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Video copilot optical flares wall of lights free.
Video copilot optical flares wall of lights free.
Video copilot optical flares wall of lights free
At length they emerged on a muddy road to find the sun coming out. They were a little beyond the Seth Bishop place, but bent trees and hideously unmistakable tracks shewed what had passed by. Only a few moments were consumed in surveying the ruins just around the bend. It was the Frye incident all over again, and nothing dead or living was found in either of the collapsed shells which had been the Bishop house and barn.
No one cared to remain there amidst the stench and tarry stickiness, but all turned instinctively to the line of horrible prints leading on toward the wrecked Whateley farmhouse and the altar-crowned slopes of Sentinel Hill. It was no joke tracking down something as big as a house that one could not see, but that had all the vicious malevolence of a daemon.
Armitage produced a pocket telescope of considerable power and scanned the steep green side of the hill. Then he handed the instrument to Morgan, whose sight was keener. After a moment of gazing Morgan cried out sharply, passing the glass to Earl Sawyer and indicating a certain spot on the slope with his finger. It was one thing to chase the nameless entity, but quite another to find it. Voices began questioning Armitage about what he knew of the thing, and no reply seemed quite to satisfy.
Everyone seemed to feel himself in close proximity to phases of Nature and of being utterly forbidden, and wholly outside the sane experience of mankind. In the end the three men from Arkham—old, white-bearded Dr.
Armitage, stocky, iron-grey Professor Rice, and lean, youngish Dr. Morgan—ascended the mountain alone. After much patient instruction regarding its focussing and use, they left the telescope with the frightened group that remained in the road; and as they climbed they were watched closely by those among whom the glass was passed around. It was hard going, and Armitage had to be helped more than once.
High above the toiling group the great swath trembled as its hellish maker re-passed with snail-like deliberateness.
Then it was obvious that the pursuers were gaining. Curtis Whateley—of the undecayed branch—was holding the telescope when the Arkham party detoured radically from the swath. He told the crowd that the men were evidently trying to get to a subordinate peak which overlooked the swath at a point considerably ahead of where the shrubbery was now bending. This, indeed, proved to be true; and the party were seen to gain the minor elevation only a short time after the invisible blasphemy h a d passed it.
The crowd stirred uneasily, recalling that this sprayer was expected to give the unseen horror a moment of visibility. Two or three men shut their eyes, but Curtis Whateley snatched back the telescope and strained his vision to the utmost. Curtis, who had held the instrument, dropped it with a piercing shriek into the ankle-deep mud of the road.
He reeled, and would have crumpled to the ground had not two or three others seized and steadied him. Curtis was past all coherence, and even isolated replies were almost too much for him. Fred Farr and Will Hutchins carried him to the roadside and laid him on the damp grass. Henry Wheeler, trembling, turned the rescued telescope on the mountain to see what he might. Through the lenses were discernible three tiny figures, apparently running toward the summit as fast as the steep incline allowed.
Only these—nothing more. Then everyone noticed a strangely unseasonable noise in the deep valley behind, and even in the underbrush of Sentinel Hill itself. It was the piping of unnumbered whippoorwills, and in their shrill chorus there seemed to lurk a note of tense and evil expectancy. Earl Sawyer now took the telescope and reported the three figures as standing on the topmost ridge, virtually level with the altar-stone but at a considerable distance from it.
One figure, he said, seemed to be raising its hands above its head at rhythmic intervals; and as Sawyer mentioned the circumstance the crowd seemed to hear a faint, half-musical sound from the distance, as if a loud chant were accompanying the gestures. The weird silhouette on that remote peak must have been a spectacle of infinite grotesqueness and impressiveness, but no observer was in a mood for aesthetic appreciation.
The whippoorwills were piping wildly, and in a singularly curious irregular rhythm quite unlike that of the visible ritual. Suddenly the sunshine seemed to lessen without the intervention of any discernible cloud. It was a very peculiar phenomenon, and was plainly marked by all.
A rumbling sound seemed brewing beneath the hills, mixed strangely with a concordant rumbling which clearly came from the sky. Lightning flashed aloft, and the wondering crowd looked in vain for the portents of storm. The chanting of the men from Arkham now became unmistakable, and Wheeler saw through the glass that they were all raising their arms in the rhythmic incantation.
From some farmhouse far away came the frantic barking of dogs. The change in the quality of the daylight increased, and the crowd gazed about the horizon in wonder.
Then the lightning flashed again, somewhat brighter than before, and the crowd fancied that it had shewed a certain mistiness around the altar-stone on the distant height.
No one, however, had been using the telescope at that instant. The whippoorwills continued their irregular pulsation, and the men of Dunwich braced themselves tensely against some imponderable menace with which the atmosphere seemed surcharged.
Without warning came those deep, cracked, raucous vocal sounds which will never leave the memory of the stricken group who heard them. Not from any human throat were they born, for the organs of man can yield no such acoustic perversions.
Rather would one have said they came from the pit itself, had not their source been so unmistakably the altarstone on the peak. It is almost erroneous to call them sounds at all, since so much of their ghastly, infra-bass timbre spoke to dim seats of consciousness and terror far subtler than the ear; yet one must do so, since their form was indisputably though vaguely that of half-articulate words.
They were loud—loud as the rumblings and the thunder above which they echoed—yet did they come from no visible being. Henry Wheeler strained his eye at the telescope, but saw only the three grotesquely silhouetted human figures on the peak, all moving their arms furiously in strange gestures as their incantation drew near its culmination.
From what black wells of Acherontic fear or feeling, from what unplumbed gulfs of extra-cosmic consciousness or obscure, long-latent heredity, were those half-articulate thunder-croakings drawn?
Presently they began to gather renewed force and coherence as they grew in stark, utter, ultimate frenzy. The pallid group in the road, still reeling at the indisputably English syllables that had poured thickly and thunderously down from the frantic vacancy beside that shocking altar-stone, were never to hear such syllables again. Instead, they jumped violently at the terrific report which seemed to rend the hills; the deafening, cataclysmic peal whose source, be it inner earth or sky, no hearer was ever able to place.
A single lightning-bolt shot from the purple zenith to the altar-stone, and a great tidal wave of viewless force and indescribable stench swept down from the hill to all the countryside. Dogs howled from the distance, green grass and foliage wilted to a curious, sickly yellow-grey, and over field and forest were scattered the bodies of dead whippoorwills. The stench left quickly, but the vegetation never came right again. To this day there is something queer and unholy about the growths on and around that fearsome hill.
Curtis Whateley was only just regaining consciousness when the Arkham men came slowly down the mountain in the beams of a sunlight once more brilliant and untainted. They were grave and quiet, and seemed shaken by memories and reflections even more terrible than those which had reduced the group of natives to a state of cowed quivering.
In reply to a jumble of questions they only shook their heads and reaffirmed one vital fact. It was an impossibility in a normal world. Only the least fraction was really matter in any sense we know. It was like its father—and most of it has gone back to him in some vague realm or dimension outside our material universe; some vague abyss out of which only the most accursed rites of human blasphemy could ever have called him for a moment on the hills.
Memory seemed to pick itself up where it had left off, and the horror of the sight that had prostrated him burst in upon him again. Only old Zebulon Whateley, who wanderingly remembered ancient things but who had been silent heretofore, spoke aloud. We have no business calling in such things from outside, and only very wicked people and very wicked cults ever try to. There was some of it in Wilbur Whateley himself—enough to make a devil and a precocious monster of him, and to make his passing out a pretty terrible sight.
Things like that brought down the beings those Whateleys were so fond of—the beings they were going to let in tangibly to wipe out the human race and drag the earth off to some nameless place for some nameless purpose. It grew fast and big from the same reason that Wilbur grew fast and big—but it beat him because it had a greater share of the outsideness in it.
It was his twin brother, but it looked more like the father than he did. Working as a team, investigators can come from disparate backgrounds and be of varied occupations—each bringing certain expertise to the group.
Together, joined in comradeship and common purpose, you will stand steadfast against the coming darkness. This chapter provides the rules for creating investigator player characters. A two-page spread that provides a handy summary for quick reference can be found on pages Before you begin rolling dice you should talk to the Keeper and ask for guidance on creating a suitable investigator for the scenario that you are going to play.
The Keeper may stipulate strict guidelines, such as which professions you can chose from, or may leave it completely open to you. The location or country in which the game is set. Does the Keeper recommend any occupations? Suggestions for how the investigators might know each other. The Keeper may tell you a great deal or very little about the scenario.
Listen to what is said and ask any questions you may have. Once you have an idea for an investigator, run it past your Keeper for approval. This conversation can serve to stimulate imagination and create links between the investigators, helping to create a suitable mix of player characters.
If the Keeper says the investigators are going to be hired for an investigation, think about making an investigator who needs the money. When beginning a game of Call of Cthulhu, it is recommended that all the players "roll-up" their investigators together in the company of the person who will be taking on the role of Keeper— this ensures that everyone helps to form the group, with each investigator taking an agreed role, ensuring that a balance of skills and occupations is found.
If the premise asks that your investigator be part of an academic team attending a conference, perhaps your character could be one of the speakers. Giving your investigator more relevance to the story and making the "hook" stronger will make the game better.
Any connections that you create between your investigator and the plot are likely to hold greater emotional resonance for you than anything the Keeper supplies. If the Keeper is unable to give much of a premise you can still create some interesting facets to your investigator without knowing how they will come into play.
The Keeper may pick up on some of these facets and incorporate them into the scenario. Creating Your Investigator There is more than one approach to creating an investigator. Some people prefer to have an idea about the type of investigator they wish to create before rolling any dice, while others prefer to let the dice rolls guide their choices.
What follows are the standard rules for creating investigators, with further options at the end of this chapter. In the game each characteristic represents an aspect of an investigator—intelligence, dexterity, and so on. These identified quantities determine the relative capability of investigators and suggest ways for them to act and react during play. Characteristic values are generated randomly by rolling two or more six-sided dice. Rolling Characteristics Initially, write your results on a piece of scrap paper before writing them onto the investigator sheet as they may be modified by the age of your investigator.
Enhancing Your Character's Background The Keeper has presented an initial premise for the game, which involves an expedition team from the Miskatonic University traveling into the wilds in search of a missing colleague. Amy asks if her investigator might work in the same department as the missing person.
The Keeper agrees. Strength measures the muscle power of an investigator. The higher it is, the more the investigator can lift or tightly cling to something. This characteristic determines the damage an investigator inflicts in hand-to-hand combat. Reduced to STR 0, an investigator is an invalid, unable to get out of bed.
Constitution represents health, vigor, and vitality. Investigators with a high constitution often have more hit points—the better to resist injury and attack. Serious physical injury or magical attack might lower the statistic, and if Constitution reaches zero the investigator dies. Introducing Harvey Walters To help illustrate the various rules of Call of Cthulhu, we are pleased to introduce you to Harvey Walters, the noted s New York journalist and investigator of the supernatural.
We use Harvey to demonstrate how character creation works. To differentiate between the person playing Harvey and the actual character of Harvey, the investigator in the game, the player is female and her investigator is male. For a walk-through of Harvey's character creation see page Investigators with higher Dexterity scores are quicker, nimbler, and more physically flexible. A DEX roll might be made to grab a support to keep from falling, to move faster than an opponent, or to accomplish some delicate task.
An investigator with zero DEX is uncoordinated and unable to perform physical tasks. In combat, the character with the highest DEX acts first. Appearance measures both physical attractiveness and personality.
A person with high APP is charming and likeable, but may lack conventional good looks. An investigator with APP of 0 is appallingly ugly or someone with a wholly detestable demeanor, provoking comment and shock everywhere.
APP may be useful in social encounters or when trying to make a good impression. Intelligence represents how well investigators learn, remember, analyze information, and solve complex puzzles. An investigator with zero INT is a babbling, drooling idiot. Size averages both height and weight into a single number. To see over a wall, to squeeze through a small opening, or even to judge whose head might be sticking up out of the grass, use size. Size helps determine hit points, damage bonus, and build.
Presumably if investigators lose all SIZ points they disappear—goodness knows to where! Often one or two low characteristic scores can help to bring the investigator "to life" and feel more real—as opposed to some incredible superhuman! Rather than rejecting a low roll, try to incorporate it into the overall makeup of your investigator. Perhaps a low dexterity means that the investigator has suffered some form of leg or hand injury while in the armed forces, or a low education is the result of never attending school and being forced to grow up on the streets.
INT also acts as the value for both Idea rolls and Intelligence rolls. For example, an investigator with high EDU and low INT might be a pedantic teacher or a sideshow performer, someone who knows facts but not their meanings. Those with an EDU greater than 80 have most likely conducted graduate level work and have a degree, as expected of a person who has been to a university of some kind.
W ay m page EDU is also used u yo e in practic d back-to-front, ee sp when making Know rolls. Any adjustments are made to that value. Power indicates force of will: the higher the POW, the higher the aptitude for, and resistance to, magic. An investigator with zero POW is zombie-like and without purpose, as well as being unable to use magic. Unless stated otherwise, POW that is lost during the game is lost permanently.
Magic points are equal to one-fifth of POW. The POW of ordinary characters and investigators rarely changes. However, those adroit in the mysteries of the magic of the Cthulhu Mythos may be able to increase their personal POW.
Education is a measure of the formal and factual knowledge possessed by the investigator, as well as indicating the time the investigator has spent in full-time education. EDU measures retained information, not the intelligent application of that information see Intelligence.
An investigator without EDU would be like a newborn baby or an amnesiac—without knowledge of the world, probably very curious and credulous. An EDU of 60 suggests the investigator is a high school graduate, while a score of around 70 indicates a person Luck: Roll 3D6 and Multiply by 5 When creating an investigator roll 3D6 and multiply by 5 for a Luck score.
Luck rolls are often called for by the Keeper when circumstances external to an investigator are in question, and when determining the fickle hand of fate. Age A player can choose any age between 15 and 90 for their investigator. If you wish to create an investigator outside this age range, it is up to the Keeper to adjudicate.
Use the appropriate modifiers for your chosen age only they are not cumulative. Deduct 5 points from EDU. Roll twice to generate a Luck score and use the higher value. Continued on page 48 45 investigator handbook What The Numbers Mean Strength 0 15 50 90 99 Enfeebled: unable to even stand up or lift a cup of tea.
Puny, weak. Average human strength. World-class Olympic weightlifter. Human maximum. Constitution 0 1 Dead. Sickly, prone to prolonged illness and probably unable to operate without assistance. Size 1 15 65 A baby 1 to 12 pounds. Note: Some humans may exceed SIZ Dexterity 0 15 Unable to move without assistance.
Slow, clumsy with poor motor skills for fine manipulation. Olympic standard. Intelligence 0 15 50 90 99 No intellect, unable to comprehend the world around them. Slow learner, able to undertake only the most basic math, or read beginner-level books. Average human intellect. Quick-witted, probably able to comprehend multiple languages or theorems. Genius Einstein, Da Vinci, Tesla, etc.
Power 0 Enfeebled mind, no willpower or drive, no magical potential. Note: Human POW can exceed , but this is exceptional. Education 0 15 60 70 80 90 96 99 A newborn baby.
Completely uneducated in every way. High school graduate. College graduate Bachelor degree. Degree level graduate Master's degree. Doctorate, professor. World-class authority in their field of study.
The player takes up a fresh investigator sheet and a pencil, and then she rolls some six-sided dice. This is abysmal. Harvey is exceptionally puny and weak, but the player is not dismayed—Call of Cthulhu is an unusual game and all kinds of investigators are needed.
This is good, and Harvey will be fairly hardy. This may help make up for his low STR. His player wants Harvey to be 42 year old, with some experience under his belt. She makes two experience checks for Education. Her first roll of 86 earns a reward of 4 points 1D Her second roll of 82 fails to earn any reward. With all of the characteristics done, his player can now write in the half and fifth values for each of them.
He is 42 years of age, and so this is reduced by a further point to MOV 6. Harvey will not be winning many chases. It's decided that Harvey will be a journalist, working for Enigma Magazine.
Now he is at home in a language often encountered in Mythos researches. As an investigative reporter, Harvey is well equipped to ask questions and get honest answers. Now occupation skill points remain. Now occupation points are left. While the Journalist occupation gives a Credit Rating range of 9—30, the player asks to invest more points as Harvey comes from a wealthy family—the Keeper agrees to this request.
Harvey has good communication skills, useful for a reporter, and a Mythos-related skill, Archaeology. These points can be spent as the player desires. With all of his points spent, his player writes down the half and fifth values for each of the skills on the investigator sheet. Harvey's player allocated 41 occupation skill points for Credit Rating, which means that he has an Average living standard.
He may stay in moderately priced hotels, eat out economically , and take the occasional taxi. This seems to fit with Harvey; he is perhaps superstitious. Meaningful Locations is next. Harvey is a studious fellow, perhaps he enjoys sitting in his study as he ponders his writings.
Next, with a roll of 1, we have an item connected with his highest skill. This ties in with his uncle. While this has been attributed to dementia, perhaps there is another cause; perhaps there is something hidden among those old artifacts he collected that led him down the path of madness? Once the percentage values for each characteristic have been determined, the next step is to write in the half and fifth values for each characteristic on the investigator sheet each characteristic has three boxes: a large box for the full value and two smaller ones for the half and fifth values.
Divide the percentage value by five, rounding down, and enter the "fifth" value after the half value. When a "characteristic value" is referred to in the text, this means the full value highest number.
Where half or 48 believes he is more determined and of stronger mind than his uncle, and that he will triumph where his uncle failed. This fits perfectly well; Harvey is a good-looking fellow. If he were to list a car among his starting gear, this would have to come out of his assets, as a car is not listed within the s Average Income bracket. Harvey is now ready to begin his adventures! Half and fifth are the only fractions used in relation to characteristics and skills in the game and all the numbers are calculated up front so that play is not hindered by mental calculations.
Larger and stronger creatures and humans do more physical damage than their lesser brethren. Each chapter 3: creating investigators range of results correlates with a die modifier or dice roll. Build is determined using the same figures. Build is used in fighting maneuvers and also to give a sense of scale. Note: Damage bonus is not applied to firearms attacks. The investigator sheet is designed to help the player keep track of hit points and wounds.
Other occupations are not those you would normally find in a Lovecraft story; however, they may interest particular players and be fun to play in a Call of Cthulhu game. An occupation ties together a cluster of skills.
Some occupations include no free choices; others may have two or more. Chapter 4: Occupations provides a wide range of possible investigator occupations. Most occupations can be applied to pretty much any historical setting in which games might take place.
However, some occupations, like Hacker, exist only in specific settings, such as the modern-day. You should choose only those skills appropriate to the time period in which your game is taking place. Once you have chosen the occupation for your investigator, write it down on the investigator sheet and then make a note of the occupational skills. Skill definitions can be found in Chapter 5: Skills. Step Three: Decide Skills and Allocate Skill Points Occupation Skills After you have chosen an occupation, calculate your occupation skill points using the characteristics specified alongside the occupation.
Points should also be allocated to Credit Rating within the range indicated for the occupation. Not all the skills need to have points allotted to them; however, points left undistributed are lost.
Note that each skill has a number in parenthesis next to it on the investigator sheet: this is the base chance of success in that skill, and any points allocated to that skill are added to this base number.
The sheet also has space to write in the half and fifth values for each skill, allowing you to reference them quickly in the middle of a game. It is advised that you allocate occupation skill points and then personal interest skill points before writing in the half and fifth values alongside the full value for each skill, as personal interest skill points can be used to bolster occupation skills, as well as other non-occupation skills see Personal Interests following.
Weapons and Firearm Skills Fighting and Firearms skills, and their various specializations, allow an investigator to use weapons. Personal interest or occupation skill points if applicable may be spent to raise any of these skills. When an occupation includes the skill of Fighting or Firearms, and no specialization is specified, it is up to the player to choose one or more specializations of that skill see Chapter 5: Skills.
In play, Credit Rating determines the amount of money a character has available. For example, criminal could be used as a profession for a poor lone pickpocket Credit Rating 09 or for a wealthy gang boss Credit Rating Any number of skill points can be invested in Credit Rating within the recommended limits for that profession. There are six living standards: penniless, poor, average, wealthy, rich, and super rich. Each one determines the lifestyle, type of accommodation, travel, and expenses that a person can comfortably afford on a day-to-day basis.
See the box nearby for more information about the different living standard based upon Credit Rating. Step Four: Create a Backstory 50 Not one man who participated in that terrible raid could ever be induced to say a word concerning it, and every fragment of the vague data which survives comes from those outside the final fighting party.
There is something frightful Choosing an Occupation When choosing an occupation, there are some things to consider: Try to have a picture in your mind about who and what your investigator is—your character concept. Look for occupations that suit this concept and add color to it.
Remember, rolling up an investigator is all about building up a story of who you want to play in the game. Your characteristics, occupation, sex, and age all help to establish a fully-rounded, breathing investigator.
Look through the skills associated with each occupation and see which of these you like the most. Certain skills are likely to appeal to you more. Perhaps you want your investigator to be a man or woman of action, leading you to choose an occupation with skills like Fighting, Climb, and Throw. Alternatively you might decide to create a more studious investigator, with skill in Library Use, Spot Hidden, and Psychology. Creating a balance of occupations means that the group has a good mix of skills that will benefit everyone.
Depending on the style of game and scenario you will be playing, your Keeper might have certain occupations in mind for you to play; perhaps he or she mentioned this when they described the initial premise of the scenario. Discuss your ideas with the other players in order to build the most appropriate group of investigators for your game. After all, it will be somewhat strange for everyone to turn up with musicians when the scenario is set in the Antarctic! If the game is to be ongoing a campaign , the investigators are going to need a reason to stay together see Chapter 6: Investigator Organizations for more ideas.
Lovecraft, The Case Of Charles Dexter Ward Most of the ideas and abilities that make an investigator interesting and fun to play are a matter of choice—not necessarily dice roll results.
Think about what personal history, friends, enemies, and achievements could have led chapter 3: creating investigators your investigator to delve into the secrets of the Cthulhu Mythos. There are ten Living Standards categories listed on the back of the investigator Accommodation: a substantial residence, Credit Rating 0: Penniless sheet; try to write down perhaps with some domestic help butler, at least one entry for A person who cannot even afford the level of housekeeper, cleaner, gardener, etc.
Beliefs, Significant People, living on the street. Meaningful Locations, Travel: first class. This person would own an Travel: walking, hitchhiking, or stowing away expensive car or equivalent. Treasured Possessions, on a train or ship. Further day. Second homes in the or existing ones altered, rental housing or fl eabag hotel. Stays in top hotels. The categories of Travel: public transport of the cheapest sort.
Travel: first class. Of course, day and occasional treats. Refer to Table II: Cash and some investigators might Accommodation: an average home or Assets if the investigator wishes to make more start the game with a apartment, either rented or privately owned.
In a modern-day period, this As Rich, but money is really no object. When Crafting Background Entries, Second, it can be called upon during the investigator be Specific, Emotional, and Emphatic development phase for the recovery of Sanity points. Try to phrase each entry to emphasize its personal nature. During episodes of insanity, G Specify a name. Name the person or place, identify or as a result of major wounds, the Keeper may add or the item or concept. G Attach a feeling. Start with positive or negative and build from there.
G Make it intense, use love instead of like, use despise instead of dislike. What are they good or bad at? Why is this? Does a high skill in shooting mean they grew up in the country and regularly went hunting with their father and brothers, or perhaps the investigator bought a handgun when they moved to the big city?
So get a Chat Pack. Your mileage may vary. But this pack helped us pass the time, and it takes up barely any space. Make time in your trip for the detours. There will be times in the car when a sort of tunnel vision can set in, and the destination becomes all-consuming.
We were alone, on an outcropping overlooking a shallow canyon. Someone had built an impromptu fire pit. You can find many ways to plan a trip. But once in a while, take a risk and make a left when all the maps and devices are telling you to go right. Amazingly affordable with great optics, these binoculars offer comparable performance to many models that cost thousands more. Binoculars might not be a necessity.
Yes they will. The waterproof and lightweight Athlon Optics Midas ED binoculars boast a rugged shock-absorbing exterior. And it needs to be durable enough to survive beach trips, sightseeing, picnics, and museum tours. Packed up, it is very discreet: nearly the size of a keychain accessory. It has reinforced stitching at stress points, allowing the Ultra-Sil to carry more weight than you would expect.
That said, since this pack is made of such thin, light material, carrying large or awkwardly shaped loads is somewhat uncomfortable, especially when compared with our more structured picks. If lightness, waterproofing, comfort, or organization are more important to you, check out the alternative picks in our review of packable daypacks for travel.
Our favorite picnic blanket rolls easily and compactly, and it will keep you dry and comfortable, even on damp grass. We stopped dozens of times on our trip, and we were glad every time we were able to take a side road, pull out a blanket, and find a place to sit down and share some food.
After considering 44 picnic blankets and testing 13 , we think the two-person Nemo Victory Blanket offers the best combination of comfort, durability, and compactness.
With an acrylic flannel top and a padded waterproof polyurethane underlayer, the Victory is thick enough for you to lie on without feeling every stick and twig underneath you. We even used the Victory Blanket as a tent pad for two nights.
Because of supply-chain issues, the Victory Blanket has been difficult to find. After 60 hours of research and interviews, we recommend Coppertone SPF 70 sunscreen for everyday use. The one exception: your youngest passengers.
Do not put sunscreen on an infant. The American Academy of Dermatology recommends keeping children who are younger than 6 months out of the sun entirely.
Even the most promising options suffer from having jumper cables that are too short, too thin, or both. On a desolate stretch of two-lane highway in northern Arizona, we were driving behind a rental camper van just as it had a rear-tire blowout after hitting a rumble strip.
And it gave us a great opportunity to put our emergency gear to the test! Basically, make sure your plan fits your needs. For example, if you live in a city, 3 miles of free towing may be enough. This kit is chock-full of bandages and cleaning supplies that are suitable for minor incidents.
On the road, a first-aid kit is useful for keeping someone comfortable until people with real medical expertise can help. For an extensive list and comparison chart, see our full guide. This small shovel slices through icy snow and can be disassembled for car storage.
As of March , this shovel appears to be unavailable. As an alternative, you could try a non-telescoping version. If the telescoping feature is important to you, we recommend looking into the Black Diamond Transfer Snow Shovel. The tool, popular with ski patrols and people clearing backcountry trails, has a solid metal scoop and a two-piece handle that clicks together to form a sturdy shovel. When not in use, the shovel breaks down into three pieces, which can be tucked neatly under a car seat or in the back.
This is the favored tire gauge of all the professionals we interviewed. After our testing, which included road-tripping with the tool ourselves, the Accu-Gage has emerged as our favorite tire gauge for several years running.
The Accu-Gage is available in several different configurations , but the performance is largely the same. We prefer a version with a hose attached and a straight chuck, because that design makes it easier to hold the gauge and check the tire pressure at the same time.
The version we tested even comes with a removable rubber bumper in case you drop it. A digital display is more precise than analog, but the pros we interviewed all use analog gauges.
If you prefer digital, get the Accutire MSB. The digital readout is easier to decipher than an analog dial though it rounds to the nearest 0. But you do need to factor in the periodic cost of two watch batteries ; according to owner reviews , they need replacing every six months.
Magazine reviewers say digital gauges are more precise than analog dial gauges—often showing one or two decimal points—but the professional mechanics we talked to all use analogs.
This model can start larger V8 engines, and it has effective safety features and sturdy clamps. They can also recharge your phone, tablet, and other devices in a pinch.
After researching 40 portable, lithium ion jump starters and testing 12 models, we recommend the PowerAll Deluxe PBJSR , which is our runner-up pick.
As of March , our top pick, the Weego Jump Starter 22s, appears to be discontinued. The redesigned model is the Jump Starter 44s , and we plan to compare it to its predecessor sometime soon. In our first round of testing, the PowerAll Deluxe had no problem starting our dead year-old Jeep Wrangler with a 4. It provided amps to boost our battery, in line with the best of the jump starters we tested.
The PowerAll Deluxe also performed well in our tests with the larger 5. When we connected the PowerAll Deluxe and hit the ignition, it delivered a little over amps, and the truck growled to life. Of the five jump starters we tested on that truck, it was one of only three that managed to revive it the other two models have since been discontinued or redesigned.
When you start your car, the starter motor pulls a lot of power from your car battery for a short amount of time. Once the internal combustion engine turns over, it sends power back to the depleted battery via the alternator. Aside from buying a new battery, generally you have two solutions to choose from. The first and arguably better option is to attach your battery to a trickle charger, which will safely and slowly charge your battery back up, typically over 12 hours or more.
A portable jump starter is also easier to use than traditional jumper cables. And if you hook it up incorrectly, the Weego safety features, like reverse protection and audible alarms and warning lights, will protect both you and your car.
The clamps are sturdier than those on most other models, and they make a solid connection to a variety of battery-post shapes and sizes. The battery pack and clamps fit in a handy carrying bag, which you can easily stow under your seat or in your glove box until you need it. This cable is long and durable enough for any situation, with a current rating that can handle SUVs.
As this image illustrates, these cables are long and thick enough for most situations, and their amp current rating means they can handle most vehicles even trucks and SUVs.
They also come with a surprisingly sturdy and convenient mesh storage bag. One thing that sets the AAA cables apart from other cables we found on Amazon is that the 6-gauge description is accurate. For example, Capri sells a 4-gauge, foot cable that reviewers say is closer to 8-gauge.
But lest you forget, AAA includes a handy diagram in the bag. The important thing to keep in mind: Do not attach the black clamp to the black post of the dead battery. Instead, clamp it to an unpainted metal surface under the hood. The Petzl emits bright light with the highest beam quality. This is the perfect headlamp for backpacking trips. Its lumen light is the brightest of all our picks.
Twice during our trip we pulled into our camping site late, and our headlamp was the first thing we reached for. Right out of the box, the Petzl Actik Core was easy to use.
It has just one button and three brightness options: low 6 lumens , medium lumens , and high lumens. If you hold down the button for several seconds, the color turns to red; double-clicking lets you access the Strobe setting. Compared with some other rechargeable headlamps, which require complicated clicking configurations to get to the desired setting, we found this one to be simpler, though we lamented its lack of a flood beam. Crushproof and waterproof, this set of three beacons comes with magnets for car mounting.
And these are much safer than traditional flares. We like the StonePoint set because, for the price of one high-intensity model like the PowerFlare , you get three separate lights that are all crushproof to 20, pounds, waterproof, magnetic, and easy to set up and turn on. The magnets are important because they let you mount the beacons on your car, which adds height; having a flare anywhere above the surface of the road greatly increases your visibility.
Traditional magnesium flares will almost always be brighter and more visible. But their hazards—both to your health and to the environment around you—are substantial read the health and environmental hazards section PDF for a breakdown of the risks and the potentially harmful chemicals involved.
Combine that with the fact that you can mitigate any differences in visibility simply by elevating an electric flare, and you end up with a compelling argument against using traditional flares. And the Smittybilt U. Only the StonePoint beacons were easy to fill with batteries and get onto the road exactly when we needed them. They also happened to be the brightest flare alternatives we had with us.
I should take a moment here and repeat what the responding officer told us when he arrived on the scene. No emergency kit is complete without a multi-tool.
Most minor situations—such as a loose Phillips-head screw or needing to create a rag for checking your oil—are easily fixed as long as you have the right tool. Multi-tools are small enough to carry in a jeans pocket or to attach to a belt, so you can take a set of useful tools almost anywhere. The Skeletool stood out from the other 19 multi-tools we tested because it focuses on the functionality, ergonomics, and solid construction of a few essential tools, instead of cramming dozens of different tools into a single bulky body that makes it difficult to use.
This tape is super-strong and sticky, flexible enough to wrap around corners, and easy to tear in a clean, straight line.
We tested the hell out of 10 rolls of duct tape and chose Duck Max Strength above the competition for its perfect blend of attributes: high material strength, a strong adhesive, and superior overall flexibility for easy wrapping around odd shapes and curved surfaces. Is it an absolute necessity on the road? Duct tape is, as any MacGyver fan will tell you, a very useful tool.
This water jug holds enough water for two people for two days, and it has a spill-proof screw-on vent cap. The general rule for water in an emergency is that one person needs one gallon of water for one day.
Four to five gallons is a good amount to throw into your trunk—enough to get you through being stranded, even with a passenger. You should increase that estimate if you plan to go out in the middle of nowhere, or if your travels take you to a desert region or some other dry place. We found on our trip through the Southwest that we were refilling our water bottles a lot more than we were stopping for gas. After researching 16 different types of water jugs, we recommend the Reliance 4-Gallon Aqua-Tainer for most situations.
The Reliance has two standout features: a screw-on vent cap and a spigot cap that reverses in on itself when not in use. These features work together to prevent major spills.
Spigot caps can be a weakness for some jugs, too. We used the 4-Gallon Aqua-Tainer on our road trip. It can provide water for two people for two days, but for more people, consider the 7-Gallon Aqua-Tainer. A pack of Poland Spring is not environmentally kind, but it is safe for a brief trip. Such jugs also have caps that pop off easily. It takes only a few minutes to get your vehicle checked out for a proper road trip. When in doubt or when preparing for a really long trip , see a mechanic first.
Use these tips to determine—based on the age of your car and what you need done—where to go for help. Getting word-of-mouth advice from family and friends remains a very good way to find reputable mechanics. Sites such as RepairPal and Yelp are also helpful.
Kit Dillon is a senior staff writer at Wirecutter. He was previously an app developer, oil derrick inspector, public-radio archivist, and sandwich shop owner. When called on, he can still make a mean sandwich. We spend a lot of time driving each year, and this is our list of essential road-trip gear to include in your packing list. The women of Wirecutter drew on our experience—many of us log thousands of miles a year—to create a packing list to help you truly enjoy flying solo.
Our photo and travel teams have spent thousands of hours testing the must-haves and the nice-but-not-necessities for documenting your next adventure. You don't have to be a digital nomad to travel like one. Here are a few gadgets and accessories to make travel as painless as possible. Stowing your gear. Cargo boxes. Our pick. Yakima Skybox 16 Carbonite The best cargo box Great aerodynamics, easy mounting and operation, and a lot of storage at a reasonable price.
Keeper Endless Loop Ratchet Tie-Down The best ratcheting straps Easier to use than non-ratcheting straps, these straps ensure that your stuff stays put. Also great. Thule Quick Loop Strap For smaller cars This strap offers a quick way to add load-stabilizing anchor points to a small car. Ratchet straps can apply a lot of force beyond just the weight of your belongings, so knowing your maximum load will help you avoid over-tensioning the straps. If the straps vibrate against the roof while you drive, adding a few twists in them can sometimes stop them from slicing the air.
Knots can cut through nylon with surprisingly little force. A knot will also significantly reduce the overall load your strap can handle.
Never use bungee cords to hold anything down. Smartphone mount. Rain-repellent coatings. Rain-X Original Glass Water Repellent Cheap but short-lived repellent This affordable hydrophobic spray offers effective protection, but it wears off after a couple of weeks.
Aquapel Glass Treatment Long-lasting but pricey repellent Aquapel bonds to your windshield for up to half a year, but it costs more than twice as much as Rain-X. Ice scraper and snow brush. Hopkins SubZero The best ice scraper and snow brush Efficient at clearing ice and sweeping snow, this scraper works on vehicles of all sizes. Paper road atlas. Buying Options Buy from Amazon. Health and cleaning supplies. Body wipes. Sea to Summit Wilderness Wipes The best body wipes Not quite a shower but pretty darn close, these wipes are amazing after a sweaty day in the desert.
Buy from Backcountry May be out of stock. Clorox Disinfecting Wipes The best disinfecting wipes Effective, EPA-approved, and usually easy to find, these pre-soaked wipes need only four minutes of contact time to neutralize the coronavirus. Enro Tech Mask Best balance of fit, comfort, filtration, and breathability The Enro Tech Mask, available in sizes XXS through XL, has a bendy nose-bridge wire and adjustable ear loops, and it should fit most faces well.
Happy Masks Pro High filtration, generous clearance This mask tents up over the nose and mouth more than any other one we tested. Proper Cloth The Everyday Mask Lots of choices, with a puffed-up silhouette This stylish mask has good clearance off the nose and mouth and—thanks to a sewn-in filter—decent filtration efficiency. Graf Lantz Zenbu Organic Cotton Face Mask with filter Best balance of fit, comfort, filtration, and breathability With the sold-separately filter stuffed in its pocket, this mask with adjustable ear loops fit all of our testers and struck the best balance of filtration and breathability in independent lab testing.
Staying comfortable. Sea to Summit Silk Stretch Mummy Liner The best sleeping bag liner This liner is a lightweight, moisture-wicking, easy-packing fix for scratchy motel sheets.
Rumpl Down Puffy The best outdoor blanket This blanket offers the greatest warmth and durability for the lowest relative weight, price, and size. Windshield protector and sun shade. WeatherTech SunShade A custom-fitted, maximum-protection shade This custom-fitted shade will ensure no sun gets in, even in the sunniest climates.
Buying Options Buy from WeatherTech. Tolerance can be increased by continual exposure to high altitudes and varies with the level of the hemoglobin and the oxygen carrying capacity of the blood.
It is decreased by fatigue, cold and poor physical conditioning. Even at 5, ft. Hypoxic hypoxia is due to a decrease in the oxygen available to the body such as typically occurs with altitude. Hypemic hypoxia is caused by a reduction in the oxygen carrying capacity of the blood for any reason. It also occurs when hemoglobin is saturated by gases for which it has a higher affinity, the most common of which is carbon monoxide. This is not only produced by exhaust leaks into the cockpit but also by cigarette smoking.
Stagnant hypoxia is a less common problem caused by a reduction in total cardiac output, pooling of the blood or restriction of blood flow. Heart failure, shock, continuous positive pressure breathing and Gforces in flight can create stagnant hypoxia. Local stagnant hypoxia can occur with tight and restrictive clothing or, in the cerebral circulation, in association with vasoconstriction due to respiratory alkalosis provoked by hyperventilation.
Histotoxic hypoxia refers to poisoning of the respiratory cytochrome system by chemicals such as cyanide or carbon monoxide but it can also be caused by the effects of alcohol. Needless to say a pilot in poor physical condition, recovering from a hangover and smoking while in flight can quickly become an unfortunate statistic!
In the seated position the lungs, due to the pull of gravity, are stretched at the apices and condensed at the bases. At the same time, the blood supply is least at the apices and greatest at the bases.
Thus in the area where the alveolar ventilation is best, perfusion is least and at the bases the opposite is true. Only in the mid section of the lung is there an ideal ventilation - perfusion ratio.
Under positive G, the situation is exaggerated and if it is of long duration in crews breathing oxygen, rapid absorption from the alveoli tends to cause basilar atelectasis. Hyperventilation may be described as a respiratory rate excessive for the body's oxygen requirements. It may be voluntary or involuntary and can occur in relation to many different activities.
In the pilot the most common precipitating causes are anxiety, fear, excessive concentration on a flight procedure and as a reaction to pain or illness.
Hyperventilation may be obvious, as in the case of children preparing to compete in underwater swimming, or it may be covert as for example when the respiratory rate increases from a required 12 per minute to an excessive 15 per minute and remains elevated for a prolonged time. Whatever the cause the results are the same. Carbon dioxide, the most potent stimulus to respiration, is blown off in excessive amounts.
The PACO2 falls and respiratory alkalosis develops. The cerebral vessels become constricted and subjectively the pilot often notices a feeling of dizziness, a coldness and tingling around the lips and a feeling as though there was a band around the head. Nausea may be present. Peripherally there is vasodilatation and stimulation of sensory nerves causing a sensation of pins and needles in the hands and in the feet.
If hyperventilation continues carpopedal spasm develops and the subject may become unconscious and develop frank tetany. With the breath held the carbon dioxide levels build up once more and the symptoms disappear in reverse order.
Obviously such a chain of events can lead to an accident. This has been documented in some incidents in young fighter pilots or untrained private pilots who have inadvertently flown into bad weather and have kept the microphone button depressed, broadcasting their breath patterns up to their final moment.
Hyperventilation is often suspected in unexplained accidents. If one considers the symptoms of hypoxia and hyperventilation it will be seen that they are very similar. Although it is usually in military pilots that problems arise with hypoxia at levels above 30, ft.
The Concorde, for example, cruises above 60, ft. Cabin pressurization in these aircraft ensures that the partial pressure of oxygen is adequate and it is rare for the cabin pressure to be above 7, ft. See Fig. However, it is wise to remember that passengers with chronic lung diseases or serious anemia, particularly those who are smokers, may be significantly hypoxic even at this altitude.
More dangerous however is the situation which develops when cabin pressure suddenly fails, usually due to the loss of a window or door. The result is rapid decompression with a sudden increase in the cabin altitude to match the ambient altitude. In aircraft such as the Concorde the windows have been made particularly small to lessen this effect but in older aircraft more serious problems have occurred.
The immediate effect of decompression is a loud noise, condensation of water vapour causing a mist and a shower of dust and small particles. The temperature falls dramatically. The resultant cabin pressure may actually fall below that of the ambient pressure due to "aerodynamic suck". This refers to the Venturi effect created by the speed of the aircraft through the air. The initial hazard to aircraft safety is hypoxia. The crew are unlikely to be wearing oxygen masks at the time of the incident and, if the final cabin altitude is high, the time of useful consciousness may be very short see Figure 8.
It may actually be lower than would be anticipated because of the sudden escape of expanding gas from the lungs due to the reduced ambient pressure. This causes reversal of the oxygen diffusion gradient across the alveolar membrane and oxygen passes back into the lung from the blood.
At 35, ft. Airlines make provision for this eventually by providing pilots with "quick-donning" oxygen masks, which can be donned in 5 seconds or less. At sea level this is - 47 x 0.
The respiratory quotient R on a pure carbohydrate diet is 1. On a balanced diet of carbohydrate, protein and fat, R is generally about 0. We have already commented on the decrease in atmospheric pressure which occurs with altitude. Boyle's Law states that, at constant temperature, the volume of a gas varies inversely with the pressure.
If the pressure of gas is halved, its volume is doubled. Application of this simple law to the closed body cavities quickly indicates where problems are likely to occur. By far the most common problems are with the middle ear. It resembles a box, closed by a flexible diaphram at one end and drained by the Eustachian tube narrow tube at the other.
The eustachian tube however is not rigid or symmetrical throughout its length and becomes slit-like at its outlet in the nasopharnyx. On ascent expanding trapped air usually escapes easily and the only thing noticed is a periodic "popping" due to movements of the drum as pressure equalizes.
On descent however equalization of pressure through the slit-like outlet is much more difficult and a negative pressure can build up in the middle ear. This leads to a decrease in hearing and to pain. The ear can be cleared by opening and closing the mouth, thus activating the tensor tympani muscle and dilating the tube, or by inflation by a Valsalva maneuver. In an U. The pressure in the middle ear on descent may then become so low relative to the outside pressure that exudation and hemorrhage may take place and ultimately the eardrum may burst.
Excessive valsalva maneuvers however may force bacteria into the middle ear, leading to infection. When an ear blocks and cannot be cleared by the usual maneuvers, the best way to deal with the situation is to reascend and start a slower descent.
This is not always possible. During World War II the pilots of vertical diving Stukas had constant ear problems and their flight surgeons solved these by periodically incising the drums! Nowadays this is not recommended! A particular problem occurs when pilots flying at high altitude on oxygen retire to sleep soon after landing.
The middle ear is full of soluble oxygen rather than inert introgen which is absorbed during sleep. On awakening they have earache due to the indrawn drums.
This is called "oxygen ear". Other air spaces are equally affected. The nasal sinuses are a common source of pain as may be poorly filled teeth if the filling has not been carefully inserted and a gas space remains below it. These various symptoms are referred to as "barotraumas" and toothache of this type is known as "barodontalgia". The best approach to these conditions is knowledge and prevention. Fortunately most professional pilots are well aware of the problems and avoid flying when they are congested.
A common irritating, embarrassing and potentially serious problem is gas in the bowel. This expands rapidly as might be expected and, if it cannot be passed, may lead to severe pain. Chewing gum, air swallowing, carbonated drinks and beer in the passenger all add to the gas, as do various gas producing foods.
Passengers with ostomy bags or various types of bowel obstruction are particularly likely to have problems. Boyle's Law must be kept in mind if you are involved in the transport by air of patients requiring cuffed tubes of any type or if casts or pneumatic dressings are being used. Cuffs should be inflated with saline or water rather than air before the trip.
The "Bends" or "Caisson disease" has been recognized since in association with "hard hat" divers or men working under pressurized conditions. By the end of WWI the possibility of decompression sickness in aviators was predicted and once high altitude balloon flights were undertaken the prediction was fulfilled. The cause of decompression sickness is the formation of gas bubbles in the body and the physical law was described by Henry. Henry's Law states that the quantity of gas that goes into solution at a given temperature is dependent upon its solubility characteristics and is proportional to the partial pressure of that gas over the surface of the liquid.
Hence as the pressure falls, the amount of gas which can be held in solution is reduced. The dominant gas in the atmosphere we breathe is nitrogen. It is inert and the body is saturated with it at ground level. During rapid ascent the reduction of barometric pressure creates a condition whereby the inert gas tension in the tissues is greater than the external barometric pressure.
This condition is called super-saturation. At this point, in association with bubble nuclei produced by muscle shear forces or turbulent blood flow, bubbles of nitrogen can be formed in the tissues and in the body fluids. It is these bubbles which give rise to decompression sickness. The symptoms of decompression sickness are described as the four "C's". These are Creeps, Cramps, Chokes and Collapse". This "formication" is believed to be caused by the formation of tiny bubbles.
Smaller joints may be affected and it is not uncommon to first notice the symptoms in joints which have previously been injured. The pain is deep and aching in character and varies from mild to severe.
It is made worse by movement of the joints and is sometimes improved by pressure on the area. It is a much more serious disorder caused by multiple pulmonary gas emboli. The subject complains of substernal chest pain, dyspnea and a dry, non-productive cough. If altitude is maintained "Collapse" will inevitably occur. The treatment is immediate descent which is generally effective. Neurological decompression sickness is the most dangerous form and often has a very serious prognosis.
It may be responsible for permanent neurological deficits particularly if hyperbaric treatment is not immediately available. In the aviator brain injuries, although uncommon, are most frequent. In divers the spinal cord type is most frequent. The reason for this variance is not known.
In the brain type visual disturbances scotoma, tunnel vision, diplopia etc. Physical signs are spotty and diffuse, both motor and sensory. The signs may be thought to be hysterical but collapse may occur. In the spinal cord the most common onset is of numbness or paraesthesia in the feet. A complete transverse spinal cord lesion may occur as bubbles obstruct the blood supply and infarct the cord. Fortunately serious decompression sickness is uncommon in commercial aviation. Generally the altitude threshold is above 18, ft.
Above 26, ft. It is much more often seen therefore in high altitude military pilots whose cockpit pressurization profiles are lower than those in commercial aircraft. There are various factors which affect it. The incidence increases with age, there being a threefold increase between the year old and the year old age groups. Nitrogen is well dissolved in fat, so obesity is a factor. It is probably more common in women than men. It is more common with exercise at altitude, with rapid ascents, with re-exposure to altitude at frequent intervals and at low temperatures.
The after effects of alcohol and intercurrent infection both increase the susceptibility. It is important to keep in mind the relationship between SCUBA diving and decompression sickness in aviators. SCUBA divers use compressed air in their tanks and are often exposed to two or more atmospheres of pressure, supersaturating the tissues. If they fly within twelve hours of emerging from diving at standard depths, decompression sickness has been recorded at altitudes as low as 10, ft.
Where they have been diving at depths which require decompression stops on the way to the surface, they should not fly for a minimum of 48 hours.
Although serious problems are uncommon, it is necessary to be aware of the danger to recognize it, particularly with neurological symptoms. Occasionally a medical emergency results when a diver ascends to the surface too rapidly, causing a bubble formation. In such cases the diver must be reexposed to a greater pressure as quickly as possible and then brought back to the surface. Sometimes the diver is too ill to undertake another dive and must be transported to a hyperbaric chamber for treatment as quickly as possible.
Pilots transporting such individuals should be cautioned that increases in altitude will worsen the patient's condition. If pressurized aircraft are not available, flights should be made at the lowest safe altitude. Recompression treatment tables are outlined in textbooks of Diving medicine.
Doctors often feel that an understanding of acceleration G and the effects of gravity g are only of importance to aerobatic or high performance aircraft pilots. This is a mistake. Because we are normally terrestrial creatures, bonding to the earth has taught us that gravity exerts a downward pull.
In an aircraft however, G-forces are often upward or outward and as they are associated with changes in both acceleration and direction, what is experienced is a resultant force. It is these forces and their effects on the vestibular organs which give rise to our recognition of position in space. In the review of orientation the importance of this will be explained. Speed is the rate of movement of a body while velocity is a vectorial quantity made up of both speed and direction.
Acceleration G is a change in velocity either in direction or in magnitude. It is described in three axes in relation to the body, x, y and z. Considerable confusion can arise if a clear distinction is not made between the applied acceleration and the resultant inertial force as these, by definition, always act in diametrically opposite directions.
The physiological effects of G vary with its magnitude, duration and axis of application and are modified by the area over which it is applied and the site. Tolerance to acceleration varies from day to day and is modified by body build, muscular tone and experience.
It is decreased by poor health or conditioning, fatigue, hypoxia and alcohol. It can be increased by continued exposure and education. Pilots exposed to heavy G loads soon learn to use a modified Valsalva manoeuvre with controlled breathing and muscle contraction to increase their tolerance the M1 manoeuvre.
G-suits mechanically increase resistance to positive Gz by exerting pressure on the lower limbs and the abdomen to prevent pooling of blood. Unfortunately there is no mechanical device to counteract negative Gz. Positive Gz forces the pilot into the seat, draining the blood towards the lower part of the body.
A lb. This interferes with muscular movement, aircraft control and the ability to change position or to escape in an emergency. As G comes on and blood is drained from the head, the first symptom is visual. This leads to "grey-out", a condition in which peripheral vision is progressively lost and central vision begins to lose its acuity. As the G load increases the retinal arterial flow is further reduced until "black-out" occurs.
At this point, although vision is absent, the cerebral blood flow is often maintained and the pilot may remain conscious. At G however most pilots become unconscious unless they are protected. This is referred to as G-LOC. G-Loss of consciousness. When the G load is reduced, consciousness will be regained although there is often a brief period of confusion before full awareness is reached.
This has been determined as the cause of several accidents in high performance aircraft. Negative Gz, acting from the foot to the head, is poorly tolerated by the body and in most cases the threshold is below -5 Gz. As might be expected the visual symptom is "red-out" as blood is forced towards the head and into the retinal arterioles.
Excessive -Gz leads to hemorrhages into the conjunctiva and ultimately into the brain. A special form of G is known as "jolt". Jolt is the rate of change of acceleration. It is descriptively used in relation to short, sharp accelerations. This type of shock can give rise to serious spinal injuries and must be minimized in the design of ejection seats.
Brief alternating positive and negative Gz forces are experienced in turbulence and may be a serious problem when flying light aircraft in hot weather or flying high speed aircraft at low levels. G-forces not only interfere with precise flying but are also a potent source of fatigue. Tolerance to transverse G Gx is much higher.
It is for this reason that the astronauts in the early vehicles were placed in a recumbent position during lift-off. Gy is not of great enough amplitude to cause problems in consciousness and is not a problem with modern day aircraft. At present, head restraint is the only problem experienced with Gy. To the earth bound individual, orientation means being aware of one's body position relative to the earth.
Gravity acts towards the centre of the earth and is recognized as down. The aviator however lives in a different world, a world in which proprioceptive senses may give rise to false information. At the top of a loop for example, where centrifugal force replaces gravity, down appears to be up and up appears to be down!
Disorientation, in the pilot's sense, sometimes described as "vertigo" is to be unable to locate oneself in space and can be one of the most terrifying and lethal of experiences. We orient ourselves by vision, the vestibular system and by proprioceptive nerve data. The mental images of orientation that we derive from these impulses are learned from birth and relate to our terrestrial habitat. So strong are these sensations that it is possible to produce nausea by placing us in an environment where what we see is different to what we feel.
This is the theoretical basis of motion sickness and will be described later. Vision is the strongest orienting sense, and the one to which we turn when other senses fail.
It is functionally divided into two parts. One, employing central foveal vision and sharp focus, is concerned with object recognition and is used together with learned conditioned reflexes in instrument flight.
The other, ambient orientation, is peripheral, less acute and is directly connected to vestibular function. That the two parts of vision are independent can be observed in a driver who reads a map and follows the road at the same time. Although we can orient ourselves and function normally when the vestibular apparatus is absent or ablated, without vision orientation is much more difficult.
However vision can also give rise to illusions both of location and of movement. The vestibular system has three functions. It acts to stabilize vision via the oculo-vestibular reflexes, to orient the body in relation to movement in the environment and to give a perception of motion.
These functions are performed by two 1. Each vestibule see Fig. Each canal lies in a separate plane of space: one is horizontal, one vertical and one lateral. The canals sense angular accelerations in the planes of yaw, pitch and roll respectively. They are connected at each end to the utricle, a dilated central area in which are the ampullae.
In the ampullae delicate hair cells topped by a gelatinous cupola project into the endolymph and move with it like river bottom plants in a current. The utricle is connected to the saccule and in the floor of these chambers are the macula sacculi.
The macula in the utricle lies in the horizontal plane and that in the saccule lies in the vertical plane. The maculae consist of hair cells projecting into the endolymph and covered by a gelatinous membrane containing tiny calcium carbonate crystals. They are referred to as otoliths and act as linear accelerometers. The vestibular apparatus has connections to the visual cortex, to the innervation of the extra-ocular muscles and to the vestibular nuclei in the cerebrum.
Try holding your hand up in front of your face and then moving it from side to side. The movement does not have to be fast before focused vision of the fingers is lost.
Holding the hand still however and moving the head from side to side allows sharp focus to be maintained at much greater rates. Occulovestibular reflexes make this possible.
Proprioception is of only secondary importance to vision on the ground, but is much less reliable in the air. While flying, centripetal and centrifugal forces compete with gravity and proprioception may be confused.
Although proprioception enables the pilot to stabilize his body in the cockpit and gives valuable clues to changing directions and attitudes in visual flying conditions, in instrument conditions "flying by the seat of the pants" can rapidly become lethal. All crashed within seconds! These may be foveal or vectional, that is concerned with central vision or orientation vision. The former type is often associated with landing approaches and is most common where visual clues are reduced or unfamiliar.
Apilot approaching an unfamiliar runway with a minor uphill slope, for example, may feel that he is too high and may fall below the normal glide slope.
If the fields runs down hill, he may land long. Pilots inexperienced in the Arctic may miscalculate their height on final approach because the trees they use for unconscious reference are shorter than trees in the South. Landing in "whiteout" conditions, where the ground and horizon are obscured, or landing on a smooth, reflective lake makes judgement of height extremely difficult.
Particular problems may occur at night when approaching a lighted runway in an otherwise featureless area if in the distance there is a well lit town at a higher elevation. The eye, in the absence of other clues, tends to place the two lighted areas on the same elevation which may lead to premature ground contact. There is a special problem at night with small light sources, such as stars or distant ground lights. When watched intently they will appear to move and may be mistaken for other aircraft.
This movement of stationary objects is known as autokinesis and has been responsible for accidents. Where the light source is bright or large this illusion is uncommon. The commonest type of vectional movement illusion is that experienced sitting in a car at a traffic light when the adjoining car creeps forward.
This causes a sensation of backward movement and often reflex braking. In the rotational plane similar illusions occur. In a darknened chamber where light from a rotating source is reflected on the walls, the movement of the light on the walls is soon replaced by a sensation of body rotation, the walls appearing fixed. Other problems are confusion between ground lights and the stars when flying over prairie areas or pilots orienting the aircraft to sloping cloud decks or to the Northern Lights rather than to the true horizon.
These may arise from the otoliths, the semicircular canals or from a combination of the two. They are among the most serious of the illusions and the most likely to cause lethal accidents.
At rest or in constant motion gravity is the only force acting on the otolithic membrane. We are used to interpreting gravity as a force pointing to the centre of the earth and, when our plane of movement is changed, falsely interpret sensations according to this precept.
A pilot accelerating down the runway and rotating to lift-off is exposed to an acceleration which pushes him back in the seat, together with the force of gravity acting downwards. The resultant is interpreted as a single force acting upwards and backwards.
Because the brain interprets the force of gravity as being vertical, the sensation is of pitch-up and the pilot may instinctively make a forward stick movement for control.
This can complicate the situation because causing negative G stimulates an oculo-vestibular reflex movement of the eyes which gives rise to the sensation that the instrument panel is moving upwards, heightening the illusion. This is the known as the oculogravic illusion. With deceleration, such as that experienced on descent when the flaps are deployed, a pitch down sensation may be felt. These sensations are normal and of no great importance if the pilot is experienced or visual flight is maintained.
At night however, particularly taking off from a lighted runway into a dark featureless area, and accident can occur due to inappropriate control movements performed in the transition from visual to instrument flight. Even an experienced pilot can take as long as 7 seconds to adjust. A common form of disorientation is a sensation of incorrect rotation or absence of rotation caused by the semicircular canals.
The cupola in its neutral position is upright. When the head rotates, the bony canals move but there is inertia in the endolymph. The cupola is therefore deflected leading to a sensation of rotation. Our sensitivity to rotation however is not perfect and can be diminished by any form of distraction. Rotation in the vertical axis of per second may not be perceived.
If a pilot, flying straight and level, gradually drops the left wing by 15 degrees whilst otherwise occupied and suddenly becomes aware from the instruments of this attitude and corrects it at a much faster rate, only the correction will be sensed.
The pilot then feels as though the aircraft has rolled 15 degrees towards the right and will lean towards the left to maintain balance. This is called "the leans" and is extremely common.
A different problem arises with prolonged turns at a constant rate, such as those encountered in a holding pattern at a busy airport. On entering a turn the cupola is deflected by the inertia of the endolymph see Fig. As the turn continues the endolymph will begin to move until it is in equilibrium with the bony canal and at this point the cupola will return to its central position.
Depending on the steepness of the turn this may occur in seconds. When the turn is terminated the bony canal will cease to rotate immediately but the endolymph, due to inertia, will continue to swirl thus moving the cupola in the opposite direction.
This gives rise to the impression that a turn in the opposite direction has been entered and the tendency will be to correct this and so to reenter the original turn. Although this is a minor distraction under most circumstances, in instrument meterological conditions it can be extremely serious and lead to a "graveyard spiral". Here the inexperienced pilot, having inadvertently entered a steep descending turn under instrument conditions, makes the correct stick movements to control the aircraft but experiencing the sensation of entering a turn in the other direction may re-enter the spiral.
As the aircraft is also descending, pulling back on the stick to stop the loss of altitude, although giving rise to a comforting feeling of gravitational pull in the seat, actually steepens the spiral, ultimately driving the aircraft into the ground.
The most extreme form of vestibular disorientation is due to the Coreolis phenomenon. This is thought to be caused when two different semi-circular canals are stimulated at the same time. As an example, a pilot taking off from an airport in instrument conditions, banks towards the left while climbing. So far there is stimulation of the otolith and of one canal.
In order to reach a switch or see a gauge however the pilot turns the head quickly downwards and towards the right. Two different canals have now been stimulated and, as all are connected, a movement of endolymph takes place in the third canal. The result is a sensation of tumbling which may be extreme and worsened by visual problems due to oculo-vestibular reflexes. Even if control of the aircraft can be maintained under these very trying circumstances, the pilot may still be subject to the leans or other abnormal sensations until able to obtain a visual reference.
Distinction is sometimes made between two different type of disorientation. Type I is unrecognized and Type II recognized. Obviously a Type I illusion is more likely to lead to an accident or incident.
Illusions are also divided into oculo-gyral somatogyral or oculogravic somato-gravic. An oculogyral illusion is defined as the apparent movement of an object in the visual field resulting from stimulation of the semi-circular canals by angular acceleration. An oculo-gravic illusion is the false perception of tilt induced by stimulation of the otolith by linear accelerations. The terms somato-gyral and somatogravic refer to the resulting body sensations.
The relationship between this condition and orientation is striking. The causes of motion sickness are both visual and mechanical, the latter arising from stimulation of the vestibular system. Animals in whom the vestibular system has been ablated or people born with non-functioning labryinths cannot be made motion sick. The cause of motion sickness has never been completely clarified but it is felt that it results from sensory conflicts, the difference between what is seen or felt and previous orientational experience.
Motion sickness, for example, can occur in aircraft simulators and is more common amongst pilots experienced on the type of aircraft being simulated than it is in an inexperienced crew.
Motion sickness increases in frequency up to puberty and then decreases. Women are more subject than men and it is more common in passengers than in aircrew. Motion sickness may be provoked by anxiety, fear or orientational insecurity. Unfortunately it can become a conditioned reflex. A trainee pilot, having been motion sick during flight, may become ill on the ground approaching an aircraft. It can be overcome by repeated exposure or adaptation and is rarely experienced by the person in charge of the aircraft or automobile who is aware, and braced for, changes in attitude or direction.
Up to one third of military flight trainees become air sick at some point in their training and about 1 in 5 suffer severe air sickness. Adaptation depends upon gradually increasing stimulation. In trainee pilots who develop severe problems, desensitization programs have been successfully employed.
Motion sickness can be much reduced by the use of Scopolamine and nowadays transcutaneous administration of this medication is used in sea sickness. The drug however creates drowsiness and cholinergic effects and is not suitable for pilots. Small doses of the drug may be used in the initial phases of training when an instructor is in the aircraft but this must be discontinued before solo flight is undertaken.
There is no place for prolonged drug therapy in aircrew. A continuing challenge for those involved in the aeromedical certification process is in making decisions which take into consideration both the rights of the individual and the safety of the public. This is not always an easy task.
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