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In- Flight EmergenciesDitchingPutting wings in the waterBy Thomas A. Horne (From AOPA Pilot, July 1999.)The subject of ditching is rarely mentioned in aviation texts or classroom sessions. That�s a real shortcoming, because all pilots should be familiar with ditching procedures. Perhaps the problem is that ditching (sometimes given the less-threatening, gentler-sounding "water landing" moniker) is too commonly thought to be an issue only in transoceanic flying. But that�s wrong. An engine failure or other serious problem can crop up over lakes, rivers, bays, or inlets just as easily as it can over dry land. In cases where setting down in rough terrain could make a forced landing�s outcome dubious, ditching in a nearby lake or other body of water may be a much better option. So knowing how to ditch ought to be right up there in priority along with standard, land-oriented forced landing procedures. The fact that ditchings can�t be practiced the way we practice for "regular" forced landings makes this all the more important. Also, being prepared for a successful ditching means that you have to understand some special rules. EquipmentBeing prepared for a ditching means having the right equipment. Life vests for each passenger are a must. A high-quality inflatable raft capable of safely carrying all occupants is another. If you�ll be flying over large, cold bodies of water, then you should seriously consider wearing an exposure suit. These suits are made of neoprene rubber and, except for their loose fit, resemble the dry suits used by scuba divers. They may be uncomfortable and clumsy to wear in the airplane, but they can mean the difference between life and death once you�re in cold water. They�ll also keep you afloat (obviating the need for a vest), and they�re fitted out with whistles and reflective tape. If you�re wearing an exposure suit and succeed in climbing into your raft, then your chance of succumbing to hypothermia is greatly reduced.Signalling is another important issue. It�s very difficult for rescuers to spot individual survivors in a large body of water, especially at night or if large waves are present. Signal mirrors, flare pistols, dye marker (also known as flourescein), portable strobe or other strong lights, and a handheld transceiver with a built-in GPS will help your chances of being found. A small crash axe (the kind with a weighted, pointy end) and a knife can also come in handy. With the axe, you can smash out any windows should a door jam and prevent a normal escape. The knife is good for cutting yourself loose from any entangling lines or safety belts. By the way, you do know how to use all this equipment, don�t you? Preparing to ditchOK, let�s say your engine has quit, and you face a ditching. Hopefully, you�ve been flying at the highest practical altitude, which means that you�ll have more time to make preparations as you glide to the water.Once establishing glide speed and performing the usual engine-failure checklist items, it�s time to make a radio call. Explain your circumstances (don�t forget to say that you�ll be ditching; this will ensure a swifter response from rescue services) and give your position. For this, it�s best to use the latitude and longitude coordinates from your GPS receiver. On the way down, secure any loose objects (actually, you should do this prior to any flight) and, if you aren�t already wearing it, don your life vest. If you�re wearing an exposure suit, make sure it�s on all the way. The usual practice is to wear it in the airplane, but only up to the waist. This leaves your hands and arms free. With practice, you can learn to wriggle your arms and head into the suit, then zip and snap it shut in a few minutes should the need arise. Then make sure you have all your signaling devices and your transceiver on your person. Photographer�s vests are good for this because they have many pockets. Seal the transceiver in a plastic bag. You should already have your raft somewhere near you in the front cockpit. If it isn�t, get it up there and put it within easy reach. Do not inflate any vests�or the raft�until you�re in the water. If the raft inflates in the cabin, you won�t be able to fly or exit the airplane. If for some reason the raft does inflate in the cabin, your only recourse is to deflate it with your knife. If you have a pillow or large bag of soft items, such as a duffel bag, then get it up front, too. Put it in front of your head just prior to ditching and it should help prevent head injuries. If you�re flying a retractable-gear airplane, make sure you leave the gear retracted for the ditching. Keep transmitting on the way down, and keep giving your position. If you haven�t already done so, give the number of souls aboard. Finally, make sure any passengers are also prepared to ditch. Make sure your safety belt is cinched up tight, and make sure the passengers� belts are on tight as well. Reassure them that help should be on its way quickly. While doing all this, try to keep your wits and get ready for the landing. Picking a spotWhere you touch down can have a huge bearing on the survivability of your ditching. If you�re ditching into a lake, then by all means try to land as close to shore as possible. If there�s a beach or shallow water, then aim for it. With luck, you�ll simply get out and walk to shore after the airplane comes to a stop.Wind and waves pose the greatest threats to pilots facing a ditching in the ocean or on large lakes. Obviously, high winds and their associated high waves and swell systems spell the greatest danger. If the surface winds are relatively light (say, 15 knots or less) the prime rule is to touch down parallel to any swells. In stronger winds, it�s recommended that you crab into the wind and try to land as parallel as possible to the main swells. This may mean flying a heading that�s split between the wind direction and the alignment of any primary or secondary swells. Whatever you do, follow the prime directives:
Those unfamiliar with low-altitude flight over waves and swells (that�s almost all of us) should know what to look for in determining wind and wave direction and velocity. The best way is to look at the wind streaks and whitecaps�if any�on the surface. Wind streaks look like strings of bubbles or foam, and they run up- and downwind. The foam on whitecaps falls forward with the wind, but it�s soon overrun by the waves that come hard on its heels. This can create the impression that the foam is moving backwards, and tempt the pilot into thinking that the wind is coming from the opposite direction. You can�t really determine the winds, waves, and swell systems until you�re at a very low altitude. Up high, the sea or lake may look uniform and undisturbed. But down low, you�ll have to learn to read the surface rather quickly�and then turn to the best heading and best spot that you can. As for the prospect of a night ditching, or a ditching in instrument meteorological conditions, well, good luck. That�s why many pilots won�t even consider a water crossing at night or on instruments in anything but a multiengine airplane. SplashdownAs you approach the water�s surface, pop open the cabin doors. Then wedge them open with whatever suitable objects may be at hand. This will help prevent the doors from becoming jammed shut by impact forces.Take up your ditching heading and look well ahead of your position to observe the sea surface. Make any final decisions about your touchdown spot (bearing in mind that your "ground roll" will be only a few hundred feet at best), then slow the airplane�s speed and descent rate as much as possible without sacrificing loss of control. Touch down too fast, and you�re likely to skip off the surface and plow under. Even if only a small amount of power is available, use it to flatten your approach profile and minimize your forward speed at the moment of impact. Perhaps the most difficult part of your splashdown will be estimating your altitude above the water. You can come close, but you�ll never know exactly when you�ll touch the surface. This is why you want a nice, shallow descent rate of no more than 100 to 200 fpm. This way, you�ll avoid dropping the airplane onto the water. There won�t be anything graceful about your "water landing." Once the airplane hits, you have no control over what the airplane does next. If luck is with you, the airplane stays upright and no one is injured to the point of incapacitation. If it isn�t, the airplane is hit by a wave and sinks immediately. But you can�t worry about outcomes at this point. Your focus should now shift to escaping from the airplane. Coping with chaosThere�s a lot to do in the moments after impact. First, you have to get the doors open. This may mean allowing some water into the cabin so that water pressure won�t hold the doors shut. Then you have to seize the raft and get yourself and your passengers out of the airplane. If the doors are jammed, you�ll have to bash out the windows before the airplane sinks. You have to make sure everybody inflates their vests once outside. You have to try to hold on to your signaling and other survival gear.This is tough enough when the airplane is level. If it�s upside down, disorientation can make it almost impossible. This is why Navy pilots are subjected to rides in something affectionately called the "Dumpster," which is a cockpit-like, enclosed contraption that shoots a pilot trainee into a swimming pool and then flips upside down. Divers wait underwater to help those pilots who become so confused that they can�t find their way to the surface. The goal is to acclimatize the pilot to the shock and confusion of being suddenly submerged in an unusual attitude, so that he knows how to escape should the real thing happen. We don�t have Dumpster practice, so the next best thing is to visualize ahead of time what your plan of action will be. Think it over, then say it out loud. This will help confirm the plan in your mind, reassure any passengers, and minimize panic. If all goes well, you�ll be right side up and floating for a few precious minutes. In cases like this, escape, raft inflation, and ingress to the raft are less risky. But if the airplane flips over�as so many high-wing airplanes are wont�or if you plow into the face of a wave, then you�re in Dumpster city and will have to undergo what kayakers call a "wet exit." Surviving this kind of scenario is much less likely, especially if the seas are high. By the way, don�t think that you�ve got it made just because everyone escaped and the raft is inflated. You have to tether the raft or it will float away faster than you can swim. Raft manufacturers say to attach a raft�s tether line to part of the airplane. But this advice is aimed primarily at airliners, which have specially designed tether fittings on their wings and doors. General aviation airplanes don�t have these luxuries, so you�ll have to wrap the line around a strut or some other suitable part of the airframe�if it�s still afloat. If it�s not, then you�ll have to inflate the raft and hold on to the tether line yourself. (You inflate the raft by yanking hard on the tether line, which can be 20-plus feet long.) What happens if you start out with your inflated raft tethered to the airplane, and then the airplane sinks? The tether line will shear off, and the raft will pop to the surface. Another issue is getting yourself and your passengers into the raft. With calm seas, warm water, and no injuries, it�s usually no problem. But if the opposite conditions prevail, then climbing aboard will prove to be a pivotal moment. Some rafts are self-ballasted and have built-in ladders, making them easier to enter. Without these features, it�s unlikely that you�d be able to haul yourself up and over the sides of the raft without flipping it over. Anyone in the market for a raft should insist on one with ballasting, ladders, and a high freeboard (the height of the raft�s "gunwales" above the water line). Expect to pay at least $1,000 for a good raft. Bottom lineUnfortunately, most ditchings are unsuccessful. Even with help close at hand, airplanes often skip once, then flip over or plow under before anyone aboard has a chance to escape. In a recent ditching northeast of Maui, Hawaii, a Cessna P210 pilot radioed that he was losing oil pressure and was going to ditch. A U.S. Coast Guard ship was in the area, and an officer reported that the airplane skipped off one swell, hit another, then nosed down. Although the airplane remained afloat for some 45 minutes, the airplane�s doors never opened, and the pilot never came out. A full accident report is pending.While that turn of events is depressingly familiar, there are those cases where ditchings turn out well. Preparing yourself mentally and carrying the right equipment remains the best�and only�way to prepare for the rare chance that you�ll have to perform a "water landing." That, or buy a float-equipped airplane. Additional information on ditching can be found on AOPA Online (www.aopa.org/pilot/links.shtml) and Equipped to Survive (www.equipped.com). Email the author at [email protected] Top
©1999. Posted Friday, June 18, 1999 9:35:23 AM
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