US 1,994,488Direct lift aircraft1935
PD-53 · US 1,994,488
Direct lift aircraft
Sikorsky's direct-lift aircraft, 1935 — the configuration that became the modern helicopter.
- Inventor
- Patented
FinishSize
Total29 €
PD-53 · US 1,994,488 · Filed June 27, 1931 ·
Pairs well with
Full collection
Common questions
- Is this a real patent?
- Yes — the original drawing as filed at the U.S. Patent Office, cleaned and printed. Public domain by law.
- How is it shipped?
- Printed in Europe on 200 g/m² matte paper. Small sizes ship flat, 50 × 70 ships rolled in a tube. Tracking by email.
- What if it arrives damaged?
- Send a photo within 7 days and we reprint and reship it free.