How's this for a though, mount a glider on top of a 747 (a big assed glider) all the passengers sit on the glider mounted on top of a 747 for example..
if there's a problem with the 747, the latches get blown off and the glider is released landing everyone safely? - obviously a redesign of everything would be in order, but a glider that can detach incase of emergency? (everyone sits in the glider which looks part of the plane)
Not too sure it would be safer. The glider would have to have an incredible wingspan, & bigger or more engines for the plane. Would it just not be adding more stuff to go wrong?
Especially when gliders need to be extremely light to minimize the effect of parasitic drag, this would then lead to the problem of a weak air frame giving way and the wings folding in on each other. With an average glide ratio of 15:1 for airliners ( 17:1 for 747 ), at 30,000 feet they can safely land close to 140km away. Gliders can have 30:1 upto 60:1, but that is when they are an empty shell.
A typical glider has about a 20m wingspan for one maybe two people, a 747 has a 64m span for hundreds ( do the maths for the glider of hundreds ). For a plane to come down without gliding would mean something catastrophic has gone wrong, which might lead to the inability to react in time and release the glider ( which could also fail ).
How many times would this come in useful?
Modern commercial airliners have very high reliability engines - so much so that many can fly across the ocean with just 2 engines; if there is trouble with 1, theyn can safely divert to land with the 2nd.
Great engines & great glass!
I love the invention of airplane glass in America.
Some other country I forget now, used a cannon to shoot plucked chickens at plane windscreen to test its ability to withstand bird strikes. American engineers thought its a great idea and embarked on their own testing of different materials.
After a while of wondering why their glass was inferior to the other country and broke on every chicken strike, they sought help. Some bright spark had the idea to defrost the chickens first.
Probably mostly an urban legend, but as an Aussie, I like to think its all true.
Lets not even get into the invention of the 'space pen'.
pYro_65:
Great engines & great glass!I love the invention of airplane glass in America.
Some other country I forget now, used a cannon to shoot plucked chickens at plane windscreen to test its ability to withstand bird strikes. American engineers thought its a great idea and embarked on their own testing of different materials.
After a while of wondering why their glass was inferior to the other country and broke on every chicken strike, they sought help. Some bright spark had the idea to defrost the chickens first.
Probably mostly an urban legend, but as an Aussie, I like to think its all true.
Lets not even get into the invention of the 'space pen'.
I visited a airplane building site once in europe and one "attraction" was the chicken cannon. They told use they used "frozen chickens" as a test once and they flew through the glass like the glass was not there.
That was after someone asked the state the chicken was in before being shot at the glass which brought up the de freezing of the chickens.
Try a web search for the Cirrus Aircraft Parachute System (CAPS).
I can't imagine what would be going through a pilot's mind the moments before they launched a parachute like that. The decision between gliding the aircraft into a landing or launching the 'chute, especially if there is a population center below... damn.
Can you imagine the size of a chute needed for hundreds of people (and their baggage) and the mass of the aircraft? Wow.
And the fuel needed to carry it. And the added maintenance for it.
And the lawsuits that would follow if it ever needed to be used.
Think I'll stick with flying the glider to the ground.
One of my favorite "stories":
Hi, they already tried the glider on the 747 idea, it was called the Space Shuttle.
Tom....... 
Honestly Pyro I never know when you are serious
Rob
pYro_65:
After a while of wondering why their glass was inferior to the other country and broke on every chicken strike, they sought help. Some bright spark had the idea to defrost the chickens first.
I prefer the much more dramatic (and much less believable) version of the tale that involves the pilot's seat being torn off the mounts and smashed into the back of the cockpit.
I thought the story was frozen turkeys and train engine windows...
Lots of variations.
pYro_65:
Some other country I forget now, used a cannon to shoot plucked chickens at plane windscreen to test its ability to withstand bird strikes.
No wonder those birds are so angry!
cjdelphi:
How's this for a though, mount a glider on top of a 747 (a big assed glider) all the passengers sit on the glider mounted on top of a 747 for example..
So you're essentially suggesting airliners be built twice the size they need to be? Do that, and I guarantee the airlines will just sell twice as many tickets. (The ones on the redundant craft will be more expensive, of course, but you get a complimentary bag check.)