Ever Wondered Why?

I was reading about things that pertain to airplanes and traveling on them. This got me to thinking about some things that do not make sense.

It was my understanding from a conversation I had with a pilot one day that if they have to choose between a water landing or a ground landing, they would choose a ground landing if the choice was equal in circumstance, in other words if landing on either would cause more life on the ground or water to be involved, they would choose the lesser of the two. However, if the lives on the plane are the only consideration they would choose to crash a plane on land rather than water 99% of the time.

I was shocked when they told me this until they explained why, it makes more sense to me now, water molecules at the surface, before they are disturbed, are actually stronger than the ground surface and that a plane would have a better chance of structural survival than if it hit the water. The ground has more give apparently. I am not going to get into a debate about physics or try to explain the dispersal of energy at impact, just found it interesting and wanted to share.

Why? This leads me to my second observation about planes, flotation devices seem rather useless. They could just fit each plane with an airbag, but that is not going to matter, unless the plane is able to hit the water at an angle which would allow it to pierce the water and break that seal of water molecules first, so that the impact did not cause the plane to disintegrate. Life boats would be better than flotation devices, at least those things could be designed to open on impact. They could, also, serve as beacons for the distress, make them reflective with built in l.e.d. lights, maybe.

This leads me to another suggestion maybe they could have a retractable device or a remote buoy that could be launched before the plane hits the water to break the surface molecules before the plane hits, reducing the impact of the water.

However, my last musing has to do with lessening the impact before hitting the ground or water, how about parachutes? Each plane could be fitted with 3 parachutes, catastrophic failure has most likely already occurred and wouldn't it be better to slow down the impact? This makes more sense to me than instructing people how to grab their seat cushions to float on a ground based choice for impact.

a reply to: searcherfortruth

That is interesting, never realized that. Parachutes do make more sense.

why 3 parachutes?
i must be missing something.

you expect people that have probably never strapped a chute on and pulled the cord to get into the harness, bail out, and pull before its too late. theyre supposed to do all this while mass panic is happening to them and around them?
sure, ok.
i just dont get in flying machines

a reply to: searcherfortruth

Flotation devices: Ethiopia 961 was hijacked and ordered to fly to Australia, even though the pilots told them they didn't have enough fuel. They ran out of fuel and made a water landing near a resort just off the coast of Africa.

As they were approaching the water, the left wing dropped and dragged in the water, causing the aircraft to cartwheel and disintegrate. Of The 125 people on board there were 50 survivors, four uninjured.

Even in a bad water landing there's the chance someone will survive. And if they make a good landing then there will be a lot of survivors.

Parachutes: A Boeing 777-200 weighs 297,000 pounds. That would mean one huge parachute or many small ones. Either way that's a lot of weight added. More weight means less fuel and fewer passengers.

Add that to the fact that most accidents happen in an envelope that would make parachutes almost impossible to use (takeoff and landing), and how safe aircraft have become (US commercial airline accident rates went up to 0.38 accidents per million departures) and you end up with a system that will cost you money and you'll probably never use.

They do have a parachute system for small aircraft that has been used quite a bit and has saved many lives. It just isn't feasible once you scale it up.

a reply to: TinySickTears

Size. They'd have to be huge though as heavy as aircraft are that fly internationally.

originally posted by: TinySickTears
why 3 parachutes?
i must be missing something.

you expect people that have probably never strapped a chute on and pulled the cord to get into the harness, bail out, and pull before its too late. theyre supposed to do all this while mass panic is happening to them and around them?
sure, ok.
i just dont get in flying machines

I believe the member is speaking of parachutes for the aircraft, not the people on board.
It is actually available for small aircraft.

originally posted by: Zaphod58
a reply to: TinySickTears

Size. They'd have to be huge though as heavy as aircraft are that fly internationally.

ok. i see what you and butcherguy are saying.
i missed the point. i did not know he was talking chutes for the plane.

that would be a hell of a sight

big ass double decker jumbo jet just cruising to a nice soft landing

a reply to: TinySickTears

They'd need so many parachutes for an A380 it couldn't carry any passengers. That would be something to see though.

originally posted by: TinySickTears
why 3 parachutes?
i must be missing something.

you expect people that have probably never strapped a chute on and pulled the cord to get into the harness, bail out, and pull before its too late. theyre supposed to do all this while mass panic is happening to them and around them?
sure, ok.
i just dont get in flying machines

The parachutes are for the plane, one for the front, one for the middle and one for the end.

a reply to: Zaphod58
I was going to suggest he talk to the resident aircraft expert and here you are lol.

a reply to: searcherfortruth

I used to launch the E-4B at 810,000 pounds gross weight. The size of those parachute units would be so big that it would cut that by a third at least.

a reply to: Skid Mark

I have radar for these threads.

a reply to: Zaphod58

Ah, that dreaded word, feasibility. Fiscal considerations in lieu of safety. Okay, maybe they would be cumbersome and costly and maybe they would create fuel issues and weight problems, they worked for the space program and those were reentering from space at a much greater rate a speed. Seems they could engineer something with all this new technology.

The air crash you cited for flotation devices, I wonder if the loss of life would have been lessened by life boats or parachutes? Also, I bet the fact the wing broke off and punctured the water at the time of impact allowed for the survival rate to be what it was.

You gave opinions about these things, but you failed to touch on other aspects of the OP, was there a reason for that?

a reply to: Zaphod58
I bet you can hear the ping from one being posted a mile away.

a reply to: searcherfortruth

There was nothing to comment on in the first part.

Yes, it's partly fiscal, airlines are started to make money. Do you know how safe air travel has become? You have a better chance of being hit by lightning twice on the way to the airport than of being in a plane crash.

Going back to the 777, United started service with them in 1995. They didn't lose the first hull until 2008, and the first passenger fatality didn't occur until 2013. Over 1300 have been delivered.

Yes they slowed the Apollo command module going much faster. It also weighed a fraction of what a modern aircraft weighs. In lunar orbit the command and service module combined was about a quarter of a 777 empty weight.

I get it, you want to save every life on a plane. You can't save everyone, as nice as that would be. In 2014 there were 1320 deaths worldwide in 111 crashes. In that time 3.3 billion people boarded aircraft worldwide.

a reply to: Skid Mark

It's more like a disturbance in the force.