Day 1 — Helicopter Design Day (Coach-Guided Show & Test, 45 minutes)
Focus: Aerodynamics, torque, lift, rubber winding, lightweight structures.
- S1: Flight Basics — Lift, drag, thrust, weight; safe winding and launch habits.
- S2: Rotor Design — Try different rotor chord, pitch (twist), and diameter; build smooth hubs.
- S3: Airframe + Power — Assemble a balanced airframe; gentle practice flights with timers.
- S4: Coach-Guided Show & Test — Take turns flying, cheer peers, share one change and its effect.

