Islander Jock
18th Aug 2003, 23:31
At the invitation of Heliport I have been asked to post some information on HUET and how it applies to helicopter passengers and crew. I have been working as a safety trainer in the oil and gas industry for just over 4 years in East and Central Asia, Europe, Australia and more recently, west Africa. One of the main safety courses we conduct for offshore workers is HUET.
HUET stands for Helicopter Underwater Escape Training. It has evolved from the basic fact that a helicopter that ditches onto a body of water may well invert due to either the torque action of rotors striking the surface, failure of part of the floatation system or simply the fact that a helicopter on emergency floats is a very unstable vessel. Statistics show that there is something like 2 water immersions for every 100,000 hours of overwater flight by rotary wing aircraft. Those same statistics which are probably quite dated by now, show that 92% of people survive when they had >1minute warning prior to impact. This reduces to 78% survival when <15 seconds warning is available.
The training is usually aimed at the passenger who has perhaps never flown on a helicopter before and focuses heavily on basic aircraft safety ie, danger points in and around the aircraft, onboard safety equipment, pre flight preparation, pre ditching checks and escape drills.
With a rollover the biggest hurdle for people to overcome, even if they can swim is disorientation. Just like the non instrument rated pilot who flies into cloud, a person inside a helicopter that rolls over and fills with water is faced with:
1. Loss of visual cues,
2. Loss of sense of gravity, and
3. Disturbance of the inner ear causing spatial disorientation.
I see it every time that a person can go through all the correct drills but as soon as the module rolls over they try and go to where they think the exit is rather than where it actually is. It's the same old story, if you are in strapped in your seat and your exit is on the right hand side when you are upright, it is still on the right hand side when you are upside down. It does take a bit of discipline for the uninitiated to get used to this. Just like flying IF in the early stages of training. You swear to god your body is facing or leaning one way when in fact it is doing the opposite.
As I said in my post about the recent crash in India. One of the biggest problems for the person trying to escape is the location and activation of the door or window jettison. There are probably as many different systems of emergency release as there are types of helicopters flying. Some are quite simple to operate, others are condiderably more difficult. The B212 is probably my least favourite. Imagine 9 burly oil workers in the back dressed in heavy survival suits and their primary exit being through the cabin windows which can only be opened by the nylon release tab being. pulled from all around the perimeter of the window. :ugh:
Current teaching has trainees adopting a brace position prior to impace and placing their hand on the exit or release as soon as the aircraft impacts and as it rolls over. I tend to think that I would probably be trying to at least activate the release whilst I could still see before the cabin fills with water. Obviously, once the water pressure is against the exit on the outside you will not be able to open it until the cabin fills and the pressure equalises.
Unfortunately, due to the myriad of different types of emergency exit releases in use and the cost involved, HUET modules only have very basic systems to simulate actual door or window release mechanisms and these systems very rarely represent any actual systems in use.
Those who come back for training on a regular basis obviously do much better but many oil companies are now trying to cut costs and creep up to 3 and even 4 years between re-qualification. Clearly not regular enough to maintain any sort of competency at all.
We are starting to see more and more flight crews come through our training. And some of our modules are rigged with a dummy cyclic and collective for the handling pilot to hold onto until the simulated impact. This puts a bit of extra workload on the co pilot in that in addition to the radio work, securing the cabin and carrying out his own pre ditching checks he might also have to do a quick final check of the pilot also. This is all on the assumption that we are dealing with a controlled autorotation from say 1500' or higher. Little things such as lifejackets are a critical check. You do not want the activation tab caught under your seatbelt as any movement resulting from a hard impact could be enough to pull the handle and inflate the jacket whilst you're still in your seat.
In a situation where you have less than 15 seconds warning ie takeoff or landing on a rig. The best you will be able to do if not actually trying to control the aircraft is brace for impact.
The exit drill is pretty standard for a rollover:
1. Upon impact place your exit hand on the exit handle or release and the other hand on your harness release, DO NOT UNDO YOUR SEATBELT YET.
2. Wait until movement ceases, This might mean waiting as the airframe rolls over and the cabin fills with water.
3. Open the exit and grasp an outside part of the airframe or the exit opening- DO NOT BRING YOUR HAND OR ARM BACK INSIDE AS THIS IS YOUR LINK TO THE OUTSIDE!!
4. Undo your seatbelt with your other hand,
5. Pull yourslef clear and swim to the surface,
6. Don't inflate your jacket until you are on the surface and satisfied it is safe to do so, ie you are not swimming around in a massive pool of Jet A1. If need be, duckdive down and swim to a clear area.
-----------------------------------------------------
I'd really like to hear any personal experiences some of you might have had. In the absence of having had to survive a ditching myself I can only teach what I read or what I believe to be the best course of action in a given circumstance.
Regards,
IJ
ps. I only fly fixed wing but my wife who is a CFI is learning to fly an R22.. She just likes to hover about 6' off the ground though
:confused:
HUET stands for Helicopter Underwater Escape Training. It has evolved from the basic fact that a helicopter that ditches onto a body of water may well invert due to either the torque action of rotors striking the surface, failure of part of the floatation system or simply the fact that a helicopter on emergency floats is a very unstable vessel. Statistics show that there is something like 2 water immersions for every 100,000 hours of overwater flight by rotary wing aircraft. Those same statistics which are probably quite dated by now, show that 92% of people survive when they had >1minute warning prior to impact. This reduces to 78% survival when <15 seconds warning is available.
The training is usually aimed at the passenger who has perhaps never flown on a helicopter before and focuses heavily on basic aircraft safety ie, danger points in and around the aircraft, onboard safety equipment, pre flight preparation, pre ditching checks and escape drills.
With a rollover the biggest hurdle for people to overcome, even if they can swim is disorientation. Just like the non instrument rated pilot who flies into cloud, a person inside a helicopter that rolls over and fills with water is faced with:
1. Loss of visual cues,
2. Loss of sense of gravity, and
3. Disturbance of the inner ear causing spatial disorientation.
I see it every time that a person can go through all the correct drills but as soon as the module rolls over they try and go to where they think the exit is rather than where it actually is. It's the same old story, if you are in strapped in your seat and your exit is on the right hand side when you are upright, it is still on the right hand side when you are upside down. It does take a bit of discipline for the uninitiated to get used to this. Just like flying IF in the early stages of training. You swear to god your body is facing or leaning one way when in fact it is doing the opposite.
As I said in my post about the recent crash in India. One of the biggest problems for the person trying to escape is the location and activation of the door or window jettison. There are probably as many different systems of emergency release as there are types of helicopters flying. Some are quite simple to operate, others are condiderably more difficult. The B212 is probably my least favourite. Imagine 9 burly oil workers in the back dressed in heavy survival suits and their primary exit being through the cabin windows which can only be opened by the nylon release tab being. pulled from all around the perimeter of the window. :ugh:
Current teaching has trainees adopting a brace position prior to impace and placing their hand on the exit or release as soon as the aircraft impacts and as it rolls over. I tend to think that I would probably be trying to at least activate the release whilst I could still see before the cabin fills with water. Obviously, once the water pressure is against the exit on the outside you will not be able to open it until the cabin fills and the pressure equalises.
Unfortunately, due to the myriad of different types of emergency exit releases in use and the cost involved, HUET modules only have very basic systems to simulate actual door or window release mechanisms and these systems very rarely represent any actual systems in use.
Those who come back for training on a regular basis obviously do much better but many oil companies are now trying to cut costs and creep up to 3 and even 4 years between re-qualification. Clearly not regular enough to maintain any sort of competency at all.
We are starting to see more and more flight crews come through our training. And some of our modules are rigged with a dummy cyclic and collective for the handling pilot to hold onto until the simulated impact. This puts a bit of extra workload on the co pilot in that in addition to the radio work, securing the cabin and carrying out his own pre ditching checks he might also have to do a quick final check of the pilot also. This is all on the assumption that we are dealing with a controlled autorotation from say 1500' or higher. Little things such as lifejackets are a critical check. You do not want the activation tab caught under your seatbelt as any movement resulting from a hard impact could be enough to pull the handle and inflate the jacket whilst you're still in your seat.
In a situation where you have less than 15 seconds warning ie takeoff or landing on a rig. The best you will be able to do if not actually trying to control the aircraft is brace for impact.
The exit drill is pretty standard for a rollover:
1. Upon impact place your exit hand on the exit handle or release and the other hand on your harness release, DO NOT UNDO YOUR SEATBELT YET.
2. Wait until movement ceases, This might mean waiting as the airframe rolls over and the cabin fills with water.
3. Open the exit and grasp an outside part of the airframe or the exit opening- DO NOT BRING YOUR HAND OR ARM BACK INSIDE AS THIS IS YOUR LINK TO THE OUTSIDE!!
4. Undo your seatbelt with your other hand,
5. Pull yourslef clear and swim to the surface,
6. Don't inflate your jacket until you are on the surface and satisfied it is safe to do so, ie you are not swimming around in a massive pool of Jet A1. If need be, duckdive down and swim to a clear area.
-----------------------------------------------------
I'd really like to hear any personal experiences some of you might have had. In the absence of having had to survive a ditching myself I can only teach what I read or what I believe to be the best course of action in a given circumstance.
Regards,
IJ
ps. I only fly fixed wing but my wife who is a CFI is learning to fly an R22.. She just likes to hover about 6' off the ground though
:confused: