In the prototypes the trailing edge of the wings were taken up by steel-framed fabric covered flaps and ailerons, all deflectable to improve thermalling and approach control, but later production aircraft had the flaps eliminated, upper surface spoilers fitted for approach control, with the Mü13D-3 gaining increased span wings, a lengthened fuselage and an enlarged fin and rudder.

The pilot sat just forward of the main-spar with his head flanked by the wing leading-edges, severely restricting sideways vision.

[2] The performance of the Mü13 was regarded as particularly good at an L/D ratio of 28 and the ability to fly at relatively high speeds due to the slender Mü Scheibe aerofoil section.

'Merlin', flown by Hans Wiesehöfer, flew around southern Germany and the Alps on point to point flights, but 'Atalante' achieved fame as the mount of Kurt Schmidt, who at the age of 16 had been responsible for building a large part of 'Atalante as well as piloting the glider at the 1935 Rhön competition at the Wasserkuppe, achieving the longest flight at 252 km (156.6miles) from the Wasserkuppe to Trier.

[2] Tony Troeger's 'Merlin' had an 18 hp (13 kW) Kroeber M4 Köller two cylinder horizontally opposed engine fitted in the nose, re-designated Mü13M Motormerlin, reaching a top speed of 125 km/h (78 mph) and landed at 45 km/h (28 mph) making wheel brakes on the retractable mainwheel superfluous.