Is this chopper about to crash?

[Trentus]

It would appear that the majority in aus.aviation seem to think this shot
http://www.thedamnedestthing.com/page15.html was moments from impact, but
then they fly the wrong type of aircraft in that newsgroup, so what would
they know.

If not how is it still in the air at that angle? My "hunch" is that it could
be feasible to fly at that angle while towing a load, but it's certainly
just a hunch, my knowledge of physics is high school level, and helicopter
flight knowledge even less.

Trentus

[Larry Fransson]

Ask the question again when the server is serving.

[Larry Fransson]

On 2003-12-17 21:39:35 -0800, Larry Fransson > said:

> Ask the question again when the server is serving.

Okay, it's working now.

I don't know, but it doesn't look good to me!

[SelwayKid]

"Trentus" > wrote in message >...
> It would appear that the majority in aus.aviation seem to think this shot
> http://www.thedamnedestthing.com/page15.html was moments from impact, but
> then they fly the wrong type of aircraft in that newsgroup, so what would
> they know.
>
> If not how is it still in the air at that angle? My "hunch" is that it could
> be feasible to fly at that angle while towing a load, but it's certainly
> just a hunch, my knowledge of physics is high school level, and helicopter
> flight knowledge even less.
>
> Trentus

That picture has been around for a long time now and is amazing to
those of us, well at least me!, who fly helicopters for a living. I'm
sure the crew lifted off wondering what it would take to make this
work and had some help on the ground to tell them what was happening
where they couldn't see.
As they pulled pitch and forward cyclic I can only imagine what the
view was in the cockpit and certainly someone was watching the blade
tips to avoid ground contact while they waited to see if the load
would move or not.
There is no doubt in my military mind they were VERY cognizant of what
they were doing. This kind of ranks up there with the USMC flag
raising on Suribachi for dramatic impact.
Before you holler at me...I am an old 10 year active duty Marine and
still stand at attention when the Marine Hymn is played and I've got
more than 21,000 hours of interesting flying.

[Bob]

Actually as seen in that that photo, the Boeing Vertol 107 is towing the
sled seen behind it. The photo was shot in Greenland. and I actually have
or did have an original copy from the film.

Bob

[John Roncallo]

Clark wrote:

> "Trentus" > wrote in
> :
>
>
>>It would appear that the majority in aus.aviation seem to think this
>>shot http://www.thedamnedestthing.com/page15.html was moments from
>>impact, but then they fly the wrong type of aircraft in that newsgroup,
>>so what would they know.
>>
>>If not how is it still in the air at that angle? My "hunch" is that it
>>could be feasible to fly at that angle while towing a load, but it's
>>certainly just a hunch, my knowledge of physics is high school level,
>>and helicopter flight knowledge even less.
>>
>
> No, it's not about to crash. Check out http://www.colheli.com/colheli.html
> and look at the The Hover Barge Photo under the Nesw & Events menu.


According to the article they only had a 25° nose down attitude. It
looks alot worse than that in the picture. Since most helicopters of
this size typically lift twice there own weight (when empty). I would
estimate that the maximum theoretical nose down angle whould be 60°.
This gives you a thrust vector component of twice youre vertical
component. However the transmission lube systems would not like this at all.

John Roncallo

[Rhodesst]

>According to the article they only had a 25° nose down attitude. It
>looks alot worse than that in the picture. Since most helicopters of
>this size typically lift twice there own weight (when empty). I would
>estimate that the maximum theoretical nose down angle whould be 60°.
>This gives you a thrust vector component of twice youre vertical
>component. However the transmission lube systems would not like this at all.
>
>John Roncallo

As long as you can maintain a vertical component of lift equal to the weight of
the helicopter, you'll be Ok. Either way, that looks like one hell of a
balancing act.

I don't know for sure but that looks like it might not be too much different
from a simple (huh?) hover with a heavy sling load as far as control imputs are
concerned. Of course, I'm probably wrong about that. It's never that easy, if
hovering is considered easy. :-)

Fly Safe,
Steve R.

[Trentus]

"Bob" > wrote in message
...
> Actually as seen in that that photo, the Boeing Vertol 107 is towing the
> sled seen behind it. The photo was shot in Greenland. and I actually have
> or did have an original copy from the film.
>
> Bob

Yes, I was aware it was towing, but that's a scarey angle, the view from the
cockpit must have been pretty amazing, they'd see little more than the
ground, but I just had a "hunch" that it would still be ok, despite how it
appears, and that a crash ISN'T imminent. But that's gotta be one pretty
damned brave, or very confident in his abilities, pilot.

Trentus

[[email protected]]

"Trentus" > wrote:


> Yes, I was aware it was towing, but that's a scarey angle, the view from the
> cockpit must have been pretty amazing, they'd see little more than the

The camera that took the photo was above the helicopter in the photo.
This makes it look like its at a lower angle than it really is. Not
only that, but the article says that a telephoto lense was also used
which can also alter perception.

If you have ever seen MASH on TV, the opening credits show what
appears to be helicopters flying backwards. In reality, its
helicopters flying forward with the camera behind them flying forward
faster.



Dennis Hawkins
n4mwd AT amsat DOT org (humans know what to do)

"A RECESSION is when you know somebody who is out of work.
A DEPRESSION is when YOU are out of work.
A RECOVERY is when all the H-1B's are out of work."

To find out what an H-1B is and how Congress is using
them to put Americans out of work, visit the following
web site and click on the "Exporting America" CNN news
video: http://zazona.com/ShameH1B/MediaClips.htm

[John]

"Rhodesst" > wrote in message
...
> >According to the article they only had a 25° nose down attitude. It
> >looks alot worse than that in the picture. Since most helicopters of
> >this size typically lift twice there own weight (when empty). I would
> >estimate that the maximum theoretical nose down angle whould be 60°.
> >This gives you a thrust vector component of twice youre vertical
> >component. However the transmission lube systems would not like this at
all.
> >
> >John Roncallo
>
> As long as you can maintain a vertical component of lift equal to the
weight of
> the helicopter, you'll be Ok. Either way, that looks like one hell of a
> balancing act.
>
> I don't know for sure but that looks like it might not be too much
different
> from a simple (huh?) hover with a heavy sling load as far as control
imputs are
> concerned. Of course, I'm probably wrong about that. It's never that
easy, if
> hovering is considered easy. :-)
>
> Fly Safe,
> Steve R.

Ok i have read all the posts up to 23rd dec on this thread, i understand
it's some sort of an illusion.

I know next to nothing about sling operations.

I'm just surprised that no one seemed to think about the principles of
dynamic roll over and try to apply them here ?

I know the sling load probably isn't stuck to the ground ..but could become
stuck, then there is inertia and acceleration considerations, i have only a
fuzzy understanding of all this ...but i think that the maximum nose down
angle when towing would be a lot less than
anyones gut feeling or quick calculation based only on thrust to weight
ratios and thrust vectors.

Do i have a point ?
I'm sure someone will elaborate on this?

[John Roncallo]

John wrote:
> "Rhodesst" > wrote in message
> ...
>
>>>According to the article they only had a 25° nose down attitude. It
>>>looks alot worse than that in the picture. Since most helicopters of
>>>this size typically lift twice there own weight (when empty). I would
>>>estimate that the maximum theoretical nose down angle whould be 60°.
>>>This gives you a thrust vector component of twice youre vertical
>>>component. However the transmission lube systems would not like this at
>
> all.
>
>>>John Roncallo
>>
>>As long as you can maintain a vertical component of lift equal to the
>
> weight of
>
>>the helicopter, you'll be Ok. Either way, that looks like one hell of a
>>balancing act.
>>
>>I don't know for sure but that looks like it might not be too much
>
> different
>
>>from a simple (huh?) hover with a heavy sling load as far as control
>
> imputs are
>
>>concerned. Of course, I'm probably wrong about that. It's never that
>
> easy, if
>
>>hovering is considered easy. :-)
>>
>>Fly Safe,
>>Steve R.
>
>
> Ok i have read all the posts up to 23rd dec on this thread, i understand
> it's some sort of an illusion.
>
> I know next to nothing about sling operations.
>
> I'm just surprised that no one seemed to think about the principles of
> dynamic roll over and try to apply them here ?
>
> I know the sling load probably isn't stuck to the ground ..but could become
> stuck, then there is inertia and acceleration considerations, i have only a
> fuzzy understanding of all this ...but i think that the maximum nose down
> angle when towing would be a lot less than
> anyones gut feeling or quick calculation based only on thrust to weight
> ratios and thrust vectors.
>
> Do i have a point ?
> I'm sure someone will elaborate on this?
>
>

There is no potential for DR. Because of the sling load is still within
the correct CG envelope.

JR

[Bob]

Can somebody post the link to the helicopter photo again please?

[Bob Roberts]

Isn't this a Columbia Helicotpers Picture? It's in their colors - and
nope, it didn't crash. :)


Bob

[Bob Roberts]

"Bob" > wrote in message >...
> Can somebody post the link to the helicopter photo again please?

Actually, you can find it here :

http://www.colheli.com/colheli.html

That's Columbia Helicopter's website. You'll see pictures of this and
others in their operations in the Photo Gallery!

Best Regards!


Bob