Sikorsky Cypher

Lore & Background

Sikorsky started developing the Cypher in the late 1980s. This small drone used coaxial rotors housed inside a doughnut-shaped shroud. The circular duct made the vehicle safer to handle and generated extra lift. The first test model was 1.75 meters across, 55 centimeters tall, and weighed 20 kilograms. It first flew in the summer of 1988, powered by a 2.85 kW four-stroke engine. For early forward-flight tests, engineers mounted it on a truck.

A bigger prototype came next, measuring 1.9 meters in diameter and weighing 110 kilograms. It ran on a 40 kW Wankel engine. That aircraft first flew in April 1992 and achieved its first free flight in 1993. Over the rest of the decade, it completed more than 550 demonstration flights for U.S. government agencies.

The Cypher could carry a sensor package on top of its fuselage or haul external loads up to 23 kilograms. This program led to the larger Cypher II, which Sikorsky entered into the U.S. Navy’s VT-UAV competition.

Reader's Guide

The Sikorsky Cypher represents an early and distinctive approach to vertical takeoff and landing unmanned aerial vehicles, using a shrouded coaxial rotor system that enhanced safety and lift. Its development spanned from a proof-of-concept aircraft in 1988 to a larger prototype that first flew in 1992 and achieved free flight in 1993. The vehicle accumulated over 550 demonstration flights for U.S. government agencies, indicating sustained interest from military and civilian authorities. The Cypher's design allowed it to carry sensor payloads above the fuselage or external loads up to 23 kg, demonstrating versatility for reconnaissance or light transport roles. The program directly led to the Cypher II, an enlarged derivative with a rear-mounted pusher propeller and detachable wings for extended endurance, which was evaluated by the United States Marine Corps under the designation Dragon Warrior and submitted to the U.S. Navy's VT-UAV competition. The Cypher thus served as a technological foundation for subsequent ducted-rotor UAV concepts, influencing later vertical-lift unmanned aircraft development.

Did You Know?

• The first proof-of-concept Cypher flew in the summer of 1988.
• The larger Cypher prototype had a diameter of 1.9 m and weighed 110 kg.
• The Cypher could carry external loads of up to 23 kg.
• The Cypher II was evaluated by the United States Marine Corps as the Dragon Warrior.