...2 weeks ago at a local contest I judged a FAI competitor who flew the F sequence with a YS DZ170/19x11 APCcombo on an Osmose. The individual is a very skilled pilot however the aircraft performance was anemic. On a calm no wind day maybe, add wind this engine prop combo becomes a liability in my opinion.

Recently I switched to using the 18.1x11 APC on the DZ 170 on my Beryll~GP. This combo has very good speed control likeI had experienced with the APC 15x11 4bld with excellent vertical which I needed for the new AMA Masters sequence.