Basic Configuration for a "Safe" airplane

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Doran Jaffas

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Granted I don't have much experience in the Ercoupe. Only about a 1000 miles in one when I was asked to fly 1 back from out of state for someone who just purchased it. My 1st 3 landings were in 18 kt crosswinds. In that 1000 miles I grew to truly enjoy that little airplane and how it landed. I would own one in a heartbeat. And have actually thought lately about looking for 1.
 

Bigshu

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I know the higher/faster/further pundits insist on high aspect thin slender wings,
It's interesting that the most vibrant growth in homebuilt kits is in low and slow, or STOL aircraft. Even Vans and Sonex are coming out with high wing designs, to no doubt be modified by builders to include tundra tires and VGs, or other wing mods to make them more STOL capable.
 

Victor Bravo

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All this talk about airbags and electronic gizmos and even the comments by myself and others on pilot training are not relevant to the intent of this thread. It was about aircraft configuration - the size, shape and alignment of the big pieces - not any particular piece of equipment or add-ons.

I believe it's fair to say this thread is specifically about the big airplane-shaped thing that is there before any equipment, gadgetry, recovery chute, autopilot, etc. etc. is added on.

The three-view drawing, essentially.
 

Bigshu

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All this talk about airbags and electronic gizmos and even the comments by myself and others on pilot training are not relevant to the intent of this thread. It was about aircraft configuration - the size, shape and alignment of the big pieces - not any particular piece of equipment or add-ons.

I believe it's fair to say this thread is specifically about the big airplane-shaped thing that is there before any equipment, gadgetry, recovery chute, autopilot, etc. etc. is added on.

The three-view drawing, essentially.
I'd go back to your post #20, and say the ventral fin, and design features to give pronounced buffet prior to stall are the most obvious features you can see. I still think an aileron /rudder connection to keep flight coordinated, along with limited elevator travel are two good ideas that won't show up on the three view.
 

challenger_II

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The PA-22 Tripacer had linked aileron/rudder controls, from the factory. In the 40 years I have been dabbling in all things Aviation, I have seen exactly ONE that hadn't had the link removed. While there are many gimmicks to aircraft that were to make them more user-friendly, none have been as truly successful as quality training, quality practice of good piloting skills, and the connection between the seat, and the control column being of the constant attitude of knowing the machine they are operating will kill them from the least attention to what the machine/operating conditions require.
 

Dan Thomas

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The PA-22 Tripacer had linked aileron/rudder controls, from the factory. In the 40 years I have been dabbling in all things Aviation, I have seen exactly ONE that hadn't had the link removed. While there are many gimmicks to aircraft that were to make them more user-friendly, none have been as truly successful as quality training, quality practice of good piloting skills, and the connection between the seat, and the control column being of the constant attitude of knowing the machine they are operating will kill them from the least attention to what the machine/operating conditions require.
Exactly. It really doesn't take much longer to learn to use all the separate controls than it would if you had nothing more than throttle and ailerons. The human brain is capable of great learning. So many of these "simplification" ideas for the control systems come from people who seem to have little or no flight training; they imagine that it's too complicated. Maybe some of them are the computer-gaming nuts that operate numerous controls with great skill, too. How did they ever learn to ride a bike? A machine that will dump you the instant you let it? I learned to ride a unicycle when I was 12 or 14 or so; much, much harder and more dangerous than a bicycle, but as a kid I did it. So did lots of other kids. Learned to downhill ski and water ski, like millions of other people. Skateboard? Nope. Yet millions of kids do it with great finesse. BMX biking too. There are an awful lot of things harder to master than the "flying" part of flight training. It's the academic stuff that slows most students down. Some of them are coming out of school with no frame of reference for the physics involved. Making the airplane itself simpler wont fix that; it will just hide the deficiency until the accident happens.
 

cluttonfred

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What would be really telling is an analysis of stall/spin accidents in Tripacers to see the likelihood of such incidents with and without the rudder-aileron link. I suspect that most pilots aren't as good as they think they are, at least not on their worst days.

The PA-22 Tripacer had linked aileron/rudder controls, from the factory. In the 40 years I have been dabbling in all things Aviation, I have seen exactly ONE that hadn't had the link removed.
 

gtae07

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At risk of over-simplification, it would be nice to include some inter-links between the throttles and flaps. For example: pushing the throttle full-forward should apply full power, retract dive brakes and set flaps to take-off (say 15 degrees).
Pushing the throttle past a detent/button trims the airplane in full Short Take-off mode.
Many airliners and other large aircraft have something a little like this--for example, a system that will retract the spoilers if the power is advanced beyond a certain setting, or a system that will retract the flaps a notch if you exceed a certain speed with the flaps fully extended. But they're in place to catch mistakes, not simplify operation.
I'm not sure how much it would buy you on a light airplane, other than perhaps retracting the flaps to some certain setting. I know of a couple of fatal Cessna crashes where someone tried to go around (or do a T&G) and left the flaps at 40, for example. But such a system presupposes electric flaps and some way of determining position. Frankly I'd rather just have enough power to climb with full flaps.


The Cirrus has a single-lever power control. It controls the throttle and has a cam that adjusts the prop governor. That makes it impossible to reduce power and increase pitch to get max range or time aloft if you're short on fuel or there's someone stuck on the runway.
Really doing single-lever right means a FADEC. Adds cost and complexity to the aircraft (though it could be done for less of both if it didn't need to meet the one-size-fits-all requirements made for jets), simplifies operation. It's a little different; rather than commanding an engine setting, you command a power/thrust level and the engine does whatever it needs to do (you don't care) to give you that power/thrust at the lowest safe fuel burn.

I don't see a true FADEC coming to many piston aircaft outside of a handful of commercially-targeted ones, and perhaps a few enterprising homebuilders. The returns just aren't there in most of the piston market (which faces competition from turbines at the upper end, and now electric in certain applications).
 

Pops

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What would be really telling is an analysis of stall/spin accidents in Tripacers to see the likelihood of such incidents with and without the rudder-aileron link. I suspect that most pilots aren't as good as they think they are, at least not on their worst days.
Same here. I have never seen a Tripacer with the coupled rudder-aileron. My first airplane ride was in a Tri-Pacer in 1953.
 

Dan Thomas

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What would be really telling is an analysis of stall/spin accidents in Tripacers to see the likelihood of such incidents with and without the rudder-aileron link. I suspect that most pilots aren't as good as they think they are, at least not on their worst days.
The interconnect just helps maintain coordination. Without it the airplane will slip (adverse yaw), not skid, which is the stall-spin problem.
 

Bigshu

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How did they ever learn to ride a bike?
Good question. How many controls does a bike have? Pedals and handlebars, right? A simple bike with coaster brakes is arguably easier to master than a multi gear mountain bike with hand controls for brakes and shifting. It doesn't go as fast and isn't as cool, but riding the bike is really just balance and coordination, regardless of how it's configured.
 

Bigshu

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There are an awful lot of things harder to master than the "flying" part of flight training. It's the academic stuff that slows most students down. Some of them are coming out of school with no frame of reference for the physics involved.
Interesting observation. Are you saying that the earliest pilots had a deep understanding of the physics of flight? I think they just went by "feel", flying the wing and learning about the rest as they gained experience. To the degree they ever had to learn the physics, it was in it's most rudimentary form. No way to quantify this of course, but I think it's likely you can be a safe and proficient pilot without much of that knowledge.
 

Dan Thomas

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Interesting observation. Are you saying that the earliest pilots had a deep understanding of the physics of flight? I think they just went by "feel", flying the wing and learning about the rest as they gained experience. To the degree they ever had to learn the physics, it was in it's most rudimentary form. No way to quantify this of course, but I think it's likely you can be a safe and proficient pilot without much of that knowledge.
A big part of loss of control accidents is the lack of understanding of AoA. Accelerated stalls cause way too many accidents. The student is taught all about stall speed but little or nothing about how that speed rises in most maneuvers. That's physics. A whole bunch more accidents are the result of a poor understanding of carb ice and when it can happen. More physics. AOPA did some research some years ago and found that the biggest single cause of power failure was carb ice. Fuel starvation came second.

Sure, we can computerize the airplane to the point that the pilot can't so easily kill himself, but can you afford that? Will it stop him from flying VFR into IMC, or do we need software to take control and turn it around?

The whole discussion in an affordable-airplane homebuilder group, is crazy. Training, which means studying and understanding, is way more effective and affordable than a bunch of gizmos you have to buy for every airplane you own.

The early aviators had little choice but to learn most of it the hard way. We can learn from their mistakes, not make them all over again.
Remember, too, that the Wrights built a wind tunnel to learn rather than die.
 

Dan Thomas

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I think the skidding turn is the bigger spin issue, no? Inboard wing slower than outboard, with rudder deflection toward the slower wing??
That's what I said. Removing the interconnect will result in a slip instead of coordinated flight if the pilot doesn't apply some rudder. Since the interconnect applies rudder into the turn, it also makes it easier to apply pro-skid rudder.

And: the ailerons are usually neutralized once the turn is established. The interconnect will also neutralize the rudder, allowing some slip. So the pilot needs to use the rudder anyway if he's going to fly properly. And the interconnect increases the control forces if the pilot wants to slip the airplane. It's a crutch that cures one disease and causes two more.
 

BBerson

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If the inattentive pilot is near stall in a left turn to final and tries to roll level rapidly and only applies rapid full right aileron control that would stall the left wing and initiate a spin.
Rudder interconnect would add some anti spin with top rudder in that case.
 

BJC

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Learning how to properly turn an airplane is fundamental to becoming a pilot. A proper training syllabus will include that, as well as spins, because becoming proficient in spins teaches a pilot how to avoid an unintended spin. The current syllabus is deficient, and some within the FAA know that, but, for some reason (unknown to me) the FAA strenuously opposes including spins in training.

The difficult thing is to develop good judgement. Find a way to do that, both airplane crashes and insurance rates for teenage car drivers will go down.


BJC
 
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TFF

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I noticed a couple of things about operation of complex machines.

My son is not into any vehicle fun. Although he can ride a bike, he never liked to. Teaching him how to drive a car was hard. Video games are not full motion sims. He would get up to a turn and not know to slow down, balance through the turn, power out. No instincts. I have friends with kids who have similar bike and driving stories. Riding a bike is a big teacher.

I also noticed a couple of young guys learn how to fly helicopters somewhat easily. They grew up operating heavy machines. One’s family had a crane business, the other’s was farming. They knew how to use their feet independent of their hands doing complex things. The crane kid was flying fine in five hours or so. Operating a $500,000 machine since 12, just a lateral move to a helicopter.

I am a terrible dancer but flying well is like dancing. It’s not heavy duty coordination like hitting a baseball, it’s more like welding. Welding is like doodling with both hands. That is what the student is trying to learn. Cocky learn the stuff because they are not scared to fail until they get it along with motivation. Most kids have an inhibition to failing. They do great until they learn that trait, then it’s a fight.

When you are an older flying student, it’s tough to assess your own issues to break through the training. Lots learn crutches and stay with certain airplanes as crutches. The crashes seem to be people getting away from their crutches without fixing the training.
 

Bigshu

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The whole discussion in an affordable-airplane homebuilder group, is crazy. Training, which means studying and understanding, is way more effective and affordable than a bunch of gizmos you have to buy for every airplane you own.
I'm not disputing the importance of training, I just think being taught AOA and energy management during maneuvers can be taught without ever mentioning physics. But, to get back to what was pointed out several posts ago, we're talking about aircraft configuration that can make small aircraft safer, not training or "gizmos". I'm with you 1000% on the value of training, and that changes to that training might be the best bang for the buck on fixing LOC accidents.
 

BJC

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I just think being taught AOA and energy management during maneuvers can be taught without ever mentioning physics.
It is physics, whether or not the instructor says the word.
to get back to what was pointed out several posts ago, we're talking about aircraft configuration that can make small aircraft safer, not training or "gizmos".
OK, will repeat my answer from 8 pages ago:
A design safety feature, for me, would be flight controls that have self-centering and provide feedback to the pilot. Example: a Pitts can be flown right at the edge of a stall, because the controls provide feedback that the airplane is within a fraction of a degree of AoA of a stall, regardless of speed.

BJC
 
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