### Help Support Homebuilt Aircraft & Kit Plane Forum:

Sure, why not?

Here’s one:

#### jedi

##### Well-Known Member
From the Raptor NG thread post #191 Raptor NG Discussion by Toobuilder:

Earlier post said - "...Look at the popularity of ultralights. Lots of room for development in the low and slow off airport operations. "

Toobuilder Replied -" Interesting perspective. I'm a fairly active flier and do get around quite a bit, but I can't remember the last time that I've seen an ultralight in person. And I'm talking a decade or more.
Based on my experience, I thought 103 flying died off completely. "

Thread drifted from light jets to FAR 103 ultralights. To continue the drift ultralights are as different from GA as on the other side of the spectrum Boeing aircraft are different from Pipers.

In my life as "airline person" I do not see any GA aircraft at O'hare, LAX or JFK. In my life as a GA pilot I generally do not see Boeing aircraft hanging around the GA airports. I do see both flying overhead because they make noise, leave contrails, and fly high. I do not commonly see ultralights because paragliders fly quietly and in specific areas and the powered ULs fly low altitude and over sparsely populated areas.

A typical GA airplane is good for trips of 200 miles or more. A typical UL is good for trips of 60 miles or less. A typical airline trip covers 500 miles or more.

I propose that the typical homebuilder/experimenter/developer has a better chance of making a significant development in the short range more user friendly end of the spectrum than in furthering the high speed long range projects.

Folding wings, STOL, and off airport operations are where the current development is most active. Glasairs (low wing), Lancairs and Harman Rockets are all ready available designs but I do not see a Piper Cub that I can easily take home (because all the Cub type airports are shopping centers) and use for a trip of 20 to 60 miles or have a nice 30 minute flight in the evening after a days work.

The need to travel 200 miles or more only comes up once every several months. The need to travel 60 miles or less (but more than a 5 mile bike ride) comes up frequently. I want an aircraft that is practical to fly three times per week and I can not find one.

That's my two cents. Where is yours?

#### Pilot-34

##### Well-Known Member
I think I drift is common because there’s no general chat feature here.
Although when I first saw the name that’s what I thought hanger flying was.

#### Hot Wings

##### Grumpy Cynic
HBA Supporter
Log Member
The need to travel 200 miles or more only comes up once every several months.
My desire to travel 200 miles or more comes up almost weekly. It is not the desire for travel just to travel, but to go to a destination, do something there or buy something there and then return.
Time and/or payload are generally the limiting factors. Aircraft limit one parameter and ground transport limits the other.

Many of those destinations are just not accessible and/or practical with normal fixed wing aircraft. I suppress the desire and do without
...............unless there are 's to be made. Then it is a very different mission

That leaves flying for just the fun of flying. I also do without that far too much.

Less typing, more working might change that?

Am I the only one that finds that this software inserts emoticons where ever it feels lkie doing so rather than at the point where my cursor is at the moment I try to insert the emoticon?
Kind of nuisance to have to insert twice to get the thing where I want it and then delete the first randomly place one.

#### jedi

##### Well-Known Member
Just to clarify, the the 200 miles is the non-stop direct line one way approximate limit, not the empty tank limit. Might go there and back without refueling. Same for other numbers. It might be for an overnight or just an out and return. That is my interpretation.

That's about 40 gallons (at 10 miles per gallon, your mileage may vary) or $200 for aviation fuel out and return and is my limiting factor. As an example, I want my cabin closer to home and travel more often. My weekly trips are less than 100 miles direct one way. But then I live in an area where there is lots to do with the 100 mile radius. That is why I moved out of the Chicago area. Also the 100 mile radius includes a lot of water and ferry rides if forced to go surface travel. A former airplane was a Cessna 310. Glad I do not have that anymore but it was nice at the time. The step down to a Cessna 150 changed the trip planning drastically. Latest example: Two CFI pilots in a Cessna 150 did a 180 mile distant out and return last week and it was great fun, but then the destination was an airport (KALW) for a day of motor gliding. We wouldn't do that by car. Last edited: #### Toobuilder ##### Well-Known Member HBA Supporter Log Member Jedi wrote: "A typical GA airplane is good for trips of 200 miles or more. A typical UL is good for trips of 60 miles or less. A typical airline trip covers 500 miles or more." Again, a matter of perspective. Several weeks ago I drove from my house to Whiteman airport to pick up a new tail for the Rocket. Its about a 75 mile drive through some of the worst freeways the US has to offer. Pretty much a half day ordeal to complete the mission. As it turns out, I had some of the owners needed parts mixed in with mine and he needed them back. I could have thrown them in the mail, but the flight to KWHP is only 43 NM. So I jumped in the Rocket and blasted off - 14 minutes later I was shutting down in front of the guys hangar. This is a flight over mountains, open desert, and like the freeways, some of the more congested airspace in the US - all culminating in a landing at a towered airport. In my mind, this short flight is a perfectly acceptable use of a "GA" airplane vs. an ultralight. And in this particular case, I would not even attempt the flight in a 103 ship. It might be "possible" in the strictest sense, but it sure would not be enjoyable or safe. If you believe that airplanes are impractical "toys" (and many do), then its easy to assign neat categories for each mission profile. And there are almost certainly places in the US that its probably easier to drive 60 miles than fly, but SoCal is not one of them. Even with the few airports we have left out here it still relatively easy to get from the High Desert to anywhere in the LA basin in minutes - and it would even be more practical if we had 50 more airports like we did decades ago. All that said, marketing generally hints at the "practical" side of airplanes, even if it is rarely achieved in reality. Like swimming pools and boats, many consumers buy with the expectation of much more useage than is actually realized. But that does not impugn the hardware itself, because some of us DO "live the dream". I wont argue the fact that we need more low end airplane designs because I am not active in that market - all I do know was that when I wanted something low and slow all I had to do was write a check and BOOM a Taylorcraft appeared in my hangar. That itch has been scratched, and it took almost no effort to make it happen. I also can tell you that I would be among the first in line to buy the "imagineered" Raptor - if it actually met performance and price points. I have the capability to do 1000NM in an easy half day of flying in the Rocket... Id be very interested to do 2000NM for my next airplane. Last edited: #### Hephaestus ##### Well-Known Member My desire to travel 200 miles or more comes up almost weekly. It is not the desire for travel just to travel, but to go to a destination, do something there or buy something there and then return. Time and/or payload are generally the limiting factors. Aircraft limit one parameter and ground transport limits the other. I live my life one airline ticket at a time Besides covid - it's rare I'm not hoping on a jet at least weekly between work, family, personal obligations - never mind my own personal wants... With some of my routes having crappy service or the large airports being hours from destination & expensive taxi/uber options - its often preferable to fly myself. With most airline tickets being bought fairly last minute - often its cheaper to fly. There's a reason I've been hunting for a smaller/more efficient fast commuter for all these years. #### challenger_II ##### Well-Known Member What? You don't have any PT-13/17's around? In my life as "airline person" I do not see any GA aircraft at O'hare, LAX or JFK. In my life as a GA pilot I generally do not see Boeing aircraft hanging around the GA airports. That's my two cents. Where is yours? #### jedi ##### Well-Known Member Toobuilder and Hephaestus: Great examples and good uses. I am pleased to hear your practical uses as it is people like you that are keeping GA alive. I have had enjoyed similar experiences but see a lot of want-a-be pilots that do not have an airport to airport use and hanger space at my local airport is restricting my use. Toobuilder: I envy your Mojave location. You have a great setup. I would like to ask a specific question and I hope it involves aviation. If you wanted to take a grandchild to the Griffith Observatory in Los Angeles how far is that and how would you accomplish the trip? Same question for Sea World in San Diego and with your wife for a weekend in Carlsbad CA. All sound like a good destination for you. And no they are not a trip for an Ultralight. #### Toobuilder ##### Well-Known Member HBA Supporter Log Member If I was doing Griffith as a specific destination I'd fly to Burbank and Uber over. If it was part of a weekend, then it would probably make more sense to drive my own car - but again, depends on the goals of the weekend. Carlsbad and the SD Zoo would likely involve a hotel as a base of operations, so a flight to Palomar and an Uber works just fine. As a practical example, I am going to Palm Springs for a friends birthday party in a few weeks and many times I've taken the car. Its a nearly 3 hour drive each way. Last year I flew into PSP and it worked great. Its a 25 minute flight and I take a 5 minute Uber to the AirBnB house we have set up. #### jedi ##### Well-Known Member Toobuilder - from Rapter NG thread - "I guess a cross country in the Mojave desert in an ultralight isn't a whole lot of fun." Since you live in the desert I am interested in your comments on Rich Parker's You tube channel where he does just that in his Light Sport Quicksilver. Fast forward the first minute or so if you like. or as an example. Last edited: #### WonderousMountain ##### Well-Known Member Sorrell Guppy, which I'm prepping to construct, has a range of 150 miles on 5 Gal with half Gal in reserve, speed of 60 to 70. Typical build with Cushman OMC does not climb well and weighs in at 330#. A true ultralight would need 1.5 Gal hr cruise for that kind of range, and of course there is the top speed cap. #### Toobuilder ##### Well-Known Member HBA Supporter Log Member Toobuilder - from Rapter NG thread - "I guess a cross country in the Mojave desert in an ultralight isn't a whole lot of fun." Since you live in the desert I am interested in your comments on Rich Parker's You tube channel where he does just that in his Light Sport Quicksilver... My comments? I can tell you that if I had a GoPro running on yesterdays Rocket flight it would have looked very similar to the first video, except we (me and another Rocket) were doing 220 knots, more G's, more inverted, and my right hand wasnt working the stick like I was churning butter. looks like some 103 guys like to have fun like I do. The difference though, is that I can load my wife and 100 pounds of stuff into the same machine and be in Ft.Worth in 5 hours. #### blane.c ##### Well-Known Member HBA Supporter I am trying to get some weights vs energy for hydrogen system compared to gasoline system. So far it seems 1 kilo of hydrogen has approximately the same energy as 2.8 kilo's of gasoline? (from, Alternative Fuels Data Center: Hydrogen Basics ) "The energy in 2.2 pounds (1 kilogram) of hydrogen gas is about the same as the energy in 1 gallon (6.2 pounds, 2.8 kilograms) of gasoline. Because hydrogen has a low volumetric energy density, it is stored onboard a vehicle as a compressed gas to achieve the driving range of conventional vehicles." (From, Now With Three Hydrogen Tanks, the 2021 Toyota Mirai Gets a 400-Mile Range ) 12 lbs of hydrogen and 6 percent of the system weight so 200lbs for the fuel system including 12 lbs of hydrogen would compare to approximately 33.8 lbs of gasoline plus the fuel system weight say around a lb so call it 35lbs? For practical purposes a ratio of 6 to 1? (From an earlier model, Toyota Mirai Fuel Cell Sedan Priced At$57,500 - Specs, Videos ) the fuel cell weighs about 124lbs and is 151hp, the newer model from the preceding paragraph has fewer cells in the stack at a higher power density and 171hp so for now assuming about the same weight for the 171hp.

No weights yet for any of the other components and also trying to figure weights for the Hyundai.

#### Pops

##### Well-Known Member
HBA Supporter
Log Member
I miss what Toobuilder has. I built and flew the Falconar F-12 for 5 years. Cruise down at 3K was 150 mph and with a 2200 FPM climb solo and 1700 FPM at GW , I could get up 10K/12K in a short amount of time and get some good GS tailwinds. Remember going to work at 3 pm one day and mentioned about flying to Huntsville, Alabama and back that morning to look at an airplane for sale, then drove 45 minutes to work and they didn't think you could do that in a "Piper Cub".

I miss the couple local grass field airports that closed. Would call in a order for Pizza for home delivery. Told to deliver at the end of Scott street at the green gate to an open field. I will be setting by the gate in a low wing airplane. They thought it was a joke the first time. 8 minute flight for me from startup to engine shutdown. Everyone always ask why the F-12 smelled like Pizza inside. Hauled Pizza out of that field for about 15 years. The other grass field ran parallel behind the business strip of a town. Land and short walk to about any kind of store and fast food, auto parts, Krogers, etc. Both fields shut down when the owner's died and the family wanted to sell the land.
My little SSSC gets 26 mpg and cost almost nothing to fly a couple hours in the evening and watch the sun set. Since our airport is down in the valley, I know that when the car head lights are on in the valley and I'm still in the sunshine , I need to get on the ground.

#### Aesquire

##### Well-Known Member
I am trying to get some weights vs energy for hydrogen system compared to gasoline system.
If you assume an ICE then it's simple, the Hydrogen storage systems cost and weigh a lot more, and the fuel isn't available at airports over almost the entire planet.

If you assume fuel cells, then that's a tiny bit different, and unfortunately not easy info to get, since it's proprietary. You lose the mass of the ICE, but then add the mass of the fuel cell stack and electric motor. Also unfortunately, it's still hard to get the fuel where you want it without a lot of money. ( you can have it trucked to your location if you want to )

Hydrogen Tank : Doosan Mobility Innovation Can't find a mass spec. for this small tank.

I'm sure there are other sources.

Fuel cell weights... good luck. Remember it isn't just the mass of the cell stack, there's the electronics and other stuff like mounts to deal with.

#### TFF

##### Well-Known Member
Although I’m on the side of hydrogen fuel, they have to fix the infrastructure in two ways.

One is just stations. Like first day Tesla said they will be making a car. Got to build them.

The second is actually more serious and could be what makes or breaks it. Fueling at the station. The fueling cycle can be very long between cars. From what I understand, the storage tank fills a tank at the pump, and that tank is what fills your car. Sounds simple. It fills with equilibrium. The lower pressure the main tank is, the longer the fill time of the other tank is. It fills less and less. If you fill yours before the pump tank is full, you only can fill the partial amount. You can only fill the car tank to the pressure of the fill tank. Also as an inconvenience, when the pump is between customers, it goes off line as inop as it fills the pump tank. Lower the pressure the longer the cycle. You might have to wait 20 minutes for the cycle to complete. Someone is going to have to build a compressor to to fill the service tank in reasonable times.

#### Hot Wings

##### Grumpy Cynic
HBA Supporter
Log Member
From what I understand, the storage tank fills a tank at the pump, and that tank is what fills your car.
Then why not use a cascade system? The only limit would be the rate of replenishing the system between customers. The cylinder swap behind the customer interface could all be automatic.

#### Aesquire

##### Well-Known Member
That's an interesting concern.

sizing the pumping and storage, while a solvable engineering problem, is also an economic one.

Typically at a gas station you limit flow to what your system can handle by limiting the number of hoses.

# hoses installed is determined by the marketing department.

Time, deliveries, pumps. # of outlets, and a guesstimate WAG at volume.

So pretty much the same as gasoline, except the infrastructure is small and growing.

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#### Aesquire

##### Well-Known Member
Then why not use a cascade system? The only limit would be the rate of replenishing the system between customers. The cylinder swap behind the customer interface could all be automatic.
The cylinder swap is "automatic" just like at a gas station, a truck drives up and hooks up at an interface. ( hoses ) If a station uses a cascade system alone or with high pressure pumps & a header tank is determined by anticipated volume & delivery frequency.

The deeper philosophical question is "will infrastructure keep up with demand?"