View Full Version : Ditching?
Flock1 3rd May 2004, 23:19 Hi all,
This is just a query.
Imagine if me and another person set out, in say a PA-28 type aircraft (i.e. with only one door/hatch), across a large stretch of water (perhaps the Irish Sea) and then the unimaginable happens - the engine conks out!
Okay then, because me and the passenger (who also happens to be a fellow PPL) are good pilots, we have been routing along a Class F advisory route, and we are both wearing (uninflated lifejackets.)
Whilst I (as P1) trim for 80 knots, and try to restart the engine (to no avail), my friend, makes the mayday call and then we prepare for the ditching.
We can see some ships below us, and also a couple of oilrigs, and so we head for them. As we approach the water, we try to look for the swell of the waves (as mentioned in the manuals) so that we can touch down on the crest of one.
And now we are only about twenty feet above the surface of the water.
So what would we do now?
Would the passenger unlatch the door and then sit and wait for the impact?
Or should he attempt to get out, and maybe climb onto the wing - which would leave me (as LHS pilot) more room and time to escape once we make contact with the water?
Would it be a good idea for my passenger (who is on the wing and gripping on hard with his by now inflated life jacket) to perhaps jump in the sea at the last moment?
Or would we both remain in the plane until we 'land'.
The only reason I'm asking all of this, is because my friend and I are planning such a trip in the near future, and we have talked about what we would both do.
Cheers in advance for any replies.
Flock1
Timothy 3rd May 2004, 23:50 It is imaginable. I have had loads of engine failures and a ditching (though, ironically, not as a result of an engine failure.)
There is no question that the passenger should remain in his seat, firmly strapped in, otherwise he might be killed in the impact, especially if you misjudge and hit the swell leading edge.
The question of popping the door is more difficult. We certainly had a heart-stopping moment as the aircraft sank when we thought that we were not going to be able to open the door, but we did get it open with the application of considerable force. That is an argument for popping it.
The argument against is that it will affect the flying characteristics of the aircraft, and the last moment just before you try to judge it perfectly onto the crest of the swell isn't when you want a sudden swing to the right, and increase in ROD or decrease in airspeed.
I would suggest that you make your mate "door monitor". It is his job to familiarise himself with the handles and be ready to open it the moment you touch down. This is particularly important in a high wing type, when the fuselage will be submerged immediately.
If you have an axe you should make sure it is to hand.
Or, if you are now sufficiently scared...go in a twin :}
Timothy
Timothy
It has been variously claimed that the average time between engine failures is 3000-10000 hours, so if you have had "loads" of failures you either must have tens of thousands of hours, or have been very unlucky.
What has caused all these engines to fail? Do you fly vintage aircraft?
Re the original question, I discussed this recently with a liferaft manufacturer. They agreed with my suggestion (which I base on watersports experience) that if the raft is in the water and you are not holding it, it will very likely float away due to wind faster than one can swim after it. So one must hold onto it. I would try to get the raft out onto the wing and inflate it there, then both people get into it.
Having had a door lock jam in a PA28 (on the ground) I would definitely try to pop the upper lock at least before the impact.
What does one do in a high-wing plane??
The statistics don't appear to favour low-wing planes, which is suprising.
DubTrub 4th May 2004, 00:33 Or should he attempt to get out
Err...have you ditched yet? If I were Mr Right Hand Seat, I should punch you on the nose for suggesting I get out before the aircraft smoothly collides with aqua firma.
Just my opinion, no offence intended.
DT
Timothy 4th May 2004, 00:48 It has been variously claimed that the average time between engine failures is 3000-10000 hours, so if you have had "loads" of failures you either must have tens of thousands of hours, or have been very unlucky.This is a route I have trodden in so many threads here and elsewhere that I really can't get up the energy to go through it again. I suggest that you search for my previous discussions on the subject.
The hightlights are seven failures in pistons, two in jets, most (but not all) have been in multi-engined aircraft. None have been "vintage" in the sense you mean. The ones in SEPs I have managed to either restart or limp/glide to a runway.
I have had far, far more engine failures than the average, and equally computers, cars and, above all, wrist watches all fail for me big time. I have been given physical and meta-physical explanations ranging from luck, karma, an intense aura, to high levels of static electricity to an ability to create a discontinuity in space/time, a talent which apparently I share with Yuri Geller...except he makes money out of the "skill" and I lose it every time anything breaks :(
Hey, pal, I don't know why engines and every other ****ing thing fails for me...I just know it's a pain. Go and talk to the guy who did the avionics refit in my Aztec and ask for an explanation as to why so much brand new kit failed within a month...or talk to the TBM700 pilot with wet shoes....or talk to the Citroen garage that has sepnt more in spares during my C5's waranty period than I spent on the car.
I just don't know the answer.
Timothy
radarcontrol 4th May 2004, 00:54 If I were you, I'd stay on the ground, sounds like fate has it in for you.
Timothy 4th May 2004, 01:04 If I were you, I'd stay on the ground, sounds like fate has it in for you.In broken down trains, cars or bicycles? :p
Oh, btw, I've also had two cockpit fires, two total electrical failures at night, two double radio failures in IMC...the list goes on and on...:(
yawningdog 4th May 2004, 01:16 What about marriages?
Timothy 4th May 2004, 01:29 What about marriages?One ended peacefully, the second continues noisily ;)
Every time someone quips I am going to come up with another example:
I lost my data projector in the Tay, so it was replaced. The first one failed (undramatically) in a presentation to 15 people on its third day. Its replacement exploded (yes, exploded, with a mushroom cloud) on its third or fourth day in a presentation to 20 people.
andyb79 4th May 2004, 01:42 timothy, i must thank you for making my day...... no wait year!
i thought i was unlucky, but dear god man you must of been really bad in a past life!;)
Timothy 4th May 2004, 01:48 Well, now we have moved on to past lives, read this (http://forums.flyer.co.uk/viewtopic.php?p=78205#78205) :sad:
Timothy is walking proof of the total unreliability of statistics in any real-world situation.
I've got a bit over 500 hours, one engine failure, several "two green lights" situations, one loud warning horn moment, and one total electrical failure.
I've flown with Timothy several times, and have been there for several "events" which have resulted in engineering effort on his aircraft before it flew again.
He's never flown with me, but then I fly a single and that's risky...
kokpit 4th May 2004, 04:30 Tim,
Brilliant, just bloody brilliant! :)
You have made my day seem much better, and I suspect, for others too.
Take care out there, it does look like something has it in for you.....
Conversly, something's also looking after you it seems. ;)
futurshox 4th May 2004, 07:21 Not as spectacular, but I have a friend who cannot wear a watch of any type or description, as they all invariably stop within a day of wearing. She often gives people electric shocks, even without actually touching them. Sounds like thee and she have something in common?
Timothy 4th May 2004, 08:47 Keef
D'you know, I'd forgotten I'd crashed an aeroplane with two greens till you reminded me? It's a sad thought that my history is such that I forget the odd crash here and there! :p
futurshox
Sounds electric! Tell her I'll be under the clock at Waterloo at 6.00pm Thu. No need to wear a carnation, we'll be the ones looking at the clock rather than our wrists.:}
kokpit
My engineer tells me just that. I'm beginning to believe him!
Maxflyer 4th May 2004, 09:56 Buy a lottery ticket your luck has got to change at some point.
I used to share a tack room with a friend and it was locked with a very expensive combination lock. Whenever I attempted to open it it remained locked. In the end we had to change it to the old fashioned key variety, but not before everyone else at the yard managed to open it except of course - Moi!
englishal 4th May 2004, 14:22 I wouldn't get your mate to jump out, unless you're after some life insurance money or something:D
I would try and find (or have ready before the flight) the frequency of the ops room on the rig. I dunno if they monitor 121.5, though I suspect they do. They could possibly pass wind and sea information to you if you had time, they also have fast rescue craft onboard so try and ditch near the rig if possible. You could always checkout weather buoys (http://www.buoyweather.com/wxnav.jsp?region=UK&program=Maps) before the flight to give an idea of what to expect if the worse happens.
I would crack the door open, incase the fusalage becomes distorted in the ditching. Better to have the door fly open that get stuck. The arguement could be that this will reduce the strength of the cockpit, but judging by the flimsiness of light aircraft, I don't think this will be an issue (give me a composite A/C with a 25g impact cockpit shell any day :D).....
EA
Timothy 4th May 2004, 16:03 They could possibly pass wind I've heard that of rig-workers.
Flock1 5th May 2004, 00:22 Thanks all,
So basically, we would both remain inside the aircraft, and then - just before landing - the passenger would unlatch the door.
Then we would vacate in an orderly manner!
Out of interest, how long would it take for the average light aircraft to sink? In other words, how long would we have to get out?
Gertrude the Wombat 5th May 2004, 00:32 how long would it take for the average light aircraft to sink? Should say that in the safety card for the passengers - it does in a Trislander!
DubTrub 5th May 2004, 00:55 how long would it take for the average light aircraft to sink?
Less time than you could imagine.
Flock1
On a PA28, I would definitely unlatch the top latch before the touchdown. (I think all PA28s have TWO door locks on the single door).
As for time to sink, what I've read suggests several minutes for a low-wing plane
englishal 5th May 2004, 10:49 Suppose it depends how much fuel you have onboard and how much damage you do in the process of ditching. Full tanks, with no leaks might lead to the aircraft partially submerging, but remaining afloat as fuel is lighter than water. Never done it so I can't really speak from experience.
Could always get an "air pocket" to go between the chambers of your life jacket if you're worried about not getting out. A small pouch which attaches to the life jacket, and in an energency, you rip the velcro, and pull out a mouthpiece and nose clip. Before you go under, you pull out the mouthpiece and inflate the bag (which also has a small air cylinder activated by hydrostatic pressure), and you can get up to five minutes of breathing under water. Used to carry them on North Sea helicopters, and they work really well (though never had to use it in Anger :D)
EA
englishal
I am not sure either would work.
Is there a plane whose empty tank volume is enough to float it? (i.e. empty tank volume in litres exceeds the empty weight in kg) That would be pretty amazing. I am sure every light plane will sink quickly, no matter what it is in the tanks.
On the other one, do you mean being able to breathe when the plane is submerged? If so, isn't that assuming a certain max water depth?
owenlars 5th May 2004, 18:20 Have a look at these links
http://www.avweb.com/news/safety/182976-1.html
http://www.avweb.com/news/safety/183010-1.html
englishal 5th May 2004, 18:23 Good point on the fuel tank weight. If 200l is the tank size, a maximum bouyancy of 200Kg could be expected I suppose......not much. Full fuel (if a s.g of 0.75) and you'd only have 50Kg of buoyancy.
The airpockets do work, and work well. I guess they wouldn't work very deep, though they work well at the bottom of a swimming pool:D As you initially breath out into the mouthpiece, it inflates an airbag which as you get deeper is pressurized by the water, so its not like using a snorkel. Plus the extra charge of air from a small (30g?) cannister gives you a bit more than a lungs volume in the bag, which is easily re-breathed for several minutes.
And they wouldn't impede an exit from a submerged aircraft, which is why the likes of Shell use them on their helos....
Cyer
EA
LowNSlow 5th May 2004, 18:58 Jodels float quite well being wood and all. A chap ditched off the Isle of Man a few years ago and the SAR bods found him sitting on his upturned aeroplane.
englishal
I think that the instant the aircraft is fully submerged, it will sink very rapidly (at several kt at least, and nose-down) all the way to the bottom. This is what happens with ships; I've seen a few documentaries on it (back when BBC2 used to have "intelligent" material :O )
So the objective must be to get out before that happens, unless one is sure of the depth. And even then, let's say the water is 40m deep, you have very little time down there before you can escape; I've done the BSAC scuba course and it is only a few mins before you get the bends after a straight ascent. IOW, I would be amazed to hear of anybody escaping after a plane has fully submerged, but it's possible.
The first of the two links posted by owenlars suggest that one can get out when submerged but that appears to be based on pool experiments. If escaping from a Cessna, one might well have to escape from a water-filled cockpit but one still needs to get out before the wings go under; after that it will sink rapidly. In the 2nd one, the pics of the ditched Cessna were taken shortly after it touched down, judging from the white area of the water. I bet they got out very quick.
LowNSlow
Would a Jodel float with the engine still attached, if full of water?
I suppose there is no reason why a plane's wings could not be foam-filled. It could make it buyoant, at the expense of not being able to inspect the spar :O
LowNSlow 5th May 2004, 20:40 IO540 the one in the picture did! It had flipped onto it's back upon hitting the water. I'd imagine this would have trapped a lot of air in the fuselage plus the wings are virtually air sacks. The Conti O-200 in the nose isn't all that heavy compared to some engines either
Would anyone be interested in a ditching course???
We ran one a few years ago, in the sea, of the Donegal cost,
Had great help from, Irish Air Corps, RNLI, Coast Guard, & Local diving club.
Very real & very cold,
Tony
I read an accident report a few years back where a double engine failure (caused by fully closing the wastegates of a naff RayJay turbo system and briefly attaining stratospheric power before jettisoning the molten cylinders down the exhaust pipes) ended in a frozen lake and sinking. The engineer - who was along for the ride - kicked the co-pilot's window clean out and they were able to escape. All the more amazing was the fact that this was a pressurized twin (might've been an old 340) with seriously beefy windows.
The body is capable of some amazing stuff when under duress dontchathink?
I'd have thought that some kind of pointed escape hammer would be useful for such an event.
An axe would be better; I don't think a car-style pointed hammer would do anything at all on polycarbonate.
LowNSlow 6th May 2004, 00:12 Having done the North Sea survival course (many moons ago) I would recommend it to anybody who thinks they don't need a survival suit in our (UK) coastal waters. The level of disorientation experienced when you go upside down and submerged has to be experienced to be believed. The cold that seeps into your bones very quickly (summer or winter) that dulls your reactions and thinking also has to be experienced to appreciate how quickly you are reduced to an automaton.
englishal 6th May 2004, 09:22 Good point. Assuming you survive the ditching (and statistics show that most ditchings are sucessful according to the NTSB), thats when your problems start.
I watched a video on a North Sea survival course of Duncan Goodhew and Sharon whatshername (Olympic swimmers) dumpped in a swimming pool at average UK water temps, and after 10 minutes they were both useless, and they are sh*t hot swimmers.I can vouch that the costal waters are still bloody cold, even in a 5mm wetsuit, the Channel Light Vessel is showing 10°C at the moment. There are some interesting graphs around showing survival time vs water temp, and its not very long at these temps.
EA
I am sure that without either a raft or a drysuit (or a wetsuit, but one isn't likely to be flying with one of those :O ) one would not survive for longer than an hour or two around here.
But... if you are in the water without a raft, how will they find you in a sea state other than calm, other than pure luck? Only your head/shoulders will stick out.
Unless I am missing something, I think a raft is very necessary.
Obviously one could get lucky and be seen by a boat or such.
Re the ditching course: I could be very wrong on this but I think the purpose of these "North Sea oil platform worker" ditching courses is to get out of a ditched helicopter which is upside down, but will not sink because it has floats; it just won't stay upright if the sea is too rough.
I am very sure that by the time a plane's cockpit is really filled with water (which for a non-pressurised aircraft means most of the water came in via the engine compartment and via the tail section which must also be full of water) the whole thing will sink rapidly to the bottom.
So one must get out very quickly. I am not suggesting a ditching course would be a waste of time; anything that brings people into rapid contact with cold water is worth doing - just that it isn't going to be representative of any survivable situation.
Having had the dubious pleasure of being "dunkered" every couple of years, plus wet winched at the same sort of periodicity, I can vouch for the fact that there is no substitute for doing it in the cold sea. I did dinghy drills every 6 months (IIRC) in a swimming pool, and it was far from realistic, in fact it often turned into a bit of a laugh.
One SurvO decided to make sea drills a bit more realistic, by dropping us about 5 or 6 miles offshore and leaving us alone for a while. All went well until the SAR diver did his usual dirty trick of turning the one man life rafts over unexpectedly, dumping us all back into the sea one by one. It was April, and the sea temp was around 9 deg C.
One of my colleagues had the misfortune to have the CO2 bottle pulled off his raft, causing it to deflate. He struggled for about 5 minutes or so to board the soggy mass (they stay afloat from the floor and canopy inflation) before giving up. Two of us paddled over to help him out, only to find that he appeared to be drunk, was giggling and couldn't care less whether he got into the raft or not. We sorted him out as best we could and pinged off a miniflare to call in the helo, as the guy was clearly hypothermic.
Bear in mind that we were all dressed for the occasion, with thick underwear, wooly bear, immersion suit flying gloves and helmet and this chap had only been in the water for ten minutes tops.
Those flying over UK waters in shirtsleeves really don't stand much of a chance of being able to help themselves I think. Certainly I always wear a survival suit, even for relatively short water crossings.
QDMQDMQDM 7th May 2004, 00:42 But... if you are in the water without a raft, how will they find you in a sea state other than calm, other than pure luck? Only your head/shoulders will stick out.
Carry a McMurdo Fastfind Plus GPS PLB in your lifejacket, accurate to a few metres.
QDM
Timothy 7th May 2004, 08:49 The TBM sank in seconds rather than minutes.
Timothy
QDM
If you have a 400MHz EPIRB with you, definitely, and everybody should have one. But at £600-£1000, very few people going cross-channel will though. I have one in my emergency bag and would hope to grab that on the way out. But if you only just managed to escape in your drysuit, the chances are that you didn't manage to retrieve it...
Timothy
Presumably if it was badly damaged then it would? Otherwise, how did the water get in?
LowNSlow 7th May 2004, 14:23 The water gets in because the winscreen shatters when the nosewheel (mainwheels in a taildragger) drags the nose down and the thin perspex windscreen isn't designed to resist water hitting it at 40+mph so it fails.
I've been told that most taildraggers flip over on ditching whereas trikes tend to plough in as the drag of the wheel is better spread along the heavy end of the aeroplane. Anybody got any examples to back up / disprove this?
bluskis 8th May 2004, 18:09 How many successful ditchings are made in a given year in UK waters?
What is the secret of landing on the surface and not just stalling in or plowing in?
Jamming the door open with something very solid is advisable, the force of the water that breaks windscreens also shuts open doors very effectively.
The failure rates for engines given by IO are apparently dreamed up by someone. How do you get an average between 3000 and 10000 hours?
My personal statistics of engine failures are more in line with Timothys experiences
Life rafts have been known to sink.
bluskis
You appear to suggest that engines fail a lot more frequently than every 3k to 10k hours.
This cannot be right, if you think about it.
The TBO on most engines is of the order of 2k hours. It is a fact that most engines that come in for an overhaul are removed from a plane that is still in one piece and functional. They are not carted in on the back of a pick-up truck, surrounded by wreckage of a plane that had to do a forced landing.
Most planes, even flying school spamcans, spend most of their airborne time out of gliding range of an airfield.
So if the average life of an engine was say 1k hours, not only would there be a huge number of forced landings (of the order of every plane used for training ending up in a field every two years) but also not many engines would ever make TBO before they end up wrecked. At the very least, nearly every overhaul would involve a shock load inspection, which for a fact isn't the case.
For me, it is easy enough to see why some people have had bad experience with engines.
For a start, any statistically rare event, be it engine failures or rare diseases, are subject to clustering. So you can always dig up somebody who has done 10k hours and has had 10 failures.
Also there is a huge range of engines flying, in terms of condition, treatment by users, and maintenance standards. The average UK GA fleet age is 24 years, according to a CAA CofA inspector I spoke to. But this average conceals a huge standard deviation. A lot of planes are 50 years old. A very small % are brand new. Most training / self fly hire planes are 20-30 years old but they are looked at more often (Transport CofA) and don't get a chance to rust too much inside.
So there will be a big variation in engine reliability, with most of the factors being controllable by a careful operator. I bet you could say the same for accidents, too.
Regarding rafts, I spoke to a well established manufacturer selling various rafts including GA and (although they would say this) they claim at least 99% do work just fine - IF they are overhauled by the schedule, usually annually. In GA, few people carry rafts and those that do rarely overhaul them by the book - it costs about £100-£200 and there is no legal requirement to do it.
Timothy 9th May 2004, 01:56 Picking up a couple of points:
The water came into the TBM via the door, which opens upwards from floor level.
Most of my engine failures....correction...all of my engine failures have resulted in both the engine and airframe being returned to service, either with new mags, CSUs, replacement fuel feed pipes, new turbine blades or whatever. Those in multis have been flown at leisure to convenient runways, those in singles have been limped or glided to runways.
So IO's vision of "rivers of oil" doesn't really bear analysis.
bluskis 9th May 2004, 09:54 IO
My query of the statistics you quoted was the impossibility of having an 'average' somewhere between an enormous spread like 3000 hrs to 10000 hrs. An average, while not a precise figure without qualifications, should be more precise than this very large spread.
Engine failures do happen , and if they happen while over mountains or water you are going to have to be lucky to walk/swim away.
bluskis
Fair enough, but such an average would be meaningless, for the reasons given: the operator has a lot of control over the actual MTBF (unfortunately, without knowing what it will be)
Timothy
What % of GA ditchings are survived by all aboard? But even in asking that question, I am going right back to what I say to bluskis. What is needed is a breakdown of survivability versus sea state, carriage of rafts, carriage of EPIRBs, etc. Without that, it is like saying the average of 0 and 10 is 5.
QDMQDMQDM 9th May 2004, 10:30 If you have a 400MHz EPIRB with you, definitely, and everybody should have one. But at £600-£1000, very few people going cross-channel will though. I have one in my emergency bag and would hope to grab that on the way out. But if you only just managed to escape in your drysuit, the chances are that you didn't manage to retrieve it...
I carry it in my lifejacket pocket for that reason.
For general reference www.equipped.com has lots of info on dicthing and equipment and lots of ditching stories.
QDM
bluskis 9th May 2004, 19:08 interesting link QDM
Yes, a very good summary of EPIRBs, thank you QDM. No suprise that McMurdo weren't happy about the test results :O
I spoke to Sartech at the time of getting the Kannad non-GPS unit I have, and their view was that for normal UK/Europe (cross-channel over water) flying a GPS is not needed because the 400MHz satellite homing, combined with the low power 121.5 VDF signal, are sufficient for getting found reasonably fast. But outside the "civilised world" one may be relying solely on commercial shipping for SAR and a GPS EPIRB is essential.
englishal 9th May 2004, 21:36 For cross channel flying,or in "populated" areas, a SART radar transponder might be of more use. If you activate it, it'll show up on every ships radar screen for miles around, and possibly (depending on type of radar) trigger an alarm on their bridge. They can home directly to you using radar.
The amount of shipping traffic is the channel is amazing, (and scary if you're on a yacht, in fog, no radar, no wind, and you're slap bang in the middle of the shipping lanes north of Casquets :ooh: )
EA
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