Question: What type of aircraft did the Italian engineer Enrico Forlanini work on that was an aerostat?
Sentence (from "Enrico Forlanini"): Enrico Forlanini (13 December 1848 – 9 October 1930) was an Italian engineer, inventor and aeronautical pioneer, known for his works on helicopters, aircraft, hydrofoils and dirigibles.
Relevant evidence: Yes