Tow DROID

[Frank Whiteley]

http://www.aerotechnews.com/news/2014/02/05/drydens-droid-demonstrates-autonomous-uas-to-uas-air-tow/

[Dan Marotta]

The glider is so far out of position that I'm surprised the tow pilot has
not released him.

....And did you see that little rigging stand? Where was the solo rigging
device?


"Frank Whiteley" > wrote in message
...
> http://www.aerotechnews.com/news/2014/02/05/drydens-droid-demonstrates-autonomous-uas-to-uas-air-tow/

[Tom Gardner[_2_]]

On 06/02/14 06:38, Frank Whiteley wrote:
> http://www.aerotechnews.com/news/2014/02/05/drydens-droid-demonstrates-autonomous-uas-to-uas-air-tow/

Wow. They are behind the curve :)

Search youtube for combinations of rc/glider/towed and similar,
and you will see many many videos of rc enthusiasts doing just that!

[Eric Bick (1DB)]

On Wednesday, February 5, 2014 10:38:00 PM UTC-8, Frank Whiteley wrote:
> http://www.aerotechnews.com/news/2014/02/05/drydens-droid-demonstrates-autonomous-uas-to-uas-air-tow/

And ... they get paid to do this ...
Eric Bick

[Martin Gregorie[_5_]]

On Thu, 06 Feb 2014 09:21:26 -0700, Dan Marotta wrote:

> The glider is so far out of position that I'm surprised the tow pilot
> has not released him.
>
....but did you notice that the towline attaches to the tug on top of the
wing at the CG position? That's SOP on the RC world and I imagine it
makes the glider position a lot less critical since it can't jerk the tow
plane's tail around.



--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

[Martin Gregorie[_5_]]

On Thu, 06 Feb 2014 16:32:14 +0000, Tom Gardner wrote:

> On 06/02/14 06:38, Frank Whiteley wrote:
>> http://www.aerotechnews.com/news/2014/02/05/drydens-droid-demonstrates-
autonomous-uas-to-uas-air-tow/
>
> Wow. They are behind the curve :)
>
> Search youtube for combinations of rc/glider/towed and similar,
> and you will see many many videos of rc enthusiasts doing just that!
>
I thought that too, until I read the text a bit more carefully. They
verified that the UAVs were trimmed correctly, etc by hand flying a tow
or two before they did a number of completely autonomous flights.

Its just unfortunate that the main picture shows one of the manually
flown launches and that they didn't publish any pictures of an antonomous
launch.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

[Tom Gardner[_2_]]

On 06/02/14 21:32, Martin Gregorie wrote:
> On Thu, 06 Feb 2014 16:32:14 +0000, Tom Gardner wrote:
>
>> On 06/02/14 06:38, Frank Whiteley wrote:
>>> http://www.aerotechnews.com/news/2014/02/05/drydens-droid-demonstrates-
> autonomous-uas-to-uas-air-tow/
>>
>> Wow. They are behind the curve :)
>>
>> Search youtube for combinations of rc/glider/towed and similar,
>> and you will see many many videos of rc enthusiasts doing just that!
>>
> I thought that too, until I read the text a bit more carefully. They
> verified that the UAVs were trimmed correctly, etc by hand flying a tow
> or two before they did a number of completely autonomous flights.
>
> Its just unfortunate that the main picture shows one of the manually
> flown launches and that they didn't publish any pictures of an antonomous
> launch.

You're right, but you do have to read it carefully to see past all
the future tense and "...to evaluate the research pilot's ability to..."

The biggest clue is the "autonomous" in the URL!

[Martin Gregorie[_5_]]

On Thu, 06 Feb 2014 22:38:33 +0000, Tom Gardner wrote:

> On 06/02/14 21:32, Martin Gregorie wrote:
>> On Thu, 06 Feb 2014 16:32:14 +0000, Tom Gardner wrote:
>>
>>> On 06/02/14 06:38, Frank Whiteley wrote:
>>>> http://www.aerotechnews.com/news/2014/02/05/drydens-droid-
demonstrates-
>> autonomous-uas-to-uas-air-tow/
>>>
>>> Wow. They are behind the curve :)
>>>
>>> Search youtube for combinations of rc/glider/towed and similar,
>>> and you will see many many videos of rc enthusiasts doing just that!
>>>
>> I thought that too, until I read the text a bit more carefully. They
>> verified that the UAVs were trimmed correctly, etc by hand flying a tow
>> or two before they did a number of completely autonomous flights.
>>
>> Its just unfortunate that the main picture shows one of the manually
>> flown launches and that they didn't publish any pictures of an
>> antonomous launch.
>
> You're right, but you do have to read it carefully to see past all the
> future tense and "...to evaluate the research pilot's ability to..."
>
> The biggest clue is the "autonomous" in the URL!

Yes, you're right: the description is not at all well written. It would
have helped a lot if the guy at the next desk had read the text and then
helped to rewrite it.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

[son_of_flubber]

Returning for a moment to the 19th century tow hook designs that are on most tugs.

Why does the pilot need to pull the release if the glider kites? Why is the release for a deadly tow position not fully automatic? Is a simple purely mechanical, totally foolproof and 100% automatic release not possible?

As the guy in the glider, I would be fine with a 100% automatic release. If I kite, release me immediately.

[Dan Marotta]

The standard setup is to use a Schweizer hook which is rigidly mounted in
pitch and can swivel around the yaw axis. So, if the glider kites, it
exerts sufficient force on the release mechanism that the tow pilot may not
have the strength to pull the lever. It's also possible that, should the
glider get too wide, the axis of the release cable is too far off center to
operate the release. So... Stay in position on tow!

The Tost release does not suffer from this design problem. I've also seen
the Schweizer release mounted to a heavy duty gate hinge for use in ground
launching. This allows it to align with the axis of the rope so there's no
difficulty with the driver or observer releasing the rope. I don't think
you'd get such a system approved for mounting on the tail of an aircraft.

"son_of_flubber" > wrote in message
...
> Returning for a moment to the 19th century tow hook designs that are on
> most tugs.
>
> Why does the pilot need to pull the release if the glider kites? Why is
> the release for a deadly tow position not fully automatic? Is a simple
> purely mechanical, totally foolproof and 100% automatic release not
> possible?
>
> As the guy in the glider, I would be fine with a 100% automatic release.
> If I kite, release me immediately.

[son_of_flubber]

On Saturday, February 8, 2014 11:50:52 AM UTC-5, Dan Marotta wrote:
> The standard setup is to use a Schweizer hook which is rigidly mounted in
>
> pitch and can swivel around the yaw axis.

Yeah but. Why does the tug pilot have to pull anything when a glider kites? The tug pilot should of course have the option to release at any time.

Here is the 1870 patent for something that look a lot like the Schweitzer tow hook. Click on the thumbnail for a drawing. http://rec.aviation.soaring/

The Tost hook still requires the tug pilot to pull a lever (though the automatic "back release" on the glider side is nice.)

[Dan Marotta]

That's a good question.

As a glider pilot, I don't want any part of an automatic release (back
release excepted).

As a tow pilot, I'd rather the glider be released automatically than have
the tug upset and, possibly, driven to the ground.

"son_of_flubber" > wrote in message
...
> On Saturday, February 8, 2014 11:50:52 AM UTC-5, Dan Marotta wrote:
>> The standard setup is to use a Schweizer hook which is rigidly mounted in
>>
>> pitch and can swivel around the yaw axis.
>
> Yeah but. Why does the tug pilot have to pull anything when a glider
> kites? The tug pilot should of course have the option to release at any
> time.
>
> Here is the 1870 patent for something that look a lot like the Schweitzer
> tow hook. Click on the thumbnail for a drawing.
> http://rec.aviation.soaring/
>
> The Tost hook still requires the tug pilot to pull a lever (though the
> automatic "back release" on the glider side is nice.)
>

[son_of_flubber]

On Saturday, February 8, 2014 6:42:52 PM UTC-5, son_of_flubber wrote:

> Here is the 1870 patent for something that look a lot like the Schweitzer tow hook. Click on the thumbnail for a drawing.

http://www.google.ca/patents/US102067

[Bill T]

I've seen heavy duty gate (barn door) hinges used with auto tow start to pull apart.
If you use one, keep up on the inspections during the day!

BillT

[Martin Gregorie[_5_]]

On Sat, 08 Feb 2014 19:24:59 -0800, son_of_flubber wrote:

> On Saturday, February 8, 2014 6:42:52 PM UTC-5, son_of_flubber wrote:
>
>> Here is the 1870 patent for something that look a lot like the
>> Schweitzer tow hook. Click on the thumbnail for a drawing.
>
> http://www.google.ca/patents/US102067

That doesn't look to be any more an automatically releasing hook than the
Schweitzer is.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

[Dan Marotta]

That patented release mechanism appears to be superior to the Schweizer hook
by having a slot for the clevis to be captured within. With the Schweizer
assembly, the ring can move forward (towards the release mechanism) and,
with the high upward force applied by a kiting glider, render the release
inoperative. Not so, apparently with the older design.


"son_of_flubber" > wrote in message
...
> On Saturday, February 8, 2014 6:42:52 PM UTC-5, son_of_flubber wrote:
>
>> Here is the 1870 patent for something that look a lot like the Schweitzer
>> tow hook. Click on the thumbnail for a drawing.
>
> http://www.google.ca/patents/US102067

[kirk.stant]

On Saturday, February 8, 2014 10:50:52 AM UTC-6, Dan Marotta wrote:
> The standard setup is to use a Schweizer hook which is rigidly mounted in
>
> pitch and can swivel around the yaw axis. So, if the glider kites, it
>
> exerts sufficient force on the release mechanism that the tow pilot may not
>
> have the strength to pull the lever. It's also possible that, should the
>
> glider get too wide, the axis of the release cable is too far off center to
>
> operate the release. So... Stay in position on tow!
>

Dan, there is a 337 for an inverted mounting of the Schweizer hook on Pawnees - Turf soaring developed it many years ago. It simply mounts the fixed arm at the top, and the swinging arm at the bottom - so that when the glider kites, the rope tension is taken by the fixed arm and there isn't any additional pressure on the release gate (which is what makes the Schweizer hook so hard to release in an kiting situation).

Roy Couillete at Turf may still have access to the 337 documentation, if you are interested.

[[email protected]]

On Saturday, February 8, 2014 9:31:13 AM UTC-5, son_of_flubber wrote:
> Returning for a moment to the 19th century tow hook designs that are on most tugs. Why does the pilot need to pull the release if the glider kites? Why is the release for a deadly tow position not fully automatic? Is a simple purely mechanical, totally foolproof and 100% automatic release not possible? As the guy in the glider, I would be fine with a 100% automatic release. If I kite, release me immediately.

There was a design and prototype of a release like this created many years ago and published, I believe, in Soaring magazine. I know if no one that has adopted this which makes it fairly clear that this is not perceived as a huge problem.
Many of us have inverted our Schweizer hooks to help avoid the problem of high release force when the glider is high.
FWIW
UH

[Dan Marotta]

Thanks, Kirk, but the three tugs that I fly belong to Sundance Aviation in
Moriarty. I'll mention the 337 to the owner and see if he's interested.


"kirk.stant" > wrote in message
...
On Saturday, February 8, 2014 10:50:52 AM UTC-6, Dan Marotta wrote:
> The standard setup is to use a Schweizer hook which is rigidly mounted in
>
> pitch and can swivel around the yaw axis. So, if the glider kites, it
>
> exerts sufficient force on the release mechanism that the tow pilot may
> not
>
> have the strength to pull the lever. It's also possible that, should the
>
> glider get too wide, the axis of the release cable is too far off center
> to
>
> operate the release. So... Stay in position on tow!
>

Dan, there is a 337 for an inverted mounting of the Schweizer hook on
Pawnees - Turf soaring developed it many years ago. It simply mounts the
fixed arm at the top, and the swinging arm at the bottom - so that when the
glider kites, the rope tension is taken by the fixed arm and there isn't any
additional pressure on the release gate (which is what makes the Schweizer
hook so hard to release in an kiting situation).

Roy Couillete at Turf may still have access to the 337 documentation, if you
are interested.