S5 (Scale Altitude) Introduction

[TD Willard]

Scale Altitude competition is under class S5 in the FAI Sporting Code.  S5B (5 Ns total) is flown by Juniors and S5C (10 Ns total) is flown by Seniors.  Staging is not required under FAI rules but to win a medal, it is the only way to achieve the altitude.
(Correction per James Duffy's reply.) 

Follow this link to the information on the NAR website for S5 competition: S5 – Scale Altitude

[James Duffy]

Staging is not required under FAI rules but to win a medal, it is the only way to achieve the altitude.

That was certainly the case under the old (2002ish-2014) rules, which were optimized for rockets with fat boosters and skinny sustainers, and the event quickly became a one-design contest that coalesced around a single prototype, the Bumper WAC.  The new dimension rules that became effective in 2015 have opened the scope of viable prototypes widely, and the highest altitudes since that time have been earned by single-stage prototypes.  Both single- and two-stage prototypes have earned gold medals at Euro and World Champs since the rule change.

James