Details

Phase 5 is a highly efficient, fully aerobatic sailplane designed by Chris Foss in the late 1970’s.  The wing has an aspect ratio of 1:9 and uses a semi-symmetrical root aerofoil section that transitions to fully symmetrical at the tip for good axial roll characteristics.  The fuselage has a long nose, generous side area and a high aspect ratio fin and rudder giving good knife edge characteristics for hesitation rolls and positive stall turns.  The all-moving tailplane is mounted on flexible wire joiners.  The prototype Phase 5 was flown to 5th place at the 1977 British Nationals Multi-Task competition.  The original plan shows coupled ailerons and flaps using pushrods and bell cranks but fitting four modern digital servos in the wing will allow full mixing.

The plan can be ordered by contacting Chris Foss through his website:  https://www.chrisfoss.co.uk/constructional-plans/4538948935/ . Construction is more complex than Phase 6 but flying characteristics are about the same. 

Many thanks to Graham N. for his great picture