Survivability VS landing speed

Hi All,

Some time ago, kitplane had an article concerning the survivability as
a function of landing speed, at least I think that was the nature of
the article. Anyway, does anybody know about the article, or where I
can find a copy. If I remember correctly, the article was very well
written, and I am in need of some data that was presented.

Thanks in advance for the help

Best Regards,

Dave

wrote in message
ups.com...

Thanks in advance for the help

I can't help you on the specific article (I would like to see it myself).
Remember that Energy = MV^2, and the landing ain't over until all of that energy
has somehow been dissipated. It can be dissipated in aerodynamic drag, rolling
resistance, and by heating up brakes; or it can be dissipated by deforming the
airframe and its occupants. We naturally prefer the former.

Assume any weight you like for your airframe and do the math for different
speeds. You will quickly discover that ten knots one way or the other makes a
heluva difference. A lighter airframe also makes a significant difference.

This is why the Sport Pilot regulations limit both gross weight and stall
speed... to limit the landing energy the pilot must deal with.

Vaughn

"Vaughn Simon" wrote in message
...

wrote in message
ups.com...

Thanks in advance for the help

I can't help you on the specific article (I would like to see it
myself).
Remember that Energy = MV^2, and the landing ain't over until all of that
energy
has somehow been dissipated. It can be dissipated in aerodynamic drag,
rolling
resistance, and by heating up brakes; or it can be dissipated by deforming
the
airframe and its occupants. We naturally prefer the former.

Assume any weight you like for your airframe and do the math for
different
speeds. You will quickly discover that ten knots one way or the other
makes a
heluva difference. A lighter airframe also makes a significant
difference.

This is why the Sport Pilot regulations limit both gross weight and
stall
speed... to limit the landing energy the pilot must deal with.

Vaughn

Presuming, of course, that the plan is to crash--which has been one of my
biggest criticisms of both Ultralight Vehicles and LSA from the beginning.

OTOH, other things being equal, higher landing speed also equates to greated
crosswind capability. Given excellent pilot proficiency, 10 knots change in
landing speed means up to 4 knots change in maximum crosswind
component--which is also a heluva difference!

Peter

On Jul 7, 8:46 pm, "Peter Dohm" wrote:
"Vaughn Simon" wrote in message

...



wrote in message
oups.com...

Thanks in advance for the help

I can't help you on the specific article (I would like to see it
myself).
Remember that Energy = MV^2, and the landing ain't
over until all of that energy
has somehow been dissipated. ...

... You will quickly discover that ten knots one way or the other
makes a heluva difference. ...

This is why the Sport Pilot regulations limit both
gross weight and stall
speed... to limit the landing energy the pilot must deal with.

...

Presuming, of course, that the plan is to crash--which has been one of my
biggest criticisms of both Ultralight Vehicles and LSA from the beginning.

OTOH, other things being equal, higher landing speed also equates to greated
crosswind capability. Given excellent pilot proficiency, 10 knots change in
landing speed means up to 4 knots change in maximum crosswind
component--which is also a heluva difference!


OTOH if it is low enough you never have to do a cross wind landing...

--

FF

On Wed, 11 Jul 2007 09:16:09 -0700, wrote:

On Jul 7, 8:46 pm, "Peter Dohm" wrote:
"Vaughn Simon" wrote in message

...



wrote in message
oups.com...

Thanks in advance for the help

I can't help you on the specific article (I would like to see it
myself).
Remember that Energy = MV^2, and the landing ain't
over until all of that energy
has somehow been dissipated. ...

... You will quickly discover that ten knots one way or the other
makes a heluva difference. ...

This is why the Sport Pilot regulations limit both
gross weight and stall
speed... to limit the landing energy the pilot must deal with.

...

Presuming, of course, that the plan is to crash--which has been one of my
biggest criticisms of both Ultralight Vehicles and LSA from the beginning.

OTOH, other things being equal, higher landing speed also equates to greated
crosswind capability. Given excellent pilot proficiency, 10 knots change in
landing speed means up to 4 knots change in maximum crosswind

I like that "up to" which means from nothing to the max of 4. IOW a
faster landing speed gives no guarantee of being able to handle more
cross wind component. How much cross wind can an F-16 handle?


component--which is also a heluva difference!


OTOH if it is low enough you never have to do a cross wind landing...

On 2007-07-06 20:07:25 -0700, " said:

Hi All,

Some time ago, kitplane had an article concerning the survivability as
a function of landing speed, at least I think that was the nature of
the article. Anyway, does anybody know about the article, or where I
can find a copy. If I remember correctly, the article was very well
written, and I am in need of some data that was presented.

Thanks in advance for the help

Best Regards,

Dave

I remember that article, but I am not sure it was Kitplane. I know it
was at least 3 or 4 years ago.
--
Waddling Eagle
World Famous Flight Instructor

On Wed, 11 Jul 2007 11:30:01 -0700, C J Campbell
wrote:

On 2007-07-06 20:07:25 -0700, " said:

Hi All,

Some time ago, kitplane had an article concerning the survivability as
a function of landing speed, at least I think that was the nature of
the article. Anyway, does anybody know about the article, or where I
can find a copy. If I remember correctly, the article was very well
written, and I am in need of some data that was presented.

There was also a TV program about the closing of the NASA testing
facility some where out east. They were doing a test on what
*appeared* to be a Lancair. They were showing the survivability from a
level attitude with a fair amount of downward momentum was not at all
good in the new composit planes as they are so strong structurally.
BUT they showed a dramatic improvement with energy absorbing seats.


Thanks in advance for the help

Best Regards,

Dave

I remember that article, but I am not sure it was Kitplane. I know it
was at least 3 or 4 years ago.

Roger (K8RI) wrote:
On Wed, 11 Jul 2007 11:30:01 -0700, C J Campbell
wrote:

On 2007-07-06 20:07:25 -0700, " said:

Hi All,

Some time ago, kitplane had an article concerning the survivability as
a function of landing speed, at least I think that was the nature of
the article. Anyway, does anybody know about the article, or where I
can find a copy. If I remember correctly, the article was very well
written, and I am in need of some data that was presented.

There was also a TV program about the closing of the NASA testing
facility some where out east. They were doing a test on what
*appeared* to be a Lancair. They were showing the survivability from a
level attitude with a fair amount of downward momentum was not at all
good in the new composit planes as they are so strong structurally.
BUT they showed a dramatic improvement with energy absorbing seats.

Nasa Langley, you can see that gantry from most of the base.

Dan, U.S. Air Force, retired

Its true that collision energy is proportional to relative speed
squared. But if on landing you don't collide with anything (or flip
over, etc.) you should have a good chance not getting hurt. Just like
cars spinning out of control, they are ok if they don't bump into
anything - roll over, etc.

Loss of control during takeoff is more problematic. There typically
you don't have room to "slide" on the runway but bump into trees,
housing or whatever.

On Jul 6, 10:07 pm, " wrote:
Hi All,

Some time ago, kitplane had an article concerning the survivability as
a function of landing speed, at least I think that was the nature of
the article. Anyway, does anybody know about the article, or where I
can find a copy. If I remember correctly, the article was very well
written, and I am in need of some data that was presented.

Thanks in advance for the help

Best Regards,

Dave

wrote:

Its true that collision energy is proportional to relative speed
squared. But if on landing you don't collide with anything (or flip
over, etc.) you should have a good chance not getting hurt. Just like
cars spinning out of control, they are ok if they don't bump into
anything - roll over, etc.

Loss of control during takeoff is more problematic. There typically
you don't have room to "slide" on the runway but bump into trees,
housing or whatever.



The othe important facetor is angle of impact...