Ditching a modern airliner

[dogcharlietree]

Just found where allegedly, "However, despite his composure during the accident, Sully reveals to Telegraph Travel that he had received minimal training for a water landing (or “ditching”)."
I have a few questions;
1) Do airlines/manufacturer's cover this in documents/procedures?
2) Is it ever covered in a simulator training exercise?
Or is it just the old "head in the sand, it won't happen to us" mentality?
Remembering the three ideal ingredients, 1) calm sea, 2) minimum rate of descent and 3) minimum safe water contact speed.

[fdr]

The OEM FCTM's have sections on ditching procedures which are fairly generic. Simulator sessions for ditching is not part of the training matrix for airlines as a general rule. In the military ditching drills were practiced routinely, in the simulator and aircraft. Don't recommend doing it in the aircraft, memorably the NATOPS Section 5 procedure had a number of cautions and warnings in the procedure. One particular warning was don't ditch if lateral control is compromised. Another warning was don't conduct ditching practices with an engine shut down. Having seen the blue on the wrong side of the plane at 4,000', against objections to the driver, I would consider that an understatement. The problem with an asymmetric case ditching practice is not the ditching, it is the recovery/go-around, where the pilot may have a fist full of thrust levers that are not symmetrical when he pushes them forward. As the ditching speed can be close to VMCA1 and well below VMCA2, then things can get interesting rapidly. (difficult to get a Wing CO to accept the warnings of a FNG 40 years ago...).

Ethiopians B767 swim at the Comoros was a controlled crash against all odds, with the hijacker hitting the captain about the head with the axe as he ditched the aircraft. Impacting wings level is evidently worth while, at the correct ditch speed. The ditch speed is usually minimum energy state, but that may not always be the case, geometry may require a slightly higher speed. The captain was heroic in his actions.

An OEM/regulator study done on the survival time following inflight cabin fires supports the fact that a ditching at any time over water is a possibility however remote the chance of a cabin fire may be; if there is a cabin fire, and it cannot be put out, the survival time is unlikely to stretch to an airport arrival.

Tin hat on... years ago, after passing by a red team ship that was happily plinking the sonobuys we were placing in the way of a boomer transiting in shallow water, we got a call of smoke in the cabin, looked back couldn't see the tac crew. Guys hit the smoking cabinet that was sprouting flames and smoke with a large dose of BCF, and continued for a really long time (felt like days, was less than a minute) In the interim, nav gave nearest divert as about an hour, and I prepared the crew for a possible ditch alongside the guys shooting out the sonobouys. Fire went out, so we moseyed back home once the risk was removed, crew off masks etc. A non event, however, one of the guys woke up the next day with a new top of grey hair, gained overnight. Smoking is bad for your health apparently.

[ATC Watcher]

Great Story fdr !

Back to the question : Jeff Skiles the co pilot of the US Hudson flight makes an excellent presentation explaining the various and numerous lucks they had that day. ( outside of hitting the birds that is !) and basically you cannot train for luck.
A photo of the aircraft the next morning , with ice plates everywhere on the Hudson and lots of ferries crossing in the background shows already 2 of those lucks.

[B2N2]

Couple of other things we don’t train for:

1. UFO encounters
2. Meteorotes
3. North Korean missiles making a reentry on our airway (R211)

So what else should we train for in the sim?

[Bergerie1]

dogcharlietree,

We had a generic description in our manuals, and we had discussions on the techniques to be used and watched a film of ditching trials done with a VC10 scale model. So we knew what we needed to do in relation to wind and swell but never actually practised it.

[Icarus2001]

Or is it just the old "head in the sand, it won't happen to us" mentality?

Well realistically how many ditchings of jet aircraft have there ever been? Why not train for an all engine out forced landing as well?

Sim time is best taken up with what is causing the most grief, which still appears to be loss of control and CFIT.

[Centaurus]

Why not train for an all engine out forced landing as well?

Because there has been several all engines out forced landings, that's why. As a simulator instructor I have observed many of these over the years. In just about every case the pilot would have crashed either because he was grossly overshooting or grossly undershooting. Most crews we observed needed at least three practice forced landings from 15,000 ft before they got the hang of glide control with various stages of flaps. The B767 captain of Gimli glider fame did an exceptional job of forced landing all flaps up on a 7000 ft runway. Afterwards he said if only Air Canada had given him just one practice simulator forced landing from height he would have been much more confident when he did he real one.

So much valuable simulator training is wasted by a syllabus or check pilots that insists on lengthy checklists, lengthy taxying and lengthy briefings that take up simulator time when this time could have been much more productive such as practicing dead stick forced landings and final approach ditching on a simulated black night over the simulated ocean. There is real instrument flying skill needed to set an airliner down in the ocean. With the plethora of airline crews whose manual raw data instrument flying flying skills are seriously degraded by company imposed policy on full automation from lift off to touch down, there would be no hope for all the souls aboard.

You can argue all day until the cows come home about the statistical improbability of a dead stick landing or a controlled ditching ever happening to each one of us. But it would be criminal if the captain of an airliner was so incompetent that he could not pull off a successful dead stick landing or a ditching if such an event occurred. We have multi million dollar full flight simulators to ensure we can deal successfully with such events.

Even the cabin crew are required to be competent in dinghy drill which suggests the possibility does exist an aircraft may have to ditch one day.

[dogcharlietree]

My thoughts are that as the airlines don't believe it will happen, the "company minded" aircrew also think the same.
Due to my background, I'm always considering a ditching if things go haywire.
I know I will incur the ridicule of some (like a previous poster), but I sometimes wonder if the pilots of say UPS6, SWR111 and say SAA Flight 295 even "considered" such an option.
I knew a pilot once who was so glad to have the sim exercises over early. "What did you do then?", to which the reply was, "go home."
I was astounded and I remember my reply "you are bloody mad, why didn't you do some dead-stick landings?". Needless to say, I was scoffed at.
For me, every minute in a simulator is an incredible learning experience which I valued.

[dogcharlietree]

Well realistically how many ditchings of jet aircraft have there ever been?
Very few, because very few know how to fly the approach.

[fdr]

So much valuable simulator training is wasted by a syllabus or check pilots that insists on lengthy checklists, lengthy taxying and lengthy briefings that take up simulator time when this time could have been much more productive such as practicing dead stick forced landings and final approach ditching on a simulated black night over the simulated ocean. There is real instrument flying skill needed to set an airliner down in the ocean. With the plethora of airline crews whose manual raw data instrument flying flying skills are seriously degraded by company imposed policy on full automation from lift off to touch down, there would be no hope for all the souls aboard

O sleeve valve, so much truth is such a short paragraph. We squander the asset of the 6-DOF devices to fly what we fly every day in service, wasting time running checklists that could be done in FTD's made of paper stuck on the wall, or in low fidelity flat screen systems. The greatest opportunity outside of a Pitts or a PA-18 to teach a pilot to fly is squandered with the APFD proving it more or less does what it is told (until it doesnt). none of the automation stuff needs to be done in hi-fidelity, it needs to be done in trainers that faithfully replicate the system functionality. The hi-fi systems could be used to assist in getting some basic handling competency back into the crews that is being removed by the insanity of operational procedures that remove the very skill sets that are the safety backstop of the operation. FOM rules that demand automation at all times is effectively a risk to the system through appeasement of those applying bandaids to the issues of crew competency.

AQP as it has morphed into nonsense is a risk to the industry, as is assuming audit has some equivalence with safety when implementation is not evaluated in a meaningful manner.

For those in the regulatory areas, please remove LOFTs from being required to be flown in hi-def systems, there is no rational justification for that. The ADM/NDM skill development can be done in FBT/flat screens, and arguably where those systems can permit drilling into system information, there is more merit in the lo-res FTD application to such training, as well as crew coordination training and or evaluation.

The majority of the bent metal comes from events where the humans somewhere in the activity have lost SA and have not recovered same in the time/height available. SA traiining can be done over a beer, or the lo res training devices.

Hi-res has validity to type training the first time round, and where ZFT is the game, then fidelity is important. However... for the beancounters that run airlines, Boeings are Boeings, and Airbus are Airbus... the waste in training and personnel on the basis that each aircraft type is magic is make work. A CBT and FTD with PTT's can give all that is needed to hop from one blender to another. The looniness that is the licensing system is a mill stone around the industries neck. System differences between one and another type are covered in the checklist that is called for when an issue arises; as often as not, the complications come from the human not adhering to the checklist as written due to their knowledge that may or may not be valid. Don't get me wrong, I enjoy the time out of doing another type rating, but once the slot is found to make noise, the procedures that are followed are the same, do checklists, and don't do dumb things that stop the ride early. The sim time is too valuable to be wasted in rehashing stuff that has been the same essentially since Lilienthal was a lad. The best training I ever received was not on a plane or sim, it was sitting in a classroom with the Hamilton Standard governor cardboard model, which faithfully replicated the function of the system. It was so low resolution that when i spent time looking at an overhaul of the governor it was remarkable to be able to identify each part by function only but each one was different in location and construction to the training aid; the aid however made it possible to comprehend the failure modes that occurred routinely with the Detroit Diesels. SA doesn't need perfect fidelity, it needs a basis for a rational construct that is consistent with reality, nothing more. ADM/-NDM and SA training do not need or benefit from hi-res.

FWIW, the 6-DOF sims do not model effectively the loads imposed on the pilot in a number of flight conditions, those are best experienced in a real aeroplane, but preferably not the airliner, the checks are too time consuming following stall or hard mach buffet flight.

[Willy Miller]

https://en.m.wikipedia.org/wiki/1995_Royal_Air_Force_Nimrod_R1_ditching


ok, not a MODERN airline but the technique is the same.

[CargoOne]

Because there has been several all engines out forced landings, that's why. As a simulator instructor I have observed many of these over the years. In just about every case the pilot would have crashed either because he was grossly overshooting or grossly undershooting. Most crews we observed needed at least three practice forced landings from 15,000 ft before they got the hang of glide control with various stages of flaps. The B767 captain of Gimli glider fame did an exceptional job of forced landing all flaps up on a 7000 ft runway.

Industry have long decided to invest into CRM, SOP and adherence to procedures for pilots and mechanics, because in the modern world if your aircraft is all engines out then it is indeed either pilots or mechanics mistake, or sometimes both, assuming you was not refuelling in Mogadishu. It is much more important to invest into teaching staff how not to end up in situation like Gimli or Azores glider (both wide bodies and both Canadian operators coincidentally) or Tuninter or what else. Sully's case was a gross amount of good luck, there is nothing to train for and anyway rivers do not count - there is also Garuda 737 case for you.

[wowzz]

Sorry to intrude as slf , but if ditching is considered to be such an unlikely event that no sim training is given, what really, is the point of supplying life jackets for the pax?

[fatbus]

If you had 2-4 hours of simulator time would you prefer to practice ditching/ forced landing or Eng fail V1 / landing/ contaminated rwy ops/ max cross winds?

[neilki]

If you had 2-4 hours of simulator time would you prefer to practice ditching/ forced landing or Eng fail V1 / landing/ contaminated rwy ops/ max cross winds?


For the first time in my career we had an instructor who said "Maneuvers Validation Complete; successful" ... and followed up with.. We have a little time left over; do you want to have some fun?
The answer was a) Yes.
We'd been practicing EGPWS escapes out of Innsbruck, so he dumped us at 15,000 about 20 miles north of the field. There was a bang as the RAT deployed. :-)
Long story short; made it off the runway and stopped on a taxiway. As it happens; dead stick isn't that hard. It's just energy management, right?
We followed this up with a no flaps landing contest in Chicago Midway.
That 25 minutes was probably the most i've learned about flying the Aircraft. Granted; the mindset was a little different; kudos to the instructor for setting the tone, but I found it extremely valuable..

//N

[meleagertoo]

what really, is the point of supplying life jackets for the pax?

Despite the Hudson event being one of only two controlled, intentional airline jet ditchings ever afaik there have been scores if not hundreds of overruns/excursions into water. A urprising number of airfields have runways that project into water at one or both ends. Life jackets are thus far more useful than most people imagine.

[oldchina]

After 17 posts it's strange that no-one has mentioned that Sully's A320 had a ditching checklist.
Problem being that it was written for a descent from altitude and the FO had no time to finish it.

[Cheltman]

To add to oldchina comment. Ditching is of course a design case considered by the manufacturer to try and give the best probability of success. Even knowing that a huge amount of skill and luck is needed to pull it off. Of interest the subject of how best to try it goes back to the origin of the word ditching. The cynical reason for demanding life jackets used to be that it made it less risky for the people recovering the bodies. Black humour is part of all engineers character.

[Dualbleed]

The problem is all the full flight sims I have been in over the last 30 years have absolutely crap visual representation. I’ve done B737, 767 757 and 787. They are so bad that even a normal landing is deceptive. Give me a real aeroplane any day. This talk about that VR is the same as real life is utter b...s. The only thing a sim is good at is fly by exact numbers a little situational awareness and the computer says yes. A circling approach or an engine failure is a breeze in the real aircraft, but totally unrealistic in the sim.

[Bergerie1]

I used to practise deadstick landings in the 747 simulator when there was spare time. Great fun and a good exercise in energy management as a previous poster has said. You could sideslip the sim just like a Tiger Moth to shed excess height. But does anyone on this thread know how much sideslip can be tolerated by the engine pods? And what are the sideslip limits on modern jet transports?

[fireflybob]

Despite the Hudson event being one of only two controlled, intentional airline jet ditchings ever AFAIK there have been scores if not hundreds of overruns/excursions into water. A urprising number of airfields have runways that project into water at one or both ends. Life jackets are thus far more useful than most people imagine.

Isn't that the salient point that most ditchings these days are unpremeditated, ie runway overuns etc?
Traditional ditching drills come from the days when large piston engine aircraft were halfway across an ocean and were unable to maintain height due engine failure/shutdowns and then had around 30 minutes to prepare the cabin and plan for some sort of controlled ditching. It was probably a bit before my time but I believe the ocean stations vessels located in the Atlantic could lay a flarepath on the sea within 20 minutes or so. I also believe one of the findings of the Hudson report was that there needed to be an abbreviated ditching drill for unpremeditated ditchings which just covered the essentials.
Whilst practice in a simulator may be useful I doubt modern visual systems can truly represent a swell on the ocean.
As regards lifejackets as a passenger I'd still like to have one just in case!

[tdracer]

I used to practise deadstick landings in the 747 simulator when there was spare time. Great fun and a good exercise in energy management as a previous poster has said. You could sideslip the sim just like a Tiger Moth to shed excess height. But does anyone on this thread know how much sideslip can be tolerated by the engine pods? And what are the sideslip limits on modern jet transports?

I don't know what the sideslip limits are, but we did a flight test on the 747-8 where the pilot held a 20 degree yaw for 30 seconds, then repeated in for 30 seconds in the opposite yaw. It was pretty obvious the aircraft wasn't happy about it but it did it just fine (and I'm quite sure someone looked at the design limits for yaw before the condition was approved). I was also very, very impressed with the pilot - the first direction he had trouble holding the condition with lots of corrections, but he learned so fast that when we went the other way he held it rock steady with minimal corrections.
Years ago I had a co-worker who thought we should save the cost and weight of the rafts and life jackets as there'd never been a successful ditching of a commercial jetliner. When I first saw the video of the Ethiopian 767 ditching I thought he might have a point - didn't find out until later that the pilot was having to fight off the hijacker while trying to ditch - talk about your bad day at the office.
The problem you'll always run into for simulator training is that it's a finite resource and the regulators don't want to add stuff to the requirements if the probability is less than ~1 per 10 million flights (dead stick landing falls into that category)

[metro301]

The B767 captain of Gimli glider fame did an exceptional job of forced landing all flaps up on a 7000 ft runway. Afterwards he said if only Air Canada had given him just one practice simulator forced landing from height he would have been much more confident when he did he real one.

Captain Pearson was an experienced glider pilot
https://en.wikipedia.org/wiki/Gimli_Glider

[lomapaseo]

The problem you'll always run into for simulator training is that it's a finite resource and the regulators don't want to add stuff to the requirements if the probability is less than ~1 per 10 million flights (dead stick landing falls into that category)

Don't blame it on the regulators, it's the operators who have to pay for the off-line testing that count the stats to the nearest decmil

[Winemaker]

Re simulator training, since the simulator can't generate more than one g how does the experience translate to actual flying? As an ex formula car racer I've experienced more than 2 g lateral load for extended periods of time; a simulator can't generate the head/neck loading and wind impact of the real deal. When flying the g load is generally vertical through the seat so I guess very short bumps above 1 g could be made. What I'm asking, as SLF, is how effective the simulator is at representing real flying conditions.

[oxenos]

I was on the same conversion course (from Shackleton to Nimrod in 1970 ) as the pilot who ditched the Moray Forth Nimrod 25 years later.On the course we were shown film of Nimrod model ditching trials .
The model, which was of scale strength, and fitted with g recorders, was projected into a large water tank at diferent pitch attitudes, yaw angles, and with different "sea states" It showed that at a reasonable angle and sea state the ditching would be survivable. It also showed that the fuselage would break at a point in line with the trailing edge.
The day after the ditching there on the front page of the papers was an aerial photo of the Nimrod afloat, and broken exactly as predicted.
As I recall (long time ago now) there was also film of other military model ditching trials. The Beverley looked like a duck taking to water.
It makes sense to do such trials for a maritime aircraft, and perhaps for other military aircraft, but I am not aware that civilian aircraft are similarly tested.

[Deadstick126]

Great Story fdr !

Back to the question : Jeff Skiles the co pilot of the US Hudson flight makes an excellent presentation explaining the various and numerous lucks they had that day. ( outside of hitting the birds that is !) and basically you cannot train for luck.
A photo of the aircraft the next morning , with ice plates everywhere on the Hudson and lots of ferries crossing in the background shows already 2 of those lucks.

I had the pleasure of meeting Jeff at a party at Oshkosh a couple of years ago. Everyone was still asking about Cactus, and he was politely answering the same questions for the umpteenth time. He had been selected to fly "Fifi", at the time the only remaining flying B-29, into Oshkosh for the show. When I asked him what it was like to fly"Fifi", his face lit up and he went into an animated description of landing the beast and having only differential braking for steering control, among other hilarious aspects involved in flying to old bird. I'd love to run into him this year and hear about what treasure he flew in this time.

[captainsmiffy]

Just ditched the 380 in the sim.....��

[tdracer]

Don't blame it on the regulators, it's the operators who have to pay for the off-line testing that count the stats to the nearest decmil

But the regulators have to approve the operators simulator syllabus. If they mandate a condition must be part of the syllabus, the operator has no choice (engine failure at V1 being an example). With rare exception, the regulators won't mandate training for anything that happens less than once per 10 million flights (ran into that on another issue - it's not that hard to control but the regulators said it was catastrophic because they don't train for it - we said so train for it - they said it doesn't happen often enough to justify the simulator time....)

BTW, an ocean ditching would be easier to 'get right' than a dead stick on a runway since when ditching you basically have an infinite runway length and don't need to worry about getting the touchdown point right. But the sea conditions make the ditching less likely to be successful.

[dogcharlietree]

With all due respect, by flying an approach to ditch has very little to do with visuals (in a simulator).
In my training, we used to practice in the real aircraft by using an arbitrary figure of say 5,000ft agl/amsl as our "sea level".
The main ingredients of a "successful ditching" are wings level, minimum rate of descent (less than 100fpm) and minimum speed just above stall.
If you try that in a simulator, you will see how difficult it is to achieve ALL three conditions. Try it yourself!

And again and with all due respect, again, a deadstick approach is NOTHING like a ditching approach (if it's to be successful).

[Bend alot]

Just a few points on airliners.

Airliners prior to the B747 had pretty short range, so as a result less time over water and often more "back up engines" than twin airliners.
The B747 obviously had a large range so flight time over water increased and in its early days ate lots of engines, with the exception of flying through volcanic ash 4 engines seemed enough.

We now have big twins with massive range, and a change from hub the to hub model to the point to point model. The introduction of ETOPS and various extensions. All of this leading to many more flights spending more flight time over water by taking more direct routes.

So over time we have reduced the number of "back up" engines to one, and dramatically increased the the time spent flying over water.

Being a LAME I understand a bit. Having both engines on a big twin failing at the same time or within the ETOPS limit (has new name I think) is very slim. The reasons could be a number of individual or the Swiss cheese reasons such as crew, engineering, software (upgrades) contamination and commercial pressures.

What has been highlighted over the last few years is un-contained engine failures - on what I class as modern airlines. Recently we have been lucky with these failures, except the poor lady from flight SW1380.

The secondary damage from these un-contained engine failures (QF 32) is what is likely to cause both engines of a big twin to stop producing thrust. Loss of control systems, pressurisation, fuel and electrical items in certain combinations can increase the requirement of ditching.

Good thing aircraft are designed not to have un-contained engine failures.

As for the life jackets, a few visuals need to be shown on consequences of inflating them while in the cabin, the current brief has the same impact as leave your hand luggage behind.

[Sailvi767]

After 17 posts it's strange that no-one has mentioned that Sully's A320 had a ditching checklist.
Problem being that it was written for a descent from altitude and the FO had no time to finish it.

Which is typical of Airbus checklists. They take entirely to much time to run and often have pitfalls you need to be aware of. Compare the engine out procedures on a 767 to the A330 including the overweight landing section. One is 2 checklists, the other War and Peace!

[Centaurus]

It is much more important to invest into teaching staff how not to end up in situation like Gimli
Which is about the same value as saying "I will not teach you how to swim as it is too dangerous and you may drown. Instead I will teach you not to go near the water.."

[Centaurus]

The main ingredients of a "successful ditching" are wings level, minimum rate of descent (less than 100fpm) and minimum speed just above stall.
If you try that in a simulator, you will see how difficult it is to achieve ALL three conditions. Try it yourself!

Most airline pilots would prefer to take the professional advice of the manufacturer which is somewhat different to that which you advocate.
For example from the Boeing 737 QRH (selected edits for brevity).
"Plan a flaps 40 landing unless another configuration is needed. Select VREF 40 (my note: not minimum speed just above the stall)
Ditching Final. Maintain speed at VREF. Flare the airplane to achieve the minimum rate of descent at touchdown.
Maintain 200-300fpm rate of descent until the start of the flare."

It is certainly not difficult to achieve all of the conditions above providing you are competent at basic instrument flying. After all, apart from the instrument flying bit, a PPL should be able to do that for a short field landing in a Cessna 172. A properly maintained Level D Full Flight simulator has that fidelity. It is the pilot that lacks the fidelity if he can't fly that in a simulator.

[dogcharlietree]

Select VREF 40 (my note: not minimum speed just above the stall)

I can appreciate what the airlines/manufacturers sprout. They have to to protect their butts.
Please remember that the main problem in a ditching is impact forces.
So doesn't the old equation E=mv2 come into play. If you double the speed at impact then you have four time the impact forces.
The airlines say approach at Vref (1.3 Vs), so as my mathematics is not that good, hypothetically if you came back to Vs (which you wouldn't) aren't you nearly halving the impact forces. (Donning flame jacket now).
Also, in my opening thread, I referred to aircraft that had a significant uncontrollable fire onboard. I know I'd be doing some lateral thinking in these circumstances, like the RAF pilot of the Nimrod, mentioned above. And he had the runway in sight. Good decision!

[cats_five]

Captain Pearson was an experienced glider pilot
https://en.wikipedia.org/wiki/Gimli_Glider

So was sully, so apparently was Robert piche https://en.m.wikipedia.org/wiki/Air_Transat_Flight_236

[EDLB]

The odds are not that bad for forced landings.

https://en.m.wikipedia.org/wiki/List_of_airline_flights_that_required_gliding

I would rather make a flare at Vref 40 according to the flight manual parallel to the swell and dissipate the remaining energy in the flare. The ocean runway is usually large in every direction so wind direction is of not much concern. If you fly in close to stall speed you might stall prematurely. Without working donkeys often you have lost most of the hydraulics. That the success rate of glider pilots on forced landings is high, should not be a surprise.

[nonsense]

I can appreciate what the airlines/manufacturers sprout. They have to to protect their butts.
Please remember that the main problem in a ditching is impact forces.
So doesn't the old equation E=mv2 come into play.

KE = 1/2 mv^2

If you double the speed at impact then you have four time the impact forces.

Double velocity, energy to be dissipated goes up by a factor of four. Without knowing a lot more, this only tells you the impact forces will be higher, not how much higher.

The airlines say approach at Vref (1.3 Vs), so as my mathematics is not that good, hypothetically if you came back to Vs (which you wouldn't) aren't you nearly halving the impact forces. (Donning flame jacket now).

1.3^2 = 1.69 which is close enough to double for the back of a napkin.

[Vessbot]

You guys guys are talking past each other, approach speed is different from touchdown speed.

Edit: not to mention that with engines out, your steady state descent rate on approach will be at least 2-3 times normal, so the speed loss during the time it takes to flare out of that, will be even greater than normal.

[601]

Select VREF 40
Maintain 200-300fpm rate of descent until the start of the flare.
approach speed is different from touchdown speed.

By the time you flare and touchdown, how much speed will you wash off and what will be your rate of decent at touchdown.
My guess speed a lot slower than VREF 40 and decent a lot less that 200-300fpm.

[sheppey]

With all due respect, by flying an approach to ditch has very little to do with visuals (in a simulator).
A night ditching has its own hazards. You won't see the water until the landing lights illuminate it. So in the simulator you don't have to rely on the visual scene to judge when to flare. In fact you may as well switch off the visuals to simulate a black night. The skill is in the instrument flying bit. To allow for altimeter error you need to be fully configured and on speed early.

[Vessbot]

Re simulator training, since the simulator can't generate more than one g how does the experience translate to actual flying? As an ex formula car racer I've experienced more than 2 g lateral load for extended periods of time; a simulator can't generate the head/neck loading and wind impact of the real deal. When flying the g load is generally vertical through the seat so I guess very short bumps above 1 g could be made. What I'm asking, as SLF, is how effective the simulator is at representing real flying conditions.

For regular maneuvering, the lack of G in the sim is not a factor. In a 30 deg banked turn, (which is more than what you see the vast majority of the time) the G is 1.15, which doesn't feel appreciably different from 1. So you don't notice anything.

Rolling into and out of 45 degree banked turns (1.4 G's) the lack does throw me off a bit, but it's a minor distraction.

The real difference comes in a dive pullout after a stall or unusual attitude recovery, and there's nothing that can be done about that.

[Super VC-10]

Wikipedia has just 24 articles on airliner ditchings.

https://en.wikipedia.org/wiki/Category:Airliner_accidents_and_incidents_involving_ditching

[Gysbreght]

Please remember that the main problem in a ditching is impact forces.
So doesn't the old equation E=mv2 come into play. If you double the speed at impact then you have four time the impact forces.

The impact forces are primarily a function of the rate of descent at touchdown. With unlimited runway length the flight speed is far less important. More important is the optimum pitch attitude, which will dictate the horizontal speed at impact.

Part of the problem is that manuals may provide a procedure for all engines out, and a procedure for ditching. The ditching procedure supposes that you can maintain a certain speed and control the vertical speed with engine thrust. With all engines out you cannot maintain VREF40 and 200 - 300 fpm. Your rate of descent will be more like 500 - 600 fpm. That means that the normal approach speed is too low for a successful flare to ideally zero fpm rate of descent. You need to carry some extra speed during the approach that you then bleed off at low height and minimal vertical speed.

Someone asked if model ditching test are done with airliners. Yes, they are required for certification of transport airplanes approved for long overwater flights.

[misd-agin]

The impact forces are primarily a function of the rate of descent at touchdown. With unlimited runway length the flight speed is far less important. More important is the optimum pitch attitude, which will dictate the horizontal speed at impact.

Part of the problem is that manuals may provide a procedure for all engines out, and a procedure for ditching. The ditching procedure supposes that you can maintain a certain speed and control the vertical speed with engine thrust. With all engines out you cannot maintain VREF40 and 200 - 300 fpm. Your rate of descent will be more like 500 - 600 fpm. That means that the normal approach speed is too low for a successful flare to ideally zero fpm rate of descent. You need to carry some extra speed during the approach that you then bleed off at low height and minimal vertical speed.

Someone asked if model ditching test are done with airliners. Yes, they are required for certification of transport airplanes approved for long overwater flights.

A ditching is a ditching. The difference is with power or without power? Obviously with power should be easier. Without power your rate of descent at touchdown does not have to be 500-600 FPM. You can make it as smooth as a normal touchdown if the sea state is fairly calm. You just need to maintain excess speed and trade that off, in the flare, until you're approaching the desired touchdown speed. With waves the equation to do it becomes much more difficult.

The reason US 1549 hit so hard in the Hudson is because Sully had run out of airspeed at over 100' AGL and was AOA limited. From that point on the AOA limiter prevented a stall but the lack of available airspeed (AOA) prevented any attempt at flaring to reduce the rate of descent at water impact.

The US 1549 investigation mentions using excess airspeed and converting that into a flare to reduce impact forces. Guys have to figure this out beforehand because there's no ability to regain airspeed at low altitude once you squander your airspeed and you have no power available.

[Gysbreght]

:ok:

You've got it

[Mk 1]

As regards lifejackets as a passenger I'd still like to have one just in case!

This is also probably the main reason. It gives SLF hope. Bit like the crews of various cold war bomber aircraft (particularly those in the pit below or behind the cockpit). No bang seats like the pilots but parachutes and an escape door - very slim chance of successful use if the aircraft was going down, but at least a slim chance is better than none.

[Yaw String]

For all the big Boeings,as you have no time to go for a checklist if you hoover up Jonathan Livingstone and his cousins at 2,500' on take off,.ex Dubai,Maldives,Seychelles,Nosy Be,etc..

OPO U30 BFA,.....basically,everything covered by the ditching checklist,below 5000'

O override on Gear n Terrain(least useful item but kills the warning)
P packs off
O outflow valves closed(very good idea,this one)

U undercarriage up
30 Flap 30

B Through in a "Brace Brace"..............now the lucky bit,,and once in the water

F fuel control switches to cutoff
A Apu switch,pull

Throw in the perfect manoeuvre to parallel the swell therebye avoiding smacking in to a crest,and..hey presto,there you have it,the perfect ditching...

IN YOUR DREAMS!

[Willy Miller]

At my initial SEP when I joined easyjet it was explained that " a ditching was very unlikely because we don't fly over sea much"

I mentioned that a friend of mine had ditched a large aircraft just off the scotish coast due to fire and my last employer almost put and a/c in the sea off jersey by putting both props to feather instead of cruise.

You don't have to be mid Atlantic or lose both engines to end up in the drink!