Survivability VS landing speed

[[email protected]]

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

[Vaughn Simon]

> 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

[Peter Dohm]

"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

[[email protected]]

On Jul 7, 8:46 pm, "Peter Dohm" > wrote:
> "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. ...
>
> > ... 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

[Roger (K8RI)]

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
>> 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. ...
>>
>> > ... 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...

[C J Campbell[_1_]]

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

[[email protected]]

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

[cavelamb himself]

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...
>

[Blueskies]

"cavelamb himself" > wrote in message
ink.net...
> 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...
>>


Actually it is how quickly you stop...

[cavelamb himself]

Blueskies wrote:
> "cavelamb himself" > wrote in message
> ink.net...
>
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 other important factor is angle of impact...
>>
>
>
> Actually it is how quickly you stop...
>
>


Angle of contact has a big impact :) on how fast you stop.

Even low velocity at a large angle could hurt.
But a low angle, even at high speed, shouldn't.

[Morgans[_2_]]

"cavelamb himself" < wrote
>
> Even low velocity at a large angle could hurt.
> But a low angle, even at high speed, shouldn't.

Think the opening clip of "The Six Million Dollar Man."

Except now, he would be the 27.9 million dollar man.
--
Jim in NC

[Blueskies]

"cavelamb himself" > wrote in message
ink.net...
> Blueskies wrote:
>> "cavelamb himself" > wrote in message
>> ink.net...
>>
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 other important factor is angle of impact...
>>>
>>
>>
>> Actually it is how quickly you stop...
>
>
> Angle of contact has a big impact :) on how fast you stop.
>
> Even low velocity at a large angle could hurt.
> But a low angle, even at high speed, shouldn't.
>

Unless there is a tree in the way ;-)

[Roger (K8RI)]

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.

[cavelamb himself]

Blueskies wrote:

> "cavelamb himself" > wrote in message
> ink.net...
>
>>Blueskies wrote:
>>
>>>"cavelamb himself" > wrote in message
ink.net...
>>>
>>>
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 other important factor is angle of impact...
>>>>
>>>
>>>
>>>Actually it is how quickly you stop...
>>
>>
>>Angle of contact has a big impact :) on how fast you stop.
>>
>>Even low velocity at a large angle could hurt.
>>But a low angle, even at high speed, shouldn't.
>>
>
>
> Unless there is a tree in the way ;-)
>
>
Which changes the impact angle to perpendicular?

:)

[Dan[_2_]]

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

[Blueskies]

"cavelamb himself" > wrote in message
ink.net...
> Blueskies wrote:
>
>> "cavelamb himself" > wrote in message
>> ink.net...
>>
>>>Blueskies wrote:
>>>
>>>>"cavelamb himself" > wrote in message
ink.net...
>>>>
>>>>
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 other important factor is angle of impact...
>>>>>
>>>>
>>>>
>>>>Actually it is how quickly you stop...
>>>
>>>
>>>Angle of contact has a big impact :) on how fast you stop.
>>>
>>>Even low velocity at a large angle could hurt.
>>>But a low angle, even at high speed, shouldn't.
>>>
>>
>>
>> Unless there is a tree in the way ;-)
> Which changes the impact angle to perpendicular?
>
> :)

Yes, I thought that as I sent...straight up...

;-)

[Dan[_2_]]

Blueskies wrote:
> "cavelamb himself" > wrote in message
> ink.net...
>> Blueskies wrote:
>>
>>> "cavelamb himself" > wrote in message
>>> ink.net...
>>>
>>>> Blueskies wrote:
>>>>
>>>>> "cavelamb himself" > wrote in message
>>>>> ink.net...
>>>>>
>>>>>
>>>>>> 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 other important factor is angle of impact...
>>>>>>
>>>>>
>>>>> Actually it is how quickly you stop...
>>>>
>>>> Angle of contact has a big impact :) on how fast you stop.
>>>>
>>>> Even low velocity at a large angle could hurt.
>>>> But a low angle, even at high speed, shouldn't.
>>>>
>>>
>>> Unless there is a tree in the way ;-)
>> Which changes the impact angle to perpendicular?
>>
>> :)
>
> Yes, I thought that as I sent...straight up...
>
> ;-)
>
>
Which, in terms used in physics, is said impact angle was normal to
the surface.

Dan, U.S. Air Force, retired

[C J Campbell[_1_]]

On 2007-07-11 12:24:02 -0700, said:

> 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.

So you just have to pick your emergency landing sites more carefully. A
slower stall speed means you can pick a smaller site. Here, where the
whole area is covered with mountains, forests, and water you could have
real problems finding a landing site big enough to absorb the energy of
a fast airplane.



--
Waddling Eagle
World Famous Flight Instructor

[Mark Hickey]

C J Campbell > wrote:

>So you just have to pick your emergency landing sites more carefully. A
>slower stall speed means you can pick a smaller site. Here, where the
>whole area is covered with mountains, forests, and water you could have
>real problems finding a landing site big enough to absorb the energy of
>a fast airplane.

It's easy to find a spot to "absorb the energy of a fast airplane"...
it only has to be about the size of the frontal area of the aircraft.
The trick is to find an area that will absorb the energy slowly enough
that the carbon life forms inside aren't turned into hamburger.

That's why it always bugs me when I'm flying commercial when the pilot
says "we'll be on the gound shortly"... there are a LOT of ways to
"get an airplane on the ground" that I'd prefer to avoid...

Mark "easy does it" Hickey

[Blueskies]

"Dan" > wrote in message ...
> Blueskies wrote:
>> "cavelamb himself" > wrote in message
>> ink.net...
>>> Blueskies wrote:
>>>
>>>> "cavelamb himself" > wrote in message
>>>> ink.net...
>>>>
>>>>> Blueskies wrote:
>>>>>
>>>>>> "cavelamb himself" > wrote in message
>>>>>> ink.net...
>>>>>>
>>>>>>
>>>>>>> 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 other important factor is angle of impact...
>>>>>>>
>>>>>>
>>>>>> Actually it is how quickly you stop...
>>>>>
>>>>> Angle of contact has a big impact :) on how fast you stop.
>>>>>
>>>>> Even low velocity at a large angle could hurt.
>>>>> But a low angle, even at high speed, shouldn't.
>>>>>
>>>>
>>>> Unless there is a tree in the way ;-)
>>> Which changes the impact angle to perpendicular?
>>>
>>> :)
>>
>> Yes, I thought that as I sent...straight up...
>>
>> ;-)
> Which, in terms used in physics, is said impact angle was normal to the surface.
>
> Dan, U.S. Air Force, retired
>

So, my really bad landings are normal?

;-)