EAAAirVenture OshkoshShopJoin
< Prev. Page   1  2  3  4  5  Next Page >

Modernizing the Ultralight definition

Jerry Rosie
Young Eagles Pilot or Volunteer
482
Posts
101
#21 Posted: 10/25/2009 07:48:16

Your two cents worth has a value of about $4,000,000.  All the points you make are very valuable - it IS possible to build a safe untralight under the current regs, we are very lucky that those regs still exist, and if one wants to fly farther and faster, there is LSA.  What is needed in the ultralight community is not a bigger, faster airplane, but viable training opportunities in type that meet the current Ultralight regs.  I have had many contacts from folks looking for ultralight training and have been unable to satisfy their needs.  As close as I can come is to direct them to a CFI who does training in an Aeronca Champ and then talk to them about the differences between the Champ and the ultralight they want to fly.  From that point on, it is a lot of praying when they launch for the first time.....

 

 



Cheers, Jerry NC22375 out of 07N
Dan Grunloh
Homebuilder or CraftsmanAirVenture Volunteer
66
Posts
25
#22 Posted: 10/26/2009 21:55:14

In support of the comments by Carl Conrad.  I don't know where that picture of the Sky Pup comes from but it sure pulls on my heart strings.  It look just like my SN 2318 which I completed and flew in 1986.  I still have it in the back of my hangar. It needs new fabric and an engine rebuild.

Cruise 55mph, empty weight 238 lbs, cost to build was $2300 with all new materials, no scrounging. Total time of construction 700 hours over two and half years. I built it $100 at time until it came to buy the engine. I cashed in a life insurance policy to buy the engine. It flew great except for crosswind landings and the single cylinder Rotax 277 vibrated a lot.  I loved that plane and so did my friends.

There is a discussion group on Yahoo Groups for the 2-axis Sky Pup.

http://groups.yahoo.com/group/Skypup-club/



Jerry Rosie
Young Eagles Pilot or Volunteer
482
Posts
101
#23 Posted: 10/27/2009 10:58:49

Just to reinforce my assertion that it is possible to build a safe ultralight under the current regs, I recently sold my MiniMax powered by that vibrating Rotax 277, and assisted the new owner in flying it for the first time.  Well, he didn't follow my advice to first raise the tail and not rotate until he had reached at least 50 mph and stalled it at about 10 feet off the ground.  The right wing dropped and the wing tip skimmed the ground until the nose came around and the airplane landed on its wheels just off the runway.  After inspecting the undercarriage and letting his nerves settle down, he was able to take off and fly two patterns.  The little airplane proved just how sturdy it was.  (Empty weight 252 pounds)

 



Cheers, Jerry NC22375 out of 07N
Andrew Snedden
Homebuilder or Craftsman
9
Posts
4
#24 Posted: 10/28/2009 03:56:54

 

   Good discussion.  Similar discussion can be found in www.homebuiltairplanes.com and throughout the ultralight community.  Most conclude that if the FAA opened up part 103 to changes, the results would not be pretty. We should feel lucky that the FAA has no desire or expectation to open up Part 103.  In our changing times Part 103 is fast becoming the more modern approach to aviation if not the only practical option for a lot of reasons. FAR Part 103 and A/C 103-7 is the perfect guarantee to the people that an affordable form of aviation will be available and within their reach. Granted the 254 pound limit is a challenge, but is doable when it is realized that a high performance ultralight should not look like an airplane. See  www.lightsportaircraft.ca/volume3-issue29/webcast-2/  and  www.eaa.org/experimenter/articles/2009-08_snedden.asp   The Snedden M7 at Airventure 2009 demonstrated a structurally uncompromised ultralight with 65 horsepower, short takeoff, steep climb, maneuverability, steep decent, go cart like ground handling and other new features that render airplanes the less capable flying machines by many comparisons including extreme fun and not limited to airports. There are some other very interesting fixed wing ultralight designs out there too. PPCs and PPGs are going to have a good future. People pilot for fun more than to merely go somewhere fast with their view largely obstructed and their budget busted. Nothing beats flying around the patch, sometimes weaving between the trees at a few feet AGL over rolling terrain. 30-50 MPH seems like fighter jet speeds relative to lower altitudes. Ultralights are number one for fun, capability, versatility, usability, affordability, etc. High strength, safer, completely legal Part 103 ultralights with over 100 HP and active speed control can be easily built with no exotic materials required.

   The number one and two devastating constraints facing the ultralight community and industry was the elimination of ultralight type specific flight training instructors and two seat specific ultralight type counterpart training vehicles. It’s quite shocking how little this predominate problem is acknowledged, addressed and is being covered up by several so called ultralight publications that make most of their money from the newly funded LSA industry. I still get many calls from all over Ohio from people seeking ultralight lessons for ultralights and they cannot find them. I have heard of the same problem in other states that also have been stripped of their structured USUA ultralight training safety base. You cannot manufacture and sell many ultralights when there is no viable means to train new ultralight pilots. Now fewer new ultralight pilots are taking to the air and with much less training and no testing as was common before. Never before has access to the sky and safety been so compromised with no compatible and viable replacement then, now and later.

   Regardless how true this is for the majority of the country plus growing economic uncertainties, I felt that AirVenture 2009 sported the biggest and best ultralight display in the last three years that I attended. The new separation of LSA from the ultralight area was good.  It was great that people could camp at their ultralights or in the nearby ultralight camping area.  EAA AirVenture 2009 better represented and was very kind to the ultralight community. It was well supported and viewed by AirVenture visitors. Nowhere else at AirVenture could average people identify with, see such affordable, versatile and exciting opportunity to achieve their dream of flight.

 



Don Gherardini
Homebuilder or Craftsman
3
Posts
2
#25 Posted: 10/28/2009 09:29:18

Yes, this is a good discussion. In my humble opinion, the point made here as to the elimination of the training exemption is without a doubt done the most serious damage to the ultralight industry.

But, not mentioned here, is what I think the number 2 reason Ultralites are not selling is the expense. Today, with virtually all of the designs built around light weight 2 cycle engines that are no longer available, (or about to be), I see the ultralight craft as going the way of the DoDo bird also. It wont be long that  2 cycles will be no longer mass produced. Remember..the effects of mass-production are what keeps engines affordable, No matter how good a ultra-lite designer/builder you are, the engine is procured...not built.

Today, those engines have so little market in the world, the production is very low, and the resulting cost very high. A 40 hp 2 stroke is approaching 5,000 dollars, and they will continue to go up in cost right until they dissappear.

 Low cost planes built airframes are still easy to do for 3k or less...and kits at 6K to 8K are all over the place...but add 5 grand for an engine to this and you have eliminated a very large amount of the potential customers with simple economics.

There has been in the recent past, the advent of many brands of new v-twin 4 cycles to the industrial market, and these engines are 10 time more durable and dependable than the traditionally used 2 cycles, and more importantly, due to very high production..they are much less expensive. With a design life of 2500 hours and up, and a retail cost of $1500.00 or so.

 BUT....they weigh more than the traditional 2 cycles snowmobile engines we traditionally use. (and remember ..snowmobiles dont even use these anymore). They are much better suited to constant power settings aircraft use. Read that as SAFER. 

My point is... IF the weight limit was increased to 300 lbs..a 46 lb increase over 254, I predict that the number 2 reason the ultralite biz is in the tank would be eliminated in one move.  We would see new airframe designs evolve tailored to these engines instead of the soon to be extinct 2 cycles as most all of our designs today have been. The Few ultralite Kit manufacturers left in biz today, would be scrambling to utilize engines that would lower the cost of their products by 30 to 60%. THAT is a huge market advantage.



D.A.G. KitFox Mk4 Speedster 47 Luscombe 8A
Dean Billing
104
Posts
26
#26 Posted: 10/28/2009 12:48:33
Andrew Snedden wrote:

 

 

> ... High strength, safer, completely legal Part 103 ultralights with over 100 HP and active speed control can be easily built with no exotic materials required. ...

I will wait for you to prove this point with an aircraft.  My original thesis was that reliable engine power and weight were limiting factors in the current 103 regs.  There have been promises for years of lightweight rotary engines in the 30-60 HP range and they have never happened.  Even if they did, fuel consumption rates would be high.  So far nobody has demonstrated a low power engine that gets better than about a 1/2 lb. / hp hr. fuel burn rate, so for your mythical 100 HP engine that is about 8 gph.  Pretty prohibitive for an airplane that is limited to a 5 gallon gas tank and 55 knot speed.



Carl Conrad
Homebuilder or Craftsman
8
Posts
2
#27 Posted: 10/28/2009 23:47:36

I do agree that available engines for ultralight manufacturers do seem to be in short supply, however, Compact Radial Engines seems to have a pretty complete line.  Not the cheapest things in the world, but they are there.

there is also the half VW option.  the Legal Eagle makes good use of it.  As I recall, he left the fuselage uncovered to keep it draggy enough to stay below the maximum speed.  And VW engines are anything but in short supply.

As I understand it, Rotax is still making the smaller engines for snowmobiles, just not selling them for airplanes.  A used or Replacement Rotax doesn't seem to be at all hard to come by.

!00 hp in an ultralight!  What ever for?!  Graham Lee claimed 100 mph in his Nieuport II with a Rotax 477.  Even if we discount 20% for windage, that ain't bad for an airplane with a nose like a barn door and more wires in the wind than the phone company.

And Nieuport flyers, please don't take offense, I plan to build one after I finish my Skypup.

As Dan's Skypup demonstrated, cruising at 55mph on 22 hp, 35 hp could be more than you would ever need in a well designed ultralight.

I think we really do need to push for the option of type training in ultralights though.  I do believe that is the biggest safety issue facing the fixed wing ultralight community today.  We are a very small segment of aviation in the US, and I don't think growing very fast compared to Powered Parachutes and Trikes, but still growing nevertheless. 

 

As new people come into ultralights without type training, it is just a matter of time until we see an increase in mishaps.  We really need to try to head off this situation, both for the sake of the new pilots, and the peception of or sport by the general public.  According to the most recent information I have seen, ultralight aviation is no more dangerous than general aviation.  However, much of the public still perceives it as much more dangerous.  If into this perception comes an uptick in ultralight mishaps, well, bureaucrats will do what bureaucrats do best.  Does Las Vegas ring a bell?

 

If you want to push for a change in FAR 103, this seems to me the change to push for.

Dan, I hope you get your pup out again one of these days.  I am having a heck of a lot of fun building mine, and really looking forward to flying it.  Everyone I talk to who has flown them seems to love them.

 



Dean Billing
104
Posts
26
#28 Posted: 10/29/2009 01:37:46
Carl Conrad wrote:

 

> ... the Legal Eagle makes good use of it.  As I recall, he left the fuselage uncovered to keep it draggy enough to stay below the maximum speed....

The Legal Eagle is uncovered because it would be too heavy to make 254 lbs if it was covered.  Those few that are fully covered have N numbers.  Your latitude in modifying the Legal Eagle is measured in ounces to maybe a couple of pounds, but it is legal.  I want to build a Legal Eagle but my problem is that I live at 3500 ft and summer days here exhibit density altitudes in excess of 5000 ft.  So I am looking at the new Legal Eagle XL because of the longer wing but now I really am in the ounces to remain in legal 103 land and it would be nice to have more horsepower, but then the engine gets too heavy.  There is no way you can have a starter and electrical system and dual ignition, all safety factors.



Carl Conrad
Homebuilder or Craftsman
8
Posts
2
#29 Posted: 11/3/2009 20:50:25

Hi Dean,

As for covering the fuselage of the Legal Eagle, I was just quoting what the designer had said in an article I read about it.

In reading your posts, you seem intent to build your own airplane, so my supposition is that the purchase price of new aircraft is not a major issue. You just would like more to the plane than will work under part 103.

I guess my question for you is, why not just build an experimental light sport?  It seems that you would easily get everything you want in that classification, along with the option of another seat to take someone flying with you, and you will have a greater number of airports and a lot more airspace open to you than you will with an ultralight.  And you still can do all your own work on the plane.



John Eiswirth
112
Posts
19
#30 Posted: 11/3/2009 23:20:39

A  fine point on the weight.  Part 103 doesn't just say it can't be heavier than 254 lbs; it says it has to weigh LESS than 254lbs.  I read that as a full 254 is disqualifying.



Jim Heffelfinger
Homebuilder or Craftsman
256
Posts
43
#31 Posted: 11/4/2009 10:40:16

YOu are right..... Belite has to change the name on their plane......



Carl Conrad
Homebuilder or Craftsman
8
Posts
2
#32 Posted: 11/4/2009 14:50:48

253.99?


biggrin



James R Thomas
Homebuilder or Craftsman
48
Posts
10
#33 Posted: 11/5/2009 14:09:56

I really don't have a dog in this fight since I had my CGS Hawk registered a few years ago. I called it an ultralight for years even though it was more than 100 pounds over Part 103. I've never personally known anyone to have their airplane weighed by the FAA. I was even told by an FAA employee that they didn't even own a set of scales and they had much bigger fish to fry. Most "ultralights" are flown from the family farm or from a grass strip and the FAA is not interested in tracking ultralights down and creating work for themselves to weigh an airplane that may or may not be a few pounds over weight. It's a noble jesture to obey the letter of the law but our lawmakers in Washington don't exactly dazzle us with their high standards. My advise,  for what its worth, would be, worry about the spirit but not the letter of the law. I believe that is the FAA's unofficial opinion too, at least for the agents in the field. If you build a small, light, 2 stroke, single place ultralight type airplane, behave responsibily, and stay out  of large busy airports you'll never meet an FAA person let alone have your airplane weighed. Just use some good common sense. And before any of you protest that the FAA may be reading this, they know these things better than anyone and they don't have the will or the manpower to track down and weigh airplanes. If adding things like brakes, maybe a radio, and decent gauges and instruments make your airplane safer but overweight, I'd go with "SAFER" everytime.  Just call me brutally honest but realistic.



Jerry Rosie
Young Eagles Pilot or Volunteer
482
Posts
101
#34 Posted: 11/6/2009 09:48:38

You make some very good points , James, and are probably about 99.995% correct in your evaluation.  I've only known one ultralight to be weighed, and that was in response to a complaint filed by a jealous hangarmate.



Cheers, Jerry NC22375 out of 07N
Andrew Snedden
Homebuilder or Craftsman
9
Posts
4
#35 Posted: 11/23/2009 02:39:01

   Modernizing the definition of ultralights thru government regulations is dangerous business. It seems unnecessary when there is so much more that can be done to modernize the ultralight itself into the incredible flying machine that it can be and completely within the limitations of part 103 and A/C 103-7. Other motorsports machines such as motorcycles, all terrain vehicles, jet skis and snowmobiles have blasted past us in terms of high power excitement, maneuverability and strength technology. They have gotten more powerful, stronger, lighter and improved in other ways.

   Setting aside the weight issue, many ultralighteers suggest that higher horsepower rated engines can give more reliability, safety, fuel economy and tremendously more fun. All six engine failures that I encountered were while giving ultralight flight instruction in heavier two seat Quicksilver’s powered by Rotax 503s operating at high load. These were maintained by the company that I worked part time for. On the other hand my Brother, Dad and I have never had an engine failure in any single seat using Rotax and Hirth engines and during a much longer total flight time. Of course we are exclusively responsible for our own inspections and maintenance but we have to acknowledge that running the engines under a smaller load percentage to be a major contributor to the significantly increased reliability.

   With each large increment of additional engine HP capacity that you can put into the engine means that you can gain features like less engine load percentage, less RPM percentage, dual ignition, water cooling and less fuel consumption per HP.  Our Quicksilver Sprint got better fuel economy with an ancient chrome bore DCDI 650cc Hirth than a 447 Rotax. Consider that operating with a newer 65HP 625cc Hirth uses 2.8, 3.8 and 6.5 GPH at 30, 40, and 65 HP respectively. The M7 legal ultralight if equipped with the yet unfinished lightweight float system and using the three cylinder 100 HP Hirth engine would give 2.7, 3.0 and 4.3 GPH at those same three HP levels. Similar results could be expected on an ultralight float equipped M7 ultralight with the Simonini 2 cycle 92, 102 and 110 HP models which weigh just a little more than a Rotax 582. Lighter weight cog belt reductions and in flight adjustable pitch propellers would be used. It was reported in homebuiltairplanes (2-stroke engines section) that a 92 HP Simonini could run on half the fuel of the 65 HP Rotax 582 that was in his Zenair 701. Of course the superior Simonini dual expansion chamber exhaust system was partly responsible. Someone in HBA said that their Rotax 447 could burn 5 GPH at full throttle which I think is only 40 HP while the 100 HP Hirth claims only 3 GPH at 40 HP. Yes the 100 HP Hirth will use 7.8 GPH at 100 HP, but at that burn rate you could jump to 500 feet AGL in 15 seconds and be set to glide 360 degrees and land at the point you launched from. This can be an important safety advantage if emergency landing opportunities are confined to a short runway where landing straight ahead is not a pretty picture. Another improvement to safety is here where the statistical chance of an engine failure in that short 15 second period is more unlikely. Other low power ultralights have to strain at lower altitudes over more neighboring property for a minute to get 500 feet AGL and might have long passed the best places to emergency land. Even at only 4 GPH a 447 would use twice as much fuel to get to 500 feet AGL. With enough power and automatic active speed control at the throttle level, stalls could be unlikely or impossible especially if the angle of attack measurement is factored in to the control too. I disclosed more information about this in www.homebuiltairplanes.com   Light Suff,  New UL Manufacturer section for defensive publication purposes.

   High HP short takeoff roll and healthy climb makes ultralights significantly more versatile, useable and safer from a much greater number of locations. And so much more fun.  Why would anyone intentionally select engines that are more closely sized to a weed whacker and more likely to be short lived when the opportunity to use a higher HP engine exists?  Well ok if you want to save money, fly less safe, look like an airplane, worry about clearing that obstacle on that hot humid day while packing a few extra pounds around the belly, have less fun and less places to land and takeoff from.  I wish the best engines were a lot cheaper too. It seems that ultralight engines can cost close to 100 dollars per 1 HP while the engine prices are much less for the snowmobile and jet ski true motorsports guys who stop at nothing to get the most HP and better technology.  Whenever I hear about someone wanting to buy or build an antique airplane style, LSA or ultralight that has to be powered by a weedwacker engine or four stroke engine, I wonder why and think of how many people would go see any powersports competition such as a super cross race if the machines were low power vintage motorcycles or scooters. The answer is none because there would be inadequate interest and excitement and thus no such sport under such low power limitations. Except for those of us mostly aging pilots who deeply appreciate the early machines, they just are not interesting enough or worth paying to watch in competition, sponsor or sell to new people. Engine power is the defining element to any motorsport or aircraft. The absolute best power to weight ratio is more important for an ultralight because of the weight limit and thus should not be subject to compromise.

   The 63 MPH ultralight speed limit makes for a wonderful opportunity for ultralights to focus much less on low drag airplane appearance and transfer that weight into more structural strength, maneuverability and more power. Unencumbered by traction and other issues, an ultralight should be a fun flying ATV like machine with more maneuvering power to do simple things like tight corkscrew climbs or follow steep terrain. Ultralights are the most versatile, useable, fun, unencumbered, practical and obtainable flying recreational vehicles. They can be made a lot better if newer concepts are adopted and implemented.

   I am doing a lot of work toward the development of a lighter direct drive, vibration free and more powerful broad usage engine of huge displacement that will weigh no more than __ pounds less the propeller. The part 103 weight limit indirectly implies that if you use a 4 stroke, you won’t be taking off from half the places that an equal weight 2 stroke can.  We have a lot of small places to fly in and out of here in central east Ohio. While the two strokes have gathered at many places, the four strokes are limited to a fly by.

   My favorite engine is the Aaen V4 two stroke 95 pound road racing engine 850cc 200HP@9,250RPM, but Mr. Aaen will not sell them for aviation use, not even for 25K. I would not hesitate for one minute to put such engine on the M7 with some changes already scheduled for the M7. There are a lot of cheap 100+ horsepower snowmobile and jet ski engines out there too with expansion chamber exhaust systems.

   Evinrude E-Tec, Mercury and a few others boast of their lines of DFI (direct fuel injection into the combustion chamber during the compression stroke) two stroke engines that get better performance, better fuel economy, outstanding reliability and less pollution than 4 strokes. Two stroke engines are poised to make a big comeback using the new DFI technologies. Unfortunately the automotive and aviation industries will be last to get the message and make the change. Our defense industry uses a lot of two strokes on some very expensive UAV (unmanned aerial vehicles). Hirth is the 2 stroke leader there using technology that is significantly more advanced than that what they share with the ultralight industry or other competing companies. I got to touch and examine the line of Hirth UAV engines which are not shown at Airventure or Sun-N-Fun. DFI was used on some WWII German 4 stroke airplanes and is similar to Diesel engine fuel injection.

   New 4 cylinder DFI two strokes are needed for ultralights where the 90 degree combustion spacing (not on the Hirth 4 cylinder or a few others) makes for a super simplistic cross pipe exhaust system that is well tuned at all RPMs. This is unlike bulky expansion chamber tuning where they are often highly tuned only to a very limited RPM range. Four cylinder two strokes have much less vibration than two cylinder in lines.

   The Martin jet pack 2000 cc V4 two stroke at 200 HP @ 6000 RPM with a nearly flat torque curve (due to cross pipe exhaust) is very impressive but its 132 lb engine weight does not calculate for a legal fixed wing ultralight even with ultralight weight floats. (An engine like the Martin engine (might be their prototype?) but with the cross pipe exhaust unraveled can be seen on You Tube under 2000cc V4 two-stroke revs to 200 bhp) In the 300+ comments, many of the two stroke guys criticize it for it having too little power compared to the typical high performance engines like the Suzuki 500 cc four cylinder two strokes with between 150 and 200 HP. These guys would laugh at what we call horsepower on our ultralights and LSA.

   Note that the Martin jet pack does not need wings to be part 103 legal as per AirVenture 2008 when it was shown. This extreme example should remind us that 100 or even 200 HP should not be considered an impossible ultralight goal. It also suggests yet another way more HP can give legal stall speed with a little less wing span (lower aspect ratios allow more extreme angles of attack)…a little less wing weight required means a little more weight that can be added for more HP and yet a little less wingspan…  I was told that 100 HP on an 8 foot diameter wood propeller has demonstrated 600 pounds static thrust.  A 120-140 HP 700cc V or radial 4 cylinder 2 stroke (90 degree timed) with cross pipe exhaust, + or - 4:1 cog belt reduction on a 6.5 to 7 foot prop would be a nice M7 ultralight package. This would translate to a 2800cc per prop shaft revolution displacement (only 1400cc on a 4 stroke). A traditional 1000cc 2 cylinder 4 stroke direct drive to a small propeller (500cc per revolution) makes for pitiful static thrust and dependency on the airport. This kind of power is useable for cutting grass in the riding lawn mower so long as the grass is not too deep.

   The goal that I think is very possible using a completely different propulsion system is a Part 103 fixed wing ultralight with VTOL capability (where electric power is not yet an option as much as I like it) and without any need to change part 103. We need to get out of the mind set that ultralights must be equipped with low power engines, or represent some classical antique airplane, or be designed solely for MPG or gliding, else ultralight aviation will have a slow future with no powersports excitement. Clinging to the past is a good way to prevent having a future. An ultralight with power is spectacular!

   What seems impossible to one does not make it impossible for another. Despite extensive information to the contrary, some still choose traditional misinterpretations and limitations and assert that their perceived limitations applies to everybody or else. Others are free to choose opportunities, creativity and effort toward a really exciting flying machine.

   AirVenture can draw more people if they know in advance that they can come and see such new machines, performance, STO, climb, maneuverability and back field versatility and with some resemblance to affordability. This kind of performance can lead to growth and representation/protection in numbers. Many people are drawn or limited toward the absolute lowest cost options. PPGs are a great option that I would like to try someday. However watching someone weed whacking or lawn mowering about in a straight line in a heavily skinned fixed wing machine for MPG or navigating for landmarks is not much a spectator sport or as exciting for the pilot. We do not fly everyday thus our fuel bill is a relatively small part of our flying budget. If I want range, comfort and 24-7 usability, I will use the car.

   People pilot for fun. A 15 minute flight with real maneuvering power from a nearby location can better fit our schedules and be more rewarding than a two hour flight. It’s not about miles per gallon, its all about SMILES per mile. That’s what ultralights are about.

 



Arthur Thompson
Homebuilder or Craftsman
1
Post
1
#36 Posted: 11/25/2009 09:41:44

As I recall, the original effort that got us Sport Pilot was an attempt to expand the limitations of Part 103. If you open the government can of worms again, you can expect similar results.

IMHO we would be far better off exploiting technology to build better machines that do meet 103 limitations. I own and fly a UL with a gross weight of 186 pounds. It is commercially available for around $12K, safe, has an emergency chute and folds up to fit in the back of a pickup. But it is not a "conventional" fixed wiing aircraft and that may be the key to this disscussion. Thinking outside the box, within part 103, will get us a lot further than trying to open the can of worms FAA will create for us. 



Dean Billing
104
Posts
26
#37 Posted: 11/25/2009 10:22:57

So far I have learned two things from this thread.  For the most part EAA members are very optimistic about technology and still cling to "futures" to solve problems.  I call it the Jim Bede effect.  They are also very negative about what can be done with the FAA which makes me wonder how the EAA ever got off the ground.

As far as technology is concerned, it doesn't look like we will ever get by the 0.5 lb. / hp.-hr. limit of gasoline engines, especially in small displacements.  The only thing that we might see is a slight improvement in weight of the engine.  Unless new building materials get much stronger at much less weight and cost, spruce, fabric, 4130 tube and aluminum look like good building materials.  Since the ultralight is limited to 254 lbs., how much weight will be saved by changing everything to carbon?

The proposal I made to 103 was to remove some limitations that don't actually do anything except constrain logical design.  If you limit it to single pilot, set the gross empty weight and limit the stall speed, what other limits do you need?  Let the designer decide the trade off in fuel and why care about the cruise speed?  Fuel always weighs 6 lbs. / gallon and you are always going to burn it at 0.5 lbs / hp-hr.  That is a severe design constraint with no way around it, which is going to pretty much determine everything else you do.



Jim Heffelfinger
Homebuilder or Craftsman
256
Posts
43
#38 Posted: 11/25/2009 18:17:01

Looks like Belite has shaved off 35+ pounds and still retained the 4130 "cabin framing" of the original design of the KitFox Lite.    Naturally this is at an expense and manufacturing beyond the typical UL builder. 



Benjamin Landron
Homebuilder or Craftsman
3
Posts
0
#39 Posted: 11/25/2009 19:33:40

I believe most "fat Ultralights" were heavy single place aircraft like a single place Challenger  or a single place Hawk etc.



William Czygan
Homebuilder or Craftsman
9
Posts
5
#40 Posted: 12/1/2009 17:53:10

The present situation leaves legal ultralights in a very bad position concerning training. It leaves fat ultralights in an even worse limbo. Government works so slowly (if at all) that it will not be an option to petition them for change for another generation. The present set of regulations are a very badly fitting suit. The result has been (along with other factors), a drastic reduction in UL flying. Over time though, individuals will find ways to fly. Some will get training with former BFI's and Sport Pilots. Some will fly fat single and even unregistered 2 seaters. Some will also conform or give up. Eventually, the desire to fly will push against this unreasonable situation until at some point in the future another adjustment will be necessary. But until then, you must choose your individual path.



< Prev. Page   1  2  3  4  5  Next Page >