be valid.
Alternatively, here is a new and crazy idea from the Department of Demented Designs;
Take the Robinson's 3-hinge teetering rotor. Add a simple linkage so the coning hinges cone in unison. Link the coning angle to a hub spring. The smaller the coning angle <--> the stronger the moment of the hub spring, and visa-versa. The objective is better control over a lightly loaded rotor while not increasing the 2-P vibration during forward flight.
Just food for thought.
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Dave, with great respect for your work, I try to argue on what I have seen, readed from other designers.
The engine is anybody's guess. One idea that we have previously discussed is the installation of two smaller engines for reliability.
>>>> as a great part of the final weight the engine IS a critical choice, my personnal opinion would be to start from a given engine. and build around, I Know my view is not good but it hasn't been tried.
>>>> twin certified turbines fitted by a good manufacturer are a factor of reliability, but small engines fitted by "amateurs" (sorry it is not an insult, I just miss the right english word) can a be a factor of failure as you have to r&d and fit extra non-standard devices.
The fuselage, IMHO, must be carbon composite construction, with imbedded Kevlar in the shell around the occupants. The strength of carbon composite is far superior to metal construction because the plies can be laid up to suit the structural loads. The price of carbon cloth is continually coming down.
>>>> so does epoxy resins, much much cheaper and easy to use. Btw carbon may be too stiff for certain usages. Why Kevlar ?the role of a crash-proof structure is to absorb shocks, so, to break and crumple, not to resist, it has been very welle understood in the automotive industry with coltrolled-folding bodies.
chasing high end technologies is IMHO not a way to lower costs.
means that all of the other components can now be 10% weaker and thereby 10% lighter.
>>>> wow.. whitch componants ?
>>>> rotor : why not a 2 bladed semi-rigid one ?
Take the Robinson's 3-hinge teetering rotor. Add a simple linkage so the coning hinges cone in unison.
>>>> i thought the efficiency was linked to a low coning ?
a symetrical coning means less lift on the retreating blade, and , from my poor understanding, this is not the goal of a teetering rotor.
while not increasing the 2-P vibration during forward flight.
>>>> the 2/rev shake has been successfully smoothed on gyros by adding 2 simple springs on the teeter rod ends.
Why don't you consider buying (for example) the dragonfly blades and grips and fit them on a semiriigid 3 bladed hub ?
What about the blades ? The hub is fine, right, but you could have an iron-stiff hub is the blades and their links were well thought, no ?
Bash me like the arrogant newbie I am (oh yes ! hurt me
) , but leave arguments, i will keep them for my personnal use.
cheers
The engine is anybody's guess. One idea that we have previously discussed is the installation of two smaller engines for reliability.
>>>> as a great part of the final weight the engine IS a critical choice, my personnal opinion would be to start from a given engine. and build around, I Know my view is not good but it hasn't been tried.
>>>> twin certified turbines fitted by a good manufacturer are a factor of reliability, but small engines fitted by "amateurs" (sorry it is not an insult, I just miss the right english word) can a be a factor of failure as you have to r&d and fit extra non-standard devices.
The fuselage, IMHO, must be carbon composite construction, with imbedded Kevlar in the shell around the occupants. The strength of carbon composite is far superior to metal construction because the plies can be laid up to suit the structural loads. The price of carbon cloth is continually coming down.
>>>> so does epoxy resins, much much cheaper and easy to use. Btw carbon may be too stiff for certain usages. Why Kevlar ?the role of a crash-proof structure is to absorb shocks, so, to break and crumple, not to resist, it has been very welle understood in the automotive industry with coltrolled-folding bodies.
chasing high end technologies is IMHO not a way to lower costs.
means that all of the other components can now be 10% weaker and thereby 10% lighter.
>>>> wow.. whitch componants ?
>>>> rotor : why not a 2 bladed semi-rigid one ?
Take the Robinson's 3-hinge teetering rotor. Add a simple linkage so the coning hinges cone in unison.
>>>> i thought the efficiency was linked to a low coning ?
a symetrical coning means less lift on the retreating blade, and , from my poor understanding, this is not the goal of a teetering rotor.
while not increasing the 2-P vibration during forward flight.
>>>> the 2/rev shake has been successfully smoothed on gyros by adding 2 simple springs on the teeter rod ends.
Why don't you consider buying (for example) the dragonfly blades and grips and fit them on a semiriigid 3 bladed hub ?
What about the blades ? The hub is fine, right, but you could have an iron-stiff hub is the blades and their links were well thought, no ?
Bash me like the arrogant newbie I am (oh yes ! hurt me
) , but leave arguments, i will keep them for my personnal use.cheers
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Zeeoo
Some quick answers.
"carbon composite construction, with imbedded Kevlar
Carbon brakes like glass. Kevlar makes it brake like safety glass.
" Btw carbon may be too stiff for certain usages. "
In those locations use fiberglass.
" 10% lighter. >>>> wow.. whitch componants "
The engine, the transmission, the rotor .......
" >>>> rotor : why not a 2 bladed semi-rigid one ?"
The pros and cons of different rotors ain't available as a quick answer.
"oh yes ! hurt me "
Kinky. Perhaps one of the female pilots would be better qualified.
Some quick answers.
"carbon composite construction, with imbedded Kevlar
Carbon brakes like glass. Kevlar makes it brake like safety glass.
" Btw carbon may be too stiff for certain usages. "
In those locations use fiberglass.
" 10% lighter. >>>> wow.. whitch componants "
The engine, the transmission, the rotor .......
" >>>> rotor : why not a 2 bladed semi-rigid one ?"
The pros and cons of different rotors ain't available as a quick answer.
"oh yes ! hurt me
"Kinky. Perhaps one of the female pilots would be better qualified.
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Dave,
funny, I would have a female's opinion on that.
seriously, i agree with the kevlar use, but the stiffness isnt gone even with kevlar, why not sandwich roving/foam/rOving or honeycomb.
And about blades technology ? efficient blades are the key to gain efficiency so payload. All i have read bout that seem to agree that a good blade design is a major key of improvement.
If weight could be gained on chassis, I would tend to reinforce the rotor safety/lifetime and a little engine de-rating.
thanks
funny, I would have a female's opinion on that.
seriously, i agree with the kevlar use, but the stiffness isnt gone even with kevlar, why not sandwich roving/foam/rOving or honeycomb.
And about blades technology ? efficient blades are the key to gain efficiency so payload. All i have read bout that seem to agree that a good blade design is a major key of improvement.
If weight could be gained on chassis, I would tend to reinforce the rotor safety/lifetime and a little engine de-rating.
thanks
Dave,
The configuration that I proposed offers the following improvements over existing kit helicopters:
(1) Improved payload (300kg)
(2) Improved performance (speed and range)
(3) High inertia rotor system - benign HV curve and behaviour in autorotation
(4) Massively improved reliability
(5) Massively improved crashworthiness
(6) Bullet proof, de-rated, fuel-injected engine with realistic 2000hr TBO
(7) Reduced 'real-life' operating costs
(8) Dramatically improved appearance & external aerodynamics
(9) Reduced & Simplified maintenance
(10) Improved handling qualities
(11) BCAR-VLH/EASA-VLR compliant design
Such a configuration, would allow would-be R-22 self-fly hire pilots, to own and maintain (either individually or in small groups) their own helicopter. A helicopter that has been specifically designed with the low-time pilots in mind.
Just another helicopter?
I don't thinks so, but I guess i'm biased!
We can the compare the configuration to the certified market leader, the Robinson R22 Beta II:
My configuration offers:
(1) 30% More Payload (2x225lb PAX & 3hrs Fuel)
(2) 30% Higher Cruise Speed
(3) Traditional High Inertia rotor (Similar behaviour to Jet Ranger)
(4) Fuel Injection - NO CARB ICING
(5) Dramatically improved crashworthiness
(6) Improved 'less-skittish' handling qualities
(7) Approximately 40% the purchase cost of a R22
(8) Approximately 30% the operating cost of a R22
Just another helicopter? I really don't think so. 
HOWEVER, if 'Just another helicopter' means that the aircraft is financially viable to develop and market on a tiny budget in minimum time, or that it is sufficiently familiar for people to believe that they can build and fly one safely the I guess you are right - Just another helicopter it is.
There is a place for triple-D designs and large prizes for those that get them to work and indeed I have my own collection of them. However, I believe strongly that triple-D designs have no place in an under-funded kit helicopter project...least not if you what to get something to market.
Dave, your hub sounds great in principal, better than a two blades ~ except on cost. But how will you convince people to bet their lives on the fact that:
(a) It works properly
(b) They can build it
(c) It won't break
...and would you be confident enough to do so? Remember, limited budget, limited testing, limited confidence.
Surely under circumstances such as these (realistic ones) it would be better to rely on a hub design developed in the 40's and used safely ever since - even in the worlds safest single engine aircraft? Similar argument for the configuration and the engine.
CRAN
The configuration that I proposed offers the following improvements over existing kit helicopters:
(1) Improved payload (300kg)
(2) Improved performance (speed and range)
(3) High inertia rotor system - benign HV curve and behaviour in autorotation
(4) Massively improved reliability
(5) Massively improved crashworthiness
(6) Bullet proof, de-rated, fuel-injected engine with realistic 2000hr TBO
(7) Reduced 'real-life' operating costs
(8) Dramatically improved appearance & external aerodynamics
(9) Reduced & Simplified maintenance
(10) Improved handling qualities
(11) BCAR-VLH/EASA-VLR compliant design
Such a configuration, would allow would-be R-22 self-fly hire pilots, to own and maintain (either individually or in small groups) their own helicopter. A helicopter that has been specifically designed with the low-time pilots in mind.
Just another helicopter?
I don't thinks so, but I guess i'm biased!We can the compare the configuration to the certified market leader, the Robinson R22 Beta II:
My configuration offers:
(1) 30% More Payload (2x225lb PAX & 3hrs Fuel)
(2) 30% Higher Cruise Speed
(3) Traditional High Inertia rotor (Similar behaviour to Jet Ranger)
(4) Fuel Injection - NO CARB ICING
(5) Dramatically improved crashworthiness
(6) Improved 'less-skittish' handling qualities
(7) Approximately 40% the purchase cost of a R22
(8) Approximately 30% the operating cost of a R22
Just another helicopter?
I really don't think so. HOWEVER, if 'Just another helicopter' means that the aircraft is financially viable to develop and market on a tiny budget in minimum time, or that it is sufficiently familiar for people to believe that they can build and fly one safely the I guess you are right - Just another helicopter it is.
There is a place for triple-D designs and large prizes for those that get them to work and indeed I have my own collection of them. However, I believe strongly that triple-D designs have no place in an under-funded kit helicopter project...least not if you what to get something to market.
Dave, your hub sounds great in principal, better than a two blades ~ except on cost. But how will you convince people to bet their lives on the fact that:
(a) It works properly
(b) They can build it
(c) It won't break
...and would you be confident enough to do so? Remember, limited budget, limited testing, limited confidence.
Surely under circumstances such as these (realistic ones) it would be better to rely on a hub design developed in the 40's and used safely ever since - even in the worlds safest single engine aircraft? Similar argument for the configuration and the engine.
CRAN
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Cran, Dave,Zeeoo
All of this would be possible if it wasn't for the restrictive regulation and bull**** imposed on the industry by the CAA and their like across the world. The last thing that the regulators want are the skies full of Joe Public flying around in cheap, good machines. They are frightened of the airways ending up like Britains roads. Keep it expensive and exclusive is their ethos. Mass production would reduce costs and improve quality but they are terrified of it. It is incomprehensible that in the 21st century, new aircraft are being made with carburettors and magnetos - and they wouldn't be if there was less regulation. How many truly new light helicopters have come on the market in the last 20 years? Not so many- and thats just the way they like it.
That is why we are forced to fly around in 1940s technology.
All of this would be possible if it wasn't for the restrictive regulation and bull**** imposed on the industry by the CAA and their like across the world. The last thing that the regulators want are the skies full of Joe Public flying around in cheap, good machines. They are frightened of the airways ending up like Britains roads. Keep it expensive and exclusive is their ethos. Mass production would reduce costs and improve quality but they are terrified of it. It is incomprehensible that in the 21st century, new aircraft are being made with carburettors and magnetos - and they wouldn't be if there was less regulation. How many truly new light helicopters have come on the market in the last 20 years? Not so many- and thats just the way they like it.
That is why we are forced to fly around in 1940s technology.
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CRAN,
Your list of eleven objectives certainly does not describe "Just another helicopter". A craft with all these attributes will be far more than that. The concern, in my opinion, is not the objectives. The concern has to do with the means or the ability of implementing all, or most, of these objectives.
To build a craft that does more than "Just another helicopter" requires more than a collection of yesterday's technology. I doubt that all or even most of these objectives can be met solely by stepping down to the Very Light Rotorcraft category.
In addition, there are others looking at the same category and market. The spoils will go to he who has the better craft. (or perhaps the better marketing
).
______________________
Since you asked;
We probably both agree that 3-blade rotor will not provide as good a thrust/weight ratio as a 2-blade rotor. In addition, the increased rotor moments caused by the hub spring will necessitate a stronger (& heavier) craft. The advantage, of course is a faster and more positive cyclic control.
"Dave, your hub sounds great in principal, ...... But how will you convince people to bet their lives on the fact that:
(a) It works properly
(b) They can build it
(c) It won't break"
CRAN, I'm not trying to sell this 3-blade CVJ+HS rotor. It may not work in the real world. But, I feel good enough about it to build one and have fun testing it. This testing may eventually satisfy the above (a) and (c).
A solution for (b) may be to copy the method used by the world's cheapest rotorcraft. The full set of Gyrobee plans can be freely downloaded off the Internet, but the rotor hub is a purchased item.
Your list of eleven objectives certainly does not describe "Just another helicopter". A craft with all these attributes will be far more than that. The concern, in my opinion, is not the objectives. The concern has to do with the means or the ability of implementing all, or most, of these objectives.
To build a craft that does more than "Just another helicopter" requires more than a collection of yesterday's technology. I doubt that all or even most of these objectives can be met solely by stepping down to the Very Light Rotorcraft category.
In addition, there are others looking at the same category and market. The spoils will go to he who has the better craft. (or perhaps the better marketing
). ______________________
Since you asked;
We probably both agree that 3-blade rotor will not provide as good a thrust/weight ratio as a 2-blade rotor. In addition, the increased rotor moments caused by the hub spring will necessitate a stronger (& heavier) craft. The advantage, of course is a faster and more positive cyclic control.
"Dave, your hub sounds great in principal, ...... But how will you convince people to bet their lives on the fact that:
(a) It works properly
(b) They can build it
(c) It won't break"
CRAN, I'm not trying to sell this 3-blade CVJ+HS rotor. It may not work in the real world. But, I feel good enough about it to build one and have fun testing it. This testing may eventually satisfy the above (a) and (c).
A solution for (b) may be to copy the method used by the world's cheapest rotorcraft. The full set of Gyrobee plans can be freely downloaded off the Internet, but the rotor hub is a purchased item.
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Gaseous, you're right.
Dave, take your wrench and Get busy !!
That is what i decided, remember? it is going in january 2005 and a lot of people find my design very attractive.
I will have a lot of fun doing it, but who knows if it will match my expectations...
Hey , did you think about a gyro ? making an helicopter for 2 minutes hovering is not worth the extra expense... make a gyro and make it ultra-short take off (like degraw's gyrhino)...
Gyros are as (or more) manoeuvrable as an helicopter...
thanks
Dave, take your wrench and Get busy !!
That is what i decided, remember? it is going in january 2005 and a lot of people find my design very attractive.
I will have a lot of fun doing it, but who knows if it will match my expectations...
Hey , did you think about a gyro ? making an helicopter for 2 minutes hovering is not worth the extra expense... make a gyro and make it ultra-short take off (like degraw's gyrhino)...
Gyros are as (or more) manoeuvrable as an helicopter...
thanks
Gaseous,
You're absolutely right about regulating by cost! However, the BCAR-VLH regulations and the EASA-VLR regulations do allow you to slip in with a kit aircraft at the £40-50K point, with the operating costs as I have described. While this is certainly well out of the reach of the everyday-joe, it certainly puts helicopters flight into the reach of many fixed wing aviators - a market that is 5-10 times larger! In addition, people that currently fly self-fly-hire would be able to buy, build and maintain their very own high quality, high performance rotorcraft. Reducing cost and getting much more than a R22, Rotorway or Safari can offer on top.
Dave,
Thanks for the continued discussion. I agree that we are not going to produce a next-generation rotorcraft by implementing my proposal, but however this was never the intention. The intention was to produce a high quality, safe and reliable kit helicopter that will get private fliers up and flying at the minimum cost, safely. Squeezing, the levels of payload and performance that I have described out of a IO-360 powered machine without sacrificing reliability certainly requires highly skilled engineering, but I have no doubt, it is perfectly feasible, if a little close to the asymptote.
A next-generation machine requires much more, a better engine, a better rotor and better systems, but this will take a lot of time and money to develop properly and in my opinion is that it is beyond the scope of this project.
As I understand it this thread is about building a high quality, low cost kit helicopter that could be available in a couple of years and possibly be certified at a later date via the EASA-VLR (Europe) and Primary Category Rotorcraft (US) regulations. The high levels of performance and reliability offered by the proposal will up the expectations of the market, hence raising the minimum standard required for a manufacturer to successfully enter the market with a new machine and hence put an end to dangerous kit products and inadequate/non-fit-for-purpose certified designs, benefiting all in our community.
Thanks to everyone for sticking with these long posts!
CRAN
You're absolutely right about regulating by cost! However, the BCAR-VLH regulations and the EASA-VLR regulations do allow you to slip in with a kit aircraft at the £40-50K point, with the operating costs as I have described. While this is certainly well out of the reach of the everyday-joe, it certainly puts helicopters flight into the reach of many fixed wing aviators - a market that is 5-10 times larger! In addition, people that currently fly self-fly-hire would be able to buy, build and maintain their very own high quality, high performance rotorcraft. Reducing cost and getting much more than a R22, Rotorway or Safari can offer on top.
Dave,
Thanks for the continued discussion. I agree that we are not going to produce a next-generation rotorcraft by implementing my proposal, but however this was never the intention. The intention was to produce a high quality, safe and reliable kit helicopter that will get private fliers up and flying at the minimum cost, safely. Squeezing, the levels of payload and performance that I have described out of a IO-360 powered machine without sacrificing reliability certainly requires highly skilled engineering, but I have no doubt, it is perfectly feasible, if a little close to the asymptote.
A next-generation machine requires much more, a better engine, a better rotor and better systems, but this will take a lot of time and money to develop properly and in my opinion is that it is beyond the scope of this project.
As I understand it this thread is about building a high quality, low cost kit helicopter that could be available in a couple of years and possibly be certified at a later date via the EASA-VLR (Europe) and Primary Category Rotorcraft (US) regulations. The high levels of performance and reliability offered by the proposal will up the expectations of the market, hence raising the minimum standard required for a manufacturer to successfully enter the market with a new machine and hence put an end to dangerous kit products and inadequate/non-fit-for-purpose certified designs, benefiting all in our community.
Thanks to everyone for sticking with these long posts!
CRAN