As Monday’s tragic helicopter accident in the East River vividly shows, ditching in a rotorcraft is a low-probability, high-consequence event. The reason for this is that helicopters, with their roof-mounted power trains, have a high center of mass and they always turn over, flood quickly and sink.
Because of these dismal survival aspects, many helicopters are equipped with skid-mounted float systems designed to be inflated pre-impact to provide buoyancy and a righting moment. As the videowe’ve all seen by now clearly shows, the floats failed to do this for reasons that will only become evident when the accident investigation is completed. I’m not going to speculate on the why or the how.
But I am offering a thought on what kind of risk the passengers thought they were assuming. And my guess is they had no clue. New to me in the wake of this accident is that the passengers were doing a “doors-off” photo tour of the New York skyline, in which the aircraft is flown with the doors open so the passengers can dangle their feet out the door and snap photos. I’m including an example here, taken from the website of the company selling the tours. Doors-off flights are apparently a thing now.
As anyone who knows me can attest, I have a lot of experience flying in airplanes with doors open and have launched myself through them several thousand times. So I’m not gonna go all Uncle Melvin on the risks involved. If you wanna do it, step right to the front of the line. But there’s a pernicious corner of the risk envelope here that I don’t think these passengers could possibly grasp.
In order to let the customers dangle their body parts into the picture frame, in addition to standard seatbelts, they’re also strapped in with a parachute-type harness with a single carabiner restraint in the back connected to a tether, according to a New York Times article. For obvious reasons, it’s not a quick release, but uses a screw-type carabiner closure. Because of this, the passengers are shown a safety briefing video and equipped with a knife—likely a web-cutter type—to free themselves in an emergency.
If this doesn’t cause your jaw to drop to the floor, you’re not paying attention. Refer to the second sentence above. If they’re not equipped with skid floats or the floats fail, a ditched helicopter will always invert and flood rapidly. Without doors, it will flood right now. As I learned in a safety course I took at Survival Systemson how to exit ditched helicopters, even a trained occupant will struggle with what’s known as “cold water gasp,” the involuntary intake of breath when exposed rapidly to cold water.
The East River was 40 degrees or colder on Sunday. An untrained, gasping passenger would have had little chance to even consider using a knife to saw through a tether attached from behind. I spent a full day getting cold and wet in a dunkable fuselage simulator and I’m pretty sure I could not do this, even though I could egress the fuselage OK from normal harnesses. Watching a video on how to do it would, in my view, be woefully inadequate.
Just for the record, such training has three simple key points: Wait until the aircraft stops moving, use a reference point like your knee to find the door release handle, place a hand outside the opening for reference, then release the belt and get out. I did that course 15 years ago, but I still remember it. Here’s a good video we shot on the training.
What sustains a company like Survival Systems, in part, is that the oil industry requires workers to take such courses before they ever set foot on a helicopter headed for the offshore rigs. Even at that, the industry has lost lots of people in helicopter crashes and the survivors tell harrowing tales. Here’s one from a North Sea worker: “The helicopter filled with water, instantly. The door buckled on the left-hand side and none of us had a chance to pull our rebreathers out, get our hoods on, nothing like that. And as the water came up to here” – he indicates his chin – “and I took my last breath, I could see people floating around. As soon as my head was covered with water, I looked down and pulled the tab on the window and it just came to bits in my hand. So I hit it with my elbow a couple of times. Nothing. And then I punched it – I think I punched it three times – and all of a sudden it went pop and away it went.”
Judging risk and whether to take it is an intensely personal thing and for most of us, it is a moving target. What you do one day, you might not do the next if some single point consideration is different. Personally, I have no desire to fly around New York in an open-door helicopter. I can think of better things to spend money on. And even though I suffer the same over-confidence in the reliability of turbine aircraft that so many of us do, they still quit from time to time. But getting into one with a knife to slice a tether attached to my back as the only means of extraction isn’t a survival plan, it’s a delusion. My skydiver friends will want me to mention a better approach: the same kind of three-ring system we use to cut away malfunctioned mains to clear the way for reserve deployment.
Last, a comment on word choice. When I wrote the initial story based on the video, my colleague Mary Grady chided me for using “mishap” in the headline rather than “crash.” She reasoned that mishap conveyed the wrong connotation. Too soft. But I used it for a reason. An autorotation in a helicopter is not a crash, it’s a purposeful emergency procedure and, if done right, a skillful management of finite rotor energy.
I’m not qualified to judge whether the auto was done right or not, but the touchdown itself didn’t strike me as a crash. I tried to use “hard autorotation” but it didn’t fit in two lines. I re-edited it with the word “accident.” When you lose five people, there’s no question that this word applies.