The helicopter with... one blade

Retreating blade stall does not make the helicopter want to flip over but rather just slows it down again. The rolling moment you might expect from one side of the rotor disk losing lift actually acts at 90 degrees due to gyroscopic precession, resulting in a pitch up moment, slowing the craft down, it is self regulating.

they did one blade way way back for props, the hard part is balance

3:41 PRICELESS FOOTAGE

Well there is at least one production self launching glider that uses a single blade propeller for launch(and recovery in an emergency) that folds back into the empennage when not being used. So, this concept is not as crazy as you might thing. Crazy for helicopter sure but, not in theory for fixed wings. The 50's and 60's were crazy times for aviation.

The interesting thing is when a helicopter goes to fast it doesn't flip sideways instead the nose goes up. This is because of gyroscopic precession the force is rotated 90 degrees.

The XV-2 proves that in aviation engineering, elegance often loses to brute-force practicality. A one-bladed, transforming jet is peak 1950s ambition, even if it was just too clever for its own good! 🚁

The Osprey hardly inspires confidence.

In 1984, I remember my Gunny coming into our shop and telling us Aviation Marines that a new aircraft would replace the CH-46 helicopter soon. He was referring to the V-22 Osprey. It actually took a lot longer and it wasn't fully in service until 2007.

Having landed the troops, the single rotor can be used as a mission timer, a stopwatch; and to cook perfect boiled eggs!

While still a teenager I was flying control line (U-Control in the US) model aircraft. Mostly 'Razor Blade' flying combat aircraft, but also 'team race' and 'speed' models. For speed models it was not unusual to carve solid wooden propellers to try and maximize thrust by maximizing the engine rpm. For one speed model I built I tried a single blade propeller, similar to the Sikorsky concept, using a counter weight to balance the prop. I got the idea from a model aircraft magazine. I think it may have been German or even from the Soviet Union. I learned both German and Russian in my British technical Grammar School and could buy foreign magazines easily in a couple of London newspaper stores. The principle was to reduce drag and aerodynamic turbulence from the propeller blade ahead. Propeller blades generate a lot of residual turbulence which reduces the efficiency of the 'following' blade. So with only one blade there could be no turbulence from a 'preceding' blade so, in theory, a single blade could be more efficient. The aircraft flew, and flew well, but any improvement in performance was negligible at that small scale. The math makes sense and the theory is valid, but I'd always preferred to fly than test, so I shelved the design and branched out into making and flying boomerangs. Boomerangs are aerodynamically related to single blade propellers. But that's another subject for another day. Thanks for the video. I had known a little about this Sikorsky design but the video 'put some meat on the bones'.

Thank you. This is informative.

in the late 50's the German Army developed the Bolkow BO103,. It had a Single mail rotor blade (with counter weight) and twin blade tail rotor. It was developed from the BO 102 trainer. Top speed was 87mph.

Glad you showed that model.... in 1/72 scale!! From: A Model builder!! But Interesting Topic.....well Done!!!!

If the name's not trademarked, they should call this the Blade Runner.

Float like a butterfly, sting like a bee.

wow, never heard of that one before! thank you soo much again 😍😍😍

beautiful concept

The Lockheed AH-56 Cheyenne could do 244mph no crazy one bladed rotor system needed.

Reminds me of the Arnie movie The Sixth Day which had folding helicopter jets. Cool

Well it's like Wesley Snipes said "There's only been one Blade. There's only ever gonna be one Blade."