Lifejacket. Tying a double bow.
 

After teaching safety stuff for nearly a decade I was challenged yesterday as to what constitutes a double bow, as required by our company to tie a lifejacket round the waist.
I've always assumed that a double bow is the simplest tie that you use for shoes whereby one tug on either straight section will release the lifejacket whereas the other opinion voiced was that a 'double' bow was the same knot I use plus another knot added on top to prevent the first knot coming undone.
Isn't the idea that the knot should be able to be untied even with cold hands?

Would have thought that the double bow was to prevent the thing comming undone.You wouldnt really want your lifejacket comming off in the water having been snagged on something during an evac or by a panicked passenger pulling at everything in sight.Scarry thought.

Then why not just tie a simple knot without loops on it. Surely you'd be even less likely to get snagged? We teach smokehoods to be tied without loops so as to prevent you getting snagged on armrests etc so why not lifejackets?

My understanding is:
1. Shoelace bow knot.
2. Take bows and tie in overhand knot.

Like this.

Edited to mention that, yes, the overhand knot will be difficult to undo when wet and with cold hands. Use a ballpen as a spike to open it. (I hear they can also be used for emergency tracheotomy.)

Err... Just SLF here, but bow? Double bow ? On all my flights over the last five years, both within Europe and half way accross the world, all the lifejackets which I have seen demonstrated have plastic clips to fasten the lifejacket, which you attach, then pull the excess strap to tighten... No mention of tying bows :confused:

I thought I was paying attention...

Maxbert

Well, just goes to show.
In all the flights I have done over a considerable time, I've never seen a commercial airline demo carried out with anything other than tapes.

As far as the "double-bow" is concerned, can't see the problem. Tie a bow then grab hold of both ends of the bow and tie another one.

And if there are no clips a follow up question: why tie (the double bow) at the side?

Rwy in Sight

I regularly fly with Flybe. They always tie the tapes under the lifejacket with what I would call a reef knot. As SLF I've often wondered why both the knot and its position are different from other airlines.

But then maybe I should get out more!

RHRP

Reason for tying it to the left side is that the lanyard you pull to inflate is on the other side. As to clips, we bought a load of the clip type but the CAA mandated their replacement with tape type.

The question still remains...why a double bow and not any old knot? There HAS to be a good reason, surely?

Perhaps so it is easily undone for whatever reason.

One of my previous airlines did the double bow thing and we were supposed to get people in a loop and link each other with the tapes but I can think of situations where you may need to break that link. A double bow would be easier than a knot.

Good question, though.

Spoken to the CAA. "No idea. I'll get back to you". Called the Coastguard. "No idea. I'll get back to you". Phoned the manufacturers. "No idea. I'll get back to you". Tried the Royal Yachting Association. "Not a boat? Sorry". Emailed the Royal National Lifeboat Institute. "404, file not found".

One point that might be of interest is from the CAA Safety Sense pamphlet. After the SAR Helo picks you up they need to get the old jacket off and give you a new uninflated one. How would they get an old one off??? Knife?

Any SAR types on here?

I would think that part of the reason we use bows rather than any old knot are because the tapes on some life jackets are extremely long. With just a random knot, you'd run the risk of tripping over the tapes on the way to the door but the bows take up some of the excess tape. I couldn't say that that's definitely the reason, but it seems to make sense. Also, if you do have to have to remove the old jacket for a new one as per the SAR helo, the width of the tapes make double bow knots fairly easy to undo, although it'd obviously be trickier when wet. But I may be completely wrong on all of those points!

Would be interested in the answers from those in the know if they ever come back to you!

blue up,

I will probably meet some SAR guys on Sunday. I will ask them about the removing issue.

Rwy in Sight

It's like Jetset lady mentioned, it's to do with the length of the tapes.

It's easier to tie a bow than a knot, given of the length of the tapes you have to feed through tying the knot. Also bear in mind it will probably be dark with panic setting in so you don't want to be struggling with 6 feet of tapes, a double bow is unlikely to slip therefore allowing your life jacket to ride up when floating in the water or worst still come off over your head.

One would imagine that most would know how to tie a bow, so perhaps that is the reason. Although with our shoeless brethren the newer style clips would be better.

No need to remove the lifejacket in the helo, just deflate it using the valve in the mouthpiece.

the reasoning my airline trains bow rather than knot is you may have to get it off quickly ie to swim under water to avoid a hazard and a bow is far easier to untie than a knot.

Gordon Bennet! A ditching, evacuation, and now we are into sub aqua......
Words fail me.
It really wouldn't be a good day, would it?
Do they provide the snorkel as well?

Hi Maxbert...

Indeed, you were paying attention and are correct. The minimum performance standards for the design of life preservers approved for use on board aircraft in North America (and many other parts of the world that have adopted a similar standard, such as EASA) requires the following:
Typically, in order to meet this performance standard (one attachment and one adjustment), a plastic clip is used by the manufacturers. You can see a typical example of this type of life preserver and attachment at the following links:
Eastern Aero Marine EAM XF-35
Eastern Aero Marine EAM UXF-35 - photograph
Switlik AV-35H - photograph

I spoke with a SAR captain and he said he does not care how a life jacket is done. Even if it is with a knot, the SAR crew can use a knife to cut the life jacket and give a new one.

Rwy in Sight

This thread is an example of what is wrong with cabin crew training in airlines. Pointless, trivial rubbish is taught, trained, discussed and examined. The cabin crew safety trainers are so far from reality it's criminal. Instead of focusing on "Big Picture" stuff, detritus like this keeps bobbing up to the surface. This thread shows what happens on a real evacuation (which may have been caused by yet another "smoke" incident). I don't believe anybody has ever really thought through what happens in an evacuation AND then followed it through to see a change in safety procedures. Lessons learnt from Kegworth (British Midland 737-400) did result in a changed "brace" position but seat pitches have come so reduced as to make these changes pointless.

EASA won't make things better either. This is another Euro-drinking-social club for those who can't get real job. They won't make a decision even if their lives depended on it. What we really need is a clean slate and new procedures written for the people who actually fly designed by those who understand aircraft, crew and passengers in distress.

PM

..probably they got sick and tired of people asking '..when you say a knot, what sort of knot would be best ?' so having to say something went for the one most people would have some clue about which wouldn't come undone too easily.

A bow is a slip knot that most people would remember how to tie.

Actually as a 30+ year flyer & trainer the one thing you cannot say is we have lost touch with reality, we are the 'reality' dealing with safety on a daily basis on the a/c and in the classroom, the CAA say l/j's need to be tied in a double whatever we chose bow for the afore mentioned reason earlier.
We are totally in touch with what the current climate requires, we are accredited to train both pilots & cc in security,recognition of fire arm & explosives, dangerous goods, first aid, restraint & conflict management,cabin safety & equiptment use as well as aircraft specific conversions, we under go intensive fire fighting training and the list goes on & on, our training is considered the best & most realistic you can get without actually crashing a plane and i take great offense at an earlier comment & would be interested to hear that individuals credentials!

Mr Optimistic,

Few passengers will bother questioning a crew regarding the safety demo, because not a lot of them pay attention to it.

Rwy in Sight

One way to get attention is to remove all the alternative attractions. As i recently posted on another tread, put out all the lights except for spotligts on the crew giving the briefing/demonstration.

On the B787, this could be augmented by darkening all the windows. Then there is also the Air New Zealand approach.

Maybe a briefing like this would make a difference

Pilot for 18 years, Captain for 12 years. Passenger with about 400-500 flights. And to respond...
Legislation or Safety? The two are not the same. The CAA are very slow in updating safety legislation. They normally wait for a few a crashes and fatalities before they do anything and airlines are legally prevented from trail-blasing.

By the CAA/IASA? See above.

A system that prevents a pilot flying a UK registered aircraft from taking their wife on a jumpseat, something which the rest of Europe allows. A system which pats down armed police officers to make sure they are not carrying "prohibited" liquids airside. Give me strength...

Really! If you can find and recognise molded PE you are doing the wrong job. By the time this stuff is on the plane it's too late. Or do you do bomb/ordnance disposal training as well?

And then what? Gel, water, milk, beer? But this is getting more relevant if you have the equipment to deal with the hazard.

Getting better and more relevent.

Nice concept but probably a waste of time and effort. Unless of course, you don't mind loosing your teeth.

That's more like it.

Okay.

With water (no BCF) little heat and protective clothes - not the ones you'll actually be fire-fighting in. I question the validity of such training

I bet it does!

By whom? You? Ill informed and ignorant passengers? The CAA? Or the AAIB following a major incident?

The world is a tough place, but even tougher when what you have been teaching appears to be worthless following a real emergency.

Oh, my part time job is an accident/incident investigator and flight safety analyst.

PM

Seems to me from your complete negativity and total lack of respect for others opinions it's just as well you're part time.

Oh dear! P.M. you've dared to question the status-quo.

all makes sense to me,this farcical. ridiculous ar5e-covering myth which is being perpetuated.....
Perhaps we'll have a "Sully"scenario during the next Century, In which case the grossly inadequate seat belts MAY prevent some injuries (and probably cause some when the pax jackknifes....maybe the lifejackets will
save the odd escapee who loses their footing........
realistically, this is all window-dressing flim-flam so all the "safety" industry can stay smugly on the gravy-train and self-righteously say"we're doing the best that we can"

Oxygen-generators that work by DELIBERATELY starting a combustion process and generating fuel to feed it? (note, I didn't dramatise and say "A FIRE" :p ).....and we're expected to BELIEVE this piffle is realistic?

SHACK...the Emperor really doesn't have any clothes on, HONESTLY :\

Oh Good - The Experts have arrived. To save time, allow me to distill the accumulated knowledge.

CAA/FAA are useless... Industry Tombstone Safety Protocols are useless... Most if not all cabin safety equipment is useless... Brace positions and other cabin safety procedures are useless... Flight Attendant training is useless... etc. etc.

Those of you who read this thread and actually do this for a living should be aware that the truth, as always lies between the two extremes - The slightly disturbing over-confidence and optimism of oldbalboy does no more to reassure than the absurd extremes of cockney steve and Piltdown Man: The idea that you are entirely right and everybody else is entirely wrong is something that most of us grow out of early on in life, as is the idea that we know better than the accumulated wisdom of others paid to have knowledge. The real problem, and probable loss to safety in general, is that something that might either be a good idea, or at least merit further examination gets lost in a tsunami of inflammatory and self-regarding bull**** - It's a Signal-to-Noise thing.

The Experts on this thread are no different from the other Experts that we meet on-board - Those who know that their mobile phones don't really need to be off when we ask, or who know that the turbulence has eased so that now is a good time to ignore the seatbelt sign, or know so much that they don't need to watch the briefing, and so on. Let's do what we always do and smile sweetly while thinking about something else that is more pleasant: We won't win after all - They're so much cleverer than we are. In the meantime, enhancements will be made to our safety procedures over time and some of them will be made as a result of knowledge gained from accidents and incidents: We all know, understand and accept that process because that's what we do for a living. When those enhancements occur it won't be as a result of the PPRuNe experts.

:cool:

Even the shod youth of today has difficulty with tying laces, so in ten years time passengers are quite to require a pre-departure workshop to understand the instruction "tie a bow" ...

Exactly, as can be vouched for by myself and a further 11 colleagues still around today. No training course can ever be complete and comprehensive but neither should it be dismissed as useless.

I think I've been misquoted. All I did was rattle the cage a little and some precious indignation came running out of its little house. I truly believe that unless we can carry people safely from one place to another there is no point in doing what we do. Part of that process is to use our imagination, trends and statistics, science, topical knowledge etc. and to constantly question what we do. I'm fortunate in so much that I am able to question how we go about doing our jobs.

But not for one minute do I ever accept that those who make the legislation we have to follow are always correct. Nor do I have to believe that fashionable items of training like "restraint & conflict management" will yield much in the way of a return (or more likely, loss reduction) - but I'm open to argument on this. I also know for a fact that cabin crew do an amazing job considering the some of the vicious, vindictive bullies they have to work for. We don't have to look far to see how effective cabin crew can be when a flight has a traumatic end - Glasgow, Hudson River, 777 & LHR etc.

No, my argument is that "our" procedures are not what they should be. Passenger's (and crew's) outlooks, experience and social attitudes are different from the ones who were considered when the current "safety" policies were written. Also, there have been physical changes in people and aircraft and we (and more importantly, our regulators) rarely take this into account as time moves on. Therefore, we perpetuate outdated procedures and like religious fundamentalists insist that what we do is as close to perfection as is possible (and remember, if you don't tie that double bow, you'll surely drown!).

Yes, I'm a fully paid up member of the "awkward squad." As would be expected, have to have the reason for everything explained to me and even then, I might not believe what I'm being told. However, until the procedures change, I also have to conform and comply.

I would have hoped that this was a place where a discussion could take place rather than just stick with the status quo. But maybe like some SEP Trainers, I'm a just little niaive?

PM

Going slightly off topic, I've had a reply from the RNLI who sent me some DVD videos on the life jacket design and usage.

One major factor in drowning Vs surviving is having the jacket correctly adjusted so that the head is kept out of the water. Jackets are designed to work correctly at a certain angle to the body to maximise the mouth/nose clearance from the water and a loosely fitted jacket will drop your cakehole into the path of every wave. The FAA/EASA line of requiring clip/adjust types makes perfect sense in that the jacket can be adjusted (tightened) to keep the bladders from rising up under your chin whereas the strap type, if not put on correctly, would be a total PITA to adjust. Also, having it tight to the body will preserve body heat. Food for thought?

As and when any other pertinent info comes In I'll post it here. Might be useful to someone, one day.

PS. 10,000 hrs 757/767 and 8 years CRMI.

To drown following an aircraft accident seems the ultimate irony to me. There are a lot of life jackets being ferried around the world for not too many commercial passengers saved. Not much help on AF447.........Given a choice I would rather have a smoke hood but then I would be happy to fly with neither given the odds.

From the Hudson river incident. Spot the guy who didn't manage to tie the life-jacket correctly...

http://jetsmoke.com/crashmain.jpg

Interestingly, I can't spy any tapes or straps clipped round the waists. Curious, not criticising.

Tying a life jacket in a double bow is in theory to prevent the life jacket straps from being tugged or loosened while exiting the aircraft.

If the pax should for what ever reason then become unconscious, life jackets with only a single bow or loosely tied could ride up/move and either suffocate or drown the poor pax and with cold hands be almost impossible to retie.

If you need to "avoid" an object James Bond style simply deflate your life jacket putting your finger in the manual inflation tube. No untying needed.


A life jacket strap should be tied tightly around the waist and not the hips to ensure a tight fit and best use of the floatation aid.

....My only gripe with the CAA/FAA is their stowage.

Under seats with lots of hand luggage and a tight seat pitch makes it both very hard to reach them and very hard to security check.

Next question! :)

CAA Spec. 05
 

Here's what the CAA say about the subject. Section 4 describes donning and adjustment. Therefore I'll suggest that UK registered airlines, quite reasonably, have assumed this to mean that a "double knot" is an acceptable method to secure a life jacket. I will not argue against that. But there again, so is any other non-slip knot as long as it is quick to tie. What this thread shows that cabin crew are not given sufficient background regarding the origin of their companies' procedures, as they should be. Failure to supply the relevant information means that invalid, incorrect and at times ridiculous reasons are invented to explain why we do what we do.

PM

Perhaps a reef knot might fit the bill. Easy to do;"left over right and under, right over left and under", and "breaks" easily when needed to undo.