h a l f b a k e r yIt's as much a hovercraft as a pancake is a waffle.
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Ok iv got some ideas mostly to do with aviation
I havent read to much on this site so apollogies if
i repeat any ideas.
Retro fitting existing airliners with water landing
capabilitys...
in an emergancy the captain dumps the fuel then
pulls the big red lever. this causes a series of
explotions
to detonate, on the 4 engine pylons, thus
jetisoning the jets, we now have the ability to
glide further and skid on the surface of calm water
couple this with some slow down parachutes in the
tail section (like on the space shuttle) to take
the plane from 160 mph down to 30/40 mph and you've
got a pretty survivable gear up crash landing even
in quite choppy water
US Airways Flight 1549
http://en.wikipedia...Airways_Flight_1549 A pilot with skills beyond outstanding ... [8th of 7, Sep 04 2014]
Problems with Pins
http://community.se...921227&slug=1532256 Breakaways already installed; not completely problem free [lurch, Sep 04 2014]
737 engine
http://en.wikipedia...ral_characteristics weight [EkranoMan, Sep 05 2014]
ditching of flight 961
http://en.wikipedia...Airlines_Flight_961 Ethiopian_Airlines_Flight_961 ditching hard [EkranoMan, Sep 05 2014]
[link]
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// Retro fitting existing airliners // |
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It's extremely difficult to retrofit any substantial modification to an
existing civil airframe. |
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// jetisoning the jets, // |
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If you detach the powerplants, you'll completely throw the weight and
balance of the airframe. Civil arcraft are designed to have a centre of
gravity pretty much co-located with the wing mainspar. Change that,
and you put huge - possibly unmanageable - loads on the control
surfaces. |
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// we now have the ability to glide further // |
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The drag would be reduced, as would the weight; for a given altitude,
the glideslope could be extended somewhat. |
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// and skid on the surface of calm water // |
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With a "smooth" underside - without dependant engine nacelles, or
landing gear - the chances of a smoother belly landing are improved.
However, see <link>. |
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// couple this with some slow down parachutes in the tail section (like
on the space shuttle) to take the plane from 160 mph down to 30/40
mph // |
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It is easy to shed airspeed with judicious use of flaps, speed brakes,
and attitude. Civil transport aircraft wings will stall at 120 knots. The
aircraft would then nosedive into the water. |
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Ditching calls for maintaining flying speed just above stalling, in a
nose-up attitude, until contact is made, then relying on fluid drag to
decelerate to a stop. |
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// and you've got a pretty survivable gear up crash landing even in
quite choppy water // |
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Welcome to the HalfBakery ! Aviation ideas are always welcome, and
a popular topic of highly informed debate. |
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Welcome, [EkranoMan]! Not sure this would be such
a great idea, though. I suspect that a good
pilot in control of a normal passenger aircraft could
make a water landing without losing the engines. As
[8th] pointed out, you can't slow the plane down
much below 100mph, or the thing will stall. |
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A safer option, as used by MH370 when faced with a
disaster over the ocean, is simply to vanish
completely. |
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Civil airliners will likely go to over-the-wing engine designs
for reasons of noise abatement. The absence of under wing
scoops should make for more ditch-able aircraft. |
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Wings, schmings, lose the things. Leave say a 10 foot section on each side. With any luck you're right-side up with your ass dragging in the water when this happens, then only having to worry about skipping over the pond at 100mph. |
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I think the parachutes should go on top of the aircraft, given its nose-up orientation when landing. Put them on the hind end and they'll either break when they catch the water, or pull the tail off. |
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Welcome to the HB. When you finish a post, it's a good idea to check it over for spelling mistakes and grammar and other shit either before you hit <OK> or even afterwards when you see it on the page for the world to read. |
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Every once in a while you hear of the emergency slides
inflating inadvertently on a passenger aircraft. That's kind
of expensive - a few tens of thousands of dollars to replace. |
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The same kind of scenario with the engine jettison
pyrotechnics would be much more expensive. |
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Plus - I'll bet you'd kiss ETOPS good-bye. |
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Engines are attached to the pylons, and the
pylons to the wings, with fracture bolts -
intended to fail under overload before any
other component does. |
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Incorporating pyrotechnic cutters would not
in fact be that difficult or expensive, it's a
mature technology. |
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If a plane is ditching, the engines will be BER
anway, especially in seawater. Dropping
them just at touchdown makes sense.
Dropping them at altitude does not. |
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ETOPS certification would be
challenging. |
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>you can't slow the plane down much below 100mph, or the thing will stall. |
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The logical solution is just plate the bottom of the plane with sodium. The steam forms a cushion allowing the plane to well, plane across the water, giving more time to decelerate. Coupled with small submarine clamped to the bottom of club class this should save the lives of the ones with expensive lawyers. |
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yes retro fitting a parachute system would be a monumental
upgrade, i almost wasnt gonna surgest it, but this is halfbakery.
got to have radical ideas here. |
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i dont think adjusting the pylons would be that difficult though.
if they where to make the changes to the engines before a routine
refit.
The cost isnt so much the price of the parts, its the cost
of the loss of revenue that the aircraft would have made
if it wasnt in the hanger. |
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the 737 engines weigh 1.5 to 2.1 metric tonnes (link)
dropping that amount in level flight would definitly
result in atleast a big bump....
but (if I remember correctly) there is a tactic that glider
pilots use...
that is to fill the craft with a half ton of water ballast.
nose down, build up lots of speed, then drop ballast and then
glide up to much higher than there original altitude.
if the pilot of the 737 were to nose down while dropping
the engines, there would be significantly less up pressure
on the wings, meaning much less of a bump. |
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i dissagree that the craft would become unstable because
the engines are located on the wings, the wings are at the
centre of gravity in most civil aircraft, thats why they
store most of the fuel in the wings. |
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dont get me wrong, I dont think it will be anything less
than a brutal crash land.
but when you see Ethiopian Airlines Flight 961 ditch see link.
you would think how did 50 out of 175 people manage to survive.
plus many would have survived the impact and drowned soon after |
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// and you've got a pretty survivable gear up crash landing even in quite choppy water // |
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// I suspect that a good pilot in control of a normal passenger aircraft could make a water landing without losing the engines. //
I think it would be easier without the engines.
when you ditch a plane its a complete right off, the engines would become scrap anyway, so why keep em. |
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//A safer option, as used by MH370 when faced with a disaster over the ocean, is simply to vanish completely.//
lol mean ;) |
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// Civil airliners will likely go to over-the-wing engine designs for reasons of noise abatement. The absence of under wing scoops should make for more ditch-able aircraft.
bs0u0155// |
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its a big industry, and it dont look like its changing its designs much
for a very long time. plus theres trillions of dollars worth of planes in the sky
already seee (link)
the system for maintaning/swapping engines is set up for under wing.
the're not going to care that much about the few ditchings per decade, the
designers will just moraly shift the blame to the poor mantainance of the carriers.
this idea isn't a game changer, its just a quick patch job. |
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//I think the parachutes should go on top of the aircraft, given its nose-up orientation when landing. Put them on the hind end and they'll either break when they catch the water, or pull the tail off.
FlyingToaster, Sep 04 2014//
yes that is a better place to put them in this situation. keeps the nose up for as long as possable.
but i was thinking that rear chutes would be very useful in emergency conventional landings.
but the way they do things, any type of chute would never be cost effective. |
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//
Every once in a while you hear of the emergency slides inflating inadvertently on a passenger aircraft. That's kind of expensive - a few tens of thousands of dollars to replace. |
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The same kind of scenario with the engine jettison pyrotechnics would be much more expensive.
lurch, Sep 04 2014 // |
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emergency slides are connected to the doors which are opened twice per flight.
this system would sit quietly in the background with plenty more failsafes. |
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//
Breakaways already installed; not completely problem free lurch, Sep 04 2014 //
those are uncontrolled Breakaways.
with my system the captain could make the choice of the type of emergency that would require a fast jettison
thus you would have the ability to make solid pins that would never have the problems that are in that artical. |
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The logical solution is just plate the bottom of the plane with sodium. The steam forms a cushion allowing the plane to well, plane across the water, giving more time to decelerate. Coupled with small submarine clamped to the bottom of club class this should save the lives of the ones with expensive lawyers.
not_morrison_rm, Sep 04 2014
// |
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you can tell from my name i love ground effect. |
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also ETOPS?
i would of thought that this would give the plane a dramaticaly increased glide slope.
when an engine fails it goes from being a thrust device to a great big air brake, if the captain jettisons
a failed engine the remaining engine would take you a lot lot further. or am i missing something? |
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ps
thanks for the welcome everybody thumbs up. |
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//Am I missing something ?//
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About //1.5 to 2.1 metric tonnes// halfway out on one wing. My sliderule's in the shop: I suppose ailerons could compensate. |
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large aircrafts often have a 5th pilon port on one
side so they can transport an engine that needs
repair from one country to the home base.
you can easy trim the craft by pumping some of the 20 tons
of fuel from one wing tank to the other( or just drop
fuel from one side ) |
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You could mount drag devices on the wingtips. Passenger safety notwithstanding, those engines are like $5-10mil each. |
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the less drag, the higher the etops
the higher the etops, the further into nomansland you can travel
the further into nomansland, the more of a direct
route you can take, which means more fuel savings and quicker journeys |
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lets say we have 200 passengers each paying $500 thats $100000. then lets say
that profit is then half of that.
so after 200 flights without a failed engine, they can afford a new one.
also, a failed engine, is not worth as much as a new engine.
$5-10mil may sound like a lot to you and me, but say these guys are running
>300 flights a year, per plane.
Besides, the most important thing here, is that you would
only drop an engine if it failed in ETOPS nomansland, which is probabily
<5% of the journey + i think most engines fail soon(ish) after takeoff. |
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Drag has very nearly zilch squat to do with ETOPS. All
current airliners are built to handle quite adequately with
an engine out - the thing that effects the granting of
ETOPS is the probability that you'd lose a second engine
while flying with one out. You have to keep your IFSD (in-
flight shutdown) rate down to around 0.01 occurrences
per 1000 flight hours to maintain a 180/207 minute
rating. That's around one in every 100,000 flight hours. |
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So, with a current average of about 40,000 long haul
blocks per day, averaged at about a 5 hour stage length,
we'd see about 2 IFSDs a day - if everybody was running
top-notch maintenance - which they're not. It's kind of
hard to get really good numbers, but I'd guess a real
figure would be upwards of 4. |
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Rolls Royce, GE, & Pratt&Whitney combined couldn't keep
up with you tossing that many engines in the drink. By the
middle of the second week you'd be setting up power-by-
the-hour contracts with Tumansky. |
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Oh, and nobody makes a 50% profit margin on flying
airplanes around. Nobody even makes 10% - unless you're
running drugs, or flying charters for the US Government.
Or running drug charters for the US Government. |
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// a failed engine, is not worth as much as a new engine // |
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Quite untrue. An engine may shut down with a very minor fault, to pre-
empt further damage occuring. Repair may be accomplished without
removal of the unit from the airframe. |
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Consider an oil pressure failure; the system shuts down N1 before any
actual damage occurs. A new oil seal/pipe/pump and a refill of oil and
all is well again. It's just that you just can't do that in flight. |
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Even a turbofan that's ingested a flock of geese and abruptly stopped
may still be repairable, or if not there may be a high proportion of
undamaged components that can be recovered, recertified and re-
used. |
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And when planning a route, shortest often doesn't equal best. Winds
aloft are critical. Tracking round a weather system to turn a ten knot
headwind into a ten knot tailwind is well worthwhile, and at FL300 and
above 100-knot winds aren't uncommon. That can be 20% of your IAS
in some circumstances. And since almost all transcontinental routes
are a Great Circle, or a sector of one, effectively you always have two
choices. |
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Get yourself a globe*, a couple of pins, and a length of string. Stick the
pins in a couple of major cities half the world apart. You'll soon get tge
idea. |
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*It is important not to use an inflatable globe in this case, as the
results may well exhibit significant time-variant changes. |
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I had ETOPS all WRONG, sorry, I thought it was about the maximum distance you can travel on one engine.
but more sensebly, its almost all about reliablity of the remaining enigine. |
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and i also thing lurch is much closer to me about the profit margins. but i still do
think they are making big bucks |
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Iv been schooled, tips hat. |
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in my defence, i did not say to drop an engine the minute it fails, i was just saying to drop it
if you're so far out at sea that that you can't make it back with the added weight + friction.
which i think would be <1% of IFSDs |
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//*It is important not to use an inflatable globe in this case.. |
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Especially if it's filled with helium, when you're giving your presentation.
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Strangely reminds me of the SF short story, where the Atlantic is yer common and garden ocean, but the Pacific is fractal in nature and so can never be crossed. Damned if I can remember the name of it.. |
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//Iv been schooled, tips hat. // |
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Wait 'til the spelling and punctuation pedants arrive. |
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Yup. Lined up like vultures on the telegraph
wires, waiting to swoop. |
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This is his first posting, so he gets a bit of
leeway. Next time, it'll be the rubber
truncheons and cattle prods right from the
start
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You all talking Chinese to me, you know, but welcome
[EkranoMan], to the asylum. |
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Well, as the Chinese say, you can throw a stick but
you can't make soup from it. I think that's something
we should all bear in mind. |
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So, we should all think about making Chinese sticky bear soup ? |
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Is it easier to land an airliner on bear soup than on water? Perhaps yes, if it is sticky. |
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Much lower friction than water, because it's a properly constituted
load-bearing surface ... |
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The Chinese can make a soup out of ANYTHING. That's a
scientific fact. |
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Indisputable. Unfortunately, "anything" encompasses melamine,
rattus norvegicus, cement, lupins, and unreprocessed nuclear waste. |
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