The D-38 is a non-rigid airship with a small, steel framed gondola containing the pilot, a single propane burner and its fuel.
Tests of the D-38 showed it was not large enough to cope with hot and high environments, so a version with an envelope linearly enlarged by 9.4% and a volume of 50,000 cu ft (1,416 m³) was produced, designated the D-50.