PTU B.Tech Aero Engineering? 6th Semester May 2019 60531 AIRCRAFT STABILITY AND CONTROL Question Papers

PTU Punjab Technical University B-Tech May 2019 Question Papers 6th Semester Aerospace Engineering?

Roll No.
Total No. of Pages : 02
Total No. of Questions : 09
B.Tech. (ANE) (Sem.?6)
AIRCRAFT STABILITY AND CONTROL
Subject Code : ANE-322
M.Code : 60531
Time : 3 Hrs. Max. Marks : 60
INSTRUCTIONS TO CANDIDATES :
1.
SECTION-A is COMPULSORY consisting of TEN questions carrying T WO marks
each.
2.
SECTION-B contains FIVE questions carrying FIVE marks each and students
have to attempt any FOUR questions.
3.
SECTION-C contains T HREE questions carrying T EN marks each and students
have to attempt any T WO questions.

SECTION-A
Q.1 Answer the following terms :


(a) What do you mean by asymmetric flight?

(b) List the various assumptions taken into consideration while deriving equations of

motion of an aircraft?

(c) Define `stick force gradient' and explain its importance.

(d) Define elevator power. How elevator power can be increased?

(e) Define static stability. Mention the criteria for an aircraft to be statically stable.

(f) Define neutral point with the help of a sketch.

(g) What is trim tab. Explain its function.

(h) Define `maneuver margin'.

(i) Explain the importance of damping.

(j) Explain the importance of `Frise' aileron with the help of sketch(s).
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SECTION-B
Q.2 Derive expression for rudder control power. Explain the uses of rudder.
(3, 2)
Q.3 Derive the expression for elevator angle for trim condition, Show using sketches, how trim
condition of an aircraft can be varied?
(4,1)
Q.4 What do you mean by coupling of lateral and directional effects? Explain.
(5)
Q.5 Define `Dihedral Effect' with the help of a sketch. How different parts of an airplane
contribute to dihedral effect?
(5)
Q.6 If the slope of the pitching moment curve for a given airplane is (dCm/dCL) = ?0.15 and the
pitching moment coefficient at zero lift is 0.10, at what lift coefficient the airplane will be
in trim? How much pitching moment coefficient must be supplied to achieve trim at
CL = 3?
(5)

SECTION-C
Q.7 Calculate Cmo and Cm for complete aircraft from the following geometric and aerodynamic
characteristics of an aircraft at Sea Level. Also find stick fixed neutral points.




(4,4,2)

W = 25000 N
V = 80 ms?1
Xcg = 0.3c
Xac = 0.25c

SW = 20m2

b = 11m
iw = 1.5 deg
m.a.c. = 1.82m

SHT = 4 m2

lt = 5.5 m
it = ?1.5 deg
= 0.9

(C )
0.3

1
(C )
5.1 rad
(C
)
0.12
(C
) 0.0
o
L
W
L
W
m
W
m
t

ac
ac

1
(C )
4.5 rad
1
(C )
0.12 rad (C )
0.025
I
L
Tail
m
f
y = 2000 kg-m2
a

o
m
f

Xu = ? 0.045

Zu = ? 0.369
Q.8 Explain short period and phugoid modes. Using data given in Q.7, find the Roots, Period,
t1/2 / tdouble and N1/2 / Ndouble for Phugoid approximation.
(4,3,1,1,1)
Q.9 Write notes on the following :
(6,4)

(i) Explanation of airplane dynamics using spring mass system


(ii) In flight measurement of stick free neutral point.
NOTE : Disclosure of Identity by writing Mobile No. or Making of passing request on any
page of Answer Sheet will lead to UMC against the Student.
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