Hi,

http://www.avweb.com/avwebflash/exclusivevids/HumanPoweredOrnithopterFlight_203330-1.html

http://www.youtube.com/watch?v=WpobKBR6n9U - be sure to watch it in HD for
best picture

Very cool! What a lovely machine in flight!

Congratulations to the designers for a job well done!

Paul Remde

It may interest RAS readers to know that the project was supported by
the members and facilities of the Great Lakes Gliding Club on (Mike)
Ronan Field at Tottenham Ontario in 2009 and 2010. The construction
took place in the barn and clubhouse there, and Todd had his only
glider training at the club. All flights were at Ronan Field.

It was something to behold!! The only time when you can says 'flutter
is good'!

On Thu, 23 Sep 2010 10:14:52 -0700, Bob wrote:

> It may interest RAS readers to know that the project was supported by
> the members and facilities of the Great Lakes Gliding Club on (Mike)
> Ronan Field at Tottenham Ontario in 2009 and 2010. The construction took
> place in the barn and clubhouse there, and Todd had his only glider
> training at the club. All flights were at Ronan Field.
>
AHA! That explains a comment made about this article:
http://www.theregister.co.uk/2010/09/23/pedalo/

signed by 'Great Lakes Gliding - Member' who mentioned involvement by
Todd and University Of Toronto Students Aerospace/Mechanical as well as
students from France, and Holland but not that Great Lakes Gliding was
involved.

> It was something to behold!! The only time when you can says 'flutter is
> good'!
>
A good effort, but IMO they need to do better: all other man-powered
aircraft have gained appreciable height after take-off and maintained it
for most of the flight. With all due respect for the participants, the
only published videos I've seen show a bare ability to maintain height
while well inside ground effect.


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

It is the FLAPPING WING that makes it a record. Propeller driven craft
are much easier to do of course and can take off and fly long
distances.

Are you saying 19 seconds at 25 KPH is all ground effect? Surely you
might agree that even in ground effect one loses height and speed at
some rate? Or have you discovered perpetual gliding? ;-)

The FAI representative is said to think otherwise. Approval is
expected in October.

And it was uphill on the field. I saw the late fall flights last year
in person. I guess the data will have to speak for itself.

On Thu, 23 Sep 2010 13:38:17 -0700, Bob wrote:

> It is the FLAPPING WING that makes it a record. Propeller driven craft
> are much easier to do of course and can take off and fly long distances.
>
Fairly minimal flap amplitude.

One thing I'm genuinely curious about: given the flapping amplitude, why
is the pylon so high?

> Are you saying 19 seconds at 25 KPH is all ground effect? Surely you
> might agree that even in ground effect one loses height and speed at
> some rate? Or have you discovered perpetual gliding? ;-)
>
No, of course not, just that I don't recall other MPA attempts claiming
records until the Cramer Prize had been collected.

Subsidiary question which others have asked in other places: what is the
glide performance without flapping? The aircraft looks as it it should be
a fairly efficient glider, so I'm curious about its sinking speed and
glide ratio.

> And it was uphill on the field. I saw the late fall flights last year in
> person. I guess the data will have to speak for itself.
>
What data? Apart from a couple of videos, neither of which are said to be
of the record attempt, I've seen no other information. A link to it would
be very much appreciated. So would a description of the flapping mechanism


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

snipminimal flap amplitude.
>
> One thing I'm genuinely curious about: given the flapping amplitude, why
> is the pylon so high?

I am not expert on this and was not involved in construction... the
pylon is merely for wing support at rest, the flapping is achieved by
drawing down on a cable to the underside of the wing, generated lift
makes the wing rise up, and the process repeats.

>
> > Are you saying 19 seconds at 25 KPH is all ground effect? Surely you
> > might agree that even in ground effect one loses height and speed at
> > some rate? Or have you discovered perpetual gliding? ;-)
>
> No, of course not, just that I don't recall other MPA attempts claiming
> records until the Cramer Prize had been collected.
>

This is for a flapping flight.


> Subsidiary question which others have asked in other places: what is the
> glide performance without flapping? The aircraft looks as it it should be
> a fairly efficient glider, so I'm curious about its sinking speed and
> glide ratio.

The team could likely tell you, see: hpo.ornithopter.net

As a glider pilot I would describe the sink rate as considerable, lots
of drag, not a floater to my eye.

>
> What data? Apart from a couple of videos, neither of which are said to be
> of the record attempt, I've seen no other information. A link to it would
> be very much appreciated. So would a description of the flapping mechanism

There are now lots of stories on the major news sites in Canada, big
press conference at the field with satellite trucks and all!

The FAI has attended the flight and reviewed data and is to approve
the flight officially in October I was told. I cannot say if the data
would be released to the public, but I would guess the team would tell
you what they recorded and how.

See Youtube for more videos, including one crash...:
www.youtube.com/user/OrnithopterProject

The pilot pushes out with his legs, by pulleys that draws a cable
downward on both wings, lift generated then lifts the wings back up,
repeat... very simple. They did not use arm motion as originally
planned.

Bob

It is particularly, at times like this, that our late friend Paul
MacCready is missed.

He would be the first to applaud this effort, as we all do!

Best Regards,

Gary Osoba

I really laughed when I saw it fly. I'd always thought a human-
powered ornithopter was all but impossible and I was amazed to see it
go as well as it did. I think it might have climbed a little bit and
with a bit of tweaking and a stronger pilot it might actually be
capable of doing a figure-eight course. A remarkable achievement and
presumably on a tight budget.

Nice job!

Mike

On Sep 23, 6:10*pm, Mike the Strike > wrote:
> I really laughed when I saw it fly. *I'd always thought a human-
> powered ornithopter was all but impossible and I was amazed to see it
> go as well as it did. *I think it might have climbed a little bit and
> with a bit of tweaking and a stronger pilot it might actually be
> capable of doing a figure-eight course. *A remarkable achievement and
> presumably on a tight budget.
>
> Nice job!
>
> Mike

Absolutely. Congratulations to the team. This is a major achievement
and I hope they do more.

But Eh I hope they passed over Molson and found some real beer to
celebrate with.

Darryl

Darryl

Well stated, Gary!

The first time I watched the video, it appeared the glider was just
gliding down from the ground launch and making the most out of the
ground effect. But I've watched other videos on YouTube and from the
camera angle given (the tow vehicle), it sure looks like he maintains
about a constant height above the ground.

The wave amplitude is shallow, but I think it is quite elegant.

Well done, Team Canada!


Ray Lovinggood
Carrboro, North Carolina, USA
PS: Like the Smart Car for the ground launcher! :-)
PPS: Seems like they could have found a wider runway for this type of
work!

On Thu, 23 Sep 2010 16:35:52 -0700, Bob wrote:

> I am not expert on this and was not involved in construction... the
> pylon is merely for wing support at rest, the flapping is achieved by
> drawing down on a cable to the underside of the wing, generated lift
> makes the wing rise up, and the process repeats.
>
Thanks for the link to http://hpo.ornithopter.net - its just a shame that
nobody thought to supply it earlier because its a good site and contains
a lot of information.

Now I understand the need for such a high pylon - without it the geometry
would make the cable driven wing flapping a non-starter. As it is, the
angle is still a bit flat for real efficiency: more of the pilot's effort
must go into trying to compress the spar than into bending it down but
fitting an even higher pylon must be pretty much a non-starter.

>> No, of course not, just that I don't recall other MPA attempts claiming
>> records until the Cramer Prize had been collected.
>>
>>
> This is for a flapping flight.
>
Certainly, but its still man-powered. The only difference is the way that
grunting and sweat gets converted into forward motion. And, of course,
flapping wings aren't as efficient as a prop.

That, combined with the unavoidable geometric inefficiencies of the
flapping mechanism, explains the 620 watts needed for sustained flight.

By comparison, Daedalus 88, which holds the MPA distance record of 74
miles, flown in a touch less than 4 hours, only needed 200 watts for
sustained flight and flew at about the same speed as Snowbird.

To put these in perspective, a typical human can generate 350-450 watts
continuously for several minutes, which explains quite nicely why
Snowbird ran out of steam after 20 seconds with a reasonably fit pilot
while Daedalus, with a fully fit racing cyclist flying it, was able to
fly for four hours.

Don't get me wrong: now that I've seen some numbers I think the Snowbird
team did an excellent job.

>> Subsidiary question which others have asked in other places: what is
>> the glide performance without flapping? The aircraft looks as it it
>> should be a fairly efficient glider, so I'm curious about its sinking
>> speed and glide ratio.
>
> The team could likely tell you, see: hpo.ornithopter.net
>
Glide ratio 20.9:1 - that's pretty good for an aircraft flying at 25.6
kph (16 mph, 14 kts).

At a rough guess its operating at a Reynolds number (RN) of around
300,000 and, from what I can see from the photos, the wing section looks
like one a modern F1C (a free flight engine-launched competition model)
would use. That is an entirely sensible choice for an aircraft operating
at that sort of RN. These sections are optimised for lift generation
rather than low drag, so that makes the achieved glide ratio pretty damn
good since its the whole-aircraft L/D figure, not just the wing section.

> As a glider pilot I would describe the sink rate as considerable, lots
> of drag, not a floater to my eye.
>
You might be surprised. From the flying speed and quoted L/D ratio I get
a sinking speed of 0.34 m/sec.

There are very few gliders that manage less that 0.5 m/s. Of course the
glide *angle* looked steep to you because the airspeed is so low.


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