# Flying Bike (DD-584)

> From the footage, I identify the machine as the de Lackner HZ-1 Aerocycle, a one-man 'personal helicopter' built for the US Army in the mid-1950s. It grew out of work by Charles H. Zimmerman of NACA on kinesthetic control: with the rotors below the pilot, the craft could be steered by shifting body weight, much like riding a bicycle or a surfboard. The Aerocycle had a cross-shaped frame with the pilot standing on a platform in a safety harness, above two contra-rotating 15-foot rotors driven by a 40-horsepower Mercury outboard motor. A motorcycle-style twist-grip throttle sat on the handlebars, and airbags on each arm plus a central rubber float served as landing gear. It made its first tethered flight on November 22, 1954, and its first free flight in January 1955 at the Brooklyn Army Terminal in New York. Early tests suggested untrained soldiers could learn to fly it in about 20 minutes, and the Army ordered 12. After testing moved to Fort Eustis, Virginia, in 1956, test pilot Capt. Selmer Sundby found it much harder to fly than expected. Two crashes, in which the rotors intermeshed and shattered, and the wider failure of the 'personal lifting device' concept ended the program. One HZ-1 survives at the US Army Transportation Museum at Fort Eustis.

- Department: History (also Military, Tech)
- First published: 2025-05-29
- Last updated: 2025-05-29
- Permalink: https://detailenjoyer.com/case/flying-bike/
- Author: Marcus Easterling (DetailEnjoyer), The Detail Department

## On the timeline

- **Nov. 22, 1954**: The prototype makes its first tethered flight
- **January 1955**: First free flight at the Brooklyn Army Terminal
- **1956**: Testing moves to Fort Eustis, Virginia

Full timeline: https://detailenjoyer.com/timeline/?case=flying-bike

## Quick facts

- **DD-584-F01**: The HZ-1 Aerocycle was steered by the pilot shifting his weight. _(Write-up · Exhibit A (Steer by leaning))_
- **DD-584-F02**: The Aerocycle's first free flight was in January 1955 at the Brooklyn Army Terminal. _(Write-up · Exhibit C (Brooklyn, 1955))_

## Write-up

A helicopter you flew standing up. The US Army ordered 12 Aerocycles. Only one survives.

1. **Steer by leaning**: NACA's Charles Zimmerman showed a craft with rotors below the pilot could be steered by shifting weight.
2. **An outboard motor**: A 40-horsepower Mercury outboard motor drove two contra-rotating 15-foot rotors.
3. **Brooklyn, 1955**: Its first free flight came in January 1955 at the Brooklyn Army Terminal in New York.
4. **Twelve ordered**: Early tests looked promising, and the US Army ordered 12.
5. **Harder than it looked**: Testing showed it was hard to fly, and two rotor-collision crashes ended the program.

## Related case files

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- [Ekranoplan (DD-704)](https://detailenjoyer.com/case/ekranoplan/): I think of it as another strange military craft from the same era

## Reel vs. record

- **Note**: 'Blending motorcycle mechanics with helicopter technology': I'd narrow that. The motorcycle part was mainly the twist-grip throttle. The engine came from a Mercury outboard boat motor, and the steering was by leaning (kinesthetic control), an idea from NACA.
- **Note**: 'The 1955 New York Flying Bike': I think this is the de Lackner HZ-1 Aerocycle, whose first free flight was in January 1955 at the Brooklyn Army Terminal. Its first tethered flight was on November 22, 1954.
- **Missing**: it was a US Army program, not a consumer vehicle. The Army ordered 12, then dropped the project after testing showed it was hard to fly and two crashes in which the rotors collided.

## Video: Flying Bike: A Helicopter You Flew Standing Up

- Duration: 22.1 s · Published: 2025-05-29
- File: https://detailenjoyer.com/assets/videos/DKP6OuCSpch.mp4

### Transcript

DID YOU KNOW? The 1955 New York Flying Bike refers to a prototype developed during a post war surge in personal aviation concepts, blending motorcycle mechanics with helicopter technology, in an attempt to create a compact, flying personal vehicle. This early example of a vertical takeoff craft typically featured dual rotor systems, a lightweight frame, and control systems adapted from both aviation and motorcycling. NOW YOU KNOW!

## Questions & answers

**Q: How did an Aerocycle pilot steer?**  
A: An idea called kinesthetic control. _(Source: Write-up · Exhibit A (Steer by leaning) · Wikipedia: De Lackner HZ-1 Aerocycle; Wikipedia: Hiller VZ-1 Pawnee)_

**Q: What powered the Aerocycle?**  
A: It made 40 horsepower. _(Source: Write-up · Exhibit B (An outboard motor) · Wikipedia: De Lackner HZ-1 Aerocycle)_

**Q: Where did the Aerocycle make its first free flight?**  
A: In January 1955. _(Source: Write-up · Exhibit C (Brooklyn, 1955) · Wikipedia: De Lackner HZ-1 Aerocycle)_

**Q: How many Aerocycles did the US Army order?**  
A: Only one HZ-1 survives today. _(Source: Write-up · Exhibit D (Twelve ordered) · Wikipedia: De Lackner HZ-1 Aerocycle)_

**Q: What happened in both Aerocycle crashes?**  
A: The blades shattered. _(Source: Write-up · Exhibit E (Harder than it looked) · Wikipedia: De Lackner HZ-1 Aerocycle)_

## Sources

- [Wikipedia: De Lackner HZ-1 Aerocycle](https://en.wikipedia.org/wiki/De_Lackner_HZ-1_Aerocycle)
- [Wikipedia: Hiller VZ-1 Pawnee](https://en.wikipedia.org/wiki/Hiller_VZ-1_Pawnee)

## Cite this case file

Easterling, Marcus. "Flying Bike." The Detail Department (DetailEnjoyer), case file DD-584, last updated May 29, 2025. https://detailenjoyer.com/case/flying-bike/