Comments about technological history, system fractures, and human resilience from James R. Chiles, the author of Inviting Disaster: Lessons from the Edge of Technology (HarperBusiness 2001; paperback 2002) and The God Machine: From Boomerangs to Black Hawks, the Story of the Helicopter (Random House, 2007, paperback 2008)

Saturday, April 26, 2014

Immersion Course: Escaping from flooded helicopters

This is to provide a little more detail for my LinkedIn post last week, asking for survivors of helicopter ditchings to drop me a line, because I'm researching a magazine article on helicopter-underwater-escape training, or HUET.

The reason for the obscure business known as a HUET school is that an aircraft, once upside down, flooding, and sinking, presents scary challenges that must be managed quickly in order to survive. Advance preparation and the right equipment can add margin to the survivability zone

Across all aircraft types, helicopters are unusually top-heavy and therefore prone to roll over in the water. Here's a video of an Mi-14 crash off Japan; note how quickly it rolled after the main rotor hit the water and flew apart:

 

Let's say a helicopter has emergency pop-out floats; the floats may keep a ditched helo from sinking immediately, but those people in the cabin are still underwater and they'll soon drown if they don't get out.

Tens of thousands of people travel regularly over water in helicopters and small airplanes, hence the HUET market. Singer Jimmy Buffett attributes his surviving a Widgeon crash to ditched-aircraft training he took in a Navy program.
Courses vary in how much realism they pose, since higher realism means higher risk. To manage situations with elevated risks, schools put multiple safety divers in the water, right next to students.

A course at the lesser end of the realism scale could be classroom talks, a demonstration of survival gear, and a quick dunk in the pool. At the opposite end of the scale, and more for the military and USCG rescue swimmers, a facility's pool might have big waves, wind, several people having to use the same exit door in a dunker rig, and simulated entanglement on the way.

During our course at Survival Systems Inc., we had to get out of a blacked-out cabin that was upside-down and flooded. We worked up to abandoning a blocked exit and finding another door across the cabin.

While instructors assured us that the course was quite safe for students who followed directions, the training can be stressful for those of us who are scared of drowning. I came away from the course with bruised fingers and thumbs, having gripped things somewhat too hard while groping for exit handles. But the instructors were very good at taking us one step at a time, building confidence so that we didn't freak out as the dunker splashed down and water came up our noses.
 
HUET courses aren't about memorizing and then following a one-size-fits-all checklist. We were reminded frequently that to survive a helicopter ditching we'd have to get our bearings before loosening the seat belt, think clearly, and use the methods most appropriate to the situation.
 
For example, just because a survivor of a helicopter ditching has a small compressed-air SCUBA-like tank at her side (often called HEEDs) that doesn't mean she should always activate it, even if the cabin is flooding. Here's a HEED bottle (photo, lifesavingsystems.com):


The time she'd need to get the HEED going -- say five to seven seconds -- might be better spent escaping on a breath-hold if she was sitting by an exit door. Also, that speeds things up for others who may need to use the same door.

The H-60 Black Hawk sinks like a rock once it's full of water, so time is of the essence. Instructors showed us a video of a CH-46 Sea Knight tumbling backward off the deck of an aircraft carrier: it vanished in a sheet of spray, going under in less than two seconds.
 
Though no single checklist of actions will cover all circumstances, here are three things to keep in mind:
  • Before takeoff, give close study to the exits nearest you. Some crashes come without warning to the passengers, so don't assume there'll be time to study up;
  • After a crash, don't give way to panic;
  • Don't ever give up.
So, repeating my request on LinkedIn: if you've escaped a flooded aircraft after a crash, feel free to drop me a line.

1 comment:

  1. The above information is very helpful while dealing in the Huet Training South Africa. These courses are given to the people for the protection at offshore places.

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