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Comment by imglorp | Hacker News Reader

Unscheduled airbag deployment is a terrifying concept if you're trying to lean in to access a person.

Why do military aircraft have RESCUE --> levers that disarm all the pyros but we can't make that a thing on cars? It wouldn't have to be a big red sign but it could be a standard.

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> "Why do military aircraft have RESCUE --> levers that disarm all the pyros but we can't make that a thing on cars?"

Not sure if it's standard on all EVs, but cutting the first responder loop on a Tesla will disarm the airbags & SRS, in addition to disconnecting the high voltage system.

Source: Tesla first responder guide: https://www.nfpa.org/-/media/Files/Training/AFV/Emergency-Re...

> first responder guide

This is exactly what I'm complaining about. Every car is different. Volunteers have so many trainings to take, it's unreasonable to ask them to take a whole training for EVERY MODEL CAR on the road. There should be a simple, standard, HV and pyro cutoff control, standard on ALL cars, that can be actuated without a hydraulic shear. Put it in the wheel well or behind a gascap-like door.

Imagine you are a civilian or first responder and want to help people out of a car and you don't have a hydraulic shear or hundreds of hours of model-specific training? This is an everyday usecase.

Training on fire suppression and extrication techniques for cars doesn't take THAT much training. Most techniques would be standard across the board, with a few exceptions for electric vehicles.

Additionally, never underestimate the hours of training that most firefighters go through anyway and get this, they live for that stuff.

Hmm, so it's not like the movies? You don't dial back in to a central command center where they call the guy who tells you to cut the red wire or not? Makes sense, I guess. Just interesting. It seems like there's value in centralization. Can't be two Teslas on fire at the same time in SF.

Business opportunity?

You know, perhaps it is.

I imagine the best placement is probably just about the middle of the dashboard, between where any airbags should go off. It would be something that could be jabbed by a blunt pole of any kind (the butt of a fireaxe pole for example) which would dislodge a connection between two points. That shouldn't be the main bus, but rather supply the power MOSFETs with the go bias current.

This sounds great in theory, and would work well until your 8 year old jabs a pen in there while you're going 70 on the freeway. There are two completely different scenarios you have to optimize for, and their optimizations really compete with eachother; ease of access is a benefit in one, and a danger in the other.

How could you have an external lever that would disarm airbags without someone randomly pulling it when you leave your car in the shopping centre for example? I would expect military aircraft are always guarded so wouldn't have this problem.

It could also be a wire you need to cut, or a glass you have to smash first. The problem wouldn't be much different from someone breaking your car window to get your purse while your in the shopping center.

On the off chance you get in a crash later? The car could just give an alert if it's started with the emergency lever engaged.

It probably would disable the ignition anyway.

Probably budget, and ejection seats are a bit more dramatic than airbags.

I find it hard to believe electronically controlled airbags would just pop out of nowhere. Don't they need a specific message to fire?

They contain explosives, which often don't need more than a bit of heat to go off.

There are several preconditions. It's not a computer message; think 1970s tech. There's a accelerometer to say you need a head-on crash and a seat mass sensor to say there's a large enough human in the seat. There are cases where the passenger bag did not deploy, for example a stuck-closed accelerometer, and then a responder knelt on that seat getting to the driver, satisfying the last condition, and causing a deployment with obvious injury.

But those conditions are met by computer / logic chip. Again find it hard to believe it accelerometer keeps broadcasting for more than 100ms after crash or so.

I've seen one in a pillar fire off during training while the vehicle had no battery and the same pillar was being cut through with hydraulic cutters.

A few people have pointed out that explosives can explode regardless of the message; I'd like to question, if it needs a specific message to fire them, how fragile is the system that delivers the message?

Yes, in an accident the airbag generally fires so quickly that it happens before physical damage occurs to the device firing it, but needing a specific message (over CAN bus perhaps?) makes the system much more fragile. What if there's a fender bender the week or month before, and causes light damage to the system? One bit is more robust by an order of magnitude than two, and so on.

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