GYRODYNE

 Para 1955, luego de patentar su descubrimiento de los “tips” de pala, Gyrodyne estaba buscando un diseño para aplicarlo en su rotor coaxial. Encontró un pedido del U.S. Marine corps que buscaba un helicóptero pequeño que pudiera ser lanzado detrás de las líneas enemigas, en el cual un piloto pudiera rápidamente armar al helicóptero y volar de regreso fuera de peligro. Este pedido se había basado en la experiencia de la guerra de Korea, donde muchos pilotos cayeron en manos enemigas debido a la falta de equipo de rescate. El contrato se firmo en diciembre de 1954 y se construyeron dos prototipos que fueron designados como XRON-1 Rotorcycle.

Menos de un año de la “autorización para proceder”, se realizó el primer vuelo, el cual ocurrió el 23 de noviembre de 1955. Con un peso total de 500 lb., un diámetro de rotor de 15 Ft y un motor de dos tiempos de 40 HP era 11 veces mas pequeño que el modelo 2B. La alta temperatura alcanzada por el motor Nelson, demostró que se necesitaba otro motor.

A mediados de 1956, Gyrodyne requirió a la Naval Bureau of Aeronautics (BuAer) que considerara el cambio de motor por un motor de automóvil Porsche modificado. Gyrodyne recibió la aprobación y a finales de 1956 el XRON estaba volando nuevamente. A mediado de 1957, Gyrodyne tenia tres modelos con tres motores diferentes:

Después de probar las tres versiones para finales de 1957, la mas satisfactoria fue la que equipaba el motor Porsche. Para eso obtuvo de las autoridades el permiso para entrar en negociaciones con la compañía Porsche de Alemania para desarrollar un motor estrictamente para ser aplicado sobre el Rotorcycle.

Como consecuencia se obtuvieron dos modelos, el primero con una potencia de 55 HP y el segundo con una de 72 HP. Para principios de 1958 el modelo Porsche de 55HP estaba disponible sobre un XRON de disco de rotor de 17 Ft de diámetro, el cual adquirió cinco unidades el Marine Corps para evaluarlo.

El motor Porsche requería modificaciones mas grandes para ser utilizado. Esto incluía una nueva transmisión y un rotor de 20 Ft.

 By 1955, Gyrodyne was looking for a helicopter contract to demonstrate their new innovative yaw control for their coaxial rotor system. That contract came in the form of U.S. Navy contract NOas 55-388-c. In this contract, the U.S. Marine corps was looking for a small sized helicopter that could be dropped to a stranded pilot behind enemy lines, in which the pilot could quickly "snap together" the helicopter and fly out of harms way. This contract had been issued shortly after the end of the Korean War where many a fighter pilot had become captured due to a lack of extraction capability. The contract had been awarded in December 1954 and required the design, construction and test of two (2) one-man helicopters which were designated as XRON-1 Rotorcycle.

Less than one year from the date of "authorization to proceed", the first flight of the XRON-1 occurred on November 23, 1955. With a gross weight of 500 lb. and a 15-ft. rotor diameter, the two-cycle 40 horse powered XRON-1 was 11 times SMALLER than the 5400 lb model 2B! Flight testing by the Marine Corps team soon began and the high cylinder temperatures being generated by the Nelson indicated that engine life would be too short to be successful. A different engine was needed.

In mid 1956, Gyrodyne requested the Naval Bureau of Aeronautics (BuAer) to consider changing the XRON-1 engine to that of a modified Porsche automobile engine. Gyrodyne received approval in late 1956 and by early 1957 the XRON-1 was flying again. While this was occurring, BuAer was also proceeding on its own with the development of a small turbine powered engine suitable for the XRON. By mid 1957, Mr. Papadakos now had three engines powering his company's XRON helicopter:

With all three versions having been tested by late 1957, the most satisfactory results emerged from the Porsche combination. BuAer then authorized Gyrodyne to enter into negotiations with the Porsche Company of Germany to develop a suitable engine strictly for the Rotorcycle application. 

Accordingly, two models were developed, the first one rated at 55 horsepower and the second rated at 72 horsepower. By early 1958, the 55 HP Porsche was available and was easily installed on the existing Porsche powered XRON with a 17-ft rotor and was tested at NATC, Patuxent River, Maryland in accordance with applicable specifications. The performance of the helicopter led the Marine Corps to acquire five (5) of this type of XRON Rotorcycle for evaluation purposes.

The 72 horsepower Porsche engine required more extensive modifications to be used. This included a new transmission to handle the higher power input and a 20-ft rotor diameter to handle the higher empty weight. This XRON was also evaluated at NATC, Patuxent River.
    BuAer insisted that the Solar 55 horsepower turbine engine XRON also be evaluated, as that had been their engine of choice.  The Solar was reinstalled on one of the modified XRONs and then evaluated at NATC, Patuxent River.

Thanks to Gyrodyne Helicopters

Characteristics
Características

Information
Información

Characteristics
Características

Information
Información

1955

1 Porsche
YO-95-6

 1

72 HP

550 Lb

4200 Ft

906 Lb

6000 Ft

54 Kts

11200 Ft

 66 Kts

46 NM