An amphibian that sank?

http://www.divingservices.net/aircraft.jpg
http://www.divingservices.net/9bcess2.jpg

Anyone have the story behind this? Strange that a plane designed to
float, sank!

The Monk

"Flyingmonk" wrote in message
ups.com...

http://www.divingservices.net/aircraft.jpg
http://www.divingservices.net/9bcess2.jpg

Anyone have the story behind this? Strange that a plane designed to
float, sank!


Doesn't seem any stranger than a boat sinking. I believe they're designed
to float as well.

"Steven P. McNicoll" wrote in message
ink.net...
Doesn't seem any stranger than a boat sinking. I believe they're designed
to float as well.

These days, smaller boats often have flotation chambers filled with a closed
cell type foam (e.g. styrofoam) so that in the even that they are filled
with water, they might still remain on the surface, dependent upon what else
might be loaded in the boat... It wasn't always that way though... I've
helped recover sunken boats before that sank after hitting logs and such and
knocking holes in their bottom... Larger boats aren't required to have this
sort of positive flotation though... Don't remember exactly at what length
the requirement no longer applies... Probably around 25-30 ft or so, I
guess... It's quite possible that amphibs don't have this sort of design in
them...

In article ,
"Grumman-581" wrote:

"Steven P. McNicoll" wrote in message
ink.net...
Doesn't seem any stranger than a boat sinking. I believe they're designed
to float as well.

These days, smaller boats often have flotation chambers filled with a closed
cell type foam (e.g. styrofoam) so that in the even that they are filled
with water, they might still remain on the surface, dependent upon what else
might be loaded in the boat... It wasn't always that way though... I've
helped recover sunken boats before that sank after hitting logs and such and
knocking holes in their bottom... Larger boats aren't required to have this
sort of positive flotation though... Don't remember exactly at what length
the requirement no longer applies... Probably around 25-30 ft or so, I
guess... It's quite possible that amphibs don't have this sort of design in
them...

*23.751***Main float buoyancy.

(a) Each main float must have‹

(1) A buoyancy of 80 percent in excess of the buoyancy required by that
float to support its portion of the maximum weight of the seaplane or
amphibian in fresh water; and

(2) Enough watertight compartments to provide reasonable assurance that
the seaplane or amphibian will stay afloat without capsizing if any two
compartments of any main float are flooded.

(b) Each main float must contain at least four watertight compartments
approximately equal in volume.

"Roy Smith" wrote in message
...
23.751 Main float buoyancy.

(a) Each main float must have

(1) A buoyancy of 80 percent in excess of the buoyancy required by that
float to support its portion of the maximum weight of the seaplane or
amphibian in fresh water; and

(2) Enough watertight compartments to provide reasonable assurance that
the seaplane or amphibian will stay afloat without capsizing if any two
compartments of any main float are flooded.

(b) Each main float must contain at least four watertight compartments
approximately equal in volume.

I don't see anything in there that would require the supposedly watertight
compartments to still provide floatation in the event of them no longer
being watertight...

On a side note, I've heard that for emergency floats on offshore (oil rig)
helicopters, they often end up with the floats on the surface and the
helicopter suspended underneath it in the water..

In article ,
"Grumman-581" wrote:

On a side note, I've heard that for emergency floats on offshore (oil rig)
helicopters, they often end up with the floats on the surface and the
helicopter suspended underneath it in the water..

One of the fundamental truths of boat design is that the center of gravity
has to be lower than the center of bouyancy. If it's not, then eventually
the boat (helicopter, whatever) will figure out how to turn itself over so
that it is.

"Grumman-581" wrote in message
...
"Roy Smith" wrote in message
...
23.751 Main float buoyancy.

(a) Each main float must have
[...]

I don't see anything in there that would require the supposedly watertight
compartments to still provide floatation in the event of them no longer
being watertight...

There's not.

However, I have heard of seaplane owners who have done things like fill
their wings (or other easily accessed compartments) with ping-pong balls,
for this purpose.

Generally speaking though, seaplanes don't have any filler material, such as
styrofoam or what have you the way boats do. I think it's likely that this
is because, as light as styrofoam is, when you fill every empty space of an
airplane with it, that's still useful load you lose.

Of course, there are also the certification and maintenance issues as well.
The bottom line is, I believe, that it's much simpler to put a bunch of
lightweight filler material in a boat than in an airplane.

Pete

"Flyingmonk" wrote in message
ups.com...
http://www.divingservices.net/aircraft.jpg
http://www.divingservices.net/9bcess2.jpg

Anyone have the story behind this? Strange that a plane designed to
float, sank!

The Monk

I could be wrong, but wasn't the Titanic designed to float?
:-)
DH

"Dudley Henriques" wrote in message
link.net...

"Flyingmonk" wrote in message
ups.com...
http://www.divingservices.net/aircraft.jpg
http://www.divingservices.net/9bcess2.jpg

Anyone have the story behind this? Strange that a plane designed to
float, sank!

The Monk

I could be wrong, but wasn't the Titanic designed to float?
:-)
DH


As I recall it even had lots of watertight compartments designed so that you
could flood several of them and the Titanic would still float. Unsinkable,
they called it. After it sank, the Unsinkable title was transferred to
Molly Brown of Denver. :-)

Highflyer
Highflight Aviation Services
Pinckneyville Airport ( PJY )

"Flyingmonk" wrote in message
ups.com...
http://www.divingservices.net/aircraft.jpg
http://www.divingservices.net/9bcess2.jpg

Anyone have the story behind this? Strange that a plane designed to
float, sank!

It broke the law . . . . Law of gravity

(and the law won)