Gate Flight Mechanics by Vayushastra

FLIGHT MECHANICS

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FLIGHT MECHANICS Atmosphere: Properties, standard atmosphere. Classification of aircraft. Airplane (fixed wing aircraft) configuration and various parts. Airplane performance: Pressure altitude; equivalent, calibrated, indicated air speeds; Primary flight instruments: Altimeter, ASI, VSI, Turn-bank indicator. Drag polar; take off and landing; steady climb & descent,-absolute and service ceiling; cruise, cruise climb, endurance or loiter; load factor, turning flight, V-n diagram; Winds: head, tail & cross winds. Static stability: Angle of attack, sideslip; roll, pitch & yaw controls; longitudinal stick fixed & free stability, horizontal tail position and size; directional stability, vertical tail position and size; dihedral stability. Wing dihedral, sweep & position; hinge moments, stick forces. Dynamic stability: Euler angles; Equations of motion; aerodynamic forces and moments, stability & control derivatives; decoupling of longitudinal and lat-directional dynamics; longitudinal modes; lateral-directional modes.

2007

1. For maximum range of a glider, which of the following conditions is true?

a) Lift to drag ratio is maximum

b) Rate of descent is minimum

c) Descent angle is minimum

d) Lift to weight ratio is maximum

2. An airplane with a larger wing as compared to smaller wing will necessarily have

a) More longitudinal static stability

b) Less longitudinal static stability

c) Same longitudinal static stability

d) More longitudinal static stability for an aft tail airplane if aerodynamic center of

the larger wing is behind the center of gravity of the airplane

3. Two airplanes are identical except for the location of the wing. The longitudinal

static stability of the airplane with low wing configuration will be

a) More than the airplane with high wing configuration

b) Less than the airplane with high wing configuration

c) Same as the airplane with high wing configuration

d) More if elevator is deflected

FLIGHT MECHANICS


4. For a fixed center of gravity location of an airplane, when the propeller is mounted

on the nose of the fuselage

a) Longitudinal static stability increases

b) Longitudinal static stability decreases

c) Longitudinal static stability remains same

d) Longitudinal static stability is maximum

5. Let an airplane in a steady level flight be trimmed at a certain speed. A level and

steady flight at a higher speed could be achieved by changing

a) Engine throttle only

b) Elevator only

c) Throttle and elevator together

d) Rudder only

6. An airplane model with a symmetric airfoil was tested in a wind tunnel. Cm0 (Cm at

angle of attack, α = 0) was estimated to be 0.08 and 0 respectively for elevator

settings (δe) of 5 degrees up and 5 degrees down. The estimated value of the

elevator control power (

) of the model will be

a) 0.07 per deg

b) -1.065 per deg

c) -0.008 per deg

d) -0.762 per deg

7. The lateral-directional characteristic equation for an airplane gave the following set of

roots: λ1 = -0.6, λ2 = -0.002, λ 3,4 = -0.06 ± j1.5, where . The damping ratio

a) 0.04 b) 0.66 c) 0.35 d) 0.18

8. If the center of gravity of an airplane is moved forward towards the nose of the airplane,

the CLmax (maximum value of the lift coefficient) value for which the airplane can be

trimmed (Cm = 0) will

a) Decrease b) increase c) remain same d) depends upon rudder deflection

9. If the contribution of only the horizontal tail of an airplane was considered for

estimating

, and if the tail moment arm lt was doubled, then how many times the

original value would the new

become?

a) Two lines b) three lines c) 1.414 times d) 1.732 times

FLIGHT MECHANICS


10. If the vertical tail of an airplane is inverted and put below the horizontal tail, then the

contribution to roll derivative,

, will be

a) Negative b) positive c) zero d) imaginary

11. If horizontal tail area is increased while the elevator to horizontal tail area ratio is kept

same, then

a) Both longitudinal static stability and elevator control power will increase

b) Only longitudinal static stability will increase

c) Only elevator control power will increase

d) Neither stability nor control power changes

COMMON DATA QUESTION 12,13 & 14: An airplane designer wants to keep longitudinal

static stability margin (SM) within 5% to 15% of mean aerodynamic chord. A wind tunnel

test of the model showed that for = 0.3,

Note that the distance from the

wing leading edge to the center of the gravity (XCG) has been non-dimensionalized by

dividing it with mean aerodynamic chord, such that CG = XCG/ . Note also that the

relation

holds true for this airplane.

12. The most forward location of the airplane center of gravity permitted to fulfill the

designer’s requirement on longitudinal static stability margin is

a) 0.35 b) 0.25 c) 0.15 d) 0.52

13. The most aft location of the airplane center of gravity permitted to fulfill the designer’s

requirement on longitudinal static stability margin is

a) 0.35 b) 0.45 c) 0.52 d) 0.67

14. The center of gravity location to have

is

b) 0.35 b) 0.45 c) 0.5 d) 0.4

Statement for linked answer questions 15 & 16: For a piston propeller airplane

weighing 20000 N, the flight testing at 5 km pressure altitude in standard atmosphere gave

the variation of power required versus true air speed as shown in figure below. The

student forgot to label the airspeed axis. The maximum climb rate at sea level was

calculated to be 4 m/s. Assume shaft power available to be independent of speed of flight.

FLIGHT MECHANICS


For piston propeller airplane, it can be assumed that the shaft power available is

proportional to ambient density. Values of air density at sea level and at 5 km pressure

altitude are 1.225 kg/m3 and 0.74 kg/m3, respectively.

15. The maximum rate of climb achievable by this airplane at 5 km altitude will be

a) 1.65 m/s b) 0.51 m/s c) 1.43 m/s d) 3.65 m/s

16. If during the maximum rate of climb at 5 km altitude, the airplane was flying at an angle

of attack of 4 degrees and altitude (pitch) angle of 5 degrees, what was equivalent

airspeed of the airplane?

a) 40.2 m/s b) 63.7 m/s c) 130.3 m/s d) 20.2 m/s

2008

1. The service ceiling of a transport aircraft is defined as the altitude

a) That is halfway between sea-level and absolute ceiling

b) At which it can cruise with one engine operational

c) At which its maximum rate of climb is zero

d) At which its maximum rate of climb is 0.508 m/s

2. The drag of an aircraft in steady climbing flight at a given forward speed is

a) Inversely proportional to climb angle

b) Higher than drag in steady level flight at the same forward speed

c) Lower than drag in steady level flight at the same forward speed

d) Independent of climb angle

FLIGHT MECHANICS


3. In steady, level turning flight of an aircraft at aload factor ‘n’, the ratio of the horizontal

component of lift and aircraft weight is

a) b) c) d)

4. The parameter that remain constant in a cruise-climb of an aircraft are

a) Equivalent airspeed and lift coefficient

b) Altitude and lift coefficient

c) Equivalent airspeed and altitude

d) Lift coefficient and aircraft mass

5. Which of the following statement is TRUE?

a) Wing dihedral reduces roll stability while a low wing increases roll stability.

b) Wing dihedral increases roll stability while a low wing reduces roll stability.

c) Wing dihedral as well as low wing reduces roll stability.

d) Wing dihedral as well as low wing increases roll stability.

6. An aircraft has a level flight stalling speed of 60 m/s EAS (equivalent air speed). As per

the V-n diagram, what is the minimum speed at which it should be designed to with

stand the maximum vertical load factor of 9?

a) 20 m/s b) 60 m/s c) 120 m/s d) 180 m/s

7. Match each mode of aircraft motion listed in group I to its corresponding property

from group II

Group I: Aircraft mode Group-II: Property P: Short Period mode 1: Coupled roll-yaw oscillations Q: Wing rock 2: Angle of attack remains constant R: Phugoid mode 3: Roll oscillations S: Dutch roll 4: Speed remains constant

a) P-2, Q-1, R-4, S-3 b) P-4, Q-3, R-2, S-1

c) P-4, Q-1, R-2,S-3 d)P-2, Q-3, R-4, S-1

8. In the definition of the aircraft Euler angles Φ (roll), θ(pitch), ψ (yaw), the correct

sequence of rotations required to make the inertial frame coincide with the aircraft

body frame is

a) First ψ about z axis, second θ about y axis, third Φ about x axis

b) First θ about y axis , second Φ about x axis, third ψ about z axis

c) First Φ about x axis, second θ about y axis, third ψ about z axis

d) First ψ about z axis, second Φ about x axis, third θ about y axis

FLIGHT MECHANICS


9. To maximize range of a jet engine aircraft, it should be flown at a velocity that

maximizes

Linked question statement: An aircraft has a zero-lift drag coefficient CDo = 0.0223,wing

aspect ratio ARw = 10.0 and Oswald’s efficiency factor e = 0.7

10. The thrust required for steady level flight will be minimum when the aircraft operates

at a lift coefficient of

(A)0.65 (B)0.70 (C)0.75 (D)0.80

11. The glide angle that results in maximum range in a power-off glide is

(A) 1.82 degrees (B)2.68 degrees (C)3.64 degrees (D) 5.01 degrees

2009

1. The relation between an airplane’s true airspeed VTAS and equivalent airspeed VEAS

in terms of the density ratio

, where is the air density at sea-level and ρ is

the air density at the altitude at which the airplane is flying, is given by the formula:

(B)

(C)

(D)

2. An unswept fixed-winged aircraft has a large roll stability if the wing is placed

(A) Low on the fuselage and has negative dihedral angle

(B) Low on the fuselage and has positive dihedral angle

(C) High on the fuselage and has negative dihedral angle

(D) High on the fuselage and has positive dihedral angle

3. Thrust available from a turbojet engine

(A) Increases as altitude increases

(B) Increases up to the tropopause and then decreases

(C) Remains constant at all altitudes

(D) Decreases as ltitude increases

4. If CmCG is the pitching moment cefficient about the center of gravity of an aircraft,

and α is the angle of attack, then

is

FLIGHT MECHANICS


(A) A stability derivative which represents stiffness in pitch

(B) A stability derivative which represents damping in pitch

(C) A control derivative in pitch

(D) Positive for an aircraft that is stable in pitch

5. An airplane flying at 100 m/s is pitching at the rate of 0.2 deg/s. Due to this pitching,

the horizontal tail surface located 4 metres behind the centre of mass of the airplane

will experience a change in angle of attack, which is

(A)0.01 deg (B)0.008 deg (C)0.04 deg (D)0.004 deg

6. The contribution of the horizontal tail to the pitching moment coefficient about the

center of gravity (CmCG) of an aircraft is given by Cmtail = 0.2- 0.0215α, where α is the

angle of attack of the aircraft. The contribution of the tail to the aircraft longitudinal

stability

(A) Is stabilizing

(B) Is destabilizing

(C) Is nil

(D) Cannot be determined from the given information

7. The linearized dynamics of an aircraft (which has no large rotating components) in

straight and level flight is governed by the equations

where represents the transpose of a matrix, [A], [B], [C]

and [D] are 4x4 matrices and [0] is the 4x4 null matrix. Which of the following is

true?

(A) [A] [0]

(B) [A] [0]

(C) [A] [0]

(D) [A] [0]

8. The velocity vector of an aircraft along its body-fixed axis is given by . If V is

the magnitude of , α is the angle of attack and β is the angle of sideslip, which of the

following set of relations is correct?

(A) u=V sinβ cosα; v= V sinβ; w = V cosβ sinα

(B) u=V cosβ cosα; v= V cosβ; w = V cosβ sinα

(C) u=V cosβ cosα; v= V sinβ; w = Vsinβ sinα

(D) u=Vcosβ cosα; v= V sinβ; w = V cosβ sinα

FLIGHT MECHANICS


9. An aircraft of mass 2500 kg in straight and level flight at a constant speed of 100m/s

has available excess power of 1.0 x 106 W. The steady rate of climb it can attain at

that speed is

(A) 100 m/s (B) 60 m/s (C) 40 m/s (D) 20 m/s

Common Data for Questions 10 and 11:

The roots of the characteristic equation for the longitudinal dynamics of a certain aircraft

are: λ1 = -0.02+0.2i, λ2 = -0.02-0.2i, λ3 = -2.5+2.6i; λ4 = -2.5 – 2.6i , where

10. The pair of eigenvalues that represent the phugoid mode is

(A) λ1 and λ3 (B) λ2 and λ4 (C) λ3 and λ4 (D) λ1 and λ2

11. The short period damped frequency is

(A) 2.6 rad/s (B) 0.2 rad/s (C)2.5 rad/s (D) 0.02 rad/s

2010

1. An aircraft is climbing at a constant speed in a straight line at a speed angle of climb.

The load factor it sustains during the climb is :

(A)Equal to 1.0 (B) greater than 1.0

(C) positive but less than 1.0 (D) dependent on the weight of the

Aircraft

2. All other factors remaining constant, if the weight of an aircraft increases by 30%

then the takeoff distance increases by approximately:

(A)15% (B)30% (C)70% (D)105%

3. An aircraft stalls at a speed of 40 m/s in straight and level flight. The slowest speed

at which this aircraft can execute a level turn at a bank angle of 60 degrees is:

(A)28.3 m/s (B)40.0 m/s (C)56.6 m/s (D)80.0 m/s

4. The absolute ceiling of an aircraft is the altitude above which it:

(A) Can never reach

(B) Cannot sustain level flight at a constant speed

(C) can perform accelerated flight as well as straight and level flight at a constant

speed

(D) can perform straight and level flight at a constant speed only

FLIGHT MECHANICS


5. A propeller powered aircraft, trimmed to attain maximum range and flying in a

straight line, travels a distance R from its take-off point when it has consumed a

weight of fuel equal to 20% of its take-off weight. If the aircraft continues to fly and

consumes a total weight of fuel equal to 50% of its take-0ff weight, the distance

between it and its take-off point becomes:

(A)2.5R (B)3.1 R (C)2.1 R (D)3.9R

6. The trim curves of an aircraft are of the form Cm,α = (0.05 – 0.2δe)-0.1CL where the

elevator deflection angle, δe , is in radians. The static margin of the aircraft is:

(A) 0.5 (B)0.2 (C)0.1 (D)0.05

STATEMENT FOR LINKED ANSWER QUESTIONS 7 and 8:

An aircraft is in straight and level flight at a constant speed v. It is disturbed by a symmetric

vertical gust, resulting in a phugoid oscillation of time period T.

7. Assuming that g is the acceleration due to gravity, T is given approximately by:

(A)

(B)

(C)

(D)

8. If v = 200 m/s then the wavelength of the phugoid oscillations, assuming g = 9.81

m/s2, is, approximately:

(A)1.28 x 104 m (B) 1.30 x 103 m (C) 1.81 x 104 m (D)918 m

2011

1. In an un-powered glide of an aircraft having weight W, lift L and drag D, the

equilibrium glide angle is defined as

a) Tan-1 (L/D) b) Tan-1 (D/L) c) Tan-1 (L/W) d) Tan-1 (W/L)

2. Lift on an aircraft climbing vertically up is

a) Equal to its weight b) zero

c) equal to the drag d) equal to the trust

3. If an aircraft is performing a positive yawing manoeuvre, the side slip angle

a) Is always zero b) is never zero

c) is always negative d) could be any value

4. For an airplane to be statically stable, its center of gravity must always be

FLIGHT MECHANICS


a) Ahead of the wing aerodynamic center

b) Aft of the wing aerodynamic center

c) Ahead of neutral point

d) Aft of neutral point

5. An aircraft is performing a coordinate turn manoeuvre at a bank angle of 300 and

forward speed of 100 m/s. Assume g=9.81 m/s2. The load factor and turn radius

respectively are

(A)(2/ ) and 1.76 km (B) and 17.6 km

(C) 2 and 0.18 km (D) ) and 17.6 km

6. An aircraft in a steady level flight at forward speed of 50 m/s suddenly rolls by 1800

and becomes inverted. If no other changes are made to the configuration or controls

of the aircraft, the nature of the subsequent flight path taken by the aircraft and its

characteristic parameter(s) (assume g = 9.81 m/s2)are

(A) Straight line path with a speed of 50 m/s

(B) Upward circular path with a speed of 50 m/s and radius of 127.4 m

(C) Downward circular path with a speed of 50 m/s and radius of 127.4 m

(D) Downward circular path with a speed of 25 m/s and radius of 254.8 m

7. An aircraft with a mass of 5000 kg takes off from sea level with a forward speed of

50 m/s and starts to climb angle of 150. The rate of climb and excess thrust available

at the start of the climb respectively (assume g = 9.81 m/s2) are

(A)13.40 m/s and 13146.0 N (B) 12.94 m/s and 12694.1 N

(C) 13.40 m/s and 12694.1 N (D) 12.94 m/s and 13146.0 N

8. A glider having a mass of 500 kg is taken to an altitude of 1000 m with a jeep moving

on ground at 54 kmph. Upon reaching the required altitude in 50 s, the glider is

released and starts its descent. Under the assumption of equilibrium glide, the range

and endurance of the glider for a constant lift to drag ratio of 15 are

(A) 15.0 km and 1002.2 s respectively

(B) 15.0 km and 601.3 s respectively

(C) 1.0 km and 601.3 s respectively

(D) 1.0 km and 50 s respectively

9. An aircraft in level flight encounters a vertical gust, which excites the phugoid mode.

The phugoid motion completes 10 cycles in 50 s and its amplitude reduces to half of

its maximum value in 25 s. The eigenvalues of the phogoid mode are

(A) (B)

FLIGHT MECHANICS


(C) (D)

2012

1. An aircraft in trimmed condition has zero pitching moment at

(A) its aerodynamic center

(B) its center of gravity

(C) 25% of its mean aerodynamic chord

(D) 50% of its wing root chord

2. In an aircraft, constant roll rate can be produced using ailerons by applying

(A)a step input (B) a ramp input

(C)a sinusoidal input (D) an impulse input

3. During the ground roll manoeuvre of an aircraft, the force(s) acting on it parallel to

the direction of motion

(A) is thrust alone

(B) is drag alone

(C) are both thrust and drag

(D) are thrust, drag and a part of both weight and lift

4. An aircraft in a steady climb suddenly experiences a 10% drop in thrust. After a new

equilibrium is reached at the same speed, the new rate of climb is

(A) lower by exactly 10%

(B) lower by more than 10%

(C) lower by less than 10%

(D) an unpredictable quantity

5. In an aircraft, the dive manoeuvre can be initiated by

(A) reducing the engine thrust alone

(B) reducing the angle of attack alone

(C) generating a nose down pitch rate.

(D) Increasing the engine thrust alone

6. In an aircraft, elevator control effectiveness determines

(A) Turn radius

(B) Rate of climb

(C) Forward-most location of the centre of gravity

FLIGHT MECHANICS


(D) Aft-most location of the center of gravity

7. An aircraft has a steady rate of climb of 300 m/s at sea level and 150 m/s at 2500 m

altitude. The time taken (in sec) for this aircraft to climb 500 m altitude to 3000 m

altitude is ___________.

8. If an aircraft takes off with 10% less fuel in comparison to its standard

configuration, its range is

(A)lower by exactly 10% (B)lower by more than 10%

(B)lower by less than 10% (D) an unpredictable quantity

9. An aircraft has an approach speed of 144 kmph with a descent angle of 6.60. If the

aircraft load factor is 1.2 and constant deceleration at touch down is 0.25g(g=9.81

m/s2), its total landing distance approximately over a 15 m high obstacle is

(A)1830 m (B) 1380 m (C) 830 m (D) 380 m

10. An aircraft is trimmed straight and level at true air speed (TAS) of 100 m/s at

standard sea level (SSL). Further, pull of 5 N holds the speed at 90 m/s without re-

trimming at SSL (air density = 1.22 kg/m3). To fly at 3000 m altitude (air density =

0.91 kg/m3) and 120 m/s TAS without re-trimming, the aircraft needs

(A)1.95 N upward force (B) 1.95 N downward force

(C) 1.85 N upward force (D)1.75 N downward force

COMMON DATA QUESTION FOR 11 and 12:

A wing and tail are geometrically similar, while tail area is one-third of the wing area and

distance between two aerodynamic centers is equal to wing semi-span (b/2). In addition,

following data I sapplicable:

. The

symbols have their usual aerodynamic interpretation.

11. The maximum distance that the center of gravity can be behind aerodynamic center

without destabilizing the wing-tail combination is

(A)0.4m (B) 1.4 m (C) 2.4 m (D) 3.4 m

12. The angle of incidence of tail to trim the wing-tail combination for a 5% static

margin is

(A)- 1.40 (B) - 0.40 (C) 0.40 (D) 1.40

FLIGHT MECHANICS


PRACTICE QUESTIONS:

1. Assuming International Standard Atmosphere conditions, the equations governing

troposphere are

(A)

,

(B)

,

(C)

,

(D)

,

2. Slat is a leading edge high lift device used for minimizing take-off and landing distances.

A slat

(A) Increases α0L, decreases CLα

(B) Increases α0L, increases CLα

(C) increases CLα

(D) increases CLmax

3. In the Lanchester model of the phugoid mode, the approximate phugoid frequency is

given by the expression

, where the value of constant k is equal to

(A)

(B) 2 (C) (D)

4. The center of gravity position, where the elevator angle is independent of the load factor

n of the manoeuvre is

(A)

(B)

(C)

(D)

where, μ = non-dimensionalized mass =neutral point

FLIGHT MECHANICS


5. For Lateral and directional static stability of an aircraft, which of the following is true?

(A) (B)

(C) (D)

6. The velocity vector of an aircraft along the body fixed axis is given as . If the

angle of attack is 50 and sideslip is 20, then given that velocity vector modulus is 100

m/s, which of the following is true?

(A) u = 89.56 m/s, v = 3.48 m/s

(B) u = 7.81 m/s, v = 3.48 m/s

(C) u = 99.56 m/s, v = 7.81 m/s

(D) u = 99.56 m/s, v = 8.71 m/s

7. For an aircraft in steady flight , if the zero lift drag co-efficient is 0.018, aspect ratio is 8,

Ostwald’s efficiency factor is 0.9, then what is the maximum lift to drag ratio the aircraft

can maintain under such conditions?

(A)80 (B)25 (C)44 (D)71

8. If the load factor n at the lowest point of a steady pull-out is 9.0 and the radius of

curvature of the flight path during the pull-out is 200 m, then the velocity of the airplane

during the pull-out is

(A)127 m/s (B)123m/s (C) 125 m/s (D) 152 m/s

9. The eigen value corresponding to the approximate spiral mode λ equals to

(A)

(B)

(C)

(D)

where, =

, =

, =

=

10. A positive tail incidence angle setting, as compared to a negative tail incidence angle

setting, will result in

(A) Less static stability

(B) Same static stability

(C) More static stability

(D) None of the above

11. The static longitudinal stability of an airplane is provided by

(A) The lift from wing and horizontal tail

FLIGHT MECHANICS


(B) Product of the ‘tail arm’ and ‘tail lift’

(C) Product of the ‘tail arm’ and ‘wing lift’


12. Due to some fault, pilot realized that maximum up and down elevator movement was

reduced by 20%. To ensure that during landing reduced elevator movement required

from trim, the pilot should request passenger to move

(A) Backward

(B) Forward

(C) Evenly by distribute on left and right sides of fuselage


13. The conventional vertical tail of an aircraft contributes towards

(A) Longitudinal stability

(B) Lateral stability

(C) Directional stability

(D) Both lateral and directional stability

STATEMENT FOR LINKED ANSWER QUESTIONS: In a flight test, following data was

obtained while trimming the airplane at different speeds.

Speed(m/s) α(deg) Elevator(deg) CG Location

1. 100 5 3.0 up 30% of MAC

2. 140 3 1.0 down 30% of MAC

3. 100 4 0.0 40% of MAC

4. 140 1 1.5 down 40% of MAC

14. If the Lift curve slope of a/c is 0.1 per degree and all variations are

assumed linear, then stick fixed neutral point will be

(A) 0.45 (B)0.35 (C)-0.45 (D)-0.35

15. What is the most aft location of CG such that the a/c has a minimum stability margin of

5%?

(A) – 0.5 (B) – 0.4 (C) 0.5 (D)0.4

FLIGHT MECHANICS


STATEMENTS FOR LINKED ANSWER QUESTIONS 16 and 17

The wind tunnel tests showed the following characteristics for a airplane in power off

condition: δe, fixed

16. Stick fixed and stick free neutral points are

(A)0.2 and 0.37 (B) 0.4 and 0.23

(C) 0.4 and 0.37 (D) None of these

17. If (1) Cnα = -0.02 (2) CLα(2-D, wing) = 0.1, (3) CLα(2-D, tail) = 0.1

(4)

(5)ηt=0.9 (6) k= - 0.17

(7) Tail span = 2m (8) Tail aerodynamic center to CG distance = 6.5m

(9) (10) Wing aspect ratio = 6 (11) Wing span = 12m

(12) e = 1 (13) St = 1

Then ,

for the given CG Location is

(A) -0.055 (B)0.0055 (C)-0.0055 (D)0.055

18. Let an aircraft in steady level flight be trimmed at certain speed. A level steady flight at a

higher speed be achieved by changing

-0.03

-0.02

-0.01

0

0.01

0.02

0.03

0.04

0.05

0.06

0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2

CM

,CG

XCG =0.3 δe, fixed

δe, free

Линейная (δe, free)

CL

FLIGHT MECHANICS


(A)throttle only (B)elevator only

(C)throttle and elevator together (D)None

19. An a/c model with symmetric airfoil was tested in wind tunnel and data reported is

(1)

(2) Cmα= - 0.01/deg

(3)Cm0=

= elevator setting

(4) (5)AR = 5

Find the Cmδe and CL, max’ where Cmδe is elevator control power and CL, max’ is maximum CL

that can be trimmed

(A) – 0.08 deg-1 and 0.99

(B) – 0.008 deg-1 and 0.99

(C) 0.008 deg-1 and 0.19

(D) 0.08 deg-1 and 0.99

Cm

α

-

O B

FLIGHT MECHANICS


20. If an aircraft has its center of gravity on neutral point, then

(A) Aircraft has maximum possible stability

(B) Aircraft is neutrally stable

(C) Static stability is minimum


21. A dutch-roll instability of an aircraft is

(A) A highly damped oscillatory motion with high frequency

(B) A highly damped oscillatory motion with low frequency

(C) A lightly damped oscillatory motion with low frequency


22. Characteristics of a short-term mode of longitudinal instability are

(A) Constant speed, highly damped

(B) Constant angle of attack, highly damped

(C) Constant speed, lightly damped

(D) Constant speed, lightly damped

23. The effect of tail on aircraft static stability is

(A) Stabilizing

(B) De-stabilizing

(C) Dependent on aft or forward position of tail


24. For directional stability, an aircraft should have

(A) Clβ < 0 (B) Clβ = 0 (C) Clβ > 0 (D) Cmα < 0

25. For an aircraft to be stable in pitch, roll and yaw directions, which of the following must

be valid?

(A) Cmα < 0, Cnβ < 0, Clβ < 0

(B) Cmα < 0, Cnβ > 0, Clβ < 0

(C) Cmα < 0, Cnβ < 0, Clβ > 0

(D) Cmα < 0, Cnβ > 0, Clβ > 0

26. Pitch control on an aircraft is achieved by

(A)elevator deflection (B)rudder deflection (C) wing setting angle (D)tail setting angle

27. An aircraft is flying with flight speed v and tail moment arm lt. If pitch rate is q, then

what will be change in angle of attack due to pitching?

FLIGHT MECHANICS


(A)

(B)

(C)

(D)

28. An aircraft has a L/D ratio of 16. Its damping ratio in phugoid mode will be

(A)0.45 (B)cannot be calculated (C)0.11 (D)0.22

29. The roots of characteristic equation for lateral motion of an aircraft, are complex

corresponding to

(A) Spiral mode (B)roll mode (C)dutch roll mode (D)phugoid mode

30. When the elevator angle is changed for an aircraft, the slope of Cm vs α curve

(A)increases (B)decreases (C) remain same (D)cannot be decided

31. Positive dihedral effect can be produced by using

(A)swept back wings (B) swept forward wings

(C) Canard wings (D)rectangular wings

32. High wing aircraft when compared to a low wing aircraft, produces a

(A)Greater dihedral effect (B) lower dihedral effect

(C) cannot be compared (D equal dihedral effect

33. If keeping rest conditions same, the CG of aircraft is being moved rearwards, then

(A) Longitudinal mode becomes non-periodic and eventually unstable

(B) Longitudinal mode becomes more stable

(C) Roll stability increases

(D) Roll and yaw stability increases

34. At absolute ceiling of aircraft

(A) Rate of climb is maximum

(B) Rate of climb is zero

(C) Rate of climb is 100ft/min


35. The expression for range of an aircraft is

where m1 and m2 are

initial and final masses of vehicle, QR is heat of reaction of propellant, η0 is overall

efficiency of engine and (L/D) is the lift-drag ratio. Which one of following is correct

representation of range of an aircraft with flight-Mach number?

(A)

R

FLIGHT MECHANICS


(B)

(C)

(D)None of the above

36. Dynamic response of an aircraft in longitudinal mode is in phugoid mode. Which of the

following represents its graphical time history correctly?

(A) Change in altitude

(B) change in angle of attack

R

M 1 2 3

R

M 1 2 3

TIME

FLIGHT MECHANICS


(C) Change in altitude

(D) Change in Angle of attack

37. There are two geometrically similar aircrafts. However, due to operational

requirements, the aircrafts have different sizes. If the surface area of larger aircrafts

have different sizes. If the surface area of larger aircraft is twice the smaller one and its

mass is 2.4 times the smaller one, by what percentage is the stall speed (at steady level

flight) of the larger aircraft greater than smaller aircraft (at the same flight conditions)?

(A) 10.2% (B) 21.7% (C)3.3% (D)9.5%

38. If X, Y, Z are a systems of mutually perpendicular axes and the Y-axis is perpendicular to

the plane of symmetry of the vehicle and p, q and r represent the rotation rates about

axes, then M-Iy Given that M is the moment about the Y-axis and I represents the

inertia tensor.

(A) (Ixx - Izz)pq - Ixz(p2 - q2)

(B) (Ixx - Izz)qr - Ixy(p2 - r2)

(C) (Ixx - Iyy)pr - Iyz(r2 - p2)

(D) (Ixx - Izz)pr - Ixz(p2 - r2)

TIME

TIME

TIME

FLIGHT MECHANICS


39. Which of the following sets a forward limit on the location of center of gravity in an

aircraft?

(A) Location of stick fixed and stick free neutral points

(B) Sensitvity of vehicle normal acceleration to control force being too small

(C) Damping in longitudinal dynamic stability

(D) To make the vehicle trimmable at CLmax

40. For the Dutch-roll mode approximation to the aircraft (lateral-directional motion), the

characteristic equation is of the form λ3 + a2λ2 + a1λ + a0 = 0 then the value of a0 equals

(A)Lv Np - Lp Nv (B) Lv Np + Lp Nv

(C) u0(Lv Np - Lp Nv) (D) u0(Lv Np - Lp Nv)

where v is the sideslip velocity

41. The CL/CD ratio corresponding to maximum endurance during a steady level flight

configuration (correct to the first decimal place) is

Data: Span efficiency factor = 0.91

Aspect ratio = 6

Zero lift drag co-efficient = 0.018

(A)12.2 (B)13.4 (C)11.5 (D)10.0

42. In the stick free longitudinal case of an aircraft with a tail and elevator as the control

input, the lift-curve slope for the tail and elevator as the control input, the lift-curve

slope for the tail reduces by a factor of 1 – F. The F is equal to

(A)

(B)

(C)

(D)

43. Calculate the radius of a steady level turn made by an aircraft with turn speed 75 m/s

and a bank angle of 60

(A) 4.55 km (B)6.22 km (C)5.45 km (D) 5.21 km

44. The relationship between the body fixed angular velocity vector [p q r]T and the rate of

change of Euler angles T is given by

Then J-1 equals to

(A)

FLIGHT MECHANICS


(B)

(C)

(D)

LINKED ANSWER QUESTIONS 45 and 46:

45. During the phugoid mode of an aircraft, which of the following two parameters are

excited?

(A) Air speed and angle of attack

(B) Air speed and pitch angle

(C) Pitch rate and Pitch angle

(D) Angle of attack and pitch rate

46. Using an approximation to the phugoid mode, determine

during its flight mode.

(A)

(B)

(C)

(D)

47. Which of the following is the right combination for a typical passenger aircraft to have a

stable trim flight?

(A)

(B)

(C)

(D)

48. In standard altimeter used in aircraft, which of the following quantities is measured to

determine the altitude of airplane?

(A) Static pressure (B) Stagnation pressure (C) Static temperature (D)Air density

49. In a phugoid manoeuvre, which of the following remains almost constant?

(A) Angle of attack (B) Altitude (C) Aircraft Speed (D)Pitch angle

50. To minimize power requirement of an aircraft, which of the following should be

minimized?

(A)

(B)

(C)

(D)

FLIGHT MECHANICS


51. Which of the following tends to impart rolling stability to an aircraft?

(A) Anhedral

(B) Wings positioned at top of fuselage

(C) Swept forward wing


52. For maximum range of gliding flight, which of the following holds true?

(A)

(B)

(C)

(D)

53. In a coordinated horizontal turn, the load factor was 2. What will be the load factor, if for

the same manoeuvre at same turn rate, the speed becomes twice?

(A) 4 (B) 1 (C) 3.6 (D) 5

54. An aircraft of weight 1500kg has an excess power of 300 kW, when flying at a speed of

100 m/s. At the same speed, what is the maximum acceleration it can attain while

simultaneous having a climb rate of 10 m/s? (Take g = 10 m/s2)

(A)0.5 m/s2 (B)1 m/s2 (C)2 m/s2 (D) 3 m/s2

55. An aircraft flying at 100m/s pitches at the rate 4 deg/s. The horizontal tail having lift-

curve slope 4 is located 5 m behind the CG. Assuming tail efficiency factor 1 and taking

tail volume co-efficient 0.6, the change in pitching moment coefficient felt due to tail

effect will be

(A) 0.48 (B) 1.33 (C) 0.0084 (D)0.023

STATEMENT FOR LINKED QUESTIONS 56 and 57: An airplane flying straight and level

at a speed of 130 m/s at height 10 km is distributed by a symmetric vertical just

resulting in a phugoid oscillation.

56. The approximate frequency of phugoid oscillation is

(A) 0.075 s-1 (B)0.15 s-1 (C)0.053 s-1 (D)0.107 s-1

57. If Xu/m = - 0.0446 s-1 for the airplane, what is the damping ratio of phugoid oscillation?

(A) 0.84 (B)0.42 (C)0.21 (D)0.32

58. An aircraft with a larger wing as compared to smaller wing will have

(A)more static stability (B)less static stability

(C)same (D) none of the above

59. If the C.G of the aircraft moves forward, the static longitudinal stability of the aircraft will

FLIGHT MECHANICS


(A) Always increase (B)sometimes increase (C)remain same (D)None of the above

60. A tail-less aircraft can be made stable by having its C.G. located

(A) Behind the aerodynamics center of the wing

(B) Ahead of the aerodynamic center of the wing

(C) At the landing gear


61. If tail area is increased while the elevator to tail area ratio is kept the same, then

(A) both static stability and control power will increase

(B) only static stability will increase

(C) only control power will increase

(D) neither stability nor control power changes

62. Purpose of aircraft wing dihedral angle is to

(A) Increase lateral stability

(B) Increase longitudinal stability

(C) Increase lift coefficient of the wing


63. Load factor in gliding flight is always

(A) >1 (B) <1 (C) =1 (D) None of the above

64. If the vertical tail was inverted and put below the horizontal tail of an aircraft, then its

contribution to Clβ will be

(A) Negative (B)positive (C) zero (D)None of the above

STATEMENT FOR LINKED ANSWER QUESTIONS FOR 65 and 66:

For the given CG location ( ), the stick force per g was 2.5 kg/g when CG was

placed at the stick-free neutral point the ( )

.

65. The stick-free manoeuvre point is

(A) 0.419 (B)0.205 (C)0.325 (D)None of the above

66. In continuation with the previous Q. 65, what will be the useable CG limits if the stick

force per g was to be within 1.5 and 3.5 kg/g?

FLIGHT MECHANICS


(A) 0.2524 and 0.3476 (B) 0.1512 and 0.6852 (C) 1.326 and 1.562 (D) none

67. What is the most forward CG location permissible?

Given, δemax, , CLmax, , N0

(A)

(B)

(C)

(D)

SATETMENT FOR COMMON DATA QUESTIONS 68 and 69: Given : w/s = 500 kg/m2;

s=50 m2; cruise v = 150 m/s; AR = 5, ρ = 0.8 kg/m3, iw = 10, α0=-40, Cm,CG = -0.03;

, wing airfoil

, , it= 10 m; ηt = 0.9 fuselage;

maximum width = 1.6 m; Length = 15 m; factor kf = 0.012.

68. To achieve trim at cruise flight speed end to have stability margin of 8%, find the tail

area.

(A) 0.396 m2 (B)0.64 m2 (C)0.59 m2 (D) None of these

69. In continuation with Q. 68, tail setting (it) is required

(A) 5.20 (B)3.40 (C)2.10 (D)None of these

(B)

70. The relationship between the geopotential altitude ( ) and geometric altitude ( ) is

(here is the radius of earth)

(A)

(B)

(C)

(D)

71. The minimum thrust required condition occurs for a steady-level aircraft is (Here ZLD =

zero-lift drag; DDL = drag due to lift)

(A) (B)

(C) (D)

FLIGHT MECHANICS


72. During the ground roll manoeuvre of an aircraft, the force(s) acting on it parallel to the

direction of motion

(A) is thrust alone. (B) is drag alone.

(C) are both thrust and drag. (D) are thrust, drag and a part of both weight

and lift.

73. Winglets are used on wings to minimize

(A) skin friction drag (B) profile drag

(C) wave drag (D) induced drag

74. An aircraft is performing a coordinated turn manoeuvre at a bank angle of 30o and

forward speed of 100 m/s. Assume g = 9.81 ms-2. The load factor and turn radius

respectively are

(A) and 1.76 km (B) and 17.6 km

(C) 2 and 0.18 km (D) ( ) and 17.6 km

Statement for Linked Answer Questions 75 and 76:

75. An aircraft has a zero lift drag coefficient CD0 = 0.0223, wing aspect ratio AR = 10.0, and

Oswald‘s efficiency factor e = 0.7 The thrust required for steady level flight will be

minimum when the aircraft operates at a lift coefficient of

(A) 0.65 (B) 0.70 (C) 0.75 (D) 0.80

76. The glide angle that results in maximum range in a power off glide is

(A) 1.82 deg. (B) 2.68 deg. (C) 3.64 deg. (D) 5.01 deg.

77. A sailplane weighs 4500 N and has a wing loading of 600 N/m2, its drag polar relation is

. After completing a launch at 350 m in still air.The greatest

distance the sailplane can cover is

(A) 10.5 km (B) 11.8 km (C) 9.05 km (D) 10.0 km

78. An airplane weighing 20,000 N has to fly with maximum rate of climb of 300 m/min. The

maximum available excess power for this climb is

FLIGHT MECHANICS


(A) 100 kW (B) 200 kW (C) 300 kW (D) 600 kW

79. Aerodynamic efficiency of a flying object can be defined as (Here L = lift; D = drag)

(A) (L-D)/D (B) (D-L)/D (C) L/D (D) D/L

80. The longitudinal stability curves are plotted for three different locations of wing on to the fuselage. Identify the location of wing from the following figure.

(A) P-Low wing, Q-Mid wing, R-High

wing (B) P-Mid wing, Q-Low wing, R-High

wing (C) P-High wing, Q- Mid wing, R-Low

wing (D) Insufficient data

81. When a vehicle is trimmed (longitudinally) with the controls free, which of the following

statements is/are always true? (Multiple answers may possible for this question)

(A) The net moment about the control-free neutral point is zero (B) The net hinge-moment about the elevator hinge line is zero (C) The center-of-gravity is ahead of the control-free neutral point (D) None of the above

82. The pitching moment curves of two independent aircraft (P and Q) are found as

and

.

Which aircraft is more stable to static longitudinal stability?

(A) P (B) Q (C) Both P and Q (D)

Neither P nor Q

83. The pitching moment curves of an aircraft is found as , at

trim find the elevator angle required to change the lift coefficient from 0.5 to 0.8 is

FLIGHT MECHANICS


(A) 0.75o up (B) 0.75o down (C) 1.15o up (D) 1.15o down

84. A pilot of an aircraft applies a pull force of 100 N on the control stick. Assume the length

of the stick is 1.2 m and is rotated by 13o and the corresponding angular rotation of the

elevator is 8o. Then the hinge moment about hinge line is

(A) 195 N-m (B) 73.85 N-m (C) 1560 N-m (D) 960 N-m

85. The yawing moment curves of four different aircrafts are found as:

P: Cn = -0.182β, Q: Cn = 0.132-0.352β, R: Cn = 0.182β, S: Cn = 0.132+0.352β

The aircraft(s), which are stable statically in directional case are

(A) P only (B) R only (C) P and Q (D) R and S

86. If aircraft is symmetric about XZ plane, then

(A) Ixy = 0 and Iyz = 0 (B) Ixz = 0 and Iyz = 0 (C) Ixx = 0 and Izz = 0 (D) Ixz = 0 and Izx = 0

87. Approximate natural frequency of the Lanchester approximate Phugoid mode is

(A)

(B)

(C)

(D)

88. The natural frequency of a phugoid mode is 0.26 rad/sec and the damping ratio is 0.087. The Eigen values of the phugoid mode are:

(A) (B) (C) (D)

89. An approximate short period mode is mainly characterized by (A) Pitch attitude, Velocity (B) Angle of attack and pitch attitude (C) Velocity only (D) All of the above

90. An airplane flying at 100 m/s is pitching at the rate of 0.2 deg/s. Due to pitching; the horizontal tail surface located 4 m behind the centre-of-mass of the airplane will experience a change in angle of attack. The change in the angle of attack is

(A) -0.008 deg. (B) -0.08 deg. (C) 0.08 deg. (D) 0.008 deg.

91. The longitudinal performance equation of motion for an aircraft with thrust producing

engines is given by _______________________________.

92. If the thrust is constant, the best gradient of climb will be obtained by flying at the

_______________

FLIGHT MECHANICS


93. An instruments that indicates height as the function of barometric static pressure in the atmosphere is (A) airspeed indicator (B) altimeter (C) mach meter (D) all.

94. The specific fuel consumption of thrust producing engine is given by

(A) (B) (C) ( D)

95. The generalized climb performance equation for thrust producing engines

(A)

=

(B)

=

(C)

=

(D)

=

96. percentage gradient is_______________

(A) 100tan γ =2grad (B) 10tan γ =grand (C)100tan γ2 =grad% (D)100tan γ =50

97. Which the following is the rate of climb .

(A

(B)

(C)

(D)

98. In the troposphere the pressure height relationship is given by ______________

(A)

(B)

(C)

(D)

99. In the range and endurance for aircraft with power producing engine the drag power

required for cursing flight

(A) (B) (C) (D) .

100. The specific endurance of the aircraft with the power producing engine is given

by______________

(A)

) (B)

(C)

(D)

101. The optimum altitude for cruse will be determined by combining the optimum

cruise __________and the _____________

FLIGHT MECHANICS


(A) airspeed ,critical mach no ( B) airspeed ,Re no

(c) altitude ,critical mach no (D) airspeed , mach no

102. In symmetric flight the side slip and the aerodynamic side force will be

__________________.

103. The degrees of freedom of a rigid body confined to move without rotation in space has

is

(A) one (B) two (C) three (D)five

104. The fuel consumed in the climb can be expressed as _______________

(A)

(B)

(C)

(D)

105. The load factor in pull up maneuver is given by

A).

B).

C).

D).

106. In the V-n diagram stalling region will occur by

(A) decreasing in AOA (B) increasing AOA

(C) increase in Vel (D)decreasing Vel.

107. Which of the following is the sum of the potential energy and kinetic energy of the

aircraft per unit weight

(A) specific energy (B) energy height (C) EAS (D)excess thrust

108. The parametric performance data analysis is the method, is particularly well suited to

a A/C with

(A) thrust producing Engine (B) Power producing Engine

(C) mixed power plant (D) B & C.

109. The parametric expression for the airborne distance is

(A)

(B)

(C)

(D)

110. In the parametric analysis the take off ground distance can be expressed in functional

terms as

FLIGHT MECHANICS


(A) (B)

(C) (D).

111. The take off ground run required can be estimated from the expression

(A)

(B)

(C)

(D)

112. The accelerating force acting on the A/C is independent of

(A)lift (B) weight (C)thrust (D)Drag

113. The corner velocity V* is given by

(A)

(B)

(C)

(D)

114. The longitudinal maneuver is the result of an imbalance of __________________.

115. ___________________________is the boundary associated with permanent structural

deformation of one or more parts of the airplane.

116. The altitude can be increased to allow for the decrease in weight as further fuel is

burned, thus maintaining ___________________ constant.

117. The rate of drift –Down will depend on the __________________of the A/C and on the

________________of the atmosphere.

118. If the engine failure speed is close to the lift off speed then the increase in distance

required to reach, the lift of speed under the reduced acceleration will be relatively

_________________.

119. The centrifugal force in a turning maneuver is produced by the

A).linear acceleration B).lateral acceleration C). normal acceleration D).A & B

120. The longitudinal equation of motion for maneuvering flight can be written as .

(A)

(B)

FLIGHT MECHANICS


(C)

(D)

121. The parametric form of the thrust force is given by

(A)

(B)

(D)

122. From the lateral force equation the rate of turn is given by

(A)

. (B)

(C)

(D)

123. The expression for the lift coefficient in terms of EAS for the aircraft at a test weight

Wt is

(A)

(B)

(C)

(D).

124. The distance that the airplane rolls on the ground from touch down to the point

where the velocity goes to Zero is called___________

(A)flare distance (B) approach distance

(C) Ground roll (D) total landing distance

125. The maximum endurance is achieved by A/C flying at the

(A)Max Drag Speed (B) Max Thrust

(C) Minimum Drag Speed (D) Max lift.

126. The balance between the length of the runway required either to continue or bring

the A/C to a Half.

(A) Balanced field length (B)critical field length

(C) unbalanced Field length (D) none

127. The en-route phase of the flight concerned the _______ of the A/C with one engine in

operative

(A)Landing performance (B)Take off performance

(C) descent performance (D)cruising Performance

128. Which is the max Weight of payload that can be carried in the A/C

(A) max length (B)Max structural payload

(C)Max zero fuel weight (D)All

FLIGHT MECHANICS


129. When a vehicle is trimmed (longitudinally) with the controls free, which of the following statements is/are always true?

(A) The net moment about the control-free neutral point is zero; (B) The net hinge-moment about the elevator hinge line is zero; (C) The center-of-gravity is ahead of the control-free neutral point; (D) None of the above.

130. Of the effects of the fuselage on static longitudinal stability listed below, the least

important is (A) The forward shift in the basic neutral point; (B) The positive shift in pitching moment coefficient at zero lift; (C) The increase in the lift-curve slope CL® of the configuration. (D) None of the above

131. The linear acceleration arises from an _______________ of the force in the direction of

the flight .

132. The load factor n=__________.

133. The representation of the aerodynamic force in parametric form is_____________________.

134. The power equivalent weight is more applicable to A/C with _______________engines.

135. A civil A/C must be granted with certification of ___________________before it can be used for any commercial purpose.

136. For Gulf stream-like A/C assume the +ve limit load factor is 4.5, Calculate the Airplane’s corner velocity at sea level.(W/S=76.84 lbf-2,Cl,max =1.2, =0.002377 slug ft-3)____________

137. The continued take off distance required to achieve the lift of speed becomes

______________

TRUE OR FALSE

138. Static stability is a sufficient condition for a vehicle eventually to return to an

equilibrium state following an arbitrary infinitesimal perturbation.

139. An airfoil section having conventional subsonic camber (i.e., concave down) will have

a positive pitching moment at zero lift.

FLIGHT MECHANICS


140. A flight vehicle having positive

will be statically stable to longitudinal

perturbations (with controls fixed).

141. For a given center-of-gravity location, an aircraft with a forward tail (canard) usually has less static longitudinal stability when the controls are freed than when they are fixed.

142. The lift-curve slopes of aircraft are reduced when the controls are free, relative to

when the controls are fixed, regardless of whether the tail is forward or aft of the wing.

143. A large-aspect-ratio, forward-swept wing having symmetrical sections must be twisted such that the angle of attack at the tips is less than that at the root in order for it to have a positive pitching moment at zero lift.

144. All other geometric factors being equal, the contribution of the horizontal tail to the

total lift-curve slope CLα for a vehicle will be larger for a forward tail (canard) than for an aft tail.

145. Forward wing sweep contributes to unstable dihedral effect (i.e., to positive Clβ)

146. Wing sweepback contributes to stable weathercock stability.

147. The control-free neutral point is always ahead of the basic neutral point.

148. The unforced response of a flight vehicle to a purely longitudinal perturbation from a state of longitudinal trim usually consists of two oscillatory modes.

149. The unforced response of a flight vehicle to a purely lateral/directional perturbation from a state of longitudinal trim usually consists of two oscillatory modes.

150. The long-period (phugoid) longitudinal mode is more heavily damped near the

drag-divergence Mach number (where compressibility effects are important), than at low speeds.

151. Changes in drag associated with changes in airspeed cause the short-period

longitudinal mode to be relatively heavily damped.

152. Dynamic stability for a linear, time-invariant system is guaranteed if all the roots of the characteristic equation of the plant matrix have negative real parts.

153. The response of a linear, time-invariant system to an impulsive forcing at time t = 0

is equivalent to the response to an appropriately perturbed initial condition. Match the following

FLIGHT MECHANICS


1. Pitch stiffness A Cnp 2. Dihedral effect B Cnr 3. Yawing moment due to roll rate C Clβ 4. Pitch damping D Clr 5. Yaw damping E Cmq 6. Rolling moment due to yaw rate F Cnβ 7. Weathercock stability G Cmα

Gate Flight Mechanics by Vayushastra

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