NACA cowling
The Orion was the last design using many identical elements from the Lockheed designs preceding it. It primarily used all the elements of the Altair, but included a forward top cockpit similar to the Vega, plus the NACA cowling introduced in the Air Express. Lockheed used the same basic fuselage mold and wing for all these wooden designs (the Explorer wing was unique), hence the close similarities between them. The Orion featured an enclosed cabin with seating for six passengers. The Orion received its Approved Type Certificate on 6 May 1931.