US 12,420,919 B2
Pylon restraint system
Peter Quinn Romano, Fort Worth, TX (US); Jedediah Bryce Goodell, North Richland Hills, TX (US); Joshua Andrew Emrich, Grapevine, TX (US); and Michael S. Seifert, Southlake, TX (US)
Assigned to TEXTRON INNOVATIONS INC., Providence, RI (US)
Filed by Textron Innovations Inc., Providence, RI (US)
Filed on Feb. 9, 2023, as Appl. No. 18/166,867.
Application 18/166,867 is a division of application No. 16/584,448, filed on Sep. 26, 2019, granted, now 11,584,521.
Prior Publication US 2023/0182893 A1, Jun. 15, 2023
Int. Cl. B64C 27/12 (2006.01); B64C 27/00 (2006.01)
CPC B64C 27/12 (2013.01) [B64C 27/001 (2013.01); B64C 2027/002 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method for determining parameters for a transmission restraint in a rotorcraft, the method comprising:
determining a plurality of inputs for a main rotor system, the main rotor system including a rotorcraft fuselage, a rotorcraft transmission, and a main rotor hub;
determining, according to the inputs, and by treating the main rotor system as a harmonic oscillator, a spring rate for a restraint for attaching the rotorcraft transmission to the rotorcraft fuselage;
calculating, according to the spring rate, a distance between an attachment point of the restraint on the rotorcraft transmission and a virtual focal point of the rotorcraft transmission, wherein two brackets attach the rotorcraft transmission to the rotorcraft fuselage such that the rotorcraft transmission is arranged to oscillate around the virtual focal point; and
calculating an angle of restraint between the restraint and the rotorcraft fuselage based on the spring rate and the distance, wherein the angle of restraint is between 0° and 90°, and wherein the restraint is mounted to the rotorcraft transmission at a point below the virtual focal point.