General Aviation: how to survive at sea

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the gremline digest — sea survival

The warmest sea in the world is the Arabian Gulf at about 35C, but the average sea temperature around the UK is only 11C. The colder the sea the greater is the rate of heat loss, but hypothermia will eventually occur in any ocean at any time of the year; it is only a question of time. The average life expectancy of a survivor in the seas around the UK with only a life jacket to support them can be measured in minutes rather than hours. Variables include air and sea temperature, wind speed, fatigue, age, sex and fitness. It is vital to board a life raft as quickly as possible, before the cold affects mind, limbs and body. Once in the life raft your survival chances are greatly enhanced.


Cold Shock
There are two other less well-known phenomena that reduce your chances of surviving immersion in the cold sea. The first is
cold shock. Cold shock is poorly understood but involves the loss of body functions, and occasionally death, immediately on sudden immersion in very cold water. Cold shock is likely to occur in water below 10C and very likely to occur in water below 5C. There is a massive initial gasp reaction and hyperventilation on immersion. Uncontrolled gasping may lead to water swallowing and almost immediate drowning. A combination of gasping, hyperventilation, water inhalation, an inability to remain afloat and cardiac arrest is referred to as ‘cold shock.’
To put all this theory into perspective I will quote a simple fact. A fit, uninjured survivor without a full survival suit will deteriorate to a helpless state after 30 minutes in water at 4C and will be dead in less than two hours.

 


Vasogenic Shock
If you are rescued by a helicopter winchman your first reaction may be to wrap your arms and legs around the winchman and cling to him like a limpet as soon as he arrives in the water with you. This will certainly hinder your rescue by making things more difficult for him. Helicopter winchmen are highly trained and very brave men who are risking their own lives to save you. You can best assist by remaining placid and allowing the winchman to attach you to himself and the helicopter as he sees fit. He may decide to lift you from the water in a horizontal position, particularly if you have been in the water for a long time. The temptation to grab a piece of the helicopter as you are winched aboard should be resisted; relax and let the winchman do his job.
During the Fastnet Race in 1979 when many yachts were capsized by gale force winds, fifteen people died. Four of these people were actually alive in the water but died shortly after being winched into the rescue helicopters. Their deaths were due to
vasogenic shock. When a survivor has been in a vertical position in the water for some time, the water pressure acts like a weak anti-g suit on the lower limbs reducing the tendency for the blood to pool in the lower limbs thus keeping the blood pressure slightly higher in the body core. This is called hydrostatic squeeze and actually assists survival. As soon as the survivor is lifted vertically from the water the blood dumps downwards into the legs, causing a dramatic drop in blood pressure that can lead to heart failure. In these circumstances a survivor has a greater chance of continuing to survive if lifted horizontally from the water. So, if your winchman seems to be determined to lift you out of the water in a horizontal position just accept that he has his reasons.

 


Protection & Location
Let us continue with the practical aspects of sea survival by thinking about your best course of action after you find yourself in the sea. If you have got a dinghy with everyone on board then it is time to take the first survival step –
protection. Check the dinghy for signs of damage. Give aid to anyone who has suffered injury. Secure all survival equipment to the life raft. It is all too easy to knock something vital into the water. Start to remove water from the inside of the dinghy and get the floor as dry as possible. This is an ongoing task as clothing drains and the sea splashes on board.

The next action is to plan location. Factors to consider include:
Was a distress call made and acknowledged?
Is your position known accurately?
If not, did you file a Flight Plan and how long before you will be declared overdue?
How long before the search and rescue services are likely to arrive?
What location aids have you got available?

The location aids available to you may include any or all of these:
A location beacon. You must have studied the operation of your beacon before the flight and be confident about its operation and limitations. Make sure it is operating and positioned according to instructions. When was it last serviced? Are the batteries fully charged and up to date?
A heliograph. A heliograph is a much undervalued and cheap aid to locating survivors in the water. Modern heliographs are robust, easy to operate with practice and, given sunshine, have a remarkably long range.
A mobile phone. May not work after immersion, but certainly worth a try with a 999 call to the Coastguard. It is also possible for the rescue services to get a fix on the position of an active mobile phone.
Pyrotechnics. If you have got flares be sure you know exactly how and when to use them without hazarding the survivors in the dinghy.

There is no point in trying to navigate the life raft unless you are VERY close to the shore. The search and rescue services will either home to your beacon or MAYDAY position. They can plot your drift due to wind and currents from your presumed ditching position.
Your task is to survive long enough to be rescued. You can survive, given the will, knowledge and equipment and having planned to survive before the accident happened.

 

Our thanks to the Royal Air Force School of Combat Survival and Rescue at RAF St. Mawgan for providing information on the theoretical aspects of Sea Survival and for reviewing this article before publication.

 

 

 

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Sea Survival
We previously published an article dealing with the theory and practice of ditching a light aircraft. You may recall statistics included in that article showed that your chances of surviving the actual ditching in a general aviation aircraft are good, but your chances of being rescued alive after the ditching are less than evens. Why? This article will briefly explore aspects of sea survival around the United Kingdom, introduce the theory of survival, and suggest methods of increasing your chances of living to tell the tale of your ditching.


You can survive in the sea. I did. The information in this article is realistic. I made a rather hasty descent into the sea when the water temperature was less than 10C and a full gale was blowing. I was extremely fit, well trained and wearing the very latest immersion suit with all the correct gear underneath. I was injured during the ejection and had lost my dinghy and survival pack. My jaw seemed to be broken, my left shoulder was dislocated and my spine had suffered a compression fracture. I was still tangled up in the ejection seat when it hit the water. When I got back to the surface I had a beacon with a combined two-way radio, a life jacket and some flares. I had managed a brief MAYDAY call and a very professional team set about my rescue. A combination of factors and good luck meant that a RAF ‘Nimrod’ maritime recce aircraft, a RAF SAR helicopter and HMS ‘London’, a very fast RN destroyer, all responded to my MAYDAY call. The Nimrod and the destroyer pinpointed my position with remarkable precision although I was being tumbled down the face of very big waves. The helicopter picked me up less than an hour after I hit the water. Despite my excellent equipment and my training I was unconscious by the time the winchman got me into the helicopter and we picked up a doctor from the destroyer. My core temperature was still dangerously low when I got to the theatre in a Royal Navy hospital. Plenty of tender loving care from the Royal Navy nurses did the rest.
I was wearing the right gear, I was fit and well-trained and a well planned rescue operation began as soon as I made my MAYDAY call – yet I would not have survived for much longer in the sea conditions on that day in March. I was also very lucky to have all those rescue teams close by. Luck alone is not enough.
Survival in the seas around the United Kingdom is demanding in any season of the year. The sea is a vast, lonely, inhospitable place for a survivor. Believe me, no matter how well trained and equipped you are, finding yourself tumbling about in a rough sea a long way from anywhere is very frightening. The water temperatures around the UK are never going to be comfortable and are usually cold enough to kill an unprotected survivor very quickly.

 


Survival in any environment depends on two basic factors:
Knowledge. Your chance of survival increases with knowledge. The ultimate key to survival is to KNOW that you CAN survive. The only way to KNOW is to have practised your survival techniques before you find yourself in a survival situation. Understanding the principles of survival, the correct use of survival equipment and an understanding of the search and rescue services will all add to your chances of survival and reduce the fear of the unknown. Unless you have prepared to survive before you stepped into your aircraft the stark facts are that, statistically, you have a 32% chance of being rescued alive following a ditching in UK waters. Knowledge comes from training and study. The purpose of this article is to encourage private pilots to seek training in sea survival, to be prepared to survive by understanding some of the problems involved and to present priorities for survival in the sea.
The Will to Survive. This is not an automatic instinct. Discomfort, fear and despair can lead a survivor to give up long before death actually approaches. The will to survive depends largely on the psychological make-up of the individual, on his reasons for wanting to remain alive and on his determination. Knowledge will increase your determination.

There are four basic principles of survival in any hostile environment. These are, in order of priority:
Protection. The survivor must protect himself against the cold and avoid long immersion in the water. You will become incapacitated and die very quickly unless you have protection from the hostile environment of the sea. Cold, sea sickness, drowning, confusion, fatigue, despair and fear are just some of the factors that you must overcome to survive in the sea. You cannot overcome these unless you have prepared to do so.
Location. Once the survivor has made sure that he is not going to die quickly from exposure, hypothermia and/or drowning his next priority is to assist the search and rescue services to find him as quickly as possible.
Water. You can live for some time in the seas around the UK without water but you will probably be dead from exposure long before you die from thirst, so drinking water is not a primary consideration in our particular scenario.
Food. Despite the evidence of what seems to be a good proportion of our population permanently clutching food and drink as they go about their daily life you can actually survive without permanent harm with nothing to eat for 2-3 weeks.


Be Prepared
Your survival after a ditching depends on the preparations you have made long before you began the flight. I cannot repeat that advice too often. Just wearing an immersion suit and life jacket and carrying an emergency transmitter is not enough. You need to know how to use your survival equipment while in the water and what it feels like to be faced with surviving – even in a swimming pool. The only way to increase your chances is to be prepared to survive.
Your actions before flight can increase your survival chances. The planned profile of your flight over sea should include thoughts of survival. Have you filed a Flight Plan? That alone will help the search and rescue services to react quickly and search in the right area. Have you got a sensible fuel reserve? Have you planned the crossing at a sensible altitude? When the engine fails (carb icing, dry tank, mis-selection?) have you allowed yourself enough height to sort it out or make a radio call before your ditching or are you faced with a few panic-stricken moments before the aircraft hits the water? My home is close to the beacon at Strumble Head in Pembrokeshire. I see many light aircraft setting off across the Irish Sea at low altitude. Why? Yesterday I watched a Bonanza cruising out
above the broken cloud at an altitude of five or six thousand feet. Obviously flown by a wise pilot. Have you carefully rehearsed yourself and your passengers on the sequence of actions to be taken if faced with a ditching? These drills may seem overly dramatic on the ground but they could save lives. Don’t be afraid to adopt a professional attitude to all aspects of your flying.

 


Life After Ditching
Your actions after ditching will depend on many variables including whether your aircraft is high-winged or low-winged, upright or inverted, intact or severely damaged. A high-winged aircraft will tend to float with the wings on, or just below, the sea surface. This means the cabin and doors will be below the surface. Have you thought about opening the doors and getting out from a flooded cabin? A low-winged aircraft will tend to float with the cabin mainly above the surface and should be easier to evacuate but a sliding canopy may become distorted and stuck shut during the landing impact. What does your Pilots Notes or Owners Manual have to say on that subject?
Once your aircraft comes to rest on the surface you need to get yourself, your passengers and your survival equipment out of the cabin quickly and in a planned sequence. Who gets out first, by which exit? Who is responsible for bringing which piece of survival kit out of the cabin? It’s far too late to think of this when you are in the water. It would be a great shame to see your aircraft slip below the surface taking your carefully purchased survival kit with it.
Your lifejackets must not be inflated until you are out of the aircraft. If you have a dinghy, then get that inflated and attached to yourself. The fittest person should be first into the dinghy because it is much easier to assist others to board when you are supported by the dinghy than it is to try pushing people upwards from the water. Try it in the swimming pool. Be aware that a drifting life raft can travel faster than the strongest swimmer, even in a slight breeze. The easiest way to help another survivor into a dinghy is for the survivor in the water to position himself vertically in the water with the back of his head against the flotation chamber. The person already in the dinghy then pushes down on his companion and grabs his shoulders or lifejacket lobes and ‘bounces’ him into the dinghy on his back. That’s another good thing to have tried in the swimming pool.
If you haven’t got a dinghy get all the survivors into a tight huddle and stay together. This will help to reduce heat loss and improve morale. If you are alone in the water the best survival position is with your knees bent and arms crossed to reduce heat loss. Thrashing about only increases your rate of heat loss. You may survive long enough to be found.
To understand just how vital it is to have proper protection from the cold sea it is necessary to understand what
hypothermia is and how its onset will affect your chances of surviving long enough to be rescued alive.
Water is 25 times more conductive than air. A human immersed in water loses heat very quickly and hypothermia begins as soon as your body core temperature begins to drop below the normally maintained value of 37C. The definition of hypothermia is ‘
the decrease of core temperature to a level at which normal muscular and cerebral functions are impaired.’ The table below shows the progression of this impairment as your core temperature drops when your body loses heat to the sea.

 

Core
Temperature

Effect on Muscular and Cerebral Functions

37-35C

Sensation of chilliness, skin numbness, minor impairment in muscular performance especially in the hands. Shivering begins.

35-34C

More obvious muscular coordination failure and weakness, mild confusion, apathy.

34-32C

Gross muscular coordination failure. Inability to use hands. Mental sluggishness and forgetfulness.

32-30C

Cessation of shivering, severe lack of coordination, incoherence, confusion, irrationality.

30-28C

Severe muscular rigidity, semi-consciousness, no apparent heartbeat or pulse.

28-26C

Unconsciousness, death due to failure of heart action.