Download GTU (Gujarat Technological University Ahmedabad) B.Tech/BE (Bachelor of Technology/ Bachelor of Engineering) 2020 Winter 5th Sem 3150101 Flight Mechanics Previous Question Paper
Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE- SEMESTER?V (NEW) EXAMINATION ? WINTER 2020
Subject Code:3150101 Date:27/01/2021
Subject Name:Flight Mechanics
Time:10:30 AM TO 12:30 PM Total Marks: 56
Instructions:
1. Attempt any FOUR questions out of EIGHT questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
Marks
Q.1 (a) Define: Geometric Altitude, Absolute Altitude,
03
Geo-potential Altitude
(b) What is ISA? Why it is required?
04
(c) Derive equations of motion for an airplane in
07
steady level flight.
Q.2 (a) Define: Pressure altitude, Temperature altitude
03
and Density altitude.
(b) With neat sketch explain the effect of altitude on
04
power required and power available.
(c) Show that Thrust required for steady level flight
07
is inversely proportional to Aerodynamic
efficiency (Lift to drag ratio). Also show that
zero lift drag is equal to induced drag for
minimum thrust requirement condition.
Q.3 (a) Solve the following:
03
What is the minimum glide angle and maximum
range measured along the ground for the
airplane having maximum lift to drag ratio 16.9
and power-off glide starts at an altitude of 3048
m?
(b) Define: Static and Dynamics Stability.
04
(c) Develop an expression to determine the range
07
and endurance for propeller driven airplane.
Q.4 (a) What is Static Margin? Explain.
03
(b) What is Neutral point? Explain.
04
(c) Estimate lift-off distance for the CJ-1 (data
07
given below) at sea level. Assume ?r=0.02.
During the ground roll, the angle of attack of the
airplane is restricted by the requirement that the
tail do not drag the ground. Assume that CLmax
during ground roll is limited to 1. When the
airplane is on the ground, the wings are 1.83 m
above the ground.
Data for the CJ-I:-
Wing Span: 16.25 m
1
Wing area: 29.54 m2
Normal gross weight: 88176.75 N
Power plant: Two turbofan engines of 16242.5 N
thrust each
CD,0=0.02
e=0.81
Q.5 (a) Define Absolute and Service Ceilings.
03
(b) What is Neutral point? Explain.
04
(c) State and explain the criteria for airplane's
07
longitudinal static stability. Justify role of
Horizontal stabilizer.
Q.6 (a) What is Hinge Moment? How it varies with tail
03
deflection angle?
(b) What do you mean by Elevator effectiveness?
04
Explain.
(c) Explain steady pull-up and elevator deflection
07
required for it.
Q.7 (a) Compare Stick free and Stick fixed stability.
03
(b) Explain Stick Force and force gradient.
04
(c) Show that stick free neutral point is always
07
ahead of stick fixed neutral point.
Q.8 (a) Explain role of dihedral angle in Lateral
03
stability.
(b) Explain Directional Control.
04
(c) Write a note on Directional stability.
07
2
This post was last modified on 04 March 2021