Duckhawk wins

On 5/27/2012 7:23 AM, Papa3 wrote:
On Sunday, May 27, 2012 1:37:20 AM UTC-4, Wade wrote:

The version chip was flying for the contest was the DuckHawk SV.
The max gross weight is 960 LB and he never flew above 880 LB
during the contest. Thanks, Wade

Which means that he was essentially flying at 11 lbs wingloading if
the 80sq ft wing area listed on the Website is accurate. That's
pretty amazing considering we rarely had more than 3-4kts of often
broken lift. I never went with more than 9lbs in my LS8, and that
was often too much. I know Chip didn't carry all of the water all
the time, but still...

The 80 sq feet is accurate! It provides the DuckHawk with an amazing
(for a 15 meter glider) 30:1 aspect ratio. The relatively light weight
of the glider due to the the small size and carbon pre-preg construction
gives is a significantly lighter span loading than an ASW 27, etc glider:

DuckHawk at 11 lbs/sq ft = 17.6 lbs/foot span loading
ASW 27 at 11 lbs/sq ft = 21.3 lbs/foot span loading

We're all used to thinking in terms of wing loading, but Greg Cole told
me the span loading is the important factor for thermalling - lighter is
better.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

I have to send my congratulations to Chip for flying a great contest and to Greg for designing a great sailplane! I crewed for Chip during the race and we were both impressed with the DH's ability to climb with ballast in weak conditions. Our official weight was generally about 864 lbs after ballasting in the morning and yes Chip did have to dump ballast in very weak conditions or saves but he was able to fly the entire task with ballast on several days. Considering that Chip had one flight in the DH and the DH only had 12 flights under its belt before Mifflin the performance was amazing. And we were learning more about the DH as the contest progressed. Chip was trying a variety of thermaling speeds and flap settings to get the best performance. The DH has a wide range of speeds in thermals and feels "light" even with ballast with a good sense for changes in the thermal during climb. Chip's performance in the DH got better over the contest and I am sure that his score would have been better if he had started with the experience he gained by the end of the contest. All in all this glider performed well "right out of the box" and will only get better has we tweak things like internal and external seals and flying styles.
Bill Thar

On Wednesday, May 30, 2012 1:16:38 AM UTC-4, Eric Greenwell wrote:
On 5/27/2012 7:23 AM, Papa3 wrote:
On Sunday, May 27, 2012 1:37:20 AM UTC-4, Wade wrote:

The version chip was flying for the contest was the DuckHawk SV.
The max gross weight is 960 LB and he never flew above 880 LB
during the contest. Thanks, Wade

Which means that he was essentially flying at 11 lbs wingloading if
the 80sq ft wing area listed on the Website is accurate. That's
pretty amazing considering we rarely had more than 3-4kts of often
broken lift. I never went with more than 9lbs in my LS8, and that
was often too much. I know Chip didn't carry all of the water all
the time, but still...

The 80 sq feet is accurate! It provides the DuckHawk with an amazing
(for a 15 meter glider) 30:1 aspect ratio. The relatively light weight
of the glider due to the the small size and carbon pre-preg construction
gives is a significantly lighter span loading than an ASW 27, etc glider:

DuckHawk at 11 lbs/sq ft = 17.6 lbs/foot span loading
ASW 27 at 11 lbs/sq ft = 21.3 lbs/foot span loading

We're all used to thinking in terms of wing loading, but Greg Cole told
me the span loading is the important factor for thermalling - lighter is
better.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)