Basic Configuration for a "Safe" airplane

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Dan Thomas

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The question I ask myself about my own suggestion is whether or not I could live without pitch control and with engine rpm and climb/cruise/descent state essentially locked together.
I was in severe turbulence a few times. Once was well underneath a huge cumulus that was building rapidly. I was getting serious lift (I was flying a Champ) and even with the throttle closed it was still going up. I had to dive and slip and turn back to get away from it. Even then it was too close. That pitch control saved me. A light airplane without pitch control would get sucked up into that and get torn to bits.
 

Rataplan

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Feb 14, 2021
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IMHO a safe airplane is an honest and forgiving airplane but showing you if you near the limits. Stallable and spinable , but with good recovery without the needs for tricks. enough stable, not nervous but still responding direct and acceptable roll rate. For normal piston engines I think throttle (+ prop) + mixture in 3 handles should not be a problem. Sometimes its in my eyes funny people talk about the 'significant' less load on a pilot when reduced to one throttle cq power handle, but have no problem being busy pushing 100 buttons on their garmins with their head buried in the cockpit. Ok I dont talk about IFR .
other options for a safe plane, one with a broken engine and no fuel. (grounded).

A plane chute does not make a plane safer, it makes crashes safer and can safe lives, but like some posted before, the same plane with or without chute will behave on turn from base to final in the same way.
 

Dan Thomas

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Lots of myths about the Ercoupe by people that don't know much about them. First- they can be stalled, just not from level flight. I have owned 2 Ercoupes, one with rudder pedals and one without. Never did get the one with rudder pedals to spin. Stall and slap in full rudder and it would just come down in a spiral. They are trickier to fly than a C-150 because you can't lower a wing in a crosswind while landing. Since they don't have flaps the flight manual says slow down to rock the wings right and left for a steeper decent. Third- With or without rudder pedals, the nose wheel is connected to the ailerons. Ercoupes has a higher rate of accidents of running off the end of the runway for a reason. Ercoupes have a crosswind component of 25 mph. That is higher than most airplanes. When landing in a crosswind the manual says land in a crab ( LG designed for the side load) but just as the main wheel touch down, lightly let the control wheel turn by itself when the nose gear contacts the ground the nose will serve and un-crap and line up with the ground track. That is when the trouble starts, this causes the upwind wing to increase in airspeed and the downwind wing to slow down in airspeed. this causes the upwind wing to lift and allows the crosswind to get under the wing that has a lot of dihedral and will lift the wing and main wheel on that side to come off the ground until you are rolling along on the other main wheel and the nose wheel. The airplane then will serve off in the downwind direction while running on the two wheels.
You can't stop from going off the side of the runway by turning the control wheel , if you do , you make things worse. The only thing that will help is adding power. The wing will come down and when the wheel is back on the ground and get on the brakes as much as possible to cut our airspeed. Good luck on that, the old Goodyear brakes with a 1" dia puck is about like dragging your feet. A set of Clevelands is a highly welcomed. By adding power you just increased you landing rollout and with poor brakes . Running off the end of the runway is a common thing.


Added-- One time I was landing on a 7K long runway and with rudder pedals, you just have the handbrake. Tower said to turn off the first taxi way to the right. Pulled the handbrake and there was no braking. Passed the taxiway about 35-40 mph and tower said "Just turnoff anywhere you can". The runway was slightly down hill and I rolled about 5K before turning off. Got it on the ramp. ( before a dumb Engish reporter used the term tarmac in 1974 instead of RAMP. Yes, I know about the macadam pads used to park the B-17's on in WW-2). If the brake puck wears down more that about 1/8" the master cylinder is so small in volume of brake fluid, you have no brakes. So since the puck is 1" in dia, ( same as a quarter coin) , I put a quarter behind each brake puck and had brakes again and refueled and when on my way.
Yup. Airplanes are not cars. Trying to make them like cars ends up introducing some serious limitations and new hazards.
 

Rataplan

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Feb 14, 2021
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203
I was in severe turbulence a few times. Once was well underneath a huge cumulus that was building rapidly. I was getting serious lift (I was flying a Champ) and even with the throttle closed it was still going up. I had to dive and slip and turn back to get away from it. Even then it was too close. That pitch control saved me. A light airplane without pitch control would get sucked up into that and get torn to bits.
Must have been a Cumulonimbus , also very dangerous for big planes .
 

Bigshu

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Jun 7, 2020
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Car airbags are inflated by an explosive charge. Like gunpowder. Airplane airbags, because they're strapped to your body, are inflated by compressed air that can leak away over time and is stored in a canister than can corrode and explode under your seat and send shrapnel everywhere The sensor is under the floor where, if you've ever been under the floor of an airplane, you know that there is a vast number of threats that can disable or unexpectedly trigger the system. Dirt, oil, mice, water, corrosion, chafing wires and cables, and so on. And airplanes sit 99.9% of the time, letting all this stuff happen with no interference.

Cars are NOT airplanes. I don't know how many times I've had to say that. The failure of a car airbag is a lot less serious in a 40 mph collision than in a stall-spin crash-and-burn against solid ground. Furthermore, there were around 93 million cars built and sold last year. There were about 1100 light GA airplanes. You think the manufacturing economies of scale just might be a factor here? And lawyers love airplane crashes and will sue everyone that had anything to do with that airplane, including the airbag manufacturer and the mechanic that didn't inform the owner that periodic maintenance and testing is required.

And car airbag recalls are always happening. My own Ford Ranger had to go in for one a year or two ago, and now there's another one coming up.
All good points! I didn't know that about aircraft airbags. The economies of scale problem is going to be with us forever, so if we want to build airplanes, we have to accept that there will be a premium for aviation technology. It just doesn't have to be so huge. Look at avionics. The certified and experimental versions of many new products have large price differences, with no functional differences. That's the price we pay for the FAA and lawyers...
We have so many recalls on all sorts of products because we allowed our productive capacity to be driven overseas for the extra profit that comes from exploiting workers. Airplanes aren't cars, but we can learn a lot about how to build better airplanes by looking at how other industries develop products (hint, it's not fighting every technical advance tooth and nail, or dogmatically sticking to outdated technology just because that's what a "type certificate" requires).
 

cluttonfred

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That sort of statistical data can be useful in some ways, but you need to dig deeper to get a clearer picture. Fly a plane into the side of a mountain, and the literal cause of death is likely your body and parts of the aircraft structure trying to occupy the same place at the same time. That doesn’t answer the question of why the plane flew into the mountain on the first place.

Fatal trauma due impact seems logic to rank as number 1. What options are left?
 

Rataplan

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That sort of statistical data can be useful in some ways, but you need to dig deeper to get a clearer picture. Fly a plane into the side of a mountain, and the literal cause of death is likely your body and parts of the aircraft structure trying to occupy the same place at the same time. That doesn’t answer the question of why the plane flew into the mountain on the first place.
I agree , when talking about what caused the situation. But beside fatal accidents also accidents with injuries , long life disabilities etc are important to prevent.
 

challenger_II

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Perhaps a proximity-triggered repulsor field: small objects, lighter than the plane, are deflected away, and, when approaching terrain, the aircraft is repelled away, preventing contact.

Problem solved. Miller Time!
 

Dan Thomas

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Fatal trauma due impact seems logic to rank as number 1. What options are left?
Transport Canada told us that many people survive the crash only to die in the post-crash fire, or of exposure (hypothermia) while waiting for rescue. Autopsies and other evidence point to stuff like this.
 

Riggerrob

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Amsafe makes airbag seat belts/shoulder harnesses for airplanes. They show up in newer Cessnas, for instance. They're fired by a deceleration sensor and trigger the release of compressed air into the bags from a tiny canister that has more than 6000 psi in it.

BRS makes 'chute systems for popular light airplanes. The one for the 172 weighs around 70+ pounds and takes up nearly half of the baggage compartment. You need at least 800 feet of altitude to have a chance of survival with it. Since a lot of accidents involve loss of control on takeoff or landing, there's a bunch of times when it's useless.

Both of these systems are expensive and have periodic overhaul requirements, which are also expensive.

I have worked on both systems, too.
Ignoring legalities, can you install a Cessna-style airbag in a kitplane?
 

Riggerrob

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It's not a popular point of view, but I do believe that the aircraft with the least amount of demands on the pilot is, in fact, the safest. A plane with only two controls (up/down and left/right) could, in fact, be very safe if set up correctly:
  1. A single throttle lever which, when pulled back below the idle setting deploys spoilers/air brakes/landing flaps for adjusting glide path even with the engine off.
  2. A wheel/yoke/stick for turning left and right using rudder only, ailerons only, or interconnected rudder ailerons, no pitch control.
  3. Rugged tricycle gear steerable from the same wheel or yoke, or differential hand or foot brakes.
It wouldn't be very maneuverable or terribly exciting but it would also not be subject to pilot error causing a loss of control in the usual stall/spin scenario. You'd need to test passive stall/spin recovery in the case of violent turbulence. I imagine a nice modern cockpit like a Tesla with dual yokes and a large central lever like an inverted U for throttle/air brakes.

OK, I've got my fireproof Underoos on, flame away!
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.

By the same token, an inter-connect would prevent you from pushing the throttle to take-off power with more than 15 degrees of flap extended.

In a perfect world, the auto-pilot (?) would trim the airplane to best-angle-of-climb ....
with springs or feed-back stubbornly resisting any attempt at pulling the nose any higher.

OTOH, pulling the throttle back to idle, should reduce power to idle. Then if you pull the throttle past a detent/button, it starts to lower flaps. A second detent lowers flap all the way down. Finally. pulling through the third detent sets controls (e.g. dive brakes) to full Short Landing configuration (aka. steepest approach).
 

Dan Thomas

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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.

By the same token, an inter-connect would prevent you from pushing the throttle to take-off power with more than 15 degrees of flap extended.

In a perfect world, the auto-pilot (?) would trim the airplane to best-angle-of-climb ....
with springs or feed-back stubbornly resisting any attempt at pulling the nose any higher.

OTOH, pulling the throttle back to idle, should reduce power to idle. Then if you pull the throttle past a detent/button, it starts to lower flaps. A second detent lowers flap all the way down. Finally. pulling through the third detent sets controls (e.g. dive brakes) to full Short Landing configuration (aka. steepest approach).
The problem with such stuff is that it limits the pilot's options. Takeoff from a short field often requires flaps to get off early. You might need to retract those flaps to gain safe airspeed after liftoff or you might need to leave them out to help clear the obstacle. It differs between aircraft models. The 180/182/185 need 20° flaps for takeoff. No flaps make for a really long ground run. Other airplanes need flaps, too, while many do better without them.

If the engine starts to vibrate very badly(like from throwing a rod or piece of prop blade) you need to close that throttle immediately and start looking for a place to land. Any flaps or spoilers are going to steepen the glide just when you need to reach that field at max glide range.

It's like Pop's Ercoupe. You can't slip it to a safe crosswind landing. Got to crab it on and then hope the upwind wing doesn't lift when the nosewheel hits the runway and turns and lowers the aileron on the upwind side. Ugly.

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.

Give me all the separate controls. My options become much wider and I'm a lot safer that way.
 

PMD

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Martensville SK
It's not a popular point of view, but I do believe that the aircraft with the least amount of demands on the pilot is, in fact, the safest. A plane with only two controls (up/down and left/right) could, in fact, be very safe if set up correctly:

OK, I've got my fireproof Underoos on, flame away!
Well, I think we have been there, done that and lost the T shirt(s). Remember the Icon? Then of course the canards were to save all of the homebuilders. Then along came automation in Airbus 300 series and at the end Boing Boing Max - to make these things so idiot proof any idiot with a state-granted-license-by-privilege could fly one. None seemed to deliver on these promises. BUT: one thing is clear and consistent: TRAIN the pilot to fly the darn things, and they ARE relatively "safe".

The other thing that puts me off of airbags or other passive restraint things in airplanes is the realization that we CAN make really good harnesses. Now, as a bike and kart racer, that never mattered to me but in an ice race car you can bet it did (does if our club ever gets off their aging butts and organizes a series again). The very simple item that started genuine passive safety in car design was the "safety cell" that race cars take to an extreme with a roll cage. Next thing you need is a decent seat, seat mounting and 5 point harness with 3" lap belts tokeep you off of those designed box limits. This would not be really hard or all that heavy to make the cell perimeter the load path for engines, wings, etc. I think you will find some WWII carrier Grummans and most all ag planes do just that.
 
Last edited:

Richard Roller

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Feb 15, 2018
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Olathe, Ks.
Lots of myths about the Ercoupe by people that don't know much about them. First- they can be stalled, just not from level flight. I have owned 2 Ercoupes, one with rudder pedals and one without. Never did get the one with rudder pedals to spin. Stall and slap in full rudder and it would just come down in a spiral. They are trickier to fly than a C-150 because you can't lower a wing in a crosswind while landing. Since they don't have flaps the flight manual says slow down to rock the wings right and left for a steeper decent. Third- With or without rudder pedals, the nose wheel is connected to the ailerons. Ercoupes has a higher rate of accidents of running off the end of the runway for a reason. Ercoupes have a crosswind component of 25 mph. That is higher than most airplanes. When landing in a crosswind the manual says land in a crab ( LG designed for the side load) but just as the main wheel touch down, lightly let the control wheel turn by itself when the nose gear contacts the ground the nose will serve and un-crap and line up with the ground track. That is when the trouble starts, this causes the upwind wing to increase in airspeed and the downwind wing to slow down in airspeed. this causes the upwind wing to lift and allows the crosswind to get under the wing that has a lot of dihedral and will lift the wing and main wheel on that side to come off the ground until you are rolling along on the other main wheel and the nose wheel. The airplane then will serve off in the downwind direction while running on the two wheels.
You can't stop from going off the side of the runway by turning the control wheel , if you do , you make things worse. The only thing that will help is adding power. The wing will come down and when the wheel is back on the ground and get on the brakes as much as possible to cut our airspeed. Good luck on that, the old Goodyear brakes with a 1" dia puck is about like dragging your feet. A set of Clevelands is a highly welcomed. By adding power you just increased you landing rollout and with poor brakes . Running off the end of the runway is a common thing.


Added-- One time I was landing on a 7K long runway and with rudder pedals, you just have the handbrake. Tower said to turn off the first taxi way to the right. Pulled the handbrake and there was no braking. Passed the taxiway about 35-40 mph and tower said "Just turnoff anywhere you can". The runway was slightly down hill and I rolled about 5K before turning off. Got it on the ramp. ( before a dumb Engish reporter used the term tarmac in 1974 instead of RAMP. Yes, I know about the macadam pads used to park the B-17's on in WW-2). If the brake puck wears down more that about 1/8" the master cylinder is so small in volume of brake fluid, you have no brakes. So since the puck is 1" in dia, ( same as a quarter coin) , I put a quarter behind each brake puck and had brakes again and refueled and when on my way.
I HATE tarmac!!
Lots of myths about the Ercoupe by people that don't know much about them. First- they can be stalled, just not from level flight. I have owned 2 Ercoupes, one with rudder pedals and one without. Never did get the one with rudder pedals to spin. Stall and slap in full rudder and it would just come down in a spiral. They are trickier to fly than a C-150 because you can't lower a wing in a crosswind while landing. Since they don't have flaps the flight manual says slow down to rock the wings right and left for a steeper decent. Third- With or without rudder pedals, the nose wheel is connected to the ailerons. Ercoupes has a higher rate of accidents of running off the end of the runway for a reason. Ercoupes have a crosswind component of 25 mph. That is higher than most airplanes. When landing in a crosswind the manual says land in a crab ( LG designed for the side load) but just as the main wheel touch down, lightly let the control wheel turn by itself when the nose gear contacts the ground the nose will serve and un-crap and line up with the ground track. That is when the trouble starts, this causes the upwind wing to increase in airspeed and the downwind wing to slow down in airspeed. this causes the upwind wing to lift and allows the crosswind to get under the wing that has a lot of dihedral and will lift the wing and main wheel on that side to come off the ground until you are rolling along on the other main wheel and the nose wheel. The airplane then will serve off in the downwind direction while running on the two wheels.
You can't stop from going off the side of the runway by turning the control wheel , if you do , you make things worse. The only thing that will help is adding power. The wing will come down and when the wheel is back on the ground and get on the brakes as much as possible to cut our airspeed. Good luck on that, the old Goodyear brakes with a 1" dia puck is about like dragging your feet. A set of Clevelands is a highly welcomed. By adding power you just increased you landing rollout and with poor brakes . Running off the end of the runway is a common thing.


Added-- One time I was landing on a 7K long runway and with rudder pedals, you just have the handbrake. Tower said to turn off the first taxi way to the right. Pulled the handbrake and there was no braking. Passed the taxiway about 35-40 mph and tower said "Just turnoff anywhere you can". The runway was slightly down hill and I rolled about 5K before turning off. Got it on the ramp. ( before a dumb Engish reporter used the term tarmac in 1974 instead of RAMP. Yes, I know about the macadam pads used to park the B-17's on in WW-2). If the brake puck wears down more that about 1/8" the master cylinder is so small in volume of brake fluid, you have no brakes. So since the puck is 1" in dia, ( same as a quarter coin) , I put a quarter behind each brake puck and had brakes again and refueled and when on my way.
I HATE tarmac!!
 
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