Ditch Button

[azzamang]

Sorry if this question has been asked before, but here goes anyway.

Exactly what is the purpose of the Ditch Button in airbus aircraft.

Thanks in Advance

[DBate]

Pushing the Ditching Button will close the outflow valve, the emergency ram air inlet, the avionics ventilation inlet and extract valves, the pack flow control valves and the forward cargo isolation valve.

That's to prevent water entry in case of a emergency water landing.

Hope it helps.
DBate

[Maxrev]

But even with the switch pulled don't expect to keep your feet dry for long!

A lot of older aircraft (DC9's and MD80's, in my experience) leak like a sieve anyway in a hard downpour. I'd hate to land one in the sea.

[Lu Zuckerman]

To: DBate

That's to prevent water entry in case of a emergency water landing.

How about the water that enters the fuselage when the engines and wings are ripped off in the process of ditching?

:E :E

[av8boy]

How about the water that enters the fuselage when the engines and wings are ripped off
That'd be a crash. We're talking about "emergency water landings." Sometimes it's hard to tell them apart till just the last second...

Dave :O

[jettesen]

This might soun like a silly question, but is it in your training to do emergency water landings in the sim? Not to sure if the sim can simulate a water landing. I once spoke to a pilot and he said he never did it in his training, it's all down to the individual to do his best if the unfortunate event ever occurred. Just interested to find out

[411A]

When I was doing 707 training at PanAmerican in the early seventies, was observing on one sim session where a flight engineer was undergoing upgrade training for the First officer position.
The approach was the backcourse localizer to rny 11 at KOAK (no visual on this particular sim), and PanAm allowed use of the FD105 for descent guideance, in a VS mode. It could also be programmed for correct lateral guideance, specifically required by PanAm.
The co-pilot descended a bit too soon and 'hit' the water about a mile short of the runway.
At this point, the sim instructor splashed a cup of water all over the guy and mentioned...'hey sport, you just got wet, what do you suggest now?'

The only reply from the right seat was....'oh s*it!'
Backside reaming then followed.

An absolutely true story.

[BigHitDH]

I think there are "general guidlines" for a ditching, althought I don't think they are practised.

You can see what the FAA have to say HERE (http://www.faa.gov/ATpubs/AIM/Chap6/aim0603.html#6-3-3)

[Maxrev]

Ditching isn't practiced in the sim as a rule, as it can't be simulated effectively, and ditchings by large airliners are so rare that it's not seen as a valuable utilisation of time in the sim.

The guidelines are to land with the swell, keep the gear up and land as near as dammit to the stall speed and set it down as gently as you can. That and all the usual stuff like trying to set down near an oil rig or ship, or near a beach.

A DC9 Captain had a brain fart in the 70's and after throwing away a few approaches ended up runnning out of gas in the Caribbean. The water landing was textbook and the DC9 held together and floated for ten minutes or more, but the flight crew forgot to tell the cabin crew what was going on so the pax were caught out by the ditching and quite a few drowned.

The Ethiopian 767 that ditched in the Cormoros Islands might have been successful if they'd had all the flaps out and had a hijacker not been beating the skipper round the head with a fire extinguisher at the time, meaning he dipped a wing in first.

Other tragedies might have not been so serious if they'd taken a water landing. The El Al 747 crew that went down into the apartment blocks in AMS after losing two engines off the wing were considering ditching it into a lake outside the city. I dare say that at least one or two of them would be around to tell the tale if they had.

The guys flying the Air Canada 767 that ran out of gas in 1983 were also looking at ditching in Lake Winnipeg rather than taking their chances with terra firma, but they hit lucky with Gimli. Also a cargo 707 not so long back landed short of the runway at a a small African airport and came down into a lake. The 707 pulled up with a splash and the crew jumped out and waded to the shore without a scratch.

But a loaded 747 at night, in the mid atlantic in winter? Most professionals are realistic that it wouldn't be very pleasant and your chances wouldn't be good. If you've seen the movie 'Castaway' where the MD11 goes down after an explosive decompression then you'll see the (slightly overblown) reality. Lots of noise, wind, bells, cautions, and one almighty surge of water coming through the windscreens.

Not something I'd ever want to try!

Max

[747FOCAL]

411A,

If he had thrown water on me I would have dotted his eye! :}

[Lu Zuckerman]

On the Discovery program about the Air Transat A-330 that ran out of fuel they had an A-330 Captain from “some” airline discussing the possibility of ditching the A-330 and in his words it would have been a disaster.

:E :E

[411A]

In that case Focal, side-saddle for the next ten years+ would have been the reward...if not a don't come Monday letter.:E

[Frankfurt_Cowboy]

"Backside reaming then followed."

What? There in the sim? Bit harsh I feel.

[Onan the Clumsy]

I wonder if management has to practise backside reaming drills in the disciplinary simulator once a year :E

[DBate]

How about the water that enters the fuselage when the engines and wings are ripped off

Well, I guess in that case you're lucky if you are still able to care about the water that enters via the fuselage.

:E

[square leg]

I trust and hope that the guy who was sitting on the left seat at the time of the "707" ditching event by the upgrader F/I to F/O (cup of water splashed on him in the sim) learnt what :::INTERVENTION::: is all about. I guess the 70's were quite different to nowadays.

JEBO YES:ok:

[411A]

Oddly enough...simulated crew incapacitation.
The Flight Engineer was 'out to lunch' as well...:{

The F/O learned a very valuable lesson, in the sim, where it should be learned.:ok:

[square leg]

:) I trust and hope that the guy on the right seat who "ditched", learnt a valuable lesson, namely that having an instructor spill water on him (and the sim) can cause sim breakdowns...;)

Nah, just kidding. But seriously, I hope he didn't have a negative training experience from that mishap;)

BTW, do you recall the 707 ditching in Lake Victoria after the circling :::Black Hole:::

Safe Flying

[lomapaseo]

That's to prevent water entry in case of a emergency water landing.

That doesn't sound right for a plane manufacturer that touts 4 engines over 2 as being safer.

Are you sure that the descriptive word ditching button is an Airbus description or just operator slang for a feature designed for some other purpose.

[DBate]

The Ditching Pb is indeed a Pb that can be found in the Airbus cockpit and not just merely operator slang.

The button can be found on the CABIN PRESS Control Panel.

And once again the quote from my FCOM Section 1.21.20 Page 7:

'To prepare for ditching, the flight crew must press the DITCHING pushbutton on the CABIN PRESS control panel to close the outflow valve, the emergency ram air inlet, the avionics ventilation inlet and extract valves, the pack flow control valves, and the forward cargo outlet isolation valve (if installed).'

So long, DBate

[747FOCAL]

When a Plane Crash at Sea Is the Least of Your Worries
New York Times 05/03/04
author: Matthew L. Wald
c. 2004 New York Times Company

WASHINGTON -- You might think that once your airplane crashes into the open sea, things couldn't get any worse.

Not so, according to the Flight Safety Foundation, a nonprofit organization founded in 1947 to provide information to the aviation industry. This month's Flight Safety Digest, titled "Waterproof Flight Operations," offers guidance on what to do after "ditching" an airplane in the water, including hints on how to set the plane down on a wave, who should be in charge of the life raft and whether to stay near the aircraft. (The answers: on the back side of the swell, the captain and no.)

As any B-movie fan knows, the next hazard for survivors is sharks.

Actually, the foundation says, attacks are quite rare, with far greater risks posed by hypothermia and dehydration. Still, the digest contains plenty of advice on how to handle unwelcome company. Excerpts follow.

*

First of all, there's no need to panic - most of the time:

Sharks and other ocean creatures "are really of no concern at all" - as long as the survivors are in a life raft, said George Burgess, director of the International Shark Attack File (ISAF), which investigates reports of shark-human interactions and maintains records of sharks that have bitten humans worldwide dating from the mid-1500's.

"Food, water, communication with whoever's going to save you - not to mention the health and safety of people on the raft - would all be of greater concern than a shark attack," Burgess said.

Without a life raft, however, the situation might be different. ''Once you're in the water, there is concern,'' Burgess said. "Sharks can, and occasionally do, damage human beings. Humans can be attractive targets, especially if they're bleeding.''

The unlucky can expect three types of ''unprovoked shark bites'':

"Hit-and-run" bites, in which the shark bites a human while apparently perceiving that the human is one of the shark's customary food sources - for example, a seal. These bites usually occur in the surf in turbulent water conditions that include poor visibility for the shark. ISAF specialists say that the shark probably recognizes immediately upon biting that the human is not the food it was seeking, and then releases the human and does not return.

"Bump-and-bite" bites, in which the shark circles and bumps its victim before biting. These bites usually occur in deeper water and may involve repeated bites and/or sustained bites, and severe injuries.

"Sneak" bites, which occur without warning. These bites, like bump-and-bite bites, usually occur in deeper water and may involve repeated bites and/or sustained bites, and severe injuries.

Bites involving survivors of aircraft accidents and marine-vessel accidents typically are either bump-and-bite bites or sneak bites, which ISAF said are a result of "feeding or antagonistic behaviors" by the shark.

After some harrowing first-person accounts by survivors of plane and ship disasters (''When I moved my legs slowly, with the object of resting, I touched with my feet the bodies of these animals, which were constantly below mine in order to attack me''), we learn that sharks are more likely to go after solitary swimmers and are attracted by shiny jewelry and bright colors:

"The safety orange/yellow used in [life vests] is referred to as 'yum-yum yellow' by shark biologists," said Burgess, who noted that although studies have indicated sharks' attraction to bright and/or contrasting colors, there are no data to show that sharks have been attracted to - and bitten - people because of their yellow or orange life vests. "But it's a trade-off. To be readily seen by rescue folks in the air or from a vessel, you also must be seen by sharks."

If you are in a raft and spot sharks, here's what to do:

Do not fish. If a fish has been hooked, let it go. Do not clean fish in the water.

Do not let arms, legs or equipment dangle in the water. Remain quiet and still.

Bury the dead as soon as possible by pushing the bodies into the ocean.

For those stuck in the water, "the following actions are advised":

Survivors should float vertically and move as little as possible. Someone lying horizontally in the water is more likely to resemble sharks' typical prey, said Erich Ritter, chief scientist with the Shark Research Institute's Global Shark Attack File.

Remain in a group "at all costs" and gather together as much floating material as possible, Burgess said.

Do not remove any clothing, including shoes. Sharks generally bite unclothed people - and those with bare feet - before they bite those wearing clothing. Clothing also protects against cuts and scrapes from the shark's rough skin - injuries that might occur if a shark brushes against a human.

Do not urinate or defecate while sharks are in the area.

If you are injured and bleeding, stop the bleeding as quickly as possible. If a group of people is in the water, form a circle around the bleeding survivor.

Ritter said that, if a shark actually bites and does not let go, "the best thing to do is to not fight the shark, besides trying to get its mouth open. Any motion, such as jerking away from the shark, will lead to much more severe wounds and can be much more devastating than the actual bite.

Opening a shark's mouth should not be attempted by hitting the animal, since that reflects a 'prey action.' I consider it the best to go after the gills or the eyes and poke them, if reachable."

Blood loss and drowning are the most serious risks for victims:

Wounds inflicted by a shark's rough skin or its multiple rows of sharp teeth can be relatively minor, such as skin abrasions after a shark's body brushes against a victim or relatively small cuts from bites - usually on the legs - that are inflicted during a hit-and-run bite. Other bites, especially those inflicted during bump-and-bite and sneak encounters, can result in more serious injuries.

Paul S. Auerbach, M.D., clinical professor of surgery in the Stanford University Medical Center Division of Emergency Medicine, said that when a shark bites a human, the shark most frequently bites the legs, arms and hands, as the victim tries to fight off the shark. In more severe bites, a shark often ''shakes its head and forebody in an effort to tear flesh from the victim,'' Auerbach said.

If the wound severs major arteries, the victim may suffer a ''torrential'' hemorrhage; injuries also can include broken bones and massive internal injuries, Auerbach said. ''Because the victim is generally far from medical assistance, blood loss may be profound.''

Hypovolemic shock (shock resulting from loss of blood) usually is the greatest threat to life. Recommended treatment, while a victim is in the water, includes manual compression of wounds. After a victim is out of the water, ''All means available must be used to ligate [tie off] large, disrupted blood vessels or to apply compression dressings,'' Auerbach said.

Wounds inflicted by sharks often contain a variety of contaminants, including ocean water, sand, shark teeth and marine organisms. Ideally, the wounds should be washed and bandaged, and a victim should receive antibiotics to prevent infection. This may be difficult on a life raft.

*

Apparently, sharks aren't the only creatures to worry about:

Peter Fenner, M.D., a specialist in jellyfish envenomation and an Australian designated aviation medical examiner, said that survivors of an aircraft ditching or other water-contact accident in the open ocean would have only a remote chance of being stung by jellyfish, unless the aircraft landed ''in an armada of Portuguese man-of-war.''

''[Survivors'] best protection is that they are in clothing, which prevents being stung, except in exposed areas,'' Fenner said.

The report concludes by citing yet more potential hazards, including barracuda, venomous sea snakes, electric rays (also known as torpedoes), stingrays, sea anemones and even estuarine crocodiles:

Although many ocean creatures can inflict serious injuries on humans, specialists say that the risk of an encounter with a dangerous predator is relatively slight for survivors of a water-contact accident. Nevertheless, not all dangers can be eliminated.

[EFP058]

Okay, two serious questions here:

1) Why leave the gear up when attempting to ditch? I used to think it would serve as a good speedbrake when it hits the water first and gets ripped off. The next thing that´ll hit the water would be the engines anyway, and I´d much rather prefer the gear hitting the water first.
Is it out of fear the gear will rip open big chunks of the wing when it gets ripped off upon contact with the water, therefore creating serious leaks in the wing that´ll let in water and pull the aircraft down even faster? If so, wouldn´t the engines have the same effect when they get ripped off? Maybe even more so, since they are very likely to take out the wings as well?

2) Why ditch as close to the stall speed as possible? Wouldn´t it be better to try and set it down with as little nose-up-attitude as possible? My line of thought is that the force of impact would be spread out on a much larger area that way. If you hit tail first than that´s where most of the force will go, plus the nose will go down really fast, hitting the water hard and possibly leading to a break up of the aircraft.

Sure, you´d be faster when hitting the water at a shallow angle, but I feel (and this is really just my feeling, not backed up by anything scientific or precise data whatsoever) that it´s better to land a bit fast than to concentrate all the impact force in just one spot. As soon as the engines dip in all bets are off anyway.

Sorry if these are stupid questions, but I never trained for this scenario, probably because I don´t fly the big iron. ;)

[411A]

The only ditching that I can recall offhand was the PanAmerican Stratocruiser in the mid-fifties next to ocean station November, at 30N140W. Double engine failure and the aircraft unable to reach either HNL or SFO.
The ditching was successful.
On water contact (with the flaps in the landing position, gear retracted), the tail broke away and sank rather rapidly.
All pax were able to exit by the overwing exits and floated away in rafts.
The aircraft sank after about thirty minutes.

Generally speaking, the landing gear is left retracted to minimize structural damage at impact.
Light aircraft (with fixed landing gear) will normally flip upside down at impact.

[Maxrev]

Yes gear stays up to keep it out of the way when you hit the water. Engines are designed to detach with minimum damage if they reach the pin loading limits but the gear isn't. It'll rip off and come up through the airframe or worse, leaving you with a nice big hole for the sea to rush into.

And in terms of landing faster, slower, nose first, etc, I was always taught to get the speed down as low as possible, and drop it on as gently as you can. If that means a slightly nose-up attitude then so be it.

[TopBunk]

EFP

You jumping into the water from 6ft at 2mph forward velocity has the water seeming 'soft'. Try that at 200mph at any significant rate of descent and it is anything but soft ..... hence the lowest forward speed recommendation. Landing gear up likewise stops you pitching nose down at a greater rate into the water (bad enough with the engines - and modern high bypass engines are worse). Quicker deceleration is not a problem, believe me!

Having said all of that, no one really knows what would happen - it's not part of aircraft certification requirements - it is just best guess recommendation in truth.

Just think about it - the flights most likely to ditch are transoceanic flights, which spend 50% of their flight time over water at night. Makes things even sportier, don't you think - how to judge the swell direction etc!