Building upon previous experience with the LS1 and LS2, chief designer Wolf Lemke developed a new fuselage with a larger cockpit and more generous horizontal and vertical stabilisers.

Lemke selected a relatively thick airfoil profile developed in 1967 by University of Stuttgart Professor Franz Wortmann, the FX 67-K-170, which offered the structural economy made possible by a tall spar - an important consideration as glass fibre was still the only affordable reinforcement material - as well as good performance for the time.

The flaperon drives are located at the wing roots, an elegant solution that required a large amount of lead for mass balancing the control surfaces to preclude any risk of flutter.

Due to this the LS3 wings are heavy, about 85 kg each semi-span (thus the nickname LS-Blei, a pun exploiting the phonetic similarity in the German language between 'drei' (three) and 'Blei' (lead)).

It remains a popular glider in the second-hand market although it is seldom found in club fleets, possibly due to the added complexity of flaps and undercarriage.