World Championship gliders

The only successful one design competition in the world for sailplanes that I know of is the Schweizer 1-26 Championships. I will say that it is a lot of fun setting out on task with a group all in the exact same glider. Differences in pilots get sorted out very quickly.

The one design concept for 1-26's came about due to a lot of effort in the early days by Schweizer to establish the Championships as well as supporting the early 1-26 Association. I think any future successful one design contest will also require major manufacturer support or a strong type club to get the ball rolling.

On Monday, August 11, 2014 1:33:07 PM UTC-5, Tony wrote:
The only successful one design competition in the world for sailplanes that I know of is the Schweizer 1-26 Championships.


Sorry, but I will have to disagree a bit on the 1-26 as a "One Design" class. Same external shape of the wing and horizontal, same general layout on fuselage, differeing vertical based on model and the real big change: 1-26 and 1-26A gross weight 575 lbs. 1-26B and 1-26C gross weight 600 lbs. 1-26 D and E gross weight 700 lbs. With empty weights changing almost to match.

But, the guys flying them are willing to accept the differences, and still call it a "one design contest."

Now, back to the original discussion. Small fuselages and skinny pilots have an unfair advantage. Talk to an aerodynamicist. Wing span is measured from tip to tip. You don't have "longer wings" by having a "skinnier fuselage". Wing Area INCLUDES the planform "in" the fuselage, so a skinnier fuselage does NOT change area or aspect ratio. Any performance change is due to reduced total wetted area (less on fuselage, slightly more exposed wing skin). And the benefit is likely to be larger the faster you fly. But, as others have said, the difference between planes of the same type is likely as big or bigger than what is seen between a small fuselage and the "average" fuselage of otherwise the same type.

Just my opinion.

Steve

Steve,

After flying 12 of the last 14 years in the 1-26 Champs, I can assure you that it is a one design class, and there is very very little performance differences between models. Much more difference in a well sealed and cleaned up ship and one that is not. And a real hoot to fly in the Champs.

I have seen all models win.

It is the nut on the end of the stick that makes the difference.

Kevin
92
(former 192)

On Monday, August 11, 2014 9:54:14 PM UTC+2, Steve Leonard wrote:
On Monday, August 11, 2014 1:33:07 PM UTC-5, Tony wrote:

The only successful one design competition in the world for sailplanes that I know of is the Schweizer 1-26 Championships.





Sorry, but I will have to disagree a bit on the 1-26 as a "One Design" class. Same external shape of the wing and horizontal, same general layout on fuselage, differeing vertical based on model and the real big change: 1-26 and 1-26A gross weight 575 lbs. 1-26B and 1-26C gross weight 600 lbs. 1-26 D and E gross weight 700 lbs. With empty weights changing almost to match.



But, the guys flying them are willing to accept the differences, and still call it a "one design contest."



Now, back to the original discussion. Small fuselages and skinny pilots have an unfair advantage. Talk to an aerodynamicist. Wing span is measured from tip to tip. You don't have "longer wings" by having a "skinnier fuselage". Wing Area INCLUDES the planform "in" the fuselage, so a skinnier fuselage does NOT change area or aspect ratio. Any performance change is due to reduced total wetted area (less on fuselage, slightly more exposed wing skin). And the benefit is likely to be larger the faster you fly. But, as others have said, the difference between planes of the same type is likely as big or bigger than what is seen between a small fuselage and the "average" fuselage of otherwise the same type.



Just my opinion.



Steve

Is an a-model theoretically or practically 'faster'? Almost certainly. Measurably or perceptibly so? Not in my experience (disappointingly).

What does make a substantial difference (to me, at least) is the closeness of the fuselage sides to your shoulders, giving much better feel of the air - which I imagine larger pilots enjoy in b and c model fuselages.

/-a model owner

On 12/08/2014 05:54, Steve Leonard wrote:
....
Now, back to the original discussion. Small fuselages and skinny
pilots have an unfair advantage. Talk to an aerodynamicist. Wing
span is measured from tip to tip. You don't have "longer wings" by
having a "skinnier fuselage". Wing Area INCLUDES the planform "in"
the fuselage, so a skinnier fuselage does NOT change area or aspect
ratio. Any performance change is due to reduced total wetted area
(less on fuselage, slightly more exposed wing skin).

The usual "A" in the drag equation in this context is cross-sectional
area of the fuselage (and wing, maybe), not wetted area.

GC

And the benefit
is likely to be larger the faster you fly. But, as others have said,
the difference between planes of the same type is likely as big or
bigger than what is seen between a small fuselage and the "average"
fuselage of otherwise the same type.

Just my opinion.

Steve

The guy who suggested the one-design contest using the Schweizer 2-33 and scoring altitude gain, time aloft and spot landing just described the 1975 Hang Gliding National Championships, except the 2-33 would have placed LAST!

On Monday, August 11, 2014 6:47:42 PM UTC-5, wrote:
Steve, After flying 12 of the last 14 years in the 1-26 Champs, I can assure you that it is a one design class, and there is very very little performance differences between models. Much more difference in a well sealed and cleaned up ship and one that is not. And a real hoot to fly in the Champs. I have seen all models win. It is the nut on the end of the stick that makes the difference. Kevin 92 (former 192)

Kevin, they are "one design" only in that they are all on the same TCDS. Agree completely that a lot depends on the driver. Also, that a well prepared, clean, straight, sealed A can probably knock the socks off of a crappy E on a strong day, even if flown at its much lower permitted gross weight.

As I said, you guys that race them are willing to accept that each one is different, but they are all close enough to the same to go race as a one design class.

Steve

Actually, GC, in the context I am talking about, "A" is Wing Area. CD varies with CL. There is a portion of CD that is independent of CL, and that part will be lower with a smaller fuselage because it has less wetted area. Smaller cross section usually comes along with less surface area. Chicken and egg, maybe?

You will likely find that it has less to do with the cross sectional area of the fuselage at max size than with fineness ratio of the fuselage and total wetted area. Looked at wheel pants on fixed gear airplanes lately? They have gotten bigger cross sections, and the drag has gone down. Proper shaping in the right places is the key. It seems to be less about what happens when getting thicker than how you handle getting thinner.

Steve

Damn right.

2T
I suspect that the size of the intellect, motivation, commitment, and preparation on the part of the person in the cockpit has an order of magnitude more importance than the size of the fuselage he or she is in.

UH

On Tuesday, August 12, 2014 10:09:50 AM UTC-4, Steve Leonard wrote:
On Monday, August 11, 2014 6:47:42 PM UTC-5, wrote:

Steve, After flying 12 of the last 14 years in the 1-26 Champs, I can assure you that it is a one design class, and there is very very little performance differences between models. Much more difference in a well sealed and cleaned up ship and one that is not. And a real hoot to fly in the Champs. I have seen all models win. It is the nut on the end of the stick that makes the difference. Kevin 92 (former 192)



Kevin, they are "one design" only in that they are all on the same TCDS. Agree completely that a lot depends on the driver. Also, that a well prepared, clean, straight, sealed A can probably knock the socks off of a crappy E on a strong day, even if flown at its much lower permitted gross weight..



As I said, you guys that race them are willing to accept that each one is different, but they are all close enough to the same to go race as a one design class.



Steve

It is very very rarely that the slight differences in the 1-26s ever standout. I prefer the D and the E because I like the thicker spar for ridge flying, but I would not have any qualms if someone offered me to fly an A, B or C in a 1-26 contest. If you look at results, all of the different models have been represented at the top of the scoresheet. The one that has been least represented, ironically is the E model, which has the highest wing loading. That is more due to that the E is mostly flown as a club ship rather than owned by those who race 1-26s. This is since that the E, while more durable for club operations is harder to repair if damaged in an landout. Ultimately, it is really a wash... come fly 1-26s if you want real one-design racing!

Best Regards,
Daniel