Rear seat Engine kill switch

[Scott A]

Experimental Super Cub. Standard OFF R, L, Both, and Start ignition switch on the forward panel. eMags.

What is the best way to wire an emergency engine kill switch reachable from the back seat (probably a guarded switch in the left wing root).

Don't need a debate on whether this should be done - just what is the best way to do it if installed.

My thoughts, which could be all wrong

• Wire straight from the P lead terminal on the back of each Mag up to the switch in the wing root.
• Or wire from the P lead terminals on the back of the ignition switch to the wing root (avoiding extra wires through the firewall)?

Either of those should work but the next question is will a single pole single throw switch work, or would you need a double pole single throw? With the single pole the two magneto P-leads would be 'connected' to each other at all times at the switch but of course not grounded until you flip the switch. Is that 'bad' or since it doesn't go to ground would the mags even know? The double pole would of course work and may be the best way.

Or is there an easier way yet? It's not to test mags or anything, it's just to make the noise stop all at once if needed.

Thanks for any input.

 

[skywagon8a]

Two shielded wires direct from the mag switch to two guarded toggle switches or a single double pole switch. Use shielded to avoid any possible radio interference and use the shield as the ground to the mag switch ground.

 

[RaisedByWolves]

Weird, it’s almost like piper figured out where to put the switch to reach from both seats. The things we eliminate when we re do the panel.

 

[DENNY]

Move the switch to the wing root or change to this https://www.aircraftspruce.com/cata...MI2baf9dboiAMV9Q-tBh0uUQQmEAQYByABEgKCcfD_BwE. Trying to build a bastard system is going to leave you with a hot mag one day because someone won't know how it works.
DENNY

 

[Richgj3]

I don’t think you can connect the two p leads together. Unless I’m misunderstanding, that would kill both mags in either left or tight position. Hard to do a mag check that way. On the other hand the drop would be the same on both mags .

 

[skywagon8a]

I don’t think you can connect the two p leads together. Unless I’m misunderstanding, that would kill both mags in either left or tight position. Hard to do a mag check that way. On the other hand the drop would be the same on both mags .

Separate wires for each mag not connected to each other. Two switches in each wire will both be open when the engine is running. Close one or both switches and that mag will be shut down.

 

[Scott A]

I don’t think you can connect the two p leads together. Unless I’m misunderstanding, that would kill both mags in either left or tight position. Hard to do a mag check that way. On the other hand the drop would be the same on both mags .

Yes, the point of the rear seat activated 'kill' switch is to kill both mags at the same time - even though the front panel ignition is in the Both position. The rear switch would only be to make the noise stop, it would never get used in normal operations.

 

[Richgj3]

Yes, the point of the rear seat activated 'kill' switch is to kill both mags at the same time - even though the front panel ignition is in the Both position. The rear switch would only be to make the noise stop, it would never get used in normal operations.

In that case you would need a double pole switch For the kill switch. I was thinking you proposed to tie the two p leads together at the kill switch to ground both at one flick of a single pole switch. If was that then even if you had that switch open moving the real mag switch to left or right would kill both mags. Difference between a logic “or” versus a logic “and”.

 

[Scott A]

In that case you would need a double pole switch For the kill switch. I was thinking you proposed to tie the two p leads together at the kill switch to ground both at one flick of a single pole switch. If was that then even if you had that switch open moving the real mag switch to left or right would kill both mags. Difference between a logic “or” versus a logic “and”.

Ah.. yes (lightbulb moment-duh).. connecting together at the single pole switch from the mags is the same as doing that right at the ignition key - which I sketched out and knew would not work. And why Skywagon8a said to use the two switches or a double pole from the get go

Thanks for all the input everyone.

 

[KevinJ]

Yes, the point of the rear seat activated 'kill' switch is to kill both mags at the same time - even though the front panel ignition is in the Both position. The rear switch would only be to make the noise stop, it would never get used in normal operations.

Instructing? Still not following….

 

[Scott A]

Instructing? Still not following….

Haha..I've learned you (sadly) have to keep it vague or get the insufferable opinions of those who can fly and land after a midair with a wing missing, or just know their 10 year old granddaughter in the back seat will be able to land after they have a heart attack in the front - I mean come on it is a Super Cub anyone can land it slow and safe. Or like my friend with his wife - he should have been able to land after the tail came off (RV7) and then the wings negative g and departed the aircraft, or my two flight instructor friends (40 years ago) that spun a C-152 into the ground (still no idea why or how they screwed that up). In any case all four 'may' be here today if they had a parachute installed - and my wife knows this Ha, sorry the long way of saying you need a kill switch near the activation handle of the ballistic parachute for the back seater. At some point I'll post some pics of the install if it ever helps anyone else whose wife insists on the parachute (wait, did I just 'blame' it on my wife...

 

[aktango58]

Make the 'kill' switch part of the parachute activation, so when you pull or activate the chute, it automatically kills the mags.

Not knowing how a chute is deployed I can not offer how to wire it, but by combining into single switch/release it would be more 'fool' proof, and in a panic would not be missed

 

[Scott A]

Make the 'kill' switch part of the parachute activation, so when you pull or activate the chute, it automatically kills the mags.

Not knowing how a chute is deployed I can not offer how to wire it, but by combining into single switch/release it would be more 'fool' proof, and in a panic would not be missed

The T handle you pull has about 3-4 inches of movement from stowed to fully pulled out so something like an electric trailer brake, break-away switch may work. It would need two poles and I suspect most are single. More research. Thanks for input.

 

[skywagon8a]

This is beginning to make me nervous when you speak of combining two separate emergency functions into just one switch/handle. Both of those two separate emergency functions are a commitment, but two separate independent functions. The parachute is not reversable, deploy it and it is done. Killing the engine can be reversed just by flipping a switch. I can see the engine kill switch using a third pole being used to arm the parachute but not deploying it, not both functions simultaneously.

 

[Scott A]

This is beginning to make me nervous when you speak of combining two separate emergency functions into just one switch/handle. Both of those two separate emergency functions are a commitment, but two separate independent functions. The parachute is not reversable, deploy it and it is done. Killing the engine can be reversed just by flipping a switch. I can see the engine kill switch using a third pole being used to arm the parachute but not deploying it, not both functions simultaneously.

Yes, as you say if you pull the parachute T handle there is no going back the rocket fires and the parachute is deployed - with the chute deployed you do not want the engine running. So if the secondary engine kill switch was activated by the pull of the handle that seems like it would be okay since there is no going back anyway. However I'm leery of a hidden switch attached to the handle (be it pull pin, micro, whatever).
I may just stick with the two step emergency procedure, shut down engine, pull T handle. Back in the day we had to memorize many fairly long ones so two steps for a passenger shouldn't be overwhelming - with a placard of course (the memory items now days are a joke - but maybe that's a good thing). I also have a cover over the T handle so you have to actively remove the cover to get to the handle (so I guess it is a 3 step procedure). Having the exposed T handle scared me a little.

 

[aktango58]

My opinion, but you are attributing a whole lot more brain function to passengers during an emergency than I give most passengers on a normal day. It is not often a person can even put their seatbelt on correctly without assistance, (view from pilot of the 135 and Lodge world).

 

[DENNY]

OK, now that we have the rest of the story. Keep it simple build spring loaded mag ground leads attached to T handle that activate when handle is pulled. No extra steps for the passenger. Keep it covered so someone does not play with it in flight. But easy to check if you have mag issues.
DENNY

 

[sj]

My question is... (maybe I missed the answer above) who makes a ballistic parachute big enough for a cub? Did you take it out of a Cirrus?

sj

 

[Richgj3]

There is a ballistic parachute for a C182. Don’t know who makes it but I’ve seen two sky lanes with them.

 

[sj]

There is a ballistic parachute for a C182. Don’t know who makes it but I’ve seen two sky lanes with them.

Installation kits for the Cessna 182 Skylane are $17,500 and the Cessna 172 installation kit is $15,500, plus installation fees. The BRS system is approved for Cessna 182s manufactured from 1964 and newer, and Cessna 172s manufactured in 1966 and newer. (this was a post on CPA from a number of years ago)

 

[Scott A]

My question is... (maybe I missed the answer above) who makes a ballistic parachute big enough for a cub? Did you take it out of a Cirrus?

sj

Stratos07 out of the Czech Republic makes them for many of the European aircraft (they go up to 4000 LB gross and 200 mph + deployment speeds). US dealer is out of Florida, Magnum Parachutes (uflyit.com) he mostly does them for ultralights which they also sell. Of course BRS here in the states does them too - they do the Carbon Cub. I started with them - and they held my money hostage for months and months after I canceled. I would not recommend them.

​

 

[Scott A]

OK, now that we have the rest of the story. Keep it simple build spring loaded mag ground leads attached to T handle that activate when handle is pulled. No extra steps for the passenger. Keep it covered so someone does not play with it in flight. But easy to check if you have mag issues.
DENNY

Trying to imagine how 'spring loaded ground leads' would be designed. I've looked at pull pin switches or possibly roller lever microswitch that could be fashioned into something that may work. This whole parachute thing created many challenges and slowed down the build considerable (but my engine is still not here two years later so it's all good).

 

[DENNY]

Simple spring loaded points (think clothes pin) Put a plastic spacer in the jaws connected with strap to T handle.
DENNY

 

[Scott A]

Ah yes, thanks. That gives more ideas Denny.

 

[KevinJ]

What is the minimum altitude for pulling the chute?

 

[Scott A]

What is the minimum altitude for pulling the chute?

I'll make another thread eventually with all the scoop that I have.

Both Stratos and BRS emphasis there is no minimum altitude to pull the chute - but that just means if you pretty much know you are going to die, pull the chute at any altitude. Realistically they go on to say (Stratos) that it will usually (they can't say 'always') work at 200 meters or 656 feet AGL. Stratos also says they have documented saves as low as 80 meters (262 feet). BRS doesn't specify an altitude but CubCrafters say BRS have documented saves as low as 100 feet. You for sure need to think through all the scenarios for when you would pull - for most 'everyday' engine failures you will just do what we all do and pick a spot and land.

I couldn't find the video I wanted but this interview with the founder of BRS has it in it. That link should take you to the correct spot, if not skip to about 18:30 or so and watch a 20 year old kid rip his wing off doing acro and deploy at fairly low altitude (I recall (but could be wrong) reading that this one was self induced by not installing the jury struts).

 

[RedOwlAirfield]

. Stratos also says they have documented saves as low as 80 meters (262 feet). BRS doesn't specify an altitude but CubCrafters say BRS have documented saves as low as 100 feet. You for sure need to think through all the scenarios for when you would pull - for most 'everyday' engine failures you will just do what we all do and pick a spot and land.

Mr. Scott - this is not anything about you - just what BRS claims.

This is one of my pet peeves so most of you will be excused for bailing now.

What is it with these "saves" - and "saved X lives"? This assumes that in every instance where the chute is deployed, fatality was unavoidable otherwise. This is intellectually wrong to say - yet every time you see discussion of chutes - it's there. We know that many of these instances in which the chute gets used are survivable without it. Mind you I understand advertising and don't necessarily fault anyone for indulging, but it seriously chaps my hide. I wish I were a better person and could just get over it.

I should also mention that while I am not a fan of chutes I am not completely opposed to them. They have their place and have value in certain instances. I just think that the rate of occurrence of those instances does not justify the current chute protocol. What bothers me most is that those who support them most do so fanatically - and not rationally. State the facts dispassionately. Let them tell the story. If you have to pad the facts, maybe they're not as convincing as you think.

Of course this has nothing to do with anyone here, but I keep seeing this deal where the chute people claim to have saved everyone who ever thought about pulling a handle. That bugs the stuffing out of me. I just finally thought I ought to mention it and maybe someone else who has the same idea would see they're not alone.

 

[tedwaltman1]

To your point RedOwl…

A local —very— experienced pilot was on a layover near a Cirrus training facility. Decided he’d get officially checked out in a Cirrus to add to his CFI repertoire.

On one airfield circuit, as they were departing, and with far more altitude than required to do the infamous 180, the Cirrus instructor pulled the power. The pilot/CFI, after determining they had more than sufficient altitude, started to turn back to the field.

The Cirrus check-out instructor said “you fail for not immediately reaching for the chute handle.”

 

[skywagon8a]

The Cirrus check-out instructor said “you fail for not immediately reaching for the chute handle.”

That is scary coming from a flight instructor. Aviate-navigate-communicate, not scream help!

 

[DENNY]

It makes it easy to sell more aircraft if you change the narrative from never stop flying the aircraft to without a emergency chute you will die. Despite having sound choices in front of them people will simply follow how they are trained and pass it along to the next person.
DENNY