Valley Engineering's new ultralight

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BBerson

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Huh? Ultralights are not allowed, by law, to exceed a certain empty weight. It's open to interpretation (and one's imagination and engineering skills) how much crash protection that empty weight allows.

I'm pretty familiar with Part 103 and AC103-7. I don't recall any prohibition on some certain level of crashworthiness or structure. What am I missing?
I said significant crash structure. Many legal ultralights have had to eliminate such things as cockpit, brakes, turnover protection, crumple zone, shock absorbers....
The FAA does not provide additional weight allowance for these crash structure items. In fact, AC103-7 defines roll cages, brakes, etc. as part of the structure with no extra weight credit. Many ultralights don't have these items, because to do so and still have the required 120 square feet of wing area and other flight structure built strong enough to handle normal air loads has been difficult. So many if not most go without these crash safety items.

The FAA does allow 24 additional pounds for a parachute. But a parachute only helps for structure failure at altitude, not hitting concrete barriers. I guess the FAA provided this parachute band aid because it's arbitrary weight limit has resulted in plenty of under strength ultralights that have had inflight structural failure. I would prefer a sound flight structure rather than a parachute. I have been reading the old Sport Aviation from the ultralight days in the 70’s and 80’s. It's astounding how many of these early ultralight designers were killed in those days.
So yes, in my interpretation, the law prevents my full freedom to add the needed crash devices.

p.s. My design will have crash structures. But it has taken me years to get there.
 

Topaz

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I said significant crash structure. Many legal ultralights have had to eliminate such things as cockpit, brakes, turnover protection, crumple zone, shock absorbers....
The FAA does not provide additional weight allowance for these crash structure items. In fact, AC103-7 defines roll cages, brakes, etc. as part of the structure with no extra weight credit. Many ultralights don't have these items, because to do so and still have the required 120 square feet of wing area and other flight structure built strong enough to handle normal air loads has been difficult. So many if not most go without these crash safety items.

The FAA does allow 24 additional pounds for a parachute. But a parachute only helps for structure failure at altitude, not hitting concrete barriers. I guess the FAA provided this parachute band aid because it's arbitrary weight limit has resulted in plenty of under strength ultralights that have had inflight structural failure. I would prefer a sound flight structure rather than a parachute. I have been reading the old Sport Aviation from the ultralight days in the 70’s and 80’s. It's astounding how many of these early ultralight designers were killed in those days.
So yes, in my interpretation, the law prevents my full freedom to add the needed crash devices.

p.s. My design will have crash structures. But it has taken me years to get there.
Please forgive this comment, because you know I respect your skills and your work. But all of what you've written here is a judgement call. The regs are what they are. If a designer chooses to forgo safety elements just to accommodate the weight of their wing, how is that the fault of the rule?

Is it hard to design an adequate structure that complies both with our desired performance and at least nominal crashworthiness, and still meet the Part 103 spec? Sure it is.

And? So? But? Therefore?
 

BBerson

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Please forgive this comment, because you know I respect your skills and your work. But all of what you've written here is a judgement call. The regs are what they are. If a designer chooses to forgo safety elements just to accommodate the weight of their wing, how is that the fault of the rule?

Is it hard to design an adequate structure that complies both with our desired performance and at least nominal crashworthiness, and still meet the Part 103 spec? Sure it is.

And? So? But? Therefore?
If a designer chooses to forgo safety elements just to accommodate the weight of their wing, how is that the fault of the rule?
Seriously, that is your question. Who else is at fault, other than the rules, if the designer or operator can't include these items and gets killed?
 

Topaz

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If a designer chooses to forgo safety elements just to accommodate the weight of their wing, how is that the fault of the rule?
Seriously, that is your question. Who else is at fault, other than the rules, if the designer or operator can't include these items and gets killed?
Can't? I question that. We agree that it's very hard. But "can't"? No, we're going to have to disagree there.
 

Downs

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I said significant crash structure. Many legal ultralights have had to eliminate such things as cockpit, brakes, turnover protection, crumple zone, shock absorbers....
The FAA does not provide additional weight allowance for these crash structure items. In fact, AC103-7 defines roll cages, brakes, etc. as part of the structure with no extra weight credit. Many ultralights don't have these items, because to do so and still have the required 120 square feet of wing area and other flight structure built strong enough to handle normal air loads has been difficult. So many if not most go without these crash safety items.

The FAA does allow 24 additional pounds for a parachute. But a parachute only helps for structure failure at altitude, not hitting concrete barriers. I guess the FAA provided this parachute band aid because it's arbitrary weight limit has resulted in plenty of under strength ultralights that have had inflight structural failure. I would prefer a sound flight structure rather than a parachute. I have been reading the old Sport Aviation from the ultralight days in the 70’s and 80’s. It's astounding how many of these early ultralight designers were killed in those days.
So yes, in my interpretation, the law prevents my full freedom to add the needed crash devices.

p.s. My design will have crash structures. But it has taken me years to get there.
I have to agree with this. Just as with the limit on fuel to 5 gallons. Here, 5 gallons won't even get you to the next closest airport without using a ground crew and having suitable landing areas.

IMO the FAA in their quest to make the UL segment "safe" has infact created an environment that has people taking unnecessary chances during their flights all so they can fit within some rule thought up by "big brother" for "the greater good" just so they can get to the next patch over the hill. Especially when stuck using 2-stroke engines with their notoriously greedy fuel consumption. I don't mind the low speeds that's part of the fun but give me more allowance for fuel or engine (weight) that has better economy.

Just like the Marine Corps and drinking. Many barracks on the base do not allow alcohol in them. This leaves Marines who want to drink with only one option if they want to drink and obey the rules. That is go out and drink. Which means they have to find a way to get out and back usually via driving. Where as if they were just allowed to drink in their own rooms they would probably call it a night and be able to walk to their bed.
 

kennyrayandersen

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The actual statement made was:

"Ultralights are not allowed, by law, to provide significant crash structure."

This is false. The regulations do not specify this nor do the limit the amount of built in crash-worthiness -- that is a function of the design given the constraints. An engineer faces compromises [and constraints] regardless of the regulation. There may be limited horsepower, budget, skill-level, schedule or any number of things. These exist independent of the regulation. The regulation might appear to be onerous, and it may indeed drive engineering decisions; but, it doesn't not specify that safety can't be part of the design consideration -- that's utter nonsense.
Again -- I can trade 30 Lb of engine weight for brakes,
turnover protection, crumple zone, shock absorbers, or whatever I want. IF what I want kicks me out of the ultralight category, then I guess I didn't want an ultralight to begin with -- I wanted an LSA!! The choice to sacrifice safety in this particular case was wholly unnecessary and good design practices could have met the requirement despite the category weight restrictions



Again, if it were up to me I'd have another category for heavier, but equally slow air planes, but I'm not in charge of the FAA! Just because something is hard i.e. requires though and critical problems-solving skills, doesn't mean we should give a free pass to those that are having difficulty!! In fact there are relatively safe ultralights out there to choose from. IF an ultralight doesn't meet someone's requirements for safety, range, speed etc. then move to a different category of aircraft. And if there is a particular design that isn't robust for crash worthiness (or any other desired characteristic) then simply don't buy it!
 

Topaz

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... Here, 5 gallons won't even get you to the next closest airport without using a ground crew and having suitable landing areas....
Except that the FAA never intended ultralights to be used in that fashion. Literally, the concept is to get up in the air, buzz around for a little while, and come back down. Ultralights were not intended to do cross-country flights, even "to the next closest airport". In fact, you aren't "supposed" to be using an airport at all. Sure, there's provision for it, but that was essentially tacked on later.

Ultralights were intended to be nothing more than the aerial equivalent of a non-street-legal dirt bike. No more than that. For the kind of flying you're talking about, the FAA wants you to have a pilot certificate.
 

Topaz

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If a designer chooses to forgo safety elements just to accommodate the weight of their wing, how is that the fault of the rule?
Seriously, that is your question. Who else is at fault, other than the rules, if the designer or operator can't include these items and gets killed?
Design a lighter wing.
 

Tiger Tim

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If a designer chooses to forgo safety elements just because they don't want to bother getting a license, or plan to sell to that group...
Fixed it for you.

All flying machines are compromises, that's the nature of the game. To gain any one advantage you must give up something else. Some trade-offs are more extreme than others.

-Tim
 

Hot Wings

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Who else is at fault, other than the rules, if the designer or operator can't include these items and gets killed?
This is a philosophical question, not an engineering one.

The rules are not the problem. They are just one of the parameters we engineer/designers have to work with. Who or what is at fault?

1) The person that knowingly flies a part 103 plane with known (or reasonably should be know) deficiencies. That's an assumed personal risk. I, and apparently the FAA when they crafted the part 103 regulations, think it is fine for each individual to establish their own risk tolerance level.

2) The engineer that knowingly designed a less than acceptable structure and fails to fully disclose the likely consequences of their design decisions. No one is forcing the engineer to design a plane to fit the part 103 regulations. That's the choice the engineer or the company the engineer works for made. They should accept responsibility for their actions. If they don't hide any information from the customer that compromises their informed decision then the fault flows to the purchaser/user for purchasing and using a less than perfect device. This assumes that the purchaser can reasonably be expected to have the knowledge to fully evaluate the purchase.

In the case of ultralights it can be argued that the purchaser is not likely to be so knowledgeable and our courts here in the US will then restore the fault/blame upon the engineer/company.

We can't design and build a legal part 103 vehicle that will fully protect the pilot 100% of the time. We certainly can do better than a large percentage of the part 103 vehicles on the market that seem to have only the ability to fly and be cheap to sell as the primary parameters for the designer. How we engineer/designers choose to assign value to the various parameters we must work with is up to us to decide. If society or the courts second guess our decisions that's a risk we take. We can't blame the regulations. No one is forcing us to design or fly part 103 vehicles and there is no rational reason why we might need to.
 

Topaz

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This is a philosophical question, not an engineering one. ...
Nice post.

We can't design and build a legal part 103 vehicle that will fully protect the pilot 100% of the time. We certainly can do better than a large percentage of the part 103 vehicles on the market that seem to have only the ability to fly and be cheap to sell as the primary parameters for the designer. ...
We can't design any airplane that will fully protect the occupants 100% of the time. Can we do better than the current crop? Absolutely. Is that a difficult challenge? In some cases, it is. As you've so well-said above, that's just one of the parameters the designer has to work with. However, I can guarantee one thing about upping the weight and performance limits "to allow for safer ultralights": That increased margin will be used to increase the performance and range of the aircraft, not improve their safety. That's been shown again and again. People weren't building "fat" ultralights so that they could incorporate a better cockpit cage. They were putting on wind-screens, fairings to speed up the airplane, and bigger engines.
 

kennyrayandersen

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and if the manufacturer put a placard ( to cover themselves for the liability) saying this thing is a giant POS and will likely kill you if you look at it cross-eyed, my guess is that would cut into sales! What I don't understand is that a little bit of professional engineering up front would really improve an aircraft, make is safer, quite possible better handling, easier to build etc. The cost to have someone experienced go over a design is not big money, yet so many seem to skimp on it. I just find that a bit perplexing. I don't know whether that comes about due to ignorance, or arrogance!
 

Topaz

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If I had to guess (which I do, so I am), I'd say that most ultralights are not the result of a considered marketing and production plan by a professional aircraft firm. They're the result of a guy doing a design for himself, and then deciding to sell aircraft, kits, or plans as a way to make a little money.

The level of engineering is whatever the guy has in his head, and whatever his priorities are.
 

danmoser

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The FAA did not have a "vision" for what ultralights should be.. the concept grew out of creative minds of intelligent human beings who saw a need for grass roots aviation via motorizing hang gliders.
FAR 103 was a reaction to the reality of these wonderful flying creations.
Since the early days, some designs evolved back into "normal-looking" airplanes.. in other cases, very modern & efficient designs have been created by adopting advanced technology and clever design.

The FAA is relatively permissive of ultralight flying under FAR 103 rules because legal ultralights are deemed safe enough for people and property on the ground, due to their inherently low potential for destruction (kinetic energy is proportional to mass times velocity-squared).
The FAA makes no judgement as to ultralight safety for pilots, who can accept the risks of flying of their own free will.

A Cessna 180 crashing into the side of a house at normal cruising speed will probably kill everyone in the plane (including innocent passengers) and could kill many other people who were in the now-demolished house.
A legal ultralight crashing into the same house at it's normal cruising speed will most likely not hurt anybody in the house, will cause little property damage, and the pilot will most likely survive.

It's high time we quit whining about FAR 103 rules and get to work engineering the safest ultralights we can within those rules, and develop better operating procedures and training methods.
Once you start down the path of allowing more weight, speed and fuel capacity.. you'll need more engine to push it, which leads to more weight, more fuel.. and all that leads to greater destructive potential in a crash scenario.
The end result will be increasing FAA restrictions, increasing costs and decreasing flying freedom... the exact opposite of what ultralights are all about.
So-called "fat ultralights" are illegal, inviting increased FAA scrutiny and posing a threat to flying freedom.
 
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autoreply

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Probably very true! But once dude gets it's in his head he is going commercial, help should bring in a gray beard for a look-see!
Surprisingly few people are open to critique. Far fewer seek it out themselves and listen to it. If I've learned one thing about engineering; it's that. The big majority prefers opinions (their own) to constructive criticism, to even even larger extend homebuilders.

On the other hand, there're also pretty few people that can criticise constructively, without invoking their own preferences.
 

BBerson

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I don't get why the critics here expect the Backyard Flyer to have an indestructible fuselages, yet nobody here said the Boeing 777 is a "death trap" after it hit a hard barrier and killed several young girls.
The Boeing company doesn't have any empty weight limits to contend with but apparently can't build a fuselage that survives hitting a wall any different than any other flying machine.
Looking at this photo, what part of this Boeing 777 was improperly engineered?
 

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Topaz

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I think the main objection - and certainly my own - is not that the Backyard Flyer's structure failed in that particular crash, it's how it failed. The guy hit a concrete object (sounded like a parking bumper to me) on a "high speed" taxi. The failure I would've liked to have seen was that it folded the mains back or ripped them clean off the airplane, with little or no distortion of the cockpit area. Instead, the opposite occurred, with the landing gear "relatively" intact, and a rather severe intrusion of deformed structure right into the space occupied by the pilot. When all it would take to prevent this intrusion was locating the fuselage-end pivot for the main gear drag brace about eight inches farther aft, at the bottom of the seat-back tube cluster, you have to wonder why they did it the way they did.

So that's the thing to which I personally object - the intrusion of structure into the cockpit. If this accident had merely ripped the gear off the bottom of the plane or folded them back against an intact fuselage bottom, I don't think we'd even be having this conversation.
 

BBerson

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I can't find the photo anymore, but as I recall the longeron tubes bent up on the sides, but not into the cockpit.
So if the guy was not hurt, how is it a death trap?

I don't recall any engineering report that gives details of landing gear design to minimize injury.
 
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