ASE 367K Final Exam 30 Questions with Verified Answers,100% CORRECT

ASE 367K Final Exam 30 Questions with Verified Answers Shifting CG forward will decrease the magnitude of required control forces. - CORRECT ANSWER False - Larger moment arm form center of pressure Newtons laws of ...

ASE 367K Final Exam 30 Questions with Verified Answers Shifting CG forward will decrease the magnitude of required control forces. - CORRECT ANSWER False - Larger moment arm form center of pressure Newtons laws of motion are only valid where expressed in an internal frame. - CORRECT ANSWER True- only way to account for all accelerations The aerodynamic center is the point on the mean aerodynamic chord about which the longitudinal aerodynamic axis is zero. - CORRECT ANSWER False For a wing, the neutral point is the line where the line of action of the resultant aerodynamic force crosses the mean aerodynamic chord. - CORRECT ANSWER False- Neutral point is where if the CG is placed there, the aircraft will be neutrally stable All aircraft are statically stable (longitudinal) when the CG is forward of the neutral point. - CORRECT ANSWER True- if CG is in front, lift increase after disturbance and brings the plane back up The net effect of a flap deflection is to shift the CM v. a curve leftwards, the lift v. a cruve upwards and the the E v. a curve up - CORRECT ANSWER False- E v. a has no shift The elevator angle to trim, angle of attack when an aircraft is trimmed and the derivative of the elevator angle to trim with respect to the lift coefficient when the aircraft is trimmed are all linear functions of the distance between the CG and the neutral point. - CORRECT ANSWER True- Linear moment compared to neutral point -linear*linear=linear. Force*moment arm. Both wing sweep angle and dihedral affect the stability derivative Clb. - CORRECT ANSWER True- roll moment derivative with respect to side slip The contribution of the fuselage to CnB is destabilizing. - CORRECT ANSWER True- yaw moment coefficient with respect to side slip- flow hits side of fuselage in side slip and pushes it opposite to the the weather vane direction. F Positive Deflections Of elevator, ailerons and rudder result in negative contributions to pitch, roll and yaw moments. - CORRECT ANSWER True- convention (Make sure to check with email) In phugoid motion, the pitch rate and airspeed vary. - CORRECT ANSWER True- A more negative ClB leads to a more damped pitch roll motion. - CORRECT ANSWER False The sign of CyB for a conventional aircraft is negative and the dominant contribution to this stability derivative is made by the main wing - CORRECT ANSWER False By increasing dihedral angle one can make the spiral motion (mode) stable while making the Dutch roll motion unstable. - CORRECT ANSWER True If the aircraft loses one of its engines, the rudder has to be used to counter the resulting yaw moment. - CORRECT ANSWER True A step change in throttle (thrust) always results in a change in the steady state velocity, angle of attack, and flight path angle. - CORRECT ANSWER False- can't have all three The spiral mode is always unstable. - CORRECT ANSWER False- always has negative real part. All aircraft are statically stable when Cma at the CG is positive. - CORRECT ANSWER False-Cma needs to be negative and Cmo needs to be positive Deflection of a rudder has no effect on the roll moment of the aircraft. - CORRECT ANSWER False The relative magnitudes of the moments of inertia in the principle Alex system determine the relative stability of the aircraft about these axes - CORRECT ANSWER True The linearized force equations from an aircraft climbing at a constant flight path angle are the same for an aircraft in level flight - CORRECT ANSWER No answer yet The frequency of the short period decreases as the size of the horizontal is increased. - CORRECT ANSWER False A system is unstable if the coefficients of its characteristic equation are all negative - CORRECT ANSWER False When the CG of an aircraft is moved forward, the value of the coefficient of moment at an angle of attack of zero (CMO) - CORRECT ANSWER [A] Increases [B] decreases [C] Remains the same When the elevator of an aircraft is deflected upward, the value of the coefficient of moment at an angle of attack of zero (Cmo) - CORRECT ANSWER [A] increase [B] decreases [C] remains the same If the position of the CG remains the same as the weight of the aircraft decreases (fuel burned) the elevator must be deflected - CORRECT ANSWER [A] defected upwards [B] deflected downwards [C] Remains the same When the flaps of an aircraft are extended, the Cm v. a curve shift - CORRECT ANSWER [A] upwards [B] downwards [C] remains the same The second Euler angle used in flight dynamics to describe the transformation from the vehicle-carried vertical reference frame to the body reference frame (ie the angle of the second rotation of the transformation) is - CORRECT ANSWER [A] psi [B] phi [C] theta The Euler angle phi used in flight D can take on values between - CORRECT ANSWER [A] -90 and 90 [B] -180 and 180 [C] 0 and 180 The stability derivative Mq affects the - CORRECT ANSWER [A] frequency of the long-period [B] Damping of the long-period [C] Frequency of the short-period [D] damping of the short period (Cmq is the coefficient of moment with respect to pitch rate