Lapyx 1

On May 14, 2023 — 60 days after the Lapyx 0 flight attempt — the team headed to the airfield to attempt a launch of Lapyx 1.

Despite its structural failings, the geometry, airfoil choice and general layout of Lapyx 0 were sound. As such, L1 was also a 3 m wingspan monoprop aircraft designed to be launched and landed in the exact same way as L0. To address the key stiffness issue, the wings were designed around larger-diameter spars. The wing skin was formed by plastic segments 3D-printed in lightweight PLA. A new motor and prop arrangement was used, and all internals were housed inside a fuselage made of nylon 12 (SLS).

Lapyx 1 was able to take off successfully and climb for several meters. However, as clearly shown through the onboard footage, it encountered wing flutter as it entered a turn. The wings shook violently, rendering the ailerons useless and creating unpredictable flight behavior. Thankfully, the pilot was able to regain control and skilfully crash-land the aircraft such that only minor damage was taken.

This aircraft represented a significant leap from L0, but a key issue remained: the wings needed to be much more torsionally stiff — not only for flight behavior but also to prevent damage to the eventual solar panels. To solve this and a myriad of other smaller issues, the team opted for a fundamental redesign of the wings for Lapyx 2.