McCulloch J-2

L'autogire McCulloch J-2 vu sur Wikipedia.en

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The McCulloch J-2 was a small, two-seat [Vous devez être inscrit et connecté pour voir ce lien] with an enclosed cabin, one of only three of this type of aircraft to receive a [Vous devez être inscrit et connecté pour voir ce lien] in the United States.

It was built by [Vous devez être inscrit et connecté pour voir ce lien].

It was designed by [Vous devez être inscrit et connecté pour voir ce lien] and first flew in June [Vous devez être inscrit et connecté pour voir ce lien].

McCulloch acquired the design in [Vous devez être inscrit et connecté pour voir ce lien] and put it into production, building 83 aircraft over the next three years.

The design featured a belt clutch and a transmission which could be engaged to spin the rotor blades to high speed before take-off to produce short take-off runs.

A lever on the rear cockpit wall would select the drive position for the transmission.

A single "spin-up lever" on the cockpit left side would then be pressed downward, operating as a collective pitch control to put the blades into flat pitch while simultaneously tensioning the belt clutch.

The rotor could be spun to over 500 rpm before take-off, well above the normal flight range (typically 425 rpm).

Release of the spin-up lever would disengage both the clutch and the transmission, while placing the blades into flight
pitch.

After a very brief take-off run (typically 25 to 200 feet, depending upon load and winds) adequate flight airspeed would be attained, while the rotor speed decayed to the normal flight range.

The rotor was not engine driven in flight.

A strong spring resisted accidental depressing of the spin up lever while airborne.

Dual controls were provided for all functions except the spin-up lever, which was accessible only from the left seat.

The aircraft enjoyed nimble handling with light control forces, but suffered from a shallow climb gradient.

Early versions were equipped with a two-bladed wooden [Vous devez être inscrit et connecté pour voir ce lien] propeller.

A later "Super J-2" variant employed a three-bladed Hartzell controllable pitch propeller, accompanied by an increase in allowable gross weight. Baggage of up to 95 pounds, to the extent permitted by gross weight considerations, could be carried in a large bay under the seat.

Fuel was carried in tanks in the stub wings.

A total of 24 U.S. gallons could be carried, 12 on each side, but only 20 were usable through normal flight attitudes.

At a typical fuel burn rate of about 8 gallons per hour and economy cruise at about 85 mph, with a need for a
safety reserve, this limited the aircraft's range.

The rotor system (hub and blades) is very similar to that found on the early versions of the Hughes 269 / Schweizer 300 series helicopters.

The primary difference is in the twist of the blades (or lack thereof), optimized for autorotation in the case of the J-2.

In [Vous devez être inscrit et connecté pour voir ce lien], the rights were bought by [Vous devez être inscrit et connecté pour voir ce lien], who planned to return it to production, but could not find a market for the aircraft and no more were built.