On Friday, May 8, 2015 at 6:20:38 PM UTC-7, wrote:
Hi All
I'm currently in the market for my first glider and am looking at standard class machines of the Discus/DG-300 era. Having read the Johnson tests and many posts on this forum, I'm a bit confused as to where the touted performance difference comes from though. Dick Johnson found the polars to be near enough to identical and demonstrated so with a figure overlaying them in the DG-300 article. Despite that though, there seems to be a feeling in this forum that the Discus is a superior machine and competition results seem to support that. Given the extremely similar glide performance, is there some other factor which makes the Discus a better performer or are it's superior competition results simply because better/more competitive pilots bought it?

You'll get a lot of opinions, so here's mine. I've had about 50 hours in a Discus, 40 in a DG-300, and 300 or so in a DG-303 (which is really a minor tweak, mostly the addition winglets). The Discus is easier to fly well, lighter controls (particularly pitch), basically flies itself in thermals, has wing tanks for easy filling, and has a higher wing loading at gross. The DG has a more robust structure, better gelcoat, tougher landing gear with more ground clearance, lands more slowly (meaning shorter off-field landings), climbs slightly better with comparable wing loading, and has a more comfortable cockpit. One key factor, DIscus is still well supported by SH for free, DG requires paying an annual tax to them if you want such niceties as parts and technical bulletins. Never flew any contests in a Discus, but did in the 303. I never felt at a disadvantage against a Discus, in climb or head to head final glides.

Marc