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Home > Survival Systems Training > Research & Development
Survival Systems is committed to providing the best possible instruction in emergency underwater escape training. To reach this goal, we have developed the Modular Egress Training Simulator (METS™) to replicate specific aircraft configurations, and the METS™ is used in simulating and learning how to survive from a ditching situation. A natural extension of this training relates to the trials and evaluations on hazards, egress, and procedures relating to the improvement of onboard aircraft safety.
The scientific reports listed below demonstrate the wide range of Human Factors research that Survival Systems can offer. Such research includes conducting all types of helicopter and fast rescue craft underwater escape testing using a configuration of different seating arrangements, stroking seats, exits, and cabin configurations.
Different safety survival equipment such as NBC respirators, emergency breathing apparatus, and life jackets can be evaluated.
Survival Systems has a wave tank and an instrumented thermal manikin for measuring the CLO value of immersion suits, and we have a water manikin with an instrumented nose and mouth for evaluating the performance of lifejackets.
In conjunction with Dalhousie University, we conduct human R&D experiments for the offshore oil industry on a wide range of topics such as evacuation, escape, and survival from oilrigs using TEMPSCs.
Survival Systems’ staff involved in R&D have many years of experience in maritime, aviation, and submarine operations and are very competent to conduct your applied research.
Challenge us to work with you on your next R&D project to improve safety at sea..
Research and development projects in which Survival Systems has been involved include:
1. Emergency Breathing Systems / Spare Air Evaluation for Helicopter Underwater Escape [2001] (Abstract)
Five systems were evaluated, and the results were reported to Natural Resources Canada (NRC). [Not yet available for public release.]
2. Evaluation of Escape and Survival from the new Cormorant Helicopter (Abstract)
A set of trials was conducted to evaluate the ease and/or difficulty of escaping from the pilot and Search & Rescue Technician seating positions. [Not yet available for public release.]
3. Breath-holding Ability of Offshore Workers Inadequate to Ensure Escape from Ditched Helicopters (Abstract)
Stephen S. Cheung, M.Sc., Ph.D.,
Noel J. D’Eon, B.Sc.K.,
Chris J. Brooks, M.B. Ch.B., D.Av.Med
Breath-holding ability of off-shore workers inadequate to ensure escape from ditched helicopters. Aviat Space Environ Med 2001; 72:912-8.
Background: Following a helicopter ditching in water, the survival rate of individuals not mortally injured by the impact ranges from 50-85%.
One possible cause for this low survival rate is that the crew and passengers cannot hold their breath underwater long enough to make the often difficult escape from an inverted and submerged helicopter.
Methods: We investigated pulmonary function, breath-holding times in air (BHTa) and water (BHTw) of 228 students enrolled in offshore survival courses required to work in either the offshore petroleum industry or in military marine aviation.
Comparisons were performed based on occupation, SCUBA experience, and smoking.
Results:
In 25°C pool water, the overall BHTw ranged from 5.4 to 120 s with a median of 37 s.
Of the 228 subjects, 34% had a BHTw less than the 28 s required for the complete evacuation of a Super Puma helicopter under ideal conditions.
No significant differences in BHTw were observed based on either smoking history (Non-Smoker, 41.5 ± 21.6 s; Smoker, 37.2 ± 20.2 s) or occupation (Novice, 37.5 ± 21.1 s; Offshore, 40.5 ± 21.1 s; Military, 45.2 ± 20.9 s).
However, SCUBA-trained individuals had a significantly longer BHTw (47.4 ± 21.6 s) than non-SCUBA (37.6 ± 20.6 s), as well as a greater force vital capacity (FVC), BHTa, and subjective comfort in water.
Conclusions:
It is concluded that the inability to breath-hold in emergency situations is a major contributor to the low survival rates of marine helicopter ditchings.
Therefore, efforts must be made to both decrease escape times and to increase survival time underwater.
Keywords:
helicopter, ditching, breath-holding, marine survival, cold-water immersion.
4. Requirement for Emergency Breathing Systems (EBS) in Over-Water Helicopter and Fixed-Wing Aircraft [2000] (Abstract)
A research paper submitted to NATO Research & Technology Organization written by Dr C J Brooks and Professor Mike Tipton [AG-341].
This was a study to identify the requirements for an emergency breathing system for crew and passengers of a ditched helicopter, and the steps necessary in the evaluation, integration, procurement, and training essential to bring such a system into service [ISBN 92-837-1058-4].
5. Fast Rescue Craft Ditching Trainer [2000] (Abstract)
The greatest danger faced by crew and passengers in a Fast Rescue Craft (FRC), is capsizing and death from drowning.
In the event of a sudden capsize, the crew and passengers are hurled around the FRC. The most likely scenario is that the weather will be cold and miserable, the sea conditions poor, and the crew will be taken by surprise. Indeed, they may be in the process of doing a tricky over-the-side rescue. Thus, it is unlikely that anyone will have taken a good handhold on the FRC structure before the accident. Indeed, at that point, they may, for instance, be in the process of attempting to drag a victim into the FRC, and therefore have no handhold at all, and the coxswain may be concentrating on a complex maneuver to hold the boat steady. Therefore, people are likely to be physically injured by contact with parts of the FRC and will most certainly be disoriented from inversion and submersion. Sudden immersion in cold water will also produce an uncontrollable gasp reflex even if a good protective suit is worn. At present, with no training in inversion and immersion, only diving skills, comfort underwater, and some luck will prevent someone from drowning.
Classic examples of such tragic accidents are the losses of FRC Number 244 from the Canadian Coast Guard Ship Sir Wilfred Grenfell in October 1989, where all crew perished during the process of attempting to rescue one body surfer at Middle Cove, Newfoundland. Another example is the very close call of two crew of the FRC OSV Hebron Sea that capsized near Sable Island gas field, Nova Scotia, in May 2000. They were medical evacuated to Halifax and lucky to have had only minor injuries.
Survival Systems adapted its wide-bodied underwater escape trainer, the Modular Egress Training Simulator (METS™) Model 40 to accommodate the deck, the inflatable sponsons, the inboard and outboard becketed grab lines, the coxswain console and seat, and the transom of a Fast Rescue Craft (FRC).
Survival Systems has investigated the possibility of using such a device for training coxswains and crew. Three instructors from Survival Systems Training acted in turn to be the coxswain, the port lookout, and the starboard lookout followed by the author as the first naïve student!
For the coxswain position, half of the immersions were done from the standing position and the other half from the sitting position. For each of these, the coxswain held firmly to the steering wheel throughout the roll, prior to locating the inboard port or starboard grab lines, or, just before submersion, bent down and held firmly onto the handles on the top and sides of the console. For the lookout positions, each instructor knelt down and held firmly onto the port or starboard inboard grab lines depending on which position they had been allocated.
The direction of rolls were equally distributed between anti-clockwise and clockwise, and each instructor experienced virtually an equal number of immersions directly into the water; i.e., from the water's surface at 90º to 180º underwater as well as rolls over the top beginning from the air; i.e., from 270º on the opposite side of the FRC all the way over in air to 180º underwater.
There are several important conclusions from this study. First, it is potentially very easy for the coxswain and crew to drown when the FRC capsizes. This is due to the profound disorientation effect of being rapidly rolled and submerged. Even the experienced instructors were surprised at the force of the inrushing water and the violence of being thrown around, particularly if the crew are on the topside of the roll and thus go through 270° of roll before being inverted and pinned to the underside.
Second, irrespective of direction of roll, it is imperative for the coxswain and crew to maintain a firm handhold. Loss of grip causes the body to be washed randomly about the interior of the FRC. This, in turn, intensifies the disorientation and can only lead to a greater chance of injury and / or drowning.
Third, the wearing of a buoyant survival suit, which is necessary to provide insulation in the cold, can be a serious impediment to successful escape. If a loss of handgrip occurs, then the buoyancy of the suit immediately exerts forces on the human that will drive him / her in a direction towards vertical which is flat against the inverted bottom of the FRC. This may not be the shortest route for escape, nor the original direction intended by the survivor. This is similar to the effect of righting a conventional marine life raft and attempting to swim from underneath the leeward side. The survivor in the cumbersome survival suit has neither the agility nor the strength to swim as fast as the raft is drifting. In the case of FRC hulls, where the surface is rough and non-slip, it creates a sandpaper effect against the survival suit and makes it very difficult to move without extreme effort. Continuing in this direction will only lead to exhaustion and inability to continue breath holding.
Fourth, the coxswain is in a potentially very dangerous situation whether sitting or standing. The decision has to be made at the moment of the accident (which will no doubt come as a surprise) whether to maintain a grip on the steering wheel, or on one of the grab handles on the top and down the side of the console. The decision to hold onto the steering wheel stabilizes the person and assists in overcoming the disorientation. However, the disadvantage is that it is not possible with one hand to make the reach to the inboard grab line without letting go of the steering wheel with the other hand. Under such conditions, unless a firm and determined grip is made onto the grab line, the buoyancy of the suit takes over and forces the coxswain in a different direction. The decision to quickly exchange handgrips from the steering wheel to the lower handles on the console is also fraught with danger. If a good handgrip is not made when the split decision is made, then the coxswain will be washed out of the footholds and forced, by the buoyancy of the suit, underneath the deck.
Fifth, escape for the crewmen has its own unique problem. As the FRC inverts, the body tends to be flexed around the sponson by the force of water (Figure 2). In this situation, the trapped air in the suit from mid-waist downwards gravitates into the boots. Thus, when the FRC comes to rest inverted, the lower limbs get forced against the inboard margins of the sponson and the junction between the deck and the sponson. To escape from this situation requires considerable exertion. One must first haul oneself by the inboard grab line, and then a hand exchange is necessary to the outboard grab line to extract oneself out and around the sponson.
The sixth and last observation was made related to being forced right up against the deck by the inrushing water and the buoyancy of the suit. Our students are currently taught that if they find themselves lost underwater, they should allow themselves to float up into the air gap. In practice, our instructors found that this was not an easy task to achieve. Although theoretically possible, the claustrophobia of being trapped underwater in a disoriented state, with the very real potential for drowning, caused an urgent psychological desire to get from underneath the FRC no matter what! This may overcome the more prudent decision to remain calm and locate the air gap particularly if the crewmember was swimming in an incorrect direction. Thus, unless the crew and coxswain were very experienced and trained at being underwater, they may drown before being able to achieve this. However, there is some good news. It was found that with training on techniques how to hold on firmly; the experience of the buoyancy of the suit often working against the intended direction of escape; using the suit buoyancy to one's advantage; and techniques how to drag the legs around the sponsons, it was possible to take a naïve subject and train him / her to make a very successful escape. However, the coxswain position remains a potentially hazardous one to escape from because of the reach problem. In our opinion, it is essential that these people, at the very least, be trained to have the skills to make an underwater escape. The FRC Ditching Simulator is now available to training centers with the courseware that has been developed as a result of our research.
Contact Albert Bohemier, CEO, Survival Systems Limited via email at albert@survivalsystems.info or phone 902 465 3888 x 130.
6. An Experiment to Examine the Ability to Detect the UEE™ Lighting System Underwater at Two Different Distances from the Eye [1999] (Abstract)
An experiment was conducted to measure the ability to detect the light bars underwater in different conditions: dark and bright ambient conditions (0 and 3000 lux); at two distances placed at 90 degrees to the human eye (1.54 and 3.1 metres) and in clear and turbid cold water (0. 14 mg / litre and 2.4 mg / litre Suspended Particulate Matter) at 11 -12°C. Nine naval divers or Survival Systems' instructors volunteered for the experiment. All subjects detected the lights at 1.54 metres under all conditions in less than 1.5 seconds. They also detected the lights under dark turbid conditions at 3.1 metres, but only four out of nine subjects detected the lights consistently at 3.1 metres in turbid water under bright ambient conditions. The conclusions are that (a) the lights worked according to design; i.e., to be seen by a survivor sitting in an aisle seat looking at 90° to the window in the same row or leaning across the aisle to the window in the row on the opposite side, a distance of 1.54 metres; and (b) concurrence with Allan's work that detection of light in turbid water at 3.1 metres particularly under bright daylight conditions is unreliable.
7. The Universal Escape Exit (UEE™) [1998] (Abstract)
A simplified, universally retrofit-able helicopter emergency exit has been designed and manufactured. Phases I, II, and III were completed by Survival Systems in conjunction with Captain (N) Chris Brooks with the Defence and Civil Institute of Environmental Medicine. Phase IV - the final phase (exit lighting) is described in (k), below. The Canadian Forces will share two patents with Survival Systems, and Survival Systems will market these emergency exits worldwide to military and civilian helicopter operators, and quite possibly, to bus and train manufacturers. United States Coast Guard has installed the lighting system in its helicopters.
8. Mac 200 Survival Suit Study [1998] (Abstract)
Survival Systems conducted a trial of the new MAC 200 survival suit planned for use by military helicopter pilots flying Search & Rescue and Antisubmarine Warfare missions. The concept is a large suit with open neck and wrist seals. The study was to evaluate how much the suit leaked when underwater and whether the increased buoyancy of the suit hampered escape. This experiment was completed and reported to DCIEM.
9. Development of the METS™ Model 1 [1999] (Abstract)
With the development of the METS™ Model 1, the smallest version METS™ manufactured to date, we have bridged the gap between the METS™ Model 5 and the Shallow Water Egress Trainer (SWET). The Model 1 uses the same rotation ring as the METS™ Model 5, yet it is smaller, lighter, and more portable. It has only two emergency escape exits, and it seats up to five students at any one time. It is modular so it can be used to train, for instance, two pilots in the cockpit, or two crewmen in the stern of the helicopter. It is modular, mobile, and is being marketed for start-up operations, temporary trainee populations, or low student numbers.
10. Super Puma Cabin Trials [1999] (Abstract)
Until 1999, no one had confirmed the time it took to evacuate the maximum number of passengers from the Super Puma, either in the UK configuration (18 passengers) or the Canadian Hibernia configuration (15 passengers). A study was conducted to assess this. Preliminary results show that breath holding ranges between 28 seconds and 92 seconds. These findings imply that some sort of air supply must be provided for passengers in the cabin of the helicopter in order for them to escape safely. This resulted in a paper authored by Dr C J Brooks and Dr H C Muir currently in press for the Aerospace Medical Journal regarding the basis for the development of a fuselage evacuation time for a ditched helicopter.
11. An Experiment to Compare the Disorientation Effect in the Shallow Water Egress Trainer (SWET) and the METS™ [1998] (Abstract)
A large experiment using 35 subjects was conducted to evaluate the disorientation effect in the Shallow Water Egress Trainer (SWET) compared to the METS™. Out of the 35 subjects, 18 were not disoriented in the SWET, whereas 34 out of 35 were disoriented in the window seat of the METS™, and 35 out of 35 were disoriented in the aisle seat. This confirmed our belief that the SWET (as originally designed) is only for use as a procedural training tool for familiarization underwater, prior to METS™ training.
12. Strobing Lights or Fixed Lights for Door / Window Marking [1998] (Abstract)
A study was conducted using the Universal Escape Exit (UEE™) Lighting System to compare ease or difficulty experienced during escape using fixed and strobing lights. The data confirms that the fixed lighting was an excellent tool in early escape. This was preferred to strobing lights and confirms the work done by Luria and Ryack at the US Navy Submarine Laboratory in Groton, Connecticut, USA.
13. The Development of Emergency Breathing Systems (EBS)/Lifejacket System for the Royal Malaysian Air Force [1998] (Abstract)
The object of this study was to determine if the EBS would be a useful addition to the inventory of survival training equipment provided for helicopter passengers flying offshore. The emphasis was on technical advantages and disadvantages. The conclusion was that the EBS was of great benefit to the escapee. Not only did it have a calming affect, but it provided the additional time necessary to escape, particularly if the escape path was cumbersome or partially blocked. A complete system was designed, tested, and flight qualified for the Royal Malaysian Air Force. In January 2001, the RMAF signed a contract for the EBS units and pocketry design.
14. Apache METS™ [1997] (Abstract)
In 1997, Survival Systems designed and constructed the Apache METS™, a simulator that replicates the Apache attack helicopter. The Apache METS™ was designed to be a standalone simulator and includes all exits and stroking seats. This is different from the original Apache Cockpit Modules that were used with an already existing METS™ Model 30 or Model 40.
15. The Ergonomics of Jettisoning Escape Hatches in a Ditched Helicopter (Abstract)
C.J. Brooks, M.B., Ch. B., D.Av.Med
A.P. Bohemier, B.A.
G.R. Snelling
The ergonomics of jettisoning escape hatches in a ditched helicopter. Aviat. Space Environ. Med. 1994; 65:387-95.
The first formal investigation of the problem of location, operation and jettison of escape windows and hatches of helicopters following ditching has been conducted in a new simulator. There were 48 aircrew who attempted 298 escapes using a variety of 24 escape routes and 9 different types of escape hatches. Overall results, while superfically indicating that the task was easy, in fact revealed many unforeseen problems.
Specifically, there was no standardization of hatches and levers, there were problems with location and operation of levers principally due to poor design, and an ergonomics study has not been conducted to investigate the problem.
Underwater escape training with hatches in position must be madatory for all who fly off-shore or over water for a living, and further research should be conducted to design a better standard hatch and jettison system.
The Canadian Navy and the Canadian offshore oil industry have implemented this.
As a result, this study led to the invention and patenting of the Universal Escape Exit by Survival Systems. It also led to a contract with the United States Coast Guard to fit their helicopters with emergency exit lighting systems.
16. New Ship-Borne Aircraft (EH101) Port Side Cabin Operator, Emergency Egress Trials [1993] (Abstract)
This trial evaluated the ability of an operator, sitting in the port seat, to egress from the aircraft via its primary exit for an uncontrolled ditching.
17. To Develop a Procedure/Protocol for the Transport of Medical Evacuees by Helicopter from an Offshore Platform to Shore-Based Facilities [1992] (Abstract)
Specific problems of a helicopter medical evacuation flight in the event of a ditching were examined. Attention was given to parameters such as stretcher size, weight, and configuration vis-à-vis exits, attendant handling, life raft compatibility, patient dexterity, wave and thermal protection, and flotation considerations.
18. Factors Affecting Egress from a Downed Flooded Helicopter - Canada Oil and Gas Lands Administration - Technical Report 109. (Abstract)
Surveys of offshore accidents (Brooks 1989, Kaarstad 1984) indicate that apart from the loss of a petroleum platform such as the Piper Alpha, Ocean Ranger or Alexander Kielland, the transportation of personnel to and from the work place by helicopter is one of the more risky aspects of offshore petroleum industry employment.
This is of particular concern since the helicopter is not only the vehicle for effecting routine crew changes, but is itself the primary means of evacuation during an emergency aboard an offshore platform.
When a helicopter ditches it usually capsizes and sinks rapidly. With water rushing in through cockpit windows, aircrew and passengers must overcome their inherent buoyancy to make their escape from a flooded compartment through the doors, windows or windshield. Escape is hampered by a loss of vision and the terror created by the emergency. Occupants whose passage is blocked by entanglement with debris, other passengers, or who cannot release their seat belts or who are otherwise hampered by injuries, commonly perish.
To improve the chances of surviving a helicopter ditching, all personnel employed on offshore drilling units on frontier lands are required to take survival training, including helicopter egress instruction. In addition, research is carried out to examine the problems associated with underwater egress. This work focuses on the behavior of individuals exposed to various circumstances in the safety of a helicopter underwater escape trainer (HUET).
This investigation, sponsored by the Canada Oil and Gas Lands Administration, was conducted at Survival Systems Limited of Dartmouth, Nova Scotia. The study was designed to assess the difficulty and/or attributes of the following factors that relate to underwater egress.
Phase 1 - Passenger’s seat position relative to exit
Phase 2 - Window exit mechanisms
Phase 2A- The Sikorsky S61 liferaft encasement exit
Phase 3 - Physical references as an aide-to-egress
Phase 4 - Visual aids
Phase 5 - Value of troop seating arrangement
The overall objective of this project was to document the effects of these parameters on a passenger’s ability to safely exit the helicopter, identify and define any difficulties or advantages involved, and where appropriate, suggest possible remedies.
The project design has been governed by three cardinal requirements: safety, authenticity, and quantitative results.
19. Military Emergency Breathing Systems (EBS) Evaluation [1990] (Abstract)
This military program examined various emergency breathing apparatuses to ascertain the one most appropriate for Canadian Forces personnel use. Factors taken into consideration included ease of operation and, most importantly, reliability.
20. Seatbelt Trials (Military) (Abstract)
This trial examined a proposed new seatbelt configuration in a helicopter ditching. Current seatbelts were used as a control.
21. Liferaft Evacuation from a Ditched Helicopter: Dry Shod vs. Swim Away Method (Abstract)
Liferaft evacuation from a ditched helicopter: dry shod vs. swim away method. Aviat Space Environ Med 1997; 68:35-40.
There were 23 male and 21 female subjects who conducted a series of evacuations from the NUTEC Super Puma helicopter simulator into an RFD heliraft in the Bergen Fjord.
C.J. Brooks, M.B., D.Av. Med., P.L. Potter, B. Rec.,
B. Hognestad, and J. Baranski, M.A., Ph.D.
The dry shod and swim-away methods were compared both on the windward and leeward side.
Results:
The dry shod method is the method of choice, although the swim-away method should be taught as an alternative in the event of imminent capsizing.
Irrespective of method, evacuation wherever possible should be on the windward side.
Conclusions:
Because it is critical for the aircrew to make a split-second decision concerning which method to use, they should have special training in open water after traditional pool training.
22. Helicopter Door and Window Jettison Mechanisms for Underwater Escape: Ergonomic Confusion! (Abstract)
Helicopter door and window jettison mechanisms for underwater escape: ergonomic confusion! Aviat Space Environ Med 1997; 68:844-57.
There are 23 different door, hatch, and window release mechanisms identified in 35 types of helicopters that earn their living over water.
C.J. Brooks, M.B. Ch.B., D.Av.Med. and A.P. Bohemier, B.A.
There is no standardization of the mechanism within each cockpit or among helicopter types, nor is there any standardization of the location relative to the operation, whether the mechanism matches the task or in which direction the door/hatch/window is jettisoned.
New regulations are needed by military and civilian authorities to address the ergonomic confusion.
23. Evaluation of a New Universal Jettison Mechanism for Helicopter Underwater Escape (Abstract)
Evaluation of a new universal jettison mechanism for helicopter underwater escape. Aviat Space Environ Med 1999; 70-752-8.
To date, there is no standard jettison mechanism for doors, windows, or hatches in ditched helicopters.
C.J. Brooks, M.B., Ch.B, D.Av.Med.,
L. Miller, B.Eng., S. Morton, B.A. and
J. Baranski, M.A., Ph.D.
A new Universal Escape Exit (UEE™) has been invented and the performance has been compared with two current in-service systems in a helicopter underwater escape trainer.
Method:
A total of 416 evacuations were conducted by 40 subjects in two experiments using the Survival Systems Limited’s underwater escape trainer.
Results:
The UEE™ had a distinct 2-s advantage to escape; and, in the majority of cases, was preferred to a rotating lever or a straight push out system.
Conclusions:
Further work should continue with UEE™ development for qualification in an operational helicopter.
Keywords:
helicopter, ditching, survival, cold water, breathholding, jettison, mechanisms.
24. The Effect of Wave Motion on Dry Suit Insulation and the Responses to Cold Water Immersion (Abstract)
The effect of wave motion on dry suit insulation and the responses to cold water immersion. Aviat Space Environ Med 1998; 69:957-64.
Six subjects who were each wearing a dry immersion suit system were immersed for 1 h in 16° celsius water in a number of different wave conditions, ranging from still water to 70 cm in height.
M.B. Ducharme, M.Sc., Ph.D., and C.J. Brooks, M.B. Ch.B., D.Av.Med.
Physiological and physical parameters were measured in order to calculate the total thermal resistance of the suit system and its components.
Results:
None of the physiological parameters were affected significantly by the wave conditions, except for skin heat flux, which increased with wave height from 72.0 ±1.9 W ·m¯², at 0 cm of height, to 85.5 ± 2.9 W·m¯², at 70 cm of height.
Wave heights up to 70 cm decreased the insulation (including boundary layer) of the dry suit system by 14%, and the only component of the suit affected by the wave motion was the insulation of the water boundary layer, which decreased by 75%.
The body sites that were most affected by wave motion were the head and the trunk, with an average 4f5% decrement in suit system thermal resistance at those sites at wave heights of 9 to 70 cm.
No significant effect was observed at sites on the distal limbs.
Conclusion:
To simulate open ocean conditions in the laboratory, the standards must take the reduction of suit insulation into account.
25. Underwater Disorientation as Induced by Two Helicopter Ditching Devices (Abstract)
Underwater Disorientation as induced by two helicopter ditching devices. Aviat Space Environ Med 2000; 71:879-88.
Spatial orientation is based on the integration of concordant and redundant information from the visual, vestibular, and somatosensory systems.
Bob Cheung, Ph.D., M.Sc., Kevin Hofer, M.A., B.Sc.,
Chris J. Brooks, Ch.B., D.Av.Med., and Peter Gibbs
When a person is submerged underwater, somatosensory cues are reduced, and vestibular cues are ambiguous with respect to upright or inverted position. Visual cues may be lost as a result of reduced ambient light. Underwater disorientation has been cited as one of the major factors that could inhibit emergency egress after a helicopter ditching into water. One countermeasure to familiarize aircrew with underwater disorientation is emergency egress training. This study examined the relative degree of underwater disorientation induced by the Modular Egress Training Simulator (METS™) and the Shallow Water Egress Trainer (SWET).
Methods:
There were 36 healthy subjects (28 males and 8 females) who participated in the study.
Underwater disorientation was quantified by measuring the deviation of subjective vertical-pointing from the gravitational vertical, time to egress, and subjective reports of disorientation and ease of egress.
A repeated measure design was employed with seat position (SWET chair, METS™ window, and METS™ aisle) as the sole factor.
Results:
Subjective response data indicated that the degree of disorientation is rated significantly higher, and the ease of egress is rated worse from the two METS™ seat positions than in the SWET (p< 0.01).
The time to egress is longer from the two METS™ device is effective for inducing underwater disorientation as provoked by simulated helicopter ditching.
Keywords:
disorientation, vestibular, subjective pointing.
26. The Basis for the Development of a Fuselage Evacuation Time for a Ditched Helicopter (Abstract)
The basis for the development of a fuselage evacuation time for a ditched helicopter. Aviat Space Environ Med 2001; 72:553-61.
Hypothesis: When a helicopter ditches or crashes in water, unless the buoyancy bags are inflated, it commonly sinks inverted.
C.J. Brooks, M.B., Ch.B., D.Av.Med., H.C. Muir, M.A., Ph.D., and P.N.G. Gibbs, Q.G.M.
Thus, crew and passengers must make an underwater escape. It is postulated that later passengers in the escape sequence do not have the breath-holding ability to conduct a successful escape, particularly if the water is cold. This contributes to the 20-50% mortality rate in survival accidents.
Methods:
There were 132 immersed subject evaluations which were conducted in daylight and darkness to measure escape times from a helicopter underwater escape trainer, configured to the Super Puma, seated for 15 and 18 passengers.
The subjects were highly experienced instructors or Navy clearance divers.
Results:
The time from when each subject’s head disappeared underwater until each subject surfaced and total fuselage evacuation time were measured and any problems hampering escape were noted.
Breath-holding for the last subject out ranged from 28 to 92 s.
An emergency breathing system was used by a minimum of four subjects each time and a maximum of 11 subjects in one condition.
The buoyancy of the survival suit was the principal component that hampered escape.
Conclusion:
Breath-holding times were too long for the later subjects to escape without resorting to an EBS, in spite of the fact that they were highly trained.
For regular crew and passengers flying over water, this would explain the high mortality, etc.
Therefore, a new helicopter standard should be developed requiring fuselage design to accommodate total evacuation with 20 s from underwater.
For current helicopters, where this cannot be achieved, passengers should be provided with some form of air supply, or, after ditching, the helicopter should be modified so that it will stay afloat on its side and retain an air space in the cabin.
Keywords:
helicopter ditching, evacuation.
27. Disorientation in Helicopter Ditching and Rigid Inflatable Boat Capsizement: Training is Essential to Save Crews (Abstract)
This paper discusses the disorientation problems of escape from a rigid inflatable boat (RIB) that has been capsized. It makes comparisons with executing a ditched helicopter underwater escape and emphasizes the need for realistic training for both RIB and helicopter crafts.
Dr. C.J. Brooks
Director, Research and Development
Survival Systems Limited
40 Mount Hope Avenue
Dartmouth, Nova Scotia
B2Y 4K9 Canada
Phone: +1 902 465 3888x150
Fax: +1 902 465 8755
E-mail: chrisb@sstl.com
Although very poor records are collected on RIB capsizements, each year there is a small but significant loss of life and many close calls.
A paper at the Royal Institute of Naval Architects in 1998, reported 13 deaths from an accident involving the Sea Gem in 1965, but gave no further details (Reference 5).
The Transportation Safety Board of Canada reported the case of the G.R.1 FRC (Reference 3) launched from the Gordon Reid off British Columbia, which grounded and flung the three occupants over the rocks and back into the water. Miraculously, all three survived.
Rigid inflatable boats or fast rescue crafts (FRC) are used by every Navy in the world, as well as many other paramilitary and commercial marine organizations.
In 1998, it was reported that the US Coast Guard alone operated over 700 FRCs (Reference 5).
To date, no one has examined the problem of escape from such a vessel after it has been capsized, although Oakley has examined the pros and cons of wearing head protection while operating small, fast boats (Reference 2).
This paper discusses a recent experiement conducted by Survival Systems to examine the problems of underwater escape from a capsized FRC.
28. The Abysmal Performance of the Inflatable Liferaft in Helicopter Ditchings (Abstract)
The inflatable liferaft or dinghy was introduced into aircraft in the 1930s.
Capt(N) C.J. Brooks and P.L. Potter*
Defence and Civil Institute of Environmental Medicine
1133 Sheppard Avenue West, Toronto, ON M3M 3B9 Canada
*The CORD Group Limited
50A Mount Hope Avenue
Dartmouth, NS B2Y 4K9 Canada
The Royal Navy Fleet Air Arm and the Royal Canadian Air Force (23) suspended it between the longerons at the aft end of the biplane fuselage (Fig 1).
Just prior to World War II, the free-flating multi-seat dinghy was added to the inventory of aviation lifesaving equipment (27).
Llano (22) reviewed 35% of the 4 – 5000 ditchings in World War II and the Korean War. He concluded that the liferaft had been of great value, but in virtually every case there was reference to a struggle to get into it. This was only made worse if the crewmember was injured or simply exhausted. Many survivors recommended deflating the liferaft before entry and/or climbing into an uninflkated leferaft before inflating it.
In 1965, Townsend (28) reviewed inflatable liferaft performance in commercial fixed wing aircraft accidents and concluded that often the installation of life support equipment had been done as an after-thought when the rest of the aircraft design had been completed, and in many cases, imperfect installation had not improved survival.
There are many similar comparisons with introduction of the inflatable liferaft into helicopters post World War II.
29. Options for Liferaft Entry After Helicopter Ditching
(Abstract)
Options for liferaft entry after helicopter ditching. Aviat Space Environ Med 1998; 69:743-9.
Dry and wet evacuations were conducted by 24 male and 19 female subjects from the Nutec Super Puma Simulator into two different types of aviation liferaft.
C.J. Brooks, M.B. Ch.B., D.Av.Med., P.L. Potter, B.Red., D.De Lange, J.V. Baranski, M.A., Ph.D., and J. Anderson, B.Eng., M.Eng.
Results:
Dry evacuation on the windward side is the method of choice.
The non-canopy raft is subjectively and objectively easier to enter both from the helicopter and the sea.
Conclusions:
The non-canopy raft is the raft of choice, the canopy raft needs to redesign to ensure that it always inflates the correct way and both rafts need a redesign of the painter anchor point.
Aircrew should have special training in open water after traditional pool training.
A helicopter ditching survival compass has been developed for training all who fly over water for a living.
30. What is the Survival Suit Designed to Do, and Will it Work for Me in the Event of a Ditching or Ship Abandonment? (Abstract)
Three hundred and fifty seven people attended a series of practical survival courses at Survival Systems Ltd., Dartmouth, Nova Scotia between January and June, 2001.
Prof. Christopher Brooks
Director, Research & Development
Survival Systems Ltd.
40 Mount Hope Avenue
Dartmouth, Nova Scotia
B2Y 4K9 Canada
Prof. John McCabe
School of Health and Human Performance
Dalhousie University
Halifax, Nova Scotia
B3H 3J5 Canada
Ms. Jennifer Lamont, BSc (Hons)
School of Health and Human Performance
Dalhousie University
Halifax, Nova Scotia
B3H 3J5 Canada
Each of the attendees earns their living either working on, or flying over water.
During the courses, they wore a variety of survival suits: a helicopter passenger suit; a marine, one-size-fits-all ship abandonment suit; or a military constant wear survival suit.
At the beginning and the end of the course, a questionnaire was administered to enquire about (a) the reasons for wearing such a suit, (b) the ergonomics of the suit, and (c) how much confidence they had that the suit would do its job in the case of ship abandonment or helicopter ditching.
Pre-course, little was known about the four stages of immersion, but the anecdotal evidence that there was general dissatisfaction with the suits was not generally borne out by the results.
Water integrity was better than expected; this can be attributed to better manufacturing procedures, fabrics and standards.
An interesting finding was that those people with small wrists or wearing a suit with slack fit of the wrist seal, benefited from tightening the seal with duct tape.
The opinions on the ergonomics of the suits followed a normal distribution curve, with the majority of people expressing a relatively good opinion. Most people had confidence that they would survive in them.
Post course, the degree of knowledge of the dangers of sudden cold water immersion had improved, but will require re-testing at a later date to investigate the retention factor.
31. Emergency Breathing System as an Aid to Egress from a Downed Flooded Helicopter - Canada Oil and Gas Lands Administration - Technical Report 108 (Abstract)
This study and the publication of this report were funded and managed by the Canada Oil and Gas Lands Administration. The laboratory work was undertaken by Survival Systems of Dartmouth, Nova Scotia.
A. Bohemier; P. Chandler; S. Gill May 1990
Surveys of Offshore accidents (Brooks 1989, Kaarstad 1984) indicate that apart from the loss of a Petroleum platform such as the Piper Alpha, Ocean Ranger or Alexander Kielland, the transportation of personnel to and from the work place by helicopter is probably one of the more risky aspects of Offshore Petroleum Industry employment.
When a helicopter ditches into water it usually capsizes and sinks rapidly. With water rushing in through cockpit windows, aircrew and passengers much overcome their inherent buoyancy to make their escape from a flooded compartment through the doors, windows or windshield. Escape is hampered by a loss of vision, in spite of the gasp reflex and the terror created by the emergency. Occupants whose passage is blocked by entanglement with debris, other passengers, or who cannot release their seat belts or who are otherwise hampered by injuries, commonly perish.
To improve the chances of surviving a helicopter ditching, all personnel employed on Offshore drilling units on Frontier lands are required to take survival training, including helicopter egress instruction. In addition, research is carried out at facilities specifically designed to examine the problems associated with underwater egress. Typically the work focuses on the behavior that is displayed by individuals exposed to various circumstances in the safety of an Underwater Egress Simulator.
One such investigation, sponsored by the Canadian Oil and Gas Lands Administration, was conducted at Survival Systems Limited of Dartmouth, Nova Scotia. Known as the “Factors” project this study was designed to quantify the difficulty associated with several aspects of Underwater Egress including such physical factors as the proximity of the seat to the exit, the type of exit mechanism, physical references and visual aids. The “Factors” study (like the EBS project) involved volunteers and a Helicopter Underwater Escape Trainer.
Common to all underwater escapes is the time constraint imposed by the fact that one cannot breath underwater without support equipment. An individual’s ability to hold breath underwater depends on many things such as the water temperature, physical and mental condition, and level of activity. An emergency ditching in a helicopter, that inverts almost immediately, allowing cold water to flood the cabin reducing visibility and agitating everything inside is not conducive to holding one’s breath; and then one must search, find and jettison an exit to successfully egress.
Research into the application of an Underwater Breathing System for helicopters was undertaken by the Royal Navy, the United States Navy, the United States Coast Guard, and the Canadian Armed Forces during the 1970’s. In the early 1980’s an Emergency Breathing System, EBS, developed initially for scuba divers, was put into service by the United States Navy.
The purpose of the unit is to provide a ready source of air that can be quickly accessed in the event of an emergency and used until the egress is completed. A description of the EBS is given in Section 2.1.
The life saving ability of the EBS, or of similar devices such as “Spare-Air”, and “HEED” (Helicopter Emergency Egress Device), is evident in the testimonials of those surviving a helicopter ditching. Appendix A contains to accounts of how these devices were used and contributed to a successful egress.
Statistics compiled by the United States Navy Safety Centre (1989) reveal that the proportion of survivors to total occupants of helicopter ditchings has increased subsequent to the introduction of “HEEDS” from an average of seventy-one (71%) percent in a 1982 to 1986 survey, to eighty-three (83%) percent in the 1987 survey (a 12% improvement for the one year).
On average there were fifty-seven (57) aircrew involved in ditchings per year during the five years from 1982 to 1986. The 1987 data shows that fifty-eight (58) aircrew ditched and that four (4) of the forty-eight (48) survivors used an emergency breathing supply. Assuming that these men would not have survived without this device, the availability of the EBS unit directly accounts for a 7% improvement in the 1987 survivor statistics.