[fullstop]

My neighbor, a photographer, was on a tour group which took three helicopters up and only two returned. [1] They had an aftermarket restraint system to tether the passengers in and they were required to cut the restraint to free themselves in case of emergency, or unbuckle the tether from behind them which was time consuming. One passenger's restraint accidentally engaged the emergency fuel shut off lever, and by the time the pilot figured out what had happened it was too late to correct things and he was forced to land in the river.

None of the passengers were able to cut the restraint to free themselves, and all five drowned.

It's not really the same as dropped electronics but it's an example of a safety system gone awry.

1. https://en.wikipedia.org/wiki/2018_New_York_City_helicopter_...

[partdavid]

For me, the aspect of that accident that never gets enough attention is the partial failure of the floats.

I think everyone understands that asking people who have never drilled a helicopter water escape to take special actions in an emergency, let alone reach behind them and cut a tether, is just never going to work, certainly not in the few seconds they had. If the floats had functioned as designed, according to the investigation, everyone would have survived. Instead, either because the pilot did not fully activate them, or due to some malfunction, the right float did not inflate, causing the helicopter to capsize.

It's not completely clear to me, but I don't think they ever completely identified the malfunction that resulted in this, but as far as I'm concerned, it's a malfunction in a safety-critical system that caused deaths, and I'm surprised it's not the primary highlight of this accident.

[fullstop]

Right, they would have had the time to remove the tethers if it hadn't sank. Like everything else, I'm sure that they require some amount of maintenance and I wonder if that's the sort of thing which can be tested without destroying it. I trust that my car's airbag will deploy if it's in an accident, but I really can't check that. A non-trivial number of airbags fail to deploy when they, in fact, should.

I'm not surprised that the tether is the focus, though -- it's the reason why the helicopter crashed to begin with and also prevented the passengers from escaping.

[fouc]

> ground crew were responsible for attaching and detaching a locking carabiner to the back of each passenger's supplemental harness at the start and end of each flight.

ugh, so short sighted!

[oh_sigh]

Not only were the supplemental harnesses nearly impossible to get out of by yourself in an emergency situation, but the supplemental harness is what triggered the crash in the first place, by getting stuck on the fuel shutoff lever.

I wonder how many lives those supplemental harnesses have saved, versus the 5 they cost here.

[fullstop]

> I wonder how many lives those supplemental harnesses have saved, versus the 5 they cost here.

If the story were changed and a handful of people accidentally fell out of a helicopter, we'd be asking why they weren't strapped in.

[dredmorbius]

I want to emphasize the point here that the cause of the accident was itself a component of a safety system.

One point that repeatedly gets lost in considerations of risk and security is that more complex systems intended to compensate for other risks will themselves become part of the risk and/or threat profile.

I've both read of this many times in the case of incidents which occur elsewhere, and have seen it firsthand myself where some system or method itself intended to compensate for a risk turns out to be the cause of an incident.

Power backup systems, fire suppression systems, failover / load-balancer devices, and many cases of safety or audit code, just off the top of my head.

[msie]

Ugh, the location of the fuel shutoff lever. It should be within easy reach of the pilot but not the passenger!

[partdavid]

A passenger didn't activate it (although passengers have in other aircraft), it was the restraint harness tether that got wrapped underneath it.