Chapter 1

1.1. Various configurations of Landing Gear:

Some values are taken from ADP-I

Over all weight of aircraft =23805.56Kg

1

Optimum VELOCITY 180m/s

Optimum RANGE 1500Km

Optimum ALTITUDE 8500

Optimum WEIGHT 20000Kg

Optimum ASPECT RATIO 7

Optimum W/S WING LOADING 300Kg/m2

Optimum T/W THRUST

LOADING

0.2

L/D max 3.5

2

1.2.Tyre Sizing:

Where WW –Weight of the wheel

Rr –Rolling radius

D –Diameter

W –Width

Nearly 90% of aircraft load is carried by the main landing gear and only 10% of the aircraft weight is carried by nose wheel, but it experiences high dynamic load. Nose type size can be 60-100% of the main tire size, but in the bicycle and quadricycle, the tire size can be same.

Operating tire at a lower internal pressure will greatly improve the tyre weight and largest tire causing drag weight and space occupation.

3

WW = P× Ap

Ap = 2.3×

KEbraking=1/2 V2stall ×Wlanding/g

KEbraking=1/2 V2vertical × Wlanding/g

KE absorbed =ηL ST

1.3. Gear retraction Geometry:

1.4. Loads on Landing Gear:

1. Vertical load factor

2. Spin up

3. Spring back

4. Braking

5. One wheel arrested

6. Turning loads

4

7. Taxing loads

When aircraft touches the ground, the wheels are not rotating. Then after a fraction of second it will spin up. It is called as spin up loads. Nearly 50% of the actual load acting on the landing gear. Once it starts to rotate, the rearward force is released and the gear strut springs back forward. This spring back load is greater than or equal to spin up loads. Braking load can be estimated by braking co-efficient (normally 0.8). The aircraft is subjected to drop lost to find out the vertical load factors (from 23 to 48cm) .

1.5. Three Stages of Landing Gear Design:

1. Preliminary landing gear design

2. Primary landing gear design

3. Detailed landing gear design

1. Preliminary landing gear design:

Entire layout, shock absorbers, steering system, skit control, retraction mechanism, cockpit requirement and strength. Shock absorber design is based on types of configuration and stroke length.

2. Primary landing gear design:

Selection of tires, construction methods, temperature effects and tyre friction. Kinetic analysis of the brakes, skit controls and wheels are performed in this.

3. Detailed landing gear design:

Material selection locks, bushing seals and lubrication.

Tyre sizing:

Main wheel diameter or width = 5

For transport aircraft A = 5.3

B = 0.315

D =

= 98.8576 cm

Ww = weight on wheel

10% = nose wheel

90% = main landing gear

Width A = 0.39 B = 0.480

Diameter = = 33.528 cm

Maximum pressure = 120 Psi = 828 KPa

Size SpeedKnots or mph

Max load Lb

Max width In

Max diameter In

Rolling Radius In

Wheel diameter In

No of plies

12.5-16 590 12800 12.75 38.4 15.6 16 12

1.6.Static Margin:

It is the distance between CG and neutral point. When static margin is minimum, the lateral stability of aircraft is poor and when it is maximum, more power is required to maneuver. Hence optimization of static margin in airplane is required.

6

Flight equipment weight :

Length of the fuselage

7

1.7.Calculation:

Loads on landing gear = 0.9 W0 = 0.9 23805.36 =21424.824 Kg

Loads on nose wheel landing gear = 0.1 23805.36 = 2380.536 Kg

Weight of the wheel Ww =

= 10712.412 Kg

= 23616.824 lb

But in the bicycle and quadricycle configuration the tire is same

-shock absorber efficiency

8

-tire efficiency

gear load factor

9

1.8.Moment about C.G

Distance between nose L.G and main LG=7.804+1.96

=9.764m

No of nose wheels in single strut = 2380.53/5805.99

=1

No of main wheels in single strut = 10712.412/5805.99 =210

For horizontal:

= MJ

For vertical:

= MJ

= 9.144cm

11

S=210.93cm

12

To find H

H = wheel dia +strut length+fuselage cross-section radius

=0.97+1+1.195= 3511.8Kg

Area of foot print

13

Chapter2

Structural design study –theoretical approach

Lift load on each wing = w/2

Root chord = 3.37m

Tip chord = 1.348m

Semi span = b/2 = 11.784m

Wetted area of wing, S = 4.419m2

Here, x1 = 0; x2 = semi span

Y1 = root chord

Y2 = tip chord

2.1. Weight distribution:

Weight of fuel = 8350Kg

14

Weight of fuel in one wing =4175kg

Let the volume of the fuel distributed in the wing is direct proportion with the chord length of wing

Assumption

Only 75% of wing length is accounting for using fuel weight =8.838

2.2. WING DESIGN:

Schrunk’s curve:

Lift load on each wing = w/2

15

Acosθ, Bsinθ are co-ordinates of ellipse whose area is same as plan form area

θ acosθ bsinθ0 11.82 06 11.7552 0.322

12 11.5611.241 0.64218 10.798 0.95424 10.236 1.2530 9.56 1.5436 8.78 1.8142 7.909 2.06648 6.947 2.29454 5.91 2.4960 5.91 2.67466 4.807 2.82172 3.65 2.9378 2.45 3.0284 1.235 3.0790 0 3.088

16

Air load

Resultant load = 2 airload - kCx2

2.3. Effective chord distribution:

Effective chord C' (m) Distance from wing root x (m)3.37 0

3.2015 0.98203.033 1.9640

2.8645 2.9462.696 3.928

2.5275 4.9102.359 5.8922

2.1905 6.8742.022 7.853

1.8535 8.8381.685 9.818

1.5165 10.8021.348 11.9845

17

Equivalent load distribution is made from the above plot by splitting the graph into the number of segment and plotting the load distribution curve by method of direct proportions.

s = 27.3m2

18

Area of the element that is considered in wing effective chord distribution graph is Δθ.

Δx → width of element considered

w → gross weight (23805.56Kg)

s → wetted surface area/2 = (4.416/2)=4.419m2

2.4. WEIGHT DISTRIBUTION OF FUEL:

19

2.5. WING STRUCTURAL WEIGHT DISTRIBUTION:

The structural weight is assumed to be square of the chord i.e.

Where, k = constant

Cx = chord at any distance i.e. from root, since the chord variation is linear along span.

So,

Cx = a+bx

At x =0, Cx = Cr = a

At x = max. Cx = Ct = value

If we need the “b” value at x = max then substitute in eqn.

Cx = a+bx

Some value = a + b (max. value)

Therefore, for long range large aircraft

20

At x = 0, Cx = Cr = 3.37m

At x = 11.82, Cx = Ct = 1.348m

Therefore, 1.348 = 3.37 + b(11.82)

b = -0.1710m

S.Noa/2 (m)

yo

Chord

K (Kg/m3

).1xwoxyo/2

Airload

Resultant load

Load at midpoint

1 0 3.2 3.37 _ 3808.9 128.21 128.21 149.172 1.182 3.1 3.3 94.205 3689.86 124.2 -901.7 143.26

3 2.3642.9

5 2.9 50.103 3051.8 118.12 -303.2 136.164 4.728 2.8 2.52 28.44 3332.77 112.19 -68.41 125.525 5.91 2.5 2.38 24.289 2975.69 100.17 437.41 113.686 7.092 2.3 2.1 21.627 2737.64 92.155 53.22 102.05

7 8.2742.0

1 1.98 19.825 2392.46 80.53 2.808 89.02

8 9.4561.7

5 1.7 18.567 2082.98 70.11 16.457 74.58

910.63

8 1.4 1.5 17.67 1666.39 56.09 21.45 33.14910 11.82 0 1.348 17.047 0 0 0

The general eqn. Cx = 3.37 -0.1710x

Wkt,

21

Where,

Area of shrunk curve =

= 29.706m2

Distance from fuselage Intensity of load (Kg/m)0 0

1.182 27402.364 25224.728 21645.91 2020

7.092 18768.274 15879.456 1443.16

22

10.638 1298.1611.82 1154.308

Station from free end of wing q∆x (-)

Wing structural weight (Kg)

Fuel weight (Kg)

Engine weight (Kg)

Net resultant weight (Kg)

0 566.76 0 _ _ -566.761.182 650.4 70.34 _ _ -580.062.364 748.59 281.38 5122.3 _ 2655.09

23

4.728 960.15 1125.525 3679.3 _ 3844.6755.91 991.84 1758.63 2498.8 601 3866.59

7.092 1095.6 2532.43 924.7 _ 4061.18.274 1140.53 3446.9 531.17 _ 4203.589.456 1260.2 4502.107 400 _ 4500.68

10.638 1310 5667.34 _ _ 5347.3411.82 0 7034.5 _ _ 7034.5

The total weight =2380.56Kg

Weight on each wing =1190.270Kg

24

The Wing may be consider as a cantilever beam and the structural weight as an uniformly varying load

Total weight W= 1190.278Kg

It acts as a UVL

For an uniform varying load equivalent weight at any point ‘x’ from the tip is

given by

where l = total length

x- at a point on the wing

calculation:

when x = 0

f = 0

when x= 1.182

X = l

L= 11.82

Fuel weight distribution:

The fuel weight distribution inside the wing can shown schematically as

The fuel is stored between the stations 2.364m to 9.456m

Total area =Area of the ABCD+Area of DCE

25

= 11.3472+5.319

=16.6662m2

Fuel weight carried by ABCD

The fuel weight in the part ABCD can be considered as an UDL

The fuel in element is element DCE can be considered as an UVL

Fuel weight carried by DCE = 4175 – 2843.27

= 1331.73kg

Force at

26

Station (m) Shear force (Kg) Bending moment (Kgm)0 _ 0

1.182 580.06 685.63092.364 2655.09 6276.6334.728 3844.675 18177.625.91 3866.59 22851.55

7.092 4061.1 28801.328.274 4203.58 34780.429.456 4500.68 42558.43

10.638 5347.34 5688511.82 7034.5 83147.79

27

28

29

30

31

Chapter 3

Wing and fuselage design

3.1. Aerofoil consideration:

upper surface Lower surface

station ordinate station ordinate0 0 0 0

0.435 0.819 0.565 -0.7190.678 0.999 0.822 -0.8591.169 1.273 1.331 -1.0592.408 1.757 2.592 -1.3854.898 2.491 5.102 -1.8597.394 3.06 7.606 -2.2219.894 3.55 10.106 -2.521

14.899 4.33 15.101 -2.99219.909 4.9 20.001 -3.43524.921 5.397 25.079 -3.60729.936 5.732 30.064 -3.78834.951 5.954 35.049 -3.89439.968 6.067 40.032 -3.92544.984 6.058 45.016 -3.865

50 5.915 50 -3.70955.014 5.625 54.986 -3.43560.027 5.217 59.973 -3.07565.036 4.712 64.964 -2.65270.043 4.128 69.957 -2.18475.045 3.479 74.955 -1.65980.044 2.783 79.956 -1.19185.038 2.057 84.962 -0.71190.028 1.327 89.972 -0.29395.014 0.622 94.986 0.01

32

100 0 100 0

Chord = 3.37m

Station along x-axis

Station dis.From L.E along x-axis

Upper surface Lower surface

Ordinate % Ordinate(m) Ordinate % Ordinate(m)0 0 0 0 0 05 0.1685 2.5 0.084 -1.8 -0.0606

10 0.337 3.5 0.1179 -2.5 -0.08415 0.5055 4.4 0.1482 -2.9 -0.097720 0.674 5 0.1685 -3.2 -0.10725 0.842 5.4 0.18198 -3.6 -0.12130 1.011 5.6 0.188 -3.8 -0.12835 1.1795 5.9 0.198 -3.9 -0.1340 1.348 6.01 0.202 -3.92 -0.13245 1.5165 6.03 0.203 -3.8 -0.12850 1.685 6 0.2022 -3.6 -0.12155 1.8535 5.6 0.188 -3.4 -0.11460 2.022 5.2 0.175 -3.1 -0.104465 2.1905 4.7 0.58 -2.6 -0.08770 2.359 4.2 0.141 -2.1 -0.070775 2.527 3.4 0.114 -1.6 -0.0539280 2.69 2.8 0.094 -1.3 -0.04385 2.68 2.1 0.0704 -0.8 -0.0290 3.033 1.3 0.04 -0.5 -0.01695 3.2015 0.7 0.023 -0.3 -0.01

100 3.37 0 0 0 0

3.2. Aerofoil thickness distribution:

Let us consider a box beam structural configuration with spars one nearer to L.E and 15% of chord from L.E another at the rear edge which is located at 70% chord from leading edge.

From the graph

Max. bending moment = 83147.79 Kg-m =815.67 103Nm

33

Let us take a flat rectangular spar as a member for resulting against bending moment with the two angle section riveted at top and bottom edge of rectangular section as shown in the figure.

Max. failing stress = 69.008KN

Total depth of the front spar = (0.18198+0.121)m =0.30248 m

Total depth of the rear spar = 0.3232 m

Let us consider 40% of the total B.M is carried by front par.

B.M taken by front spar, Ix1 = =

Let the radius be, r =

Area corresponding boom at 0.15149

A= = =

WKT

Let us divide the above into five divisions because we have to distribute this area to area each section

34

= =0.1558 m2

Since the area to with stand the moments is large we take 5 booms of each sections having 150 cm2 to resist against B.M without exceeding failure stress.

Now the dimensions of L-section be

t=2mm, b=375cm, h=375cm.

Appropriate cross-sectional area

375 0.2+375 0.2= 150 cm2

Remaining area = 0.1558-0.015=0.1408m2 =1408cm2

Let us consider a boom whose area = =93.8667cm2

Similarly for another L-section there will be 15 booms

Totally there will be 5 15=75 booms. Top side the booms are stringers with each

having area of 93.8667 cm2 the approximate arrangement of stringer and spar is given below

Since the stress analysis and shear flow calculations are difficult when we consider thickness of spin. Let us neglect its calculations are difficult when we consider thickness of spin, let us neglect its calculations for time being equivalent boom considerations for above wing.

35

Station no.

1 0.18198 100 18.198 0.14491 100 14.4912 0.1833 94 17.2302 0.1462 94 13.74283 0.1846 94 17.3524 0.1476 94 13.87444 0.186 94 17.484 0.148 94 13.9125 0.1873 94 17.6062 0.15 94 14.16 0.1887 94 17.7378 0.1516 94 14.25047 0.19 94 17.86 0.15299 94 14.381068 0.1914 94 17.9916 0.1543 94 14.50429 0.1927 94 18.1138 0.155694 94 14.63524

10 0.194112 94 18.24653 0.15704 94 14.7617611 0.19546 94 18.37324 0.15839 94 14.8886612 0.1968 94 18.4992 0.1597 94 15.011813 0.1981 94 18.6214 0.161 94 15.13414 0.1999 94 18.7906 0.162 94 15.22815 0.20082 94 18.87708 0.1637 94 15.387816 0.1987 94 18.6778 0.162 94 15.22817 0.1981 94 18.6214 0.161 94 15.13418 0.1964 94 18.4616 0.1596 94 15.002419 0.1953 94 18.3582 0.1582 94 14.870820 0.1943 94 18.2642 0.1569 94 14.7486

36

21 0.1932 94 18.1608 0.1546 94 14.532422 0.1912 94 17.9728 0.1542 94 14.494823 0.1908 94 17.9352 0.15208 94 14.2955224 0.1892 94 17.7848 0.1509 94 14.184625 0.1872 94 17.5968 0.15 94 14.126 0.1862 94 17.5028 0.148 94 13.91227 0.1852 94 17.4088 0.1476 94 13.874428 0.1833 94 17.2302 0.146 94 13.72429 0.1812 94 17.0328 0.1462 94 13.742830 0.1802 100 18.02 0.1449 100 14.49

Station no.

m

1 0.15502 100 15.502 0.153 100 15.3 -0.58972 0.1563 94 14.6922 0.1538 94 14.4572 -0.553 0.1577 94 14.8238 0.1542 94 14.4948 -0.5114 0.159 94 14.946 0.1552 94 14.5888 -0.47185 0.1604 94 15.0776 0.1563 94 14.6922 -0.43246 0.16176 94 15.20544 0.1577 94 14.8238 -0.39317 0.1631 94 15.3314 0.159 94 14.946 -0.35388 0.16445 94 15.4583 0.1604 94 15.0776 -0.31459 0.1658 94 15.5852 0.1617 94 15.1998 -0.275

10 0.16715 94 15.7121 0.1631 94 15.3314 -0.235911 0.1685 94 15.839 0.1644 94 15.4536 -0.1968

12 0.1698 94 15.9612 0.1658 94 15.5852 -0.15726

13 0.171196 94 16.09242 0.1675 94 15.745 -0.1179514 0.1725 94 16.215 0.1685 94 15.839 -0.078615 0.1738 94 16.3372 0.1698 94 15.9612 -0.06216 0.17254 94 16.21876 0.1685 94 15.839 0.117917 0.17119 94 16.09186 0.16255 94 15.2797 0.15726

37

18 0.1688 94 15.8672 0.1644 94 15.4536 0.196819 0.1684 94 15.8296 0.1631 94 15.3314 0.23520 0.1671 94 15.7074 0.1617 94 15.1998 0.27521 0.1658 94 15.5852 0.1604 94 15.0776 0.31422 0.1643 94 15.4442 0.159 94 14.946 0.35223 0.1628 94 15.3032 0.1577 94 14.8238 0.39324 0.1612 94 15.1528 0.1563 94 14.6922 0.432425 0.1602 94 15.0588 0.1552 94 14.5888 0.47426 0.158 94 14.852 0.1542 94 14.4948 0.511627 0.1572 94 14.7768 0.1538 94 14.4572 0.5528 0.1563 94 14.6922 0.1531 94 14.3914 0.58929 0.155 94 14.57 0.1539 94 14.4666 0.5930 0.1542 100 15.42 0.15 100 15 0.598

2.40312 -9.14153 -0.5897 -9.02241 2.3409 34.703 34.7032.296391 -8.08071 -0.55 -7.95146 2.223517 28.435 28.4352.337713 -7.57496 -0.511 -7.40684 2.235098 24.545 24.5452.376414 -7.05152 -0.4718 -6.883 2.264182 20.9239 20.92392.418447 -6.51955 -0.4324 -6.35291 2.296391 17.575 17.5752.459632 -5.97726 -0.3931 -5.82724 2.337713 14.76 14.762.500551 -5.42425 -0.3538 -5.28789 2.376414 11.76 11.762.542117 -4.86164 -0.3145 -4.74191 2.418447 9.29 9.292.584026 -4.28593 -0.275 -4.17995 2.457808 7.1087 7.10872.626278 -3.70648 -0.2359 -3.61668 2.500551 3.629 3.6292.668872 -3.11712 -0.1968 -3.04127 2.540572 2.1 2.1

2.710212 -2.51006-

0.15726 -2.45093 2.584026 1.307 1.307

2.754959 -1.8981-

0.11795 -1.85712 2.637288 1.182 1.1822.797088 -1.2745 -0.0786 -1.24495 2.668872 1.012 1.012

38

2.839405 -1.01291 -0.062 -0.98959 2.710212 1.01 1.012.798385 1.912192 0.1179 1.867418 2.668872 1.01 1.012.754766 2.530606 0.15726 2.402886 2.483715 1.012 1.0122.678383 3.122665 0.1968 3.041268 2.540572 1.182 1.1822.665705 3.719956 0.235 3.602879 2.500551 1.307 1.3072.624707 4.319535 0.275 4.179945 2.457808 2.1 2.12.584026 4.893753 0.314 4.734366 2.418447 3.629 3.6292.537482 5.436358 0.352 5.260992 2.376414 7.1085 7.10852.491361 6.014158 0.393 5.825753 2.337713 9.29 9.292.442631 6.552071 0.4324 6.352907 2.296391 11.76 11.76

2.41242 7.137871 0.474 6.915091 2.264182 14.525 14.5252.346616 7.598283 0.5116 7.41554 2.235098 17.525 17.5252.322913 8.12724 0.55 7.95146 2.223517 20.9239 20.92392.296391 8.653706 0.589 8.476535 2.203323 24.545 24.545

2.25835 8.5963 0.59 8.535294 2.22641 28.435 28.4352.377764 9.22116 0.598 8.97 2.25 34.703 34.703

39

Now,

Assuming the second section at a distance 3m from chord and is given as C=2.948 m

Station no x m y mσ(comp.) x106 N/m2

P(comp.) x103 N x'n m (-) y' m (-)

σ(tensile) x106 N/m2

P(tensile) x103 N

1 -0.5897 0.15502 7.66 76.643 0.5897 0.15502 7.64 7.6622 -0.55 0.1563 7.72 72.602 0.55 0.1563 7.71 7.73 -0.511 0.1577 7.78 73.215 0.511 0.1577 7.76 7.764 -0.4718 0.159 7.84 73.782 0.4718 0.159 7.81 7.825 -0.4324 0.1604 7.91 74.395 0.4324 0.1604 7.9 7.96 -0.3931 0.16176 7.97 74.962 0.3931 0.16176 7.96 7.967 -0.3538 0.1631 8.03 75.575 0.3538 0.1631 8.02 8

40

8 -0.3145 0.1644 8.1 76.142 0.3145 0.1644 8.1 8.129 -0.275 0.1658 8.16 76.155 0.275 0.1658 8.16 8.18

10 -0.2359 0.1698 8.22 76.276 0.2359 0.1698 8.22 8.211 -0.1968 0.17119 8.29 77.935 0.1968 0.17119 8.29 8.2912 -0.15726 0.17254 8.35 78.5 0.15726 0.17254 8.35 8.3513 -0.11795 0.1738 8.41 79.11 0.11795 0.1738 8.41 8.4114 -0.0786 0.1742 8.47 79.7 0.0786 0.1742 8.47 8.4715 -0.062 0.1756 8.523 80.11 0.062 0.1756 8.521 8.52316 0.1179 0.1756 8.457 79.501 0.1179 0.1756 8.452 8.45117 0.15726 0.1742 8.38 78.845 0.15726 0.1742 8.36 8.3818 0.1968 0.1738 8.31 78.171 0.1968 0.1738 8.3 8.3119 0.235 0.17254 8.24 77.53 0.235 0.17254 8.21 8.2420 0.275 0.17119 8.17 76.81 0.275 0.17119 8.17 8.1721 0.314 0.1698 8.1 76.22 0.314 0.1698 8.12 8.122 0.352 0.1658 8.03 75.54 0.352 0.1658 8.01 8.0323 0.393 0.1644 7.96 74.912 0.393 0.1644 7.94 7.9624 0.4324 0.1631 7.89 74.233 0.4324 0.1631 7.89 7.8925 0.474 0.16176 7.82 73.6 0.474 0.16176 7.82 7.8226 0.5116 0.1604 7.75 72.9 0.5116 0.1604 7.75 7.7527 0.55 0.159 7.69 72.3 0.55 0.159 7.69 7.6928 0.589 0.1577 7.625 71.16 0.589 0.1577 7.625 7.62529 0.59 0.1563 7.557 73.4 0.59 0.1563 7.557 7.55730 0.598 0.15502 7.52 75.75 0.598 0.15502 7.61 7.6

Station no yn x102 cm An cm2 Anyn x102 cm3 y'n x102 cm A'n cm2A'ny'n x102 cm3

41

1 0.15316 100 15.316 0.15 100 152 0.1544 94 14.55 0.1513 94 14.22223 0.155 94 14.64 0.1526 94 14.34444 0.157 94 14.766 0.1539 94 14.46665 0.158 94 14.8966 0.1553 94 14.59826 0.159 94 15.01 0.1565 94 14.7117 0.1611 94 15.147 0.1579 94 14.84268 0.162 94 15.268 0.159 94 14.9469 0.163 94 15.398 0.1605 94 15.087

10 0.1649 94 15.5006 0.1616 94 15.190411 0.1664 94 15.6416 0.1631 94 15.331412 0.1677 94 15.7638 0.1644 94 15.453613 0.169 94 15.886 0.1657 94 15.575814 0.1704 94 16.0176 0.167 94 15.69815 0.1717 94 16.1398 0.162 94 15.22816 0.1717 94 16.1398 0.162 94 15.22817 0.1704 94 16.0176 0.167 94 15.69818 0.169 94 15.886 0.1657 94 15.575819 0.1677 94 15.7638 0.1644 94 15.453620 0.1664 94 15.6416 0.1631 94 15.331421 0.1649 94 15.5006 0.1616 94 15.190422 0.163 94 15.322 0.1605 94 15.08723 0.162 94 15.228 0.159 94 14.94624 0.1611 94 15.1434 0.1579 94 14.842625 0.159 94 14.946 0.1565 94 14.71126 0.158 94 14.852 0.1553 94 14.598227 0.157 94 14.758 0.1539 94 14.466628 0.155 94 14.57 0.1526 94 14.344429 0.1544 94 14.5136 0.1513 94 14.222230 0.15316 100 15.316 0.15 100 15

42

Station noyn =y+y x102 cm An cm2 Any2

n x10-4 m4 A'n cm2y'n =y-yn x102 cm A'ny'n x10-4 m4

1 0.1482 100 2.1636 100 0.1453 2.1122 0.1493 94 2.0675 94 0.1465 2.0183 0.1502 94 2.1047 94 0.1478 2.0544 0.1508 94 2.139 94 0.149 2.0885 0.1512 94 2.177 94 0.1503 2.1256 0.1517 94 2.212 94 0.1515 2.167 0.1532 94 2.251 94 0.1529 2.1978 0.1566 94 2.287 94 0.1541 2.2329 0.1582 94 2.326 94 0.1554 2.271

10 0.1594 94 2.36 94 0.1565 2.30411 0.1601 94 2.402 94 0.1579 2.34512 0.1612 94 2.44 94 0.1591 2.38113 0.1642 94 2.48 94 0.1604 2.42114 0.1651 94 2.519 94 0.1617 2.45915 0.166 94 2.55 94 0.1629 2.42116 0.166 94 2.55 94 0.1629 2.42117 0.1651 94 2.519 94 0.1617 2.45918 0.1642 94 2.48 94 0.1604 2.42119 0.1613 94 2.44 94 0.1591 2.38120 0.1601 94 2.402 94 0.1579 2.34521 0.1594 94 2.36 94 0.1565 2.30422 0.1582 94 2.326 94 0.1554 2.27123 0.1566 94 2.287 94 0.1541 2.23224 0.1532 94 2.251 94 0.1529 2.19725 0.1517 94 2.212 94 0.1515 2.1626 0.1512 94 2.177 94 0.1503 2.12527 0.1508 94 2.139 94 0.149 2.08828 0.1502 94 2.1047 94 0.1478 2.05429 0.1493 94 2.0675 94 0.1465 2.01830 0.1482 100 2.1636 100 0.1453 2.112

43

xn m Anx2n x10-4 m2 x'n m A'nx'2

n x10-4 m4 Anxnyn x10-4 m4 A'nx'ny'n x10-4 m4

0.589 34.77 0.5897 34.322 -8.57 8.460.54 28.43 0.55 28.065 -7.57 7.48

0.512 24.54 0.511 24.22 -7.101 7.010.4716 20.92 0.4718 20.65 -6.61 6.520.4317 17.575 0.4324 17.34 -6.21 6.03

0.393 14.52 0.3931 14.3 -6.112 5.530.3436 11.766 0.3538 11.613 -5.6 5.0220.3145 9.29 0.3145 9.176 -5.08 4.5

0.275 7.108 0.275 7.016 -4.55 3.9680.2359 5.2309 0.2359 5.162 -4.01 3.428

0.15726 3.629 0.15726 3.582 -3.47 2.880.11726 2.324 0.11795 2.29 -2.91 2.320.11795 2.1 0.0786 1.29 -2.35 1.75

0.0782 1.875 0.0765 0.875 -1.77 1.180.075 1.65 0.0756 0.573 -1.19 1.120.075 1.725 0.0756 0.573 1.805 1.36

0.0782 2.324 0.0765 0.875 2.39 1.7830.11795 3.632 0.0786 1.29 2.965 2.3610.11726 5.191 0.11795 2.29 3.516 2.9280.15726 7.108 0.15726 3.582 4.08 3.472

0.2359 9.29 0.2359 5.162 4.62 4.030.275 11.766 0.275 7.016 5.169 4.591

0.3145 14.52 0.3145 9.176 5.695 5.1050.3436 11.575 0.3538 11.613 6.214 5.624

0.393 20.92 0.3931 14.3 6.722 6.1380.4317 24.54 0.4324 17.34 7.223 6.6390.4716 28.44 0.4718 20.65 7.7064 7.1333

0.512 28.228 0.511 24.22 7.6448 7.61110.54 34.77 0.55 28.065 7.548 7.55

0.589 35.6 0.5897 34.322 8.5689 7.454

44

=834.7534×10-4m4

=131.26×10-4m4

=0.98×10-4m4

45

Station no x m y mσ(comp.) x106 N/m2

P(comp.) N x' y'

σ(tensile) x106 N/m2

P(tensile) N

1 -0.5897 0.1382 6.65 66.5 -0.5897 0.1382 6.65 64.52 -0.55 0.1393 6.72 63.1 -0.55 0.1393 6.62 63.13 -0.511 0.1402 6.78 63.02 -0.511 0.1402 6.68 63.024 -0.4718 0.1408 6.84 62.98 -0.4718 0.1408 6.74 61.985 -0.4324 0.1412 6.91 62.87 -0.4324 0.1412 6.81 61.876 -0.3931 0.1417 6.97 62.74 -0.3931 0.1417 6.87 61.747 -0.3538 0.1432 7.03 62.63 -0.3538 0.1432 6.93 61.638 -0.3145 0.1466 7.1 62.54 -0.3145 0.1466 7.9 61.549 -0.275 0.1482 7.16 62.43 -0.275 0.1501 7.06 60.43

10 -0.2359 0.1494 7.22 66.43 -0.2359 0.1508 7.02 59.4311 -0.1968 0.1501 7.29 66.83 -0.1965 0.1512 7.09 60.4212 -0.15726 0.1508 7.35 69.11 -0.1572 0.1542 7.15 67.1113 -0.11795 0.1512 7.41 69.7 -0.1179 0.1551 7.43 63.1214 -0.0786 0.1542 7.47 70.11 -0.0786 0.1568 7.37 70.1115 -0.062 0.1551 7.5 69.501 -0.065 0.1501 7.42 69.1116 0.1179 0.1542 7.4 68.84 0.065 0.1494 7.3 69.7717 0.15726 0.1512 7.38 68.171 0.0786 0.1482 7.08 69.718 0.1968 0.1508 7.31 67.53 0.1179 0.1466 7.01 70.1119 0.235 0.1501 7.24 66.811 0.1572 0.1432 7.03 69.50120 0.275 0.1494 7.17 66.22 0.1965 0.1417 7.04 68.8421 0.314 0.1482 7.1 65.4 0.2359 0.1412 7.07 68.17122 0.352 0.1466 7.03 64.41 0.275 0.1408 7.09 67.5323 0.393 0.1432 6.96 64.23 0.3145 0.1383 7.01 66.81124 0.4324 0.1417 6.89 63.6 0.3538 0.1391 6.94 66.2225 0.474 0.1412 6.75 62.9 0.3931 0.1382 6.79 65.5426 0.5116 0.1408 6.69 62.3 0.4324 0.136 6.25 64.9227 0.55 0.1402 6.625 61.16 0.4718 0.14 6.4 64.2328 0.589 0.1383 6.557 65.75 0.511 0.145 6.323 63.2629 0.59 0.1391 6.58 66.1 0.55 0.148 6.12 62.930 0.598 0.138 6.59 66.3 0.559 0.149 6.08 62.3

46

, d=3m

Station no

Root load P1 x103N(-) P2 N (-)

q'1 =∆P/d x103 N/m

q =b2q'1/b1 x103 N/m P'2 N

Root load P'1 x103N

q'2 =∆P/d x103 N/m

q =b2q'2/b1 x103 N/m

1 76.643 6.65 25.525 25.16 5.55 76.243 23.2 23.1252 72.601 6.72 25.723 25.355 5.72 71.54 23.425 23.6233 73.215 6.78 25.9 25.569 5.78 71.215 23.723 23.744 73.782 6.84 26.1 25.67 5.84 71.012 23.9 23.95 74.39 6.91 26.3 25.981 5.91 70.982 24.1 24.16 74.96 6.97 26.5 26.179 5.97 70.876 24.3 24.37 75.57 7.03 26.7 26.393 5.96 70.643 24.5 24.68 76.142 7.1 26.9 26.591 6.03 70.432 24.7 24.89 76.755 7.16 27.1 26.805 6.1 70.216 24.9 24.9

10 76.276 7.22 27.3 26.987 6.16 70.012 25.1 25.111 76.755 7.29 27.6 27.215 6.22 68.567 25.3 25.312 76.935 7.35 27.8 27.413 6.29 68.043 25.6 25.613 78.5 7.41 28 27.624 6.35 67.863 25.8 25.814 79.11 7.47 28.2 27.838 6.41 66.662 26 26

47

15 79.9 7.5 28.386 27.98 6.47 65.432 26.2 26.216 80.11 7.4 27.932 27.762 6.5 66.662 26.386 26.317 79.501 7.38 27.996 27.533 6.4 67.863 26.932 26.9318 78.845 7.31 27.471 27.3 6.38 68.043 26.996 26.219 78.171 7.24 27.214 27.078 6.31 68.567 26.471 26.320 77.53 7.17 27.004 26.825 6.24 70.012 26.214 26.121 76.22 7.1 26.766 26.658 6.17 70.216 26.004 2622 75.54 7.03 26.541 26.383 6.1 70.432 25.766 24.9823 74.912 6.96 26.3 26.161 6.03 70.643 25.541 24.4324 74.233 6.89 26.074 25.91 5.96 70.826 25.3 24.325 73.6 6.75 25.833 25.7 5.89 71.12 25.074 24.0726 72.9 6.69 25.619 25.464 5.75 70.863 24.833 23.8327 72.87 6.635 25.39 25.254 5.69 71.014 24.619 23.61928 72.99 6.638 25.165 25.027 5.625 71.215 24.39 23.9929 72.93 6.89 25.12 25.01 5.638 76.243 24.165 23.10230 75.75 6.557 25.03 25.002 5.89 76.44 24.39 24.19

48

Station no Station no

15 27.996 -27.996 30 23.115 -23.115

14 27 -54.996 29 23.613 -46.728

13 26.532 -81.528 28 23.74 -70.468

12 26.112 -107.64 27 23.9 -94.368

11 25.8 -133.44 26 24.1 -118.468

10 25.8 -159.24 25 24.3 -142.768

9 25.30 -184.54 24 24.6 -167.368

8 25.30 -209.84 23 24.8 -192.168

7 25.12 -234.96 22 24.9 -217.068

6 25.0057 -259.966 21 25.1 -242.168

5 24.814 -284.78 20 25.3 -267.468

4 24.623 -309.403 19 25.6 -293.068

3 24.453 -333.856 18 25.8 -318.868

2 24.12 -357.976 17 26.6 -345.468

1 24.15 -382.126 16 26.2 -371.668

1' 24.16 -406.286 16' 26.386 -398.054

2' 24.45 -430.736 17' 26.004 -424.058

3' 24.62 -455.356 18' 25.766 -449.824

4' 24.8 -480.156 19' 25.541 -475.365

5' 25.814 -505.97 20' 25.3 -500.665

6' 25 -530.97 21' 25.074 -525.739

7' 25.12 -556.09 22' 24.833 -550.572

8' 25.3 -581.39 23' 24.619 -575.191

9' 25.8 -607.19 24' 24.39 -599.581

10' 26 -633.19 25' 24.115 -623.696

11' 26.12 -659.31 26' 24.34 -648.036

12' 26.5 -685.81 27' 24.833 -672.869

13' 26.5 -712.31 28' 25.074 -697.943

14' 27 -739.31 29' 25.541 -723.484

15' 27.9 -767.21 30' 26.942 -750.426

49

Station no q1 x103N/m (-)Shear stress τ x103N/m2 Station no q2 x103N/m (-)

Shear stress τ x103N/m2

15 783.69 17.4417 30 762.68 16.4414 757.79 16.862 29 737.47 15.813 728.79 16.217 28 708.79 15.21712 702.29 15.638 27 602.29 15.03711 685.17 15.037 26 655.17 14.4810 650.17 14.481 25 604.32 14.037

9 624.32 13.902 24 578.32 13.4818 598.32 13.323 23 552.67 12.9027 572.57 12.745 22 528.22 12.3236 548.22 12.211 21 403.77 10.2185 423.77 10.563 20 377.65 9.5634 399.65 8.423 19 331.34 7.4233 375.5 6.83 18 328.21 5.832 351.34 4.32 17 325.4 3.321 328.21 2.5 16 324.2 2.32

1' 328.21 2.5 16' 324.2 2.32 2' 351.34 4.32 17' 325.4 3.32

50

3' 375.5 6.83 18' 328.21 5.83 4' 399.65 8.423 19' 331.34 7.423 5' 423.77 10.563 20' 377.65 9.563 6' 548.22 12.211 21' 403.77 10.218 7' 572.57 12.745 22' 528.22 12.323 8' 598.32 13.323 23' 552.67 12.902 9' 624.32 13.902 24' 578.32 13.48 10' 650.17 14.481 25' 604.32 14.037 11' 685.17 15.037 26' 655.17 14.48 12' 702.29 15.638 27' 602.29 15.037 13' 728.79 16.217 28' 708.79 15.217 14' 757.79 16.86 29' 737.74 15.817 15' 783.69 17.44 30' 762.68 16.44

3.3. Shear force distribution over the fuselage:

Load acting on fuselage=0.1wo=0.1×23.568×9.81=23.353×103N

Assume area of each stringers be3cm2

Torsional shear flow, q1= =

Stringer no

Area at station ×10-4 m2 At 0 Zm At 16 Zm

At station zero σb ×109

At station σb ×109

∆P.M/16.5 ×106m

∆P.K/16.5 ×103N

Flexural shear flow x103N/m

Actual shear flow N/m

1 1.5 2.49 2.27 3.33 3.0349 18.18 16.58 16.58 6.432 3 2.119 1.956 2.85 2.615 14.24 12.989 29.479 18.7493 3 2.069 1.487 2.786 1.988 47.27 43.119 72.598 62.484 3 1.4269 1.23 1.909 1.644 16.06 14.649 87.247 77.2475 3 0.7114 0.6827 0.951 0.9127 2.321 2.1172 89.3642 79.682

51

6 3 0 0 0 0 0 0 0 07 3 0.7144 0.6827 0.951 0.9127 2.321 2.1172 89.3642 79.6828 3 1.4269 1.23 1.909 1.644 16.06 14.649 87.247 77.2479 3 2.069 1.487 2.786 1.988 47.27 43.119 72.598 62.48

10 3 2.119 1.956 2.85 2.615 14.24 12.989 29.479 18.74911 1.5 2.49 2.27 3.33 3.0349 18.18 16.58 16.58 6.43

And

at distance x=16.5m

52

1- 2.49m

2- 2.119m

3- 2.06m

4- 1.4269m

5- 0.77114m

6- 0

53

1-2.27m

2-1.956m

3-1.487m

4-1.23m

5-0.6827m

6-0

54

Chapter 4

V- n diagram for the design study

4.1. Aspect ratio correction:

55

Angle of attack ( ) Induced angle of attack

-14 -0.9 -2.345 -16.345-12 -0.05 -0.1302 -12.1302-10 -0.3 -0.7816 -10.7816-8 -0.55 -1.433 -9.433-6 -0.8 -2.084 -8.084-4 -1 -2.6055 -6.6055-2 -1.2 -3.1267 -5.12670 1.4 3.647 3.6472 1.6 4.1689 6.16894 1.8 4.690 8.696 2 5.2118 11.21187 2.05 5.314 12.3414

4.2. Velocity and load factor:

V m/s Positive load factor V m/s Negative load factor

9.6826 0.04 11.1804 0.0419.3652 0.16 22.3608 0.1629.0478 0.36 33.5412 0.3638.7304 0.64 44.7216 0.6448.413 1 55.902 158.75 1.4726 58.75 1.10439235 23.56 235 17.6718304.4 39.533 304.4 29.6506

56

velocity V m/s U m/sStall 58.75 8 0.00687 1.00683 0.993Cruise 235 8 0.0272 1.02 0.93dive 304.4 8 0.0353 1.0303 0.965

Gust alteration factor

Change in load factor:

= =2470.59

4.3. V-n diagram:

57

58

59

Chapter 5

Critical loading performance

5.1. Fittings and connections:

Bolts and rivets:

The connection involves primary and secondary connection such as fittings, bolts, rivets, welding etc. no tough that main or primary fitting involves move weight and costs than any other aerospace structure.

Secondary in fitting design:

In a wing structure fitting involving in main load carrying structure is move costly to design as well as to manufacture for economy at fabrication the structural designed should have a fabrication the structural designed should have a good knowledge of shop processes and operations .

General rules:

Usage of bolts

Bolts thread should not be placed in or shear the length of the bolts should be such that not more than one thread external fitting surface which can be done by washer.

Bolts less than 3/8’’ inch dia should not be used in major fittings and for steel bolts 3/10 inch should be small size to be used.

Bolts connecting parts having relative motion or stress reversal should have closed tolerance to decrease shock loads.

i) Protruding head level of rivet.ii) The flush type rivet.

60

For many years round head rivet was, all sections but wind tunnel experiment it was that these produce more drag so rivet head are changed to flush type which produce lesser drag.

Joggled members:

A joggle is an offset formed in a member it usually involves one or more flanges of a member of open cross section type joggles are quite common in typical airplane structured they are used most often when it is desired to fasten to gather two intersecting members without using an extra part at joint there will be slight loss in stiffness of joggled member.

Protruding head flush head

61

Shear clips:

There are hundreds of these in a typical military airplane they are used for joining together both primary and secondary structural components such as equipments mounting brackets etc. the function of shear clip is to transfer shear load from one part to another .it is not intended to transfer axial load or bending or twist.

Fillers are used to fill up a void when they become a part of the structural path that they held particular attention quite common in complicated metal structure.

Aircraft nuts:

Four standard steel nuts shown in figure nut material is more ductile than bolt material, thus when the nut is tightened the threads will deflect to seat on the bold thread. The nut is probably the most common aircraft nut. It develops the full rated

62

strength of bolts.

The shear nut is one half as thick the cast head nut and has threads only enough to develop one half bolds tensile stress.

Failure by interrivet buckling:

The effective sheet area is considered to act monolithically with stiffness however if the rivets are spot welded that fasten the rivet to the stiffener are spaced to far apart sheet will buckle before the crippling stress of the stringers is placed. In order to prevent this sort of buckling rivet spacing has to be selected on the upper surface of the wing. Rivet spacing is closer than on the lower surface because the compressive loads act on the top of the wing.

Rivet wrinkling:

The rivet spacing is relatively large the sheet will start buckling belt rivets this buckling belt rivets this buckling does not deform in flange to which the sheet is attached. The rivet spacing is such that prevent the inter-rivet buckling then the failure of the sheets occurs by wrinkling. It is also known as forced wrinkling it is

63

5.2. Shock absorber analysis:

Static load = 0.45×W0

= 0.45×23805.568

= 9783 Kg

= 21567.82 lb.

Main wheel diameter =

A = 5.3

B =0.315

= 5.3 ×97830.315

=95.775 cm

Area =

= 7238.22 cm2

Load to extended = 0.25×Ps= 2445.75 Kg

Load to compress = 0.3×Ps = 2934.9 Kg

Load (Kg) Stroke (cm)

2445.75 0

10272.15 40.344

12717.9 49.95

Assuming static pressure in strut = 10342.13 KPa (1500 psi)

Piston area = 15.09 inch2

64

V3 = 10% displacement

= 30 inch2

Maximum static pressure = 1500 psi

Total cylinder volume

= 2.182 49.95

= 198.30 inch3

= stroke piston area

= 300 inch3

Calculation of static volume:

It is confirmed that the piston and cylinder volume are enough for the static load.

Oleo sizing:

For oleo- pneumatic metered orifice

The size of oleo strut (D)

L = load on oleo

D =

D = 0.1413

65

5.3. Fuselage bending stress analysis:

Balance Diagram:

Fuel weight=40.956KN

Payload =88.29KN

Empty weight of an aircraft=75.348KN

Wing weight=23.352KN

Tail structure weight=5.838KN

RA+RB =233.784KN

RB=210.42KN

RA=23.356KN

66

Shear force and bending moment values:

Point Shear force KN Bending moment KNmA 23.356 0B 80.678 -181.32C 0 0D -64.934 119.089E -129.742 -4.2697F 5.83 -58.3309G 0 0

5.4. Shear force diagram:

67

5.5. Bending moment diagram:

68

5.6. Airworthiness requirements:

Airworthiness of an aircraft is concerned with the standards of safety incorporated in all aspects of its construction. These range from structural strength to the provision of certain guards in the event of crash landing and include design requirements related to aerodynamics, performance and electrical hydraulic systems. The selection of minimum standards of safety is largely the concern of air worthiness authorities who prepare handbooks of official requirements. In UK the relevant publications are AVP970 for military aircraft and British civil air worthiness requirements of civil aircraft. The handbooks include operation requirements, minimum safety requirements recommended practices and design data.

Clearly airworthiness implies a certain level of safety like saying that the ship is sea worthy and it takes little fore thought to release that there must be some yardstick against which air worthiness can be assessed. We might start with a general, all embracing design requirements. An airplane shall be designed and built to fly safely. Unfortunately we cannot then dust our hands and get on with the job, believing that in one swipe we have got rid of government and other official interference and struck below for freedom.

To be awarded a certificate of air worthiness an aircraft must be demonstrated to be air worthy. Air worthiness can be defined as the contribution made by the aircraft itself to he safety of the flight when the pilot has been removed from the man machine loop. It is concerned with those aspects of design, construction maintenance and the provision of all related limitations and essential information which together determine fitness for flight, thus a c of A is awarded to an aircraft and its equipment, although under certain circumstances the award may also be conditional upon the aircraft being operated under the control of certain named persons or perhaps just one individual.

69

Chapter 6

Balancing and Maneuverability of aileron, elevator and rudder

6.1. Mission profile:

6.2. Gliding:

70

In the up powered flight the aircraft begins to glide , this is the same case for the gliders or sailplane technology

The gliding angle,

For max. glide distance we need max. ratio

Since the glide angle only depending on ratio, its has move aerodynamic characteristics the max. Range that the aircraft can glide is

The max. Range covered by the aircraft by the air if it begins to glide at an altitude an altitude of 12Km and at an optimum glide at an optimum glide angle of 15094’ is 42.01 Km.

Equilibrium glides velocity:

Turn performance

The motion of aircraft during a turn is curved in contrast to the rectilinear motion. By definition, A level turn is one is which the curved flight path is in a horizontal plane parallel to the plane of ground.

For superior maneuvering the aircraft should have min. turn radius the max.load factor.

Considering the max. lift a load distribution as an uniformly varying

6.3. Maneuvering

Rolling moment co-efficient is

=1/3.5

71

=42.01Km

Velocity m/s (V) Load factor (n) Turn angle deg (ф) Turn radius m (R) Turn rate deg/s (ω)25 0.266 _ _ _

58.75 1.472 47.2 325.72 0.1883.92 3 70.52 253.81 0.33

109.107 5.07 78.62 244.14 0.447134.285 7.693 82.53 240.98 0.557

159.46 10.84 84.7 240.138 0.664

72

184.64 14.54 86.05 239.57 0.77209.82 18.78 86.94 239.3 0.87

235 23.56 87.567 239.15 0.982

73

74

Turn radius,

Turn rate,

75

Rate of climb performance:

The max climb angle,

Max rate of climb occurs at

= =2.08169

=45.28m/s

Velocity at which max rate of climb occurs

76

=184.921m/s

When θ=3.4

Velocity (m/s) Rate of climb (m/s)0 0

30 1.7860 3.59890 5.337

120 7.116150 8.89180 10.675210 12.45240 14.233

When Θ=6.8

Velocity (m/s) Rate of climb (m/s)0 0

30 3.5560 7.10490 10.65

120 14.208150 17.76180 21.31210 24.86240 28.417

When θ=10.2

Velocity (m/s) Rate of climb (m/s)0 0

30 5.31260 10.62590 15.93

120 21.25150 26.56

77

180 31.87210 37.18

When θ=13.6

Velocity (m/s) Rate of climb (m/s)0 0

30 7.0560 14.10890 21.16

120 28.21150 35.27180 42.32210 49.38

When Θ=17.74

Velocity (m/s) Rate of climb (m/s)0 0

30 9.140960 18.2890 27.4

120 36.56150 45.704180 54.84210 63.986240 73.127

When velocity=50m/s

θ deg Rate of climb (m/s)0 03 2.6166 5.226

78

9 7.82112 10.3915 12.9418 15.45

When velocity=100m/s

θ deg Rate of climb (m/s)0 03 5.2336 10.459 15.64

12 20.7915 25.8818 30.9

When velocity=150m/s

θ deg Rate of climb (m/s)0 03 7.856 15.689 23.48

12 31.1815 38.822

18 46.35

When ve

locity=200m/s

θ deg Rate of climb (m/s)

0 0

3 10.467

6 20.9

9 31.28

12 41.58

15 51.76

18 61.8When velocity=250m/s

θ deg Rate of climb (m/s)

79

0 0

3 13.08

6 26.132

9 39.108

12 51.9

15 64.704

18 77.25

Velocity (m/s) Lift (KN)30 879.66760 3518.66890 7917.004

120 14074.68150 21991.68180 31668.02210 43103.69240 56298.7

Span Lift (KN)0 0

1.182 13.80172.364 55.2064.728 220.827

5.91 345.047.092 496.8628.274 676.2859.456 883.311

10.638 1096.60511.82 1380.174

80

θ deg Lift (KN)0 233.5323 233.2176 232.2539 230.657

12 228.42915 225.5718 222.102

When V=235m/s

θ deg Rate of climb (m/s) Vh (m/s)0 0 2353 12.29 234.686 24.56 233.719 36.762 232.1

12 48.89 229.8615 60.82 226.9918 72.61 223.4920 80.37 22025 99.31 212.9830 117.5 203.5540 151 180.0250 180.02 151.0560 203.02 117.570 220.82 80.3780 231.42 40.807

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Total

Airplane pitching moment coefficient about CG:

=

=0.45

6.4. Wing contribution stability:

Assumptions:

α is small z is very small, z=0 CL»CD

6.5. Elevator effectiveness:

6.6. Moment at zero lift:

Where F=0.7-0.8(free elevator factor)

CL CmCg CmCg CmCg

0 0 0 00.35 0.277 0.2 0.1727

0.7 0.555 0.3811 0.3451.05 0.833 0.5717 0.518

1.4 1.11 0.7623 0.69081.75 1.39 0.9528 0.8635

2.1 1.667 1.143 1.036

82

CL CmCg (-) CmCg (-) CmCg (-)0 0 0 0

0.35 0.4239 0.44 0.4570.7 0.8478 0.88 0.91

1.05 1.27 1.33 1.371.4 1.69 1.77 1.82

1.75 2.12 2.218 2.282.1 2.54 2.66 2.742

CL CmCgf CmCgf CmCgf

0 0 0 00.35 0.3 0.34 0.37

0.7 0.6 0.67 0.71.05 0.97 0.989 1.1

1.4 1.12 1.16 1.21.75 1.53 1.58 1.63

2.1 1.61 1.69 1.72

CL Cmact (-) Cmact (-) Cmact (-)0 0.03 0.035 0.04

0.35 0.009 0.001 0.0460.7 0.018 0.0018 0.049

1.05 0.026 0.03 0.0531.4 0.032 0.04 0.059

1.75 0.043 0.05 0.0572.1 0.045 0.056 0.061

CL CmCg CmCg CmCg

0 -0.03 -0.035 -0.040.35 0.0631 0.099 -0.0303

0.7 0.2892 0.2693 0.0081.05 0.507 0.306 -0.153

1.4 0.481 0.203 0.01381.75 0.757 0.3098 0.0156

2.1 0.772 0.117 -0.045

83

CL CmCgt Lift (KN)0 0 0

0.35 0.45 65.0120.7 0.9 130.024

1.05 1.37 195.031.4 1.82 260.04

1.75 2.28 325.062.1 2.742 390.07

Span Lift (KN)0 0

1.182 23.042.364 91.884.728 368.78

5.91 576.227.092 829.298.274 1120.139.456 1473.26

10.638 1826.211.82 2304.9

84

CL CmCg (-) CmCg (-) CmCg (-)0 0.03 0.035 0.04

0.35 0.699 0.64125 0.5360.7 1.391 0.687 1.115

1.05 2.082 0.896 1.691.4 2.774 0.729 2.26

1.75 3.468 0.76 2.852.1 4.155 0.706 3.724

α CmCg (-)2 0.2873 0.43094 0.57455 0.7186 0.86187 1.005

85

86

87

88

89

90

91

Chapter 7

Cabin design

7.1. Description:

For an aircraft of 60 + capacity, conventional seating(mixed class ) would be

five abreast for passenger long range transport it should provide higher comfort

level typically maximum first class seat is wide providing generous aisle would

make the fuselage diameter to adding 0.2 m for the pressure cabin structure makes.

Fuselage cross-section must be also consider in relation to the cargo pallet sizes to be accommodated

below cabin floor

Cass Seat abreast Seat width

Executive 4 0.7m

Tourist 5 .56m

charter 6 0.47m

The length of the cabin is determined by the seat pitch this various as the class

Executive = 1 to 1.1 m

Tourist = 0.8 to 0.9

Charter =0.7 to 0.8

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The longest charter pitch with six abreast seating requires cabin length of 16m.

It is desirable to split the cabin in to at least two separate sectors this makes the in-

flight servicing easier and allow more options for the airline to segregate different

classes for the charter layout this division, will allow a quieter environment with

cabin.

7.2. Cabin layout:

A service module is positional at this location external service doors and hatches

are positional here and these contact as emergency exists.

This service module will account for some 2.5 meters.

93

Rear cabin Centre cabin Front cabin Total seat

charter 9 42 9 60

94

7.3. Calculation:

We have seat pitch for economy class 0.6 to 0.7 m

Let us take pitch = 0.65 m

Total cabin length = 16.5

Service module accouter = 3.5 m

Available space to arrange seats =13m

The rear cabin with = 1.95m

Centre cabin width = 9.1 m

Rear cabin width =1.95m

95

7.4. Seat dimensions:

Volume =1 =0.33m3

7.5.FARs Related to seating:

Maximum number of seats abreast.

On airplanes having only one passenger aisle, no more than three seats abreast may

be placed on each side of the aisle in any one row.

Doors.

(a) Each cabin must have at least one easily accessible external door.

(b) There must be a means to lock and safeguard each external door against

opening in flight (either inadvertently by persons or as a result of mechanical

96

failure or failure of a single structural element either during or after closure). Each

external door must be open able from both the inside and the outside, even

though persons may be crowded against the door on the inside of the airplane.

Inward opening doors may be used if there are means to prevent occupants from

crowding against the door to an extent that would interfere with the opening of the

door. The means of opening must be simple and obvious and must be arranged and

marked so that it can be readily located and operated, even in darkness. Auxiliary

locking devices may be used.

(c) Each external door must be reasonably free from jamming as a result of

fuselage deformation in a minor crash.

(d) Each external door must be located where persons using them will not be

endangered by the propellers when appropriate operating procedures are used.

(e) There must be a provision for direct visual inspection of the locking mechanism

to determine if external doors, for which the initial opening movement is not

inward (including passenger, crew, service, and cargo doors), are fully closed and

locked. The provision must be discernible under operational lighting conditions by

appropriate crewmembers using a flashlight or equivalent lighting source. In

addition, there must be a visual warning means to signal the appropriate flight

crewmembers if any external door is not fully closed and locked. The means must

be designed such that any failure or combination of failures that would result in an

erroneous closed and locked indication is improbable for doors for which the initial

opening movement is not inward.

(f) External doors must have provisions to prevent the initiation of pressurization

of the airplane to an unsafe level if the door is not fully closed and locked. In

addition, it must be shown by safety analysis that inadvertent opening is extremely

improbable.

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(g) Cargo and service doors not suitable for use as emergency exits need only meet

paragraphs (e) and (f) of this section and be safeguarded against opening in flight

as a result of mechanical failure or failure of a single structural element.

(h) Each passenger entry door in the side of the fuselage must qualify as a Type A,

Type I, or Type II passenger emergency exit and must meet the requirements of

that apply to that type of passenger emergency exit.

(i) If an integral stair is installed in a passenger entry door that is qualified as a

passenger emergency exit, the stair must be designed so that under the following

conditions the effectiveness of passenger emergency egress will not be impaired:

(1) The door, integral stair, and operating mechanism have been subjected to the

inertia forces specified in acting separately relative to the surrounding structure.

(2) The airplane is in the normal ground attitude and in each of the attitudes

corresponding to collapse of one or more legs of the landing gear.

(j) All lavatory doors must be designed to preclude anyone from becoming trapped

inside the lavatory, and if a locking mechanism is installed, it be capable of being

unlocked from the outside without the aid of special tools.

Seats, berths, safety belts, and harnesses.

(a) A seat (or berth for a nonambulant person) must be provided for each occupant

who has reached his or her second birthday.

(b) Each seat, berth, safety belt, harness, and adjacent part of the airplane at each

station designated as occupiable during takeoff and landing must be designed so

that a person making proper use of these facilities will not suffer serious injury in

an emergency landing as a result of the inertia forces specified in (c) Each seat or

berth must be approved.

(d) Each occupant of a seat that makes more than an 18-degree angle with the

vertical plane containing the airplane centerline must be protected from head injury

98

by a safety belt and an energy absorbing rest that will support the arms, shoulders,

head, and spine, or by a safety belt and shoulder harness that will prevent the head

from contacting any injurious object. Each occupant of any other seat must be

protected from head injury by a safety belt and, as appropriate to the type, location,

and angle of facing of each seat, by one or more of the following:

(1) A shoulder harness that will prevent the head from contacting any injurious

object.

(2) The elimination of any injurious object within striking radius of the head.

(3) An energy absorbing rest that will support the arms, shoulders, head, and spine.

(e) Each berth must be designed so that the forward part has a padded end board,

canvas diaphragm, or equivalent means, that can withstand the static load reaction

of the occupant when subjected to the forward inertia force specified in Berths

must be free from corners and protuberances likely to cause injury to a person

occupying the berth during emergency conditions.

(f) Each seat or berth, and its supporting structure, and each safety belt or harness

and its anchorage must be designed for an occupant weight of 170 pounds,

considering the maximum load factors, inertia forces, and reactions among the

occupant, seat, safety belt, and harness for each relevant flight and ground load

condition (including the emergency landing conditions prescribed in (1) The

structural analysis and testing of the seats, berths, and their supporting structures

may be determined by assuming that the critical load in the forward, sideward,

downward, upward, and rearward

directions (as determined from the prescribed flight, ground, and emergency

landing conditions) acts separately or using selected combinations of loads if the

required strength in each specified direction is substantiated. The forward load

factor need not be applied to safety belts for berths.

99

(2) Each pilot seat must be designed for the reactions resulting from the application

of the pilot forces prescribed in

(3) The inertia forces specified in must be multiplied by a factor of 1.33 in

determining the strength of the attachment of each seat to the structure and each

belt or harness to the seat or structure.

(g) Each seat at a flight deck station must have a restraint system consisting of a

combined safety belt and shoulder harness with a single-point release that permits

the flight deck occupant, when seated with the restraint system fastened, to

perform all of the occupant's necessary flight deck functions. There must be a

means to secure each combined restraint system when not in use to prevent

interference with the operation of the airplane and with rapid egress in an

emergency.

(h) Each seat located in the passenger compartment and designated for use during

takeoff and landing by a flight attendant required by the operating rules of this

chapter must be:

(1) Near a required floor level emergency exit, except that another location is

acceptable if the emergency egress of passengers would be enhanced with that

location. A flight attendant seat must be located adjacent to each Type A

emergency exit. Other flight attendant seats must be evenly distributed among the

required floor level emergency exits to the extent feasible.

(2) To the extent possible, without compromising proximity to a required floor

level emergency exit, located to provide a direct view of the cabin area for which

the flight attendant is responsible.

(3) Positioned so that the seat will not interfere with the use of a passageway or

exit when the seat is not in use.

100

(4) Located to minimize the probability that occupants would suffer injury by

being struck by items dislodged from service areas, stowage compartments, or

service equipment.

(5) Either forward or rearward facing with an energy absorbing rest that is

designed to support the arms, shoulders, head, and spine.

(6) Equipped with a restraint system consisting of a combined safety belt and

shoulder harness unit with a single point release. There must be means to secure

each restraint system when not in use to prevent interference with rapid egress in

an emergency.

(i) Each safety belt must be equipped with a metal to metal latching device.

(j) If the seat backs do not provide a firm handhold, there must be a handgrip or

rail along each aisle to enable persons to steady themselves while using the aisles

in moderately rough air.

(k) Each projecting object that would injure persons seated or moving about the

airplane in normal flight must be padded.

(l) Each forward observer's seat required by the operating rules must be shown to

be suitable for use in conducting the necessary enroute inspection.

101

Chapter 8

Three views of an aircraft

8.1. Side view:

102

8.2. Front view:

103

8.3. Top view:

104

CONCLUSION

Sixty seater passenger aircraft has been designed necessary comfort to the

passenger. Design, Analysis of Various Components and Determination of

Airplane Operational Characteristics. Using various methods and calculations

every step has been designed with optimum performance and aerodynamic

characteristics. Thus each trail aims at a closer approach to the final goal and is

based on a more profound study of various problem involved. Structural designs,

center of gravity, loading performance, maneuvering performance are done

successfully.

105