CFI and student die in crash SMO

nauga said:
See, that's what the singing raccoon is for. I'm all but certain some of these 'no cause determined' accidents could have been prevented by a singing raccoon, so I think everyone should carry one...just in case, y'know. Teaching him to bite more than doubles the effectiveness if you think a large percentage of these (probably not the single-occupant incidents, presumably) are due to a passenger overreacting. Win-win.

Nauga,
and the masked singer
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iu
 
dmspilot said:
So the student reaches over and grabs the other stick. Or the passenger disconnects the pilot's stick. Or any number of other likewise permutations, rendering such a hypothetical safety device pointless. The solution is don't touch stuff you're not supposed to touch. Most of us learn this before age 5.
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A pretty typical startle response is to grab onto something and planes just happen to have yokes/sticks right in front of your hands. This is not intentional but a reflexive action.
 
Daleandee said:
Maybe just wire a taser to the students seat with the switch on the instructor's side. Wired into the 24 volt system, and using a fair transformer, the jolt would likely toss the student into the rear seat of a C-172 so weight & balance might be an issue ... :D
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It could work!

 
Albany Tom said:
Yep, a verbal instruction clearly doesn't work all the time, which is why I'm proposing a mechanical or electro-mechanical solution.

If it were in the late 60's/early 70's, and NASA was trying to fix this, they'd probably use explosive bolts. Instructor hits the special protected button and 40 milliseconds or whatever later "boom", the student doesn't have a control wheel that's connected to the aircraft anymore. Very possible. Probably even fun. But noisy, expensive, and it would be a one-shot.

Those systems can be made to be reliable, though. From quick research, the Apollo rockets had more than 200 pyrotechnic devices on them, and they never had a failure. Something like .9999 reliability projected from the testing they did.

For disconnecting a student, there should be simpler, less expensive solutions though.

Will a solution happen? Probably not. Just a couple of lives a year, so nobody cares but their families. So meanwhile, if you're instructor and your student is going to take you down, key the mike like this fellow did, so maybe we can add that accident to the tally. No sarcasm intended on this one.
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yes put explosives on the yoke, what could possibly go wrong? great idea, truly
 
You guys shouldn't get into your cars, then, unless you're still driving '88 pickups. Explosives all over the place, all more or less pointed at your head. They've used explosive canopy separation for military aircraft for over 70 years. Some EV manufacturers proposed and maybe are using explosive battery disconnects for crashes, to reduce risk of fire and reduce risk to first responders. I think Bosch developed a system. Cheaper and more reliable than breakers at that size. It's a very fast, simple, and reliable method to disconnect things. But yeah, "spooky new technology."

Disconnect could also be done mechanically, and that probably would be easier to get approved. It doesn't have to be low millisecond times. I think saw stop uses a big spring. Well, the wire holding the spring is electrically fused at high current in that system, so that may cause fear, too.

And again, maybe only kills a few people a year, so maybe not that big of a deal. Just to the CFI's. All of those guys are just time builders until they get a real job, so no big deal there, either, just part of the risk of the job, right? Sarcasm intended.
 
Albany Tom said:
You guys shouldn't get into your cars, then, unless you're still driving '88 pickups. Explosives all over the place, all more or less pointed at your head. They've used explosive canopy separation for military aircraft for over 70 years. Some EV manufacturers proposed and maybe are using explosive battery disconnects for crashes, to reduce risk of fire and reduce risk to first responders. I think Bosch developed a system. Cheaper and more reliable than breakers at that size. It's a very fast, simple, and reliable method to disconnect things. But yeah, "spooky new technology."
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My 2002 BMW has an explosive battery disconnect. NOT an EV or hybrid.

Plus the explosive seat belt pre-tensioner and the airbags. LOTS of airbags.
 
Albany Tom said:
You guys shouldn't get into your cars, then, unless you're still driving '88 pickups. Explosives all over the place, all more or less pointed at your head. They've used explosive canopy separation for military aircraft for over 70 years. Some EV manufacturers proposed and maybe are using explosive battery disconnects for crashes, to reduce risk of fire and reduce risk to first responders. I think Bosch developed a system. Cheaper and more reliable than breakers at that size. It's a very fast, simple, and reliable method to disconnect things. But yeah, "spooky new technology."

Disconnect could also be done mechanically, and that probably would be easier to get approved. It doesn't have to be low millisecond times. I think saw stop uses a big spring. Well, the wire holding the spring is electrically fused at high current in that system, so that may cause fear, too.

And again, maybe only kills a few people a year, so maybe not that big of a deal. Just to the CFI's. All of those guys are just time builders until they get a real job, so no big deal there, either, just part of the risk of the job, right? Sarcasm intended.
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yes you're right. let's load up every flight control with an explosive disconnect just in case any pilot goes rogue. put one on both sides, too, since a commercial student learning from the right could be having a death grip. just in case that system fails, we should also have a little robotic hand that shoots out of the panel with a rag doused in chloroform and it can be controlled via a little remote control that the CFI controls with a double switch lockout and an xbox controller

or, i guess pilots can just let go when told to do so. but definitely the above options make the most sense
 
Hmm, there is some discussion of the MN crash that a passenger could have panicked and grabbed the yoke.

Again, we have NO idea how many of these occur. There is no reporting path for them, but when the subject comes up, a lot of people know of instances where it happened. And if it results in a crash with everyone killed, we will never know.
 
People are acting like we are talking about a pound of C4. This would be like a big firecraker.

Heck, the Russians have an automatic fire extinguisher that is pyrotechnic based. A heavy cardboard tube, full of dry agent and a small charge. Stick to the wall or upright, pull the fuse down to expose it. Fire lights the fuse, pyrotechnic charge disperses the dry agent.
 
Pinecone said:
People are acting like we are talking about a pound of C4. This would be like a big firecraker.

Heck, the Russians have an automatic fire extinguisher that is pyrotechnic based. A heavy cardboard tube, full of dry agent and a small charge. Stick to the wall or upright, pull the fuse down to expose it. Fire lights the fuse, pyrotechnic charge disperses the dry agent.
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it's not the explosive we are denigrating. it's the idea of providing a mechanism that can disengage flight control surfaces. how many pilots would crash because of an accidental activation versus how many crash because of a death-grip scenario? the answer is obvious
 
Pinecone said:
People are acting like we are talking about a pound of C4.
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No, we're acting like you're talking about a way to irreversably sever a primary flight control inceptor. It sounds simple until you start considering the failure modes and effects.

Nauga,
and his SMDC
 
I'd advocate for ejector seats before I'd agree to flying a plane with firecrackers to disable my flight controls. Seriously, are you on crack?
 
Maintenance would be pia on an explosive device like that. Probably need to be replaced every 5 years.
 
Pinecone said:
Again, we have NO idea how many of these occur. There is no reporting path for them, but when the subject comes up, a lot of people know of instances where it happened. And if it results in a crash with everyone killed, we will never know.
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You have NO idea how many of these occur, but you propose a system to mitigate it. That's not particularly effective risk management. Probability of occurrence: Unknown. Outcome: Uncertain. Solution: A singing raccoon, just in case. Only in the solution proposed, deploying the raccoon breaks a primary flight control chain.

Nauga,
who is not belted and suspended
 
I'm pretty good at risk management. We have an idea. Based on the NTSB transcript of "let go!" repeated three times before a fatal, it's absolutely at least 1 for 2022. Based on my memory of the NAL reports, I think it's less than 20, for loss of control stall/spin during an instruction flight. So that's a bracket.

The racoon analogy falls apart because there's a flight instructor that's gone because he couldn't overpower or convince a student to give him control. We have multiple people who have related stories of having to wrestle control away from students who were headed to stall/spin. We're can say with certainty that it's possible for some students to overpower an instructor during takeoff or landing and stall/spin an aircraft.

It happens somewhere between 1 and I'd guess 20 times a year, in 2022, with a fatal outcome the same as any stall/spin, and that's near 100%. The current mitigating controls for the risk are a) explaining to the student that either pulling up in a stall or not relinquishing control when asked could kill them and b) overpowering the student. Neither of those are always successful. So, when your son/daughter the flight instructor goes up with a new student, probably they'll be fine. But maybe the student will kill them. We're not exactly sure how often that happens, at least once in 2022, partly because the resulting accident isn't survivable. But at most it happens 20 times a year, or whatever the number of yearly fatal instruction flight is, so it's pretty rare.

I don't think anyone is advocating control release for aircraft in general, that does present a lot of risks. I'm specifically talking about a system to disconnect the student pilot on primary training flights. I can calculate the times when that would be a problem, it's simple math - multiple the probability of the instructor becoming incapacitated in flight while the primary student is capable of landing by the probability of inadvertent activation of the disconnect system.

Now, is all the research required, cost, etc., worth it to save 1 to 20 instructors and students a year? Forever? Maybe not. But that's the calculation we're guessing at, and until then saying "yeah, it's a risk, but it's something you sign up for when you decide to teach people to fly. Suggest working out and selecting small framed students where possible."
 
Albany Tom said:
I'm pretty good at risk management. We have an idea. Based on the NTSB transcript of "let go!" repeated three times before a fatal, it's absolutely at least 1 for 2022. Based on my memory of the NAL reports, I think it's less than 20, for loss of control stall/spin during an instruction flight. So that's a bracket.

The racoon analogy falls apart because there's a flight instructor that's gone because he couldn't overpower or convince a student to give him control. We have multiple people who have related stories of having to wrestle control away from students who were headed to stall/spin. We're can say with certainty that it's possible for some students to overpower an instructor during takeoff or landing and stall/spin an aircraft.

It happens somewhere between 1 and I'd guess 20 times a year, in 2022, with a fatal outcome the same as any stall/spin, and that's near 100%. The current mitigating controls for the risk are a) explaining to the student that either pulling up in a stall or not relinquishing control when asked could kill them and b) overpowering the student. Neither of those are always successful. So, when your son/daughter the flight instructor goes up with a new student, probably they'll be fine. But maybe the student will kill them. We're not exactly sure how often that happens, at least once in 2022, partly because the resulting accident isn't survivable. But at most it happens 20 times a year, or whatever the number of yearly fatal instruction flight is, so it's pretty rare.

I don't think anyone is advocating control release for aircraft in general, that does present a lot of risks. I'm specifically talking about a system to disconnect the student pilot on primary training flights. I can calculate the times when that would be a problem, it's simple math - multiple the probability of the instructor becoming incapacitated in flight while the primary student is capable of landing by the probability of inadvertent activation of the disconnect system.

Now, is all the research required, cost, etc., worth it to save 1 to 20 instructors and students a year? Forever? Maybe not. But that's the calculation we're guessing at, and until then saying "yeah, it's a risk, but it's something you sign up for when you decide to teach people to fly. Suggest working out and selecting small framed students where possible."
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the problem is that you're not accounting for the number of situations where your system results in an incident accidentally, which is almost certainly higher than the random handful which may possibly be changed by such a system
 
Well, stun guns are cheap and easy to hide on one's person. If I ever bother to teach, I'd seriously consider that; though I'm reasonable strong, I'm also getting old.
 
readytocopy995 said:
the problem is that you're not accounting for the number of situations where your system results in an incident accidentally, which is almost certainly higher than the random handful which may possibly be changed by such a system
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Outside of the primary training environment, I agree. Having a non-pilot in the right seat able to disconnect the pilot from the airplane would be crazy. So this would only work if the system could be removed or completely disabled for anything other than primary instruction. For primary instruction, though, the person in the left seat is just a passenger as far as safety goes, in the best case. Worse case, they're someone actively screwing up the controls.
 
Kenny Phillips said:
Well, stun guns are cheap and easy to hide on one's person. If I ever bother to teach, I'd seriously consider that; though I'm reasonable strong, I'm also getting old.
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That could work.

Thinking about it, where I learned in the PA-28, the instructor stressed that on climbout, your right hand should always be on the throttle, in case it slipped back. They'd yell if you moved your hand off that until we hit pattern altitude. I always thought that was because of the stated reason...but maybe it wasn't. Maybe it was to make sure that the standard reaction of the student would be more likely to just have their left hand on the yoke in the climb, so it would be easier for the instructor to overpower the student. Of course that doesn't work in a cub.
 
readytocopy995 said:
it's not the explosive we are denigrating. it's the idea of providing a mechanism that can disengage flight control surfaces. how many pilots would crash because of an accidental activation versus how many crash because of a death-grip scenario? the answer is obvious
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Since you have NO idea how many crash because of a death grip, the answer is NOT obvious.
 
Albany Tom said:
I'm pretty good at risk management. We have an idea. Based on the NTSB transcript of "let go!" repeated three times before a fatal, it's absolutely at least 1 for 2022. Based on my memory of the NAL reports, I think it's less than 20, for loss of control stall/spin during an instruction flight. So that's a bracket.

The racoon analogy falls apart because there's a flight instructor that's gone because he couldn't overpower or convince a student to give him control. We have multiple people who have related stories of having to wrestle control away from students who were headed to stall/spin. We're can say with certainty that it's possible for some students to overpower an instructor during takeoff or landing and stall/spin an aircraft.

It happens somewhere between 1 and I'd guess 20 times a year, in 2022, with a fatal outcome the same as any stall/spin, and that's near 100%. The current mitigating controls for the risk are a) explaining to the student that either pulling up in a stall or not relinquishing control when asked could kill them and b) overpowering the student. Neither of those are always successful. So, when your son/daughter the flight instructor goes up with a new student, probably they'll be fine. But maybe the student will kill them. We're not exactly sure how often that happens, at least once in 2022, partly because the resulting accident isn't survivable. But at most it happens 20 times a year, or whatever the number of yearly fatal instruction flight is, so it's pretty rare.

I don't think anyone is advocating control release for aircraft in general, that does present a lot of risks. I'm specifically talking about a system to disconnect the student pilot on primary training flights. I can calculate the times when that would be a problem, it's simple math - multiple the probability of the instructor becoming incapacitated in flight while the primary student is capable of landing by the probability of inadvertent activation of the disconnect system.

Now, is all the research required, cost, etc., worth it to save 1 to 20 instructors and students a year? Forever? Maybe not. But that's the calculation we're guessing at, and until then saying "yeah, it's a risk, but it's something you sign up for when you decide to teach people to fly. Suggest working out and selecting small framed students where possible."
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It is not only stall spin. As I mentioned, a CFI friend of mine had a student go full forward yoke and locked their arms. NOT a stall spin, but an pretty much straight down dive into the ground if he had not been able to get control and had training in what do it when past the vertical.
 
Pinecone said:
Since you have NO idea how many crash because of a death grip, the answer is NOT obvious.
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That's what those of us arguing against a pyro control disconnect have been saying all along. :rolleyes:

Nauga,
who has NO idea how many crash because they didn't have a singing raccoon
 
Albany Tom said:
Based on the NTSB transcript of "let go!" repeated three times before a fatal, it's absolutely at least 1 for 2022.
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You and I have different definitions of "absolutely." I can say with absolute certainty that pilots have been mistaken about other pilots' actions in extreme circumstances. I'd wait to see, at a minimum, a report of control continuity before making that judgement call.

Nauga,
jammed
 
Albany Tom said:
Outside of the primary training environment, I agree. Having a non-pilot in the right seat able to disconnect the pilot from the airplane would be crazy. So this would only work if the system could be removed or completely disabled for anything other than primary instruction. For primary instruction, though, the person in the left seat is just a passenger as far as safety goes, in the best case. Worse case, they're someone actively screwing up the controls.
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I’m not a fan of modifying primary controls to enable disable this sort of thing. I’d wager that would also result in as many accidents as it would be likely to prevent.
 
Salty said:
I’m not a fan of modifying primary controls to enable disable this sort of thing. I’d wager that would also result in as many accidents as it would be likely to prevent.
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Agree 100%.

There is nothing wrong with the controls, so equipping them with an explosive disconnect seems insane.

It would be at least as effective, probably more effective, to require the student to wear explosive bracelets and blow his hands off if he won't release the controls.
 
No need for Elon Musk. A simple and cheap way to make a disconnect would be a 2 piece yoke shaft joined by a sleeve and secured by a detent pin. Big red pull loop on the head of the pin and cotter ring safety on the other end. Remove the ring to "arm" the system for instructional flights. CFI yanks the pin and yoke falls off.

Not that I am advocating this. I'm firmly in the singing raccoon camp.
 
I'm having trouble wrapping my head around folks believing that there's some sort of risk associated with disconnecting a student during an instructional flight.

Half Fast said:
Agree 100%.

There is nothing wrong with the controls, so equipping them with an explosive disconnect seems insane.

It would be at least as effective, probably more effective, to require the student to wear explosive bracelets and blow his hands off if he won't release the controls.
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So....the solution to the actual problem of a student killing themselves and an instructor is to maim the student rather than harming the precious aircraft with a reversible disconnect? Just trying to follow the logic. I get gallows humor, but I don't follow the logic. It's only an appropriate solution for a primary student environment. I can accept the logic that it's somewhere between 1-20 lives a year and it's not worth the investment to even look at it. I can't accept the logic that because some people don't feel that it's possible that it actually must be. By that thinking, aircraft wouldn't exist at all, because clearly walking around on the ground and riding bicycles is good enough.

I'll see if I can spin the argument around, so that it's easier to follow. Why should a student pilot flying with an instructor have equal control capability as the instructor? The only reasons are that there's no risk; that the effort or cost isn't worth the reduction in risk; that it's not possible to do; or that a modification would somehow increase risk. Of those, the first is pretty clearly false from this accident, the second seems unknown, the third seems unlikely, and I can't see an argument for the last for primary instructional flight.

I'm open to hearing from CFI's on how they feel much better knowing that their primary students have the ability to save them, though. That's the only sarcasm I'll add to this post.
 
Ed Haywood said:
A simple and cheap way to make a disconnect would be a 2 piece yoke shaft joined by a sleeve and secured by a detent pin. Big red pull loop on the head of the pin and cotter ring safety on the other end. Remove the ring to "arm" the system for instructional flights. CFI yanks the pin and yoke falls off.
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Albany Tom said:
Why should a student pilot flying with an instructor have equal control capability as the instructor? The only reasons are that there's no risk; that the effort or cost isn't worth the reduction in risk; that it's not possible to do; or that a modification would somehow increase risk. Of those, the first is pretty clearly false from this accident, the second seems unknown, the third seems unlikely, and I can't see an argument for the last for primary instructional flight.
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See my earlier post # 105. A simple solenoid disconnect (much like the door lock solenoid used for autos) could be employed and controlled by the instructor with a switch on his control yoke. The instructor wouldn't have to deal physically with the student but rather just temporarily disengage the student's controls.

The hurdles with getting something like this approved for use in certified planes is what makes it a nearly impossible answer. By the time a system was designed, built, tested, and certified to meet the standards for commercial training aircraft ... we'll all be riding around in electric pilotless drones ... ;)
 
I think they should make CFI candidates arm wrestle and beat the DPE. Put that in the ACS. Problem solved.
 
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Pinecone said:
Since you have NO idea how many crash because of a death grip, the answer is NOT obvious.
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if you need any sort of evidence to prove to you that a system that can effectively and quickly render the left seat pilot's flight controls useless would be of more harm than good, then i would say whatever part of your brain is responsible for logic is taking a vacation

others on here say "oh well it's only for primary instruction" such as a pin you can yank out which makes the yoke fall off. are you people on drugs? obviously it's going to accidentally happen more than the number of times a student deliberately grabs the controls and causes a crash. or some poor bloke on a solo accidentally yanks the pin when he drops his pen. come on, people. what's next? we need a right side disengaging pin for when our CFI is depressed and their girl/boy friend just broke up with them?

the absolute worst way to address human factors like a nervous student grabbing the flight controls and yanking the plane into a stall is by disengaging the flight controls. how about a briefing? how about effective communication?
 
Ed Haywood said:
No need for Elon Musk. A simple and cheap way to make a disconnect would be a 2 piece yoke shaft joined by a sleeve and secured by a detent pin. Big red pull loop on the head of the pin and cotter ring safety on the other end. Remove the ring to "arm" the system for instructional flights. CFI yanks the pin and yoke falls off.
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Except for the possibility of having so much pressure on the pin that it won’t move. Ever Pennied a door shut?
 
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Flying Keys said:
Just dropping in to mention the resettable clutch/pawl system for split/jammed controls on various airliners. But this…



… is the best answer.
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are you sure you don't like my robotic hand holding a rag doused in chloroform idea better than just making sure you are on the same page with your student/passenger?
 
readytocopy995 said:
are you sure you don't like my robotic hand holding a rag doused in chloroform idea better than just making sure you are on the same page with your student/passenger?
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I don’t know, I was leaning toward the singing raccoon.
 
readytocopy995 said:
are you sure you don't like my robotic hand holding a rag doused in chloroform idea better than just making sure you are on the same page with your student/passenger?
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"Same page" is utterly meaningless when panic occurs.
 
Kenny Phillips said:
"Same page" is utterly meaningless when panic occurs.
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then how do you handle a CFI freezing up on the controls? cattle prod? they may panic, too

perhaps airliners should have a system that allows the passengers to vote if they don't like the way the captain is flying and then one of them can take over. it's very democratic
 
Daleandee said:
See my earlier post # 105. A simple solenoid disconnect (much like the door lock solenoid used for autos) could be employed and controlled by the instructor with a switch on his control yoke. The instructor wouldn't have to deal physically with the student but rather just temporarily disengage the student's controls.

The hurdles with getting something like this approved for use in certified planes is what makes it a nearly impossible answer. By the time a system was designed, built, tested, and certified to meet the standards for commercial training aircraft ... we'll all be riding around in electric pilotless drones ... ;)
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I think you're right, that the certification requirement would be the toughest part of this, combined with there not being any economic incentive for anyone. For most of the GA training fleet, it would be a retrofit to a 50+ year old design. Nobody cares except those who lose someone, and it's a tiny number

As far as the safety issues go, any of the options could be made safe for normal, non-instructional flight. For an electro-mechanical or pyrotechnic device, you simply remove the power source. For a mechanical fuse, you replace the breakaway part with a solid one. For a pin/mechanical disconnect, the pin becomes a bolt. Inspection would be equally simple. And none of this would ever have to be installed in normal GA aircraft. It could even be limited to aircraft solely used for 141 primary instruction.

For the singing squirrels group or the insurance folks lurking around, it's anywhere from 1 a year to something like 20 or so, out of an estimate of maybe 35 dual hours per year of primary training for something like 22,000 private pilot certificates a year lately. Something like .2 to 2/100k hours, where I think average fatal accident rate is something like 1/100k, estimated.

If GA trainers ever become fly by wire, which I doubt will happen in my lifetime, a student pilot disable would be trivial. But I don't see any reason for fly by wire to happen for GA aircraft...mechanical cables are simple, cheap and reliable.
 
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