Here are a couple of better pictures sent to me by David of the belly pan and the fuse front showing the reinforcement strips.

Roary was inquiring about where the Illusion stood with respect to the Tipo. Based on the little info I have, the Illusion was a Dave Brown "design". In essence Dave took the Tipo 720 and enlarged the wing root to produce a 750 square wing. Span was the same as the T720 but the extra squares were gained at the root. The stab anhedral was reduced (can't remember exactly how much but probably around 2-2.5" total) consistent with Dick Hanson's idea that the pronounced anhedral on the T720 was partly required due to the underwing slung pipe. In fact, Dick suggests that if a muffler is to be used on the T720, that the stab anhedral should be reduced to ~2" rather than the 4-3/8" of the original piped design.

David (and perhaps Dick as well), no doubt wanted to explore this concept and modified the T720 by changing the anhedral and tucking the pipe "into" the fuse by raising the wing and producing a belly pan in which the pipe would ride. This essentially resulted in a T720 sans pipe front profile since the overall height of the fuse was the same but allowed for the powerful piped setup. The wing was placed such that the thrust line just grazed the top of the wing at its thickest point. This placement with respect to the thrust line was common with other designs of the 80's. Of course, the front profile of the fuse between the two models was similar (the fuse bottom under the wing was better integrated in the Illusion since there was no wing portion there) but the wing location changed altering the flight characteristics. I don't believe the stab incidence (0 degrees) or location was changed with respect to the T720 - it remained the same placed along the "tuck" line (the separation of the fuse and canopy, if you will) of the two designs.

According to Tony F, although he never flew the Illusion, he was of the opinion that Dave Brown did much better with the Tipo 720 (and 750 later perhaps although I'm not sure he flew the 750 competitively) and that the model presented and flew better than the Illusion. Personally, although I like the integrated and sleeker look of the Illusion, the T720 will always remain a great classic and arguably may fly better.

I had a T720 on the bench recently alongside Matt's Saphir I and the Tipo looks like a 40 size model in comparison. The wing is quite small and narrow at 720 squares compared to the early turnaround designs such as the Saphir and the Calypso. Of course, models such as the Dirty Birdy and UFO had fewer squares yet (< 700 sq in)! BTW, the Calypso also looks small compared to the Saphir - it is. I guess the Calypso was being flown with non pumped sport ST S60's while the Saphir was being flown with pumped long stroke inverted Webra's, at the time.

David.