1  

 

ACKNOWLEDGEMENT

Of the many people who have been enormously helpful in the preparation of this

project, we are especially thankful to, Mr. Omar Chafic for his help and support in

guiding us to through to its successful completion.

We would also like to extend our since gratitude to Emirates Aviation College for the

use of their resources, such as online databases and library, without which the

completion of this project would have been extremely difficult.

A very special recognition needs to be given to Ms. Kavita, our librarian, for her

extensive help and support during research and in dealing with online resources.

In addition to this, a special thanks to be given to our friends Cibin, Omar and Yogesh

for their help, consideration and guidance.

Last but not least, we would like to say a special thank you to our parents and family

members for their moral and financial support this semester.

 2  

 

INDEX

Content Page no.

Introduction 3

Parametric Design 6

Mission 7

Gantt Chart 8

Cost Analysis 9

Man Power 10

Materials and tools 11

Electrical Parts and Servos

16

Air Radio 21

Airfoil Selection 22

3D Design(Autocad) 25

Assembly(Construction) 34

Calculations of Area 49

Graphs 58

Calculations 62

Centre of Gravity 74

Formulae 75

Troubleshooting 77

Safety and risk assessment

81

References Conclusion

83 84

 3  

 

Introduction1

What are aerobatics?

Aerobatics, stunt flying or aeros is the flying of maneuvers that are not used in ‘normal’

flight involving unusual attitudes. Usually an aerobatic sequence is flown comprising of

several figures (maneuvers).

History of aerobatics

Essential to aerobatic technique is the ability to fly an aircraft inverted (upside down),

which was first demonstrated on September 1, 1913, by the Frenchman Adolphe

Pégoud, test pilot for aviator Louis Blériot. Pégoud also flew other advanced maneuvers

as part of a research program. Other aerobatic innovators include the Russian military

pilot Petr Nesterov, who was the first pilot to “loop the loop,” on September 9,1913.

At the outbreak of World War I, military pilots were used mainly for reconnaissance work

and were not expected to possess any knowledge of aerobatics. It was not until the

development of successful fighter aircraft in 1915 that pilots began to engage in serious

aerial combat, discovering in the process that aerobatic skills could give them a

                                                                                                                         1  http://www.bruceair.com/aerobatics/aerobatics.htm  

Fig.1  

 4  

 

significant advantage in a dogfight. With this realization and with the aid of aircraft

manufactured with enhanced aerobatic capabilities, pilots began to develop a growing

range of aerobatic maneuvers, principally for evading enemy airplanes. Such skills were

entirely self-taught or acquired from comrades in arms, and only late in 1916 were the

first tentative steps taken toward the systematic teaching of aerobatic techniques, which

had hitherto been discouraged (or even prohibited) in military flight training.

After World War I, former combat pilots continued to refine their skills. The United

States saw the evolution of the barnstormers—pilots who toured rural areas performing

stunt-flying exhibitions—while in Europe the most proficient war pilots were employed

by aircraft manufacturers, displaying their skills and the manufacturers’ products at

public air shows. Competitions between pilots ensued, and these led to the

development of rules, notations, and judging criteria. The first and only World Cup of

aerobatics was held in Paris, In June 1934, with nine entries from six countries (all

European). Aerobatic events were also held in conjunction with the 1936 Olympic

Games in Berlin.

Aerobatics Today

Aerobatics has evolved a lot since its beginning. People still fly aerobatics simply for

enjoyment while others compete and display. The FAI, the Federation Aeronautique

Internationale is the world governing body for all air sports and CIVA, Commission

Internationale de Votige Aerienne is responsible for the administration of erobatic

competitions worldwide under auspices of the FAI. In Britain, all aerobatic competition

are run by the BAA, British Aerobatic Association.

Abstract

In this project, we are going to select an aerobatic aircraft as our model. We are mainly

looking to select a fighter aircraft for our model and after doing our research, we will find

the right design that will meet all our requirements. We will construct the aircraft

carefully and make it light so that it can perform the various maneuvers, but also strong

 5  

 

enough to support the load. We will test flight the aircraft so see that it meets our

expectations and that it will be able to carry out the various maneuvers.

In the research part, all the maneuvers that the aircraft is supposed to do will be studied

and verified. We will carefully study the dimensions of the aircraft and use it to perform

various calculations that are needed. We will also carefully research the various

materials needed for the aircraft so the plane can fly efficiently. We will do the test flight

and troubleshooting, where all the problems faced will be verified and explained.

 6  

 

PARAMETRIC DESIGN

NAMES

F-35 JOINT STRIKE FIGHTER

F-16 FIGHTING FALCON

F-22 RAPTOR

MiG-29 FALCRUM

Wing Area(sq m) 0.18 0.27 0.36 0.36

Wing span(m) 0.7 0.77 0.79 1.13

Weight(kg) 1.1 1.49 1.9 1.99

Length (m) 1.06 1.21 1.09 1.49

Wing Loading(g sq m)

0.7 5.52 1.08 5.53

Servos 9g light weight servos

9g high speed micro servos

8g servos 9g servos

Ducted Fan Wemotec Mini Fan 480

70mm ducted fan

64MM Electric Ducted Fans

70mm*2 electric ducted

fan Battery 3 cell 1300mAh

Lipo balance tabs

14.8V 2200mAh Li-polymer

3S 3000MAH 15C Lithium

Polymer

3 cell 2000MAH 15C Lithium

Polymer Motor Hecte edf 3w

or 2w-20 3000KV

outrunner brushless motor

Outrunner B2040 KV4300

In runner-type brushless

ESC ESC RBC 60 amp

45A Brushless speed controller

25A Brushless speed controller

2*50A ESC

Radio Controller 3 Channel Radio with delta

mixer

4 CH Radio Transmitter and

6 CH Micro Receiver

4 ch receiver & 6 mini ch

transmitter

Transmitter and Receiver 9CH

2.4G RC

 7  

 

MISSION

SPECIFICATIONS … Wing … Wing span (A) 0.7m

Root cord (m) 33.8m

Tip cord (k) 8.6m

… Horizontal stabilizer…

Root cord(r) o.167m

Tip cord (q) 0.0029m

…vertical stabilizer…

Height(f) 0.157m

Root cord (c) 0.145m

Tip cord (e) 0.0072m

….Fuselage ….

Nose to wing tip 0.45m

Length(a) 0.95m

Width (s) 0.2m

 8  

 

TARGET GANTT CHART:

RESULTANT GANTT CHART

 9  

 

COST ANALYSIS  

Items Quantity Cost per piece(aed)

Total Amount (aed)

Balsa wood -­‐ 1/16" x 3" x 36" Balsa Sheet -­‐ 1/8" x 3/8" x 36" Balsa Stick -­‐ 3/8" x 3/8" x 36" Balsa Stick -­‐ 1/2" x 1/2" x 36" Balsa Stick

10

1 2 1

10 15 15 15

 

100 15 30 15

Monokote cover 1 60 60

Super Glue 2 20 40

Sand Paper 4 5 20

Ducted Fan 1 255 255

Electric Speed Control 1 450 450

Cutter 1 15 15

Radio unit 1 1000 1000

Landing Gear unit 1 250 250

Servo pack 5 65 325

Electric Motor 1 345 345

Hinges pack 1 20 20

Transportation --- 400 400

Total 33 2940 3340

 10  

 

MAN POWER

Days for the Project 80 days

Days devoted to the project

45 days

Average hours worked per day

4hours/day

Total hours for the days worked

45 x 4 = 180 hours

Average Man power = no. of persons/ hours

4/180

Average hour per person

180/4 = 45

So each person has worked for 45 hours for this project.

 11  

 

Materials2

Balsa wood

Balsa wood is the main material that we have used to construct the aircraft. Balsa wood is

lightweight, inexpensive and relatively strong. We have used it to construct the fuselage, wing

and tailplane as well as in the sheeting of the plane.

Ply wood

We used ply wood on our model on the places where we need more strength like the root rips of

the wing, the front side cover of the fuselage, servo plates etc.

                                                                                                                         2  http://www.moneysmith.net/Soaring/soaring4.html  

Fig.2  

Fig.3  

 12  

 

Card board

We used cardboard for the intake and the outtake of the aircraft.

E-poxy Glue

Epoxy is a strong, important modeling glue but one which must be used sparingly because of its

heavy weight.

Epoxy is classified by its strength and working time. Quick cure, or five minute epoxy, is strong

enough for most modeling applications, and is very handy for quick repairs. Slow cure (30

minute or more) epoxy is used when extra strength is required.

We have used epoxy to join the major parts of the airplane. This includes joining the wing

mounts to the fuselage, and attaching the tail to the fuselage. We have also used slow cure

epoxy for bonding the wood skins to the foam wing and stabilizer core.

Fig.4  

Fig.5  

 13  

 

Masking Tape

We used masking tape for minor repairs in the airplane. Masking tape was chosen due

to its convenient size, shape and ease of removal. It was mainly used for fixing small

cracks in the balsa wood.

Tools

Drill tools

We used a small hand drill to drill holes in the balsa wood. A drill press was also used to make

sure that the holes were straight. Our hand drill was able to make holes of 2mm thickness.

Protractor

Fig.6  

Fig.7  

 14  

 

We used a protractor to measure various angles in the model aircraft, which were needed in the

calculations. For example, we used it to measure the sweptback angle and the angle of the tail

planes.

Cutter

We used a normal cutter as it was very useful to cut the balsa wood, it easily cut through the

wood and was simple to handle. We sometimes used it to file the surface of the wood to make it

smooth and even.

Rulers

We used rulers for measuring the dimensions of the aircraft like wingspan, length of the fuselage etc.

Fig.8  

Fig.9  

Fig.10  

 15  

 

Sand paper

Sandpaper is used to remove small quantities of material at a time from the surface of an object.

Sandpaper can be used to remove a specific material from an object (such as a layer of paint)

or to level and/or smooth the surface of the object. Sandpaper comes in many numbered

"grades," with smaller numbers being coarser and removing more surface material with each

pass. Higher numbers are finer and remove less material.

We have mostly used ‘low grade’ sandpaper for polishing and smoothing the aircraft. We have

also used it to shape the ribs and spars of the model aircraft.

Fig.11  

 16  

 

ELECTRICAL PARTS  

The electrical components used were recommended by the manufacturer to suit the required and desired output, and they were connected in accordance with the instruction manual.

BL15 Ducted Fan Motor, 3600Kv

Specifications

Recommended Ducted Fan Unit: Delta-V 15 69mm EDF (EFLDF15) Static Thrust: 1.7 lb on 3S (11.1V)—using recommended Delta-V 15 2.8 lb on 4S (14.8V)—using recommended Delta-V 15 RPM: 31,000 on 3S (11.1V)—using recommended Delta-V 15 40,000 on 4S (14.8V)—using recommended Delta-V 15 Brushless ESC: 50A—60A

Fig.12  

 17  

 

Product Specifications

Type: 6-pole Inrunner Brushless Size: 15-size for Ducted Fans Bearings or Bushings: Two 4 x 10 x 4mm Bearings Voltage: 11.1–16.8V RPM/Volt (Kv): 3600 Resistance (Ri): .02 ohms Idle Current (Io): 2.80A @ 10V Continuous Current: 46A Maximum Burst Current: 55A (15 sec) Cells: 3S–4S LiPo power 10–14 Ni-MH/Ni-Cd battery Speed Control: 60A brushless Weight: 106 g (3.7 oz) Overall Diameter: 28mm (1.10 in) Shaft Diameter: 4mm (0.16 in) Overall Length: 40mm (1.56 in)

Delta-V 15 69mm EDF Unit

Specifications: Rotor Diameter: 69mm (2.7 in) Shroud Outer Diameter: 73.5mm (2.9 in) Shroud Length: 58.3mm (2.3 in) Shroud Length (Including Intake Ring): 72mm (2.8 in) Center Body Inside Diameter: 28.3mm (1.1 in) – designed for 28mm motor Overall Weight: 88g (3.1 oz)

Fig.13  

 18  

 

60-Amp Pro Switch-Mode BEC Brushless ESC

Product Specifications

Brake: Yes - Programmable Continuous Maximum Current: 60A with reasonable cooling Input Voltage: 10.8V - 22.2V Input Connector Types: 13AWG with E-flite EC3 connector Output Connector Types: 13AWG with 3.5mm Female Gold Bullet Connectors Momentary Peak Current: 75A (15 sec) Length: 3.00 in (76mm) Width: 1.30 in (33mm) Height: 0.50 in (13mm) Weight: 2.3 oz (66g) Wire Gauge: 13AWG Cells w/BEC: 3-6S Li-Po or 9-18 Ni-MH/Ni-Cd

Fig.14  

 19  

 

BATTERY

2800mAh 4S 14.8V 30C LiPo, 12 AWG EC3

Product Specifications Type: LiPo

Capacity: 2800mAh

Voltage: 14.8V

Connector Type: EC3

Wire Gauge: 12 AWG

Weight: 10.9 oz (309g)

Configuration: 4S

Length: 5.25 in (133mm)

Width: 1.70 in (43mm)

Height: 0.96 in (25mm)

Maximum Continuous Discharge : 30C

Maximum Continuous Current : 84A

Fig.15  

 20  

 

Servos:

Product Specifications

Size Category: Minis and Micros

Type: Digital

Torque: 19.0 oz/in @ 4.8v

Speed: .11 sec/60° @ 4.8v

Length:0.90 in (23mm)

Width: 0.45 in (12mm)

Height: 0.94 in (24mm)

Weight: .26 oz (7.5 g)

Bushing or Bearing: Bushing

Motor Type: Coreless

Connector Type: Universal

Fig.16  

 21  

 

Gear Type: Nylon

Air Radio:

Product Specifications

No. of Channels = 9

Modulation = DSM2

Band = 2.4GHz

Receiver: = AR6210

Features = Airplane and Heli

Model Memory = 10

Mode = Mode 2

Fig.17  

 22  

 

AIRFOIL SELECTION

S8035 was selected for the airfoil for RC F-35 Joint Strike Fighter as it was more

suitable than other ones.

So the airfoil was plotted using the software “ Profili “ and hence we got all the

specifications and graphs.

The plotting of the airfoil with its specifications

The main specifications of the airfoil are:

o Max thinkness 14% at 29% of the chord

o Leading edge radius 1.4%

Fig.18  

 23  

 

This graph is the cl vs cd

These two graphs are the cl vs. alpha and cd vs. alpha

Fig.19  

Fig.20  

 24  

 

These two graphs one is the cl/cd vs. alpha and from it we can get the cl/cd for the

wing is at maximum when alpha is 7.5 degrees.

Fig.21  

 25  

 

3D DESIGN(AUTOCAD)

After the 2D design is decided , the 3D design was supposed to be made taking the dimensions and the idea 2D design. So the 3D design of the whole aircraft was made part by part. The parts made separately and then assembled together to make 1 whole aircraft.

These parts shown below:

WINGS The wings were made first being the easiest of them all.

VERTICAL STABILIZER Being similar to the wings-shape. The 2 horizontal stabilizers were designed then.

Fig.22  

Fig.23  

 26  

 

Horizontal stabilizers

The vertically placed shapes were also almost similar to the wing-shape, so these were designed then.

Fuselage

The hard part was to be designed , that is the fuselage with all the complicated shapes and dimension within it. So each dimensions and angles were taken care of and designed at the best that it could be made.

Ducted fan region

The ducted fan was a cylindrical type of shape so the diameter and length was measured and fixed along the fuselage.

Fig.24  

Fig.25  

 27  

 

Nose region

The nose region had to be a pointed cone-like structure that extends from the front of the fuselage. So the base along the fuselage and the length of the nose was taken and designed in 3D.

Cockpit shield

This shape would an irregular shape so not much detail was given for this part of the aircraft. It was designed shaping it along the fuselage and the nose.

Finally all the parts were brought together to make a fully single aircraft design.

Fig.26  

Fig.27  

Fig.28  

 28  

 

The design of the whole aircraft was done. And since the 3D view of the aircraft in a continuous orbit cannot be shown in the report, all the possible views of the 2D and 3D are shown.

2D views

Front view:

Fig.29  

Fig.30  

 29  

 

Rear view:

Side view:

Top view:

Fig.31  

Fig.32  

 30  

 

Bottom view:

Fig.33  

Fig.34  

 31  

 

3D views

Bottom side views:

Bottom rear view:

Fig.35  

Fig.36  

 32  

 

Top rear view:

Top side view:

Fig.37  

Fig.38  

 33  

 

Bottom front view:

This way the 3D design of the F35 aircraft was made giving us the picture of the aircraft that was about to be constructed mentioned in the next section.

Fig.39  

 34  

 

Assembly(Construction)3

The Design(plan) gave us a green signal to finally start with the construction of the aircraft. The component parts that were needed to form an assembled aircraft were each traced and draw on the balsa wood with the respective dimensions using the carbon paper. These designs of the parts were traced with the help of a transparent paper. And then all the shapes were cut with the help of a normal metal cutter, and then placed separately.

                                                                                                                         3  http://www.oakdaleaircraft.com/f35_manual/f35_edf.pdf  

Fig.40  

 35  

 

So we decided to begin with the wing, which had the following units:

• 8 airfoil shaped ribs for both the sides(Each with decreasing size according to the chord distance while going from root to tip chord) . 4 for each side.

• 4 joining pieces that would help in supporting the airfoil cross-sections ribs. • Small size slabs that would keep the joining pieces fixed to the root cross-

sectional airfoil. • 4 Balsa sheets that are cut into the shape of the covering of the wings.(2 for each

side) So we first start fixing 2 of the joining pieces to the biggest airfoil rib with the help of a superglue.

-­‐ Leaving holes in the cross-section and later fixing the joining pieces with the help of the small slabs in such a way that we have a cylindrical space for the wing –fuselage attachment.

-­‐ After having the root airfoil part fixed with the joining pieces we do the same for the second and the third joining piece.

-­‐ Then the second(smaller), third and fourth(smallest) airfoil rib are placed each on the joining pieces perpendicularly in certain distances till the tip of the joining pieces. The ribs section of the aircraft is done. It was made sure that the wing had a strong and rigid support from all sides. So extra balsa pieces were stuck to the ends.

Fig.41  

 36  

 

-­‐ The balsa sheets are then cut into perfect size of the wing and placed it to shape the whole part covering all the ribs and the joining pieces inside.

-­‐ The ribs and joining pieces were stuck to the balsa sheets with a superglue. No air was to be left in between the sheet and the ribs so the balsa sheet was pressed and stuck to the ribs along its shape. These ribs would give support and a perfect airfoil shape to the entire wing.

Fig.42  

Fig.43  

Fig.44  

 37  

 

-­‐ After the covering and shaping of the wing in a perfect airfoil shape and when the

construction of the whole wing is made the aileron section is cut at a particular distance from the trailing edge.

-­‐ This cut part of the wing is fixed to the main wing with the help of paper hinges making it easier for it to move at an angle(later controlled by the servos).

-­‐ Now that the construction of the whole wing is done, the servos had to be fitted. The servo plates are made out of plywood as it can take the heavy loads and keep the servo rigid on its place. So the servo is fitted at the bottom centre of both the wings.

Fig.45  

 38  

 

FUSELAGE

The construction of the fuselage was the most complicated task for our team. All the components that were traced on the balsa wood after insuring they were in correct scale, were cut and brought together. Fuselage consisted the following units:

• Battery holder • Nose section • Cockpit shield section • Intake duct canopy • Support section for the wing-fuselage attachment. • Ducted fan holder • Vertical stabilizer holder • Horizontal stabilizer holder

The fuselage construction began

-­‐ At first, the battery holder is made, making it easier for reference in making any further parts. Four long pieces of balsa wood with large holes in it(for further connections through them) are stuck together to make a cuboid-like structure.

-­‐ The cockpit shield region is made attached to the top part of battery holder. The

base of the cockpit region resting on top of the battery holder and a certain height of 3 pieces of semi-circled balsa wood are fixed to each other with superglue.

Fig.46  

 39  

 

-­‐ The nose section is made as an extension to the battery holder, starting from under the cockpit shield area. The triangular shaped balsa pieces are placed together making a cone-like shape ending at a point at the front the nose.

The front part of the fuselage is done. Which leaves us with the rear part that consists of the intake duct path, Ducted fan holder , vertical stabilizer holder and the Horizontal stabilizer holder. So the side part of the fuselage,

-­‐ Has the wing-fuselage attachment which is supported by the airfoil-like shaped balsa piece that’s stuck for the purpose of holding the wing and the fuselage together. These pieces even held the parts that are mentioned in the next point of this construction.

The rear part of the fuselage,

-­‐ The shapes that have multiple purpose(as shown in the figure below); vertical stabilizer holder and the path that takes in the intake duct chart is cut from the traced balsa wood. These parts are placed one after the another at a certain distance and held together by long balsa pieces. These pieces are basically the ribs of the fuselage.

Fig.47  

 40  

 

-­‐ The making of intact duct canopy is started by covering the inside part of

the path so that it is placed against it and acts as a base for the canopy. 2 pieces of cardboard chart were cut into rectangular shapes and folded into the shape of the canopy and pushed inside the path so that the chart takes the shape of the perfect intake duct . From the start of the fuselage the two charts begin and they end together in a single circle at the rear-end area.

-­‐ (The path of the canopy is created by the balsa pieces accordingly)

Fig.48  

Fig.49  

 41  

 

(The folded chart fit along the path lead by the ribs)

-­‐ The ribs are attached with small sections of closed pieces just like the figure, to support the wing-fuselage attachment rigidly making sure it is tight enough to hold the fuselage

-­‐ .

-­‐ The Ducted fan holder is then made with a base that can make the ducted fan seated at a fixed position. The ducted fan is held by its sides by screwing the holder to plywood.

Fig.50  

Fig.52  

Fig.51  

 42  

 

-­‐ The ribs that are at the end have a space that provides a holder to the horizontal

stabilizer. The horizontal stabilizer is cut exactly according to the design with the appropriate dimensions. And both the horizontal stabilizers are placed on provided spaces on the ribs, but they are a bit angled away.

-­‐ The vertical stabilizer is also cut according to the design with the help of the

transparent paper and carbon paper. This part is attached differently, A wooden rod is used to attach the vertical stabilizer to the two extended fuselage parts that protrude from the Ducted fan area.

Fig.53  

 43  

 

-­‐ The vertical stabilizers are cut at a distance to make it a movable elevator by attaching it to the main vertical stabilizer with the help of paper hinges, giving it a function of moving vertically.

-­‐ Servos for the vertical stabilizers are fitted at the bottom of the part ,made out of plywood, but as light as possible as the load would affect the part as the vertical stabilizer is a sensitive and small part.

The construction has reached the sheeting part.

-­‐ Sheeting is started from the bottom part of the fuselage, 4 thin and long strips of balsa are placed next to each other that goes along the shape of the bottom, starts from the cockpit shield section and ends at the Air Duct at the rear end.

Fig.54  

Fig.55  

 44  

 

-­‐ -­‐ Now the nose part is sheeted covering up the top sides of the structure, filing the

balsa wood along the nose resulting in a good aerodynamic shape. The bottom section of the Nose is covered by flat balsa sheet taking the shape of the outline.

-­‐ Lengthy sheets of balsa wood are placed at the bottom sides starting from the opening of the canopy to the rear tip of the fuselage. Two slabs in the 2 sides at the bottom.

Fig.56  

Fig.57  

 45  

 

-­‐ At the top part of the fuselage, 2 lengthy sheets of balsa wood(just like the bottom covering) are placed on the either sides of the Ducted Fan leaving us with only the middle part of the top of the fuselage to be covered. This starts from the start of the middle of the cockpit shield section till the opening of the air duct.

-­‐

-­‐ The distance of the area that consists of the Ducted fan is covered by small strips placed next to each other at a flat level along the circular shape. This is the top part of the fuselage.

Fig.58  

Fig.59  

 46  

 

-­‐ The rest of the bottom of the fuselage is covered with balsa wood that is cut according to the space left uncovered and is fit exactly covering up all the area of the bottom of the fuselage.

-­‐ Now it’s the sides of the fuselage that have to be covered, so the balsa wood is cut in a shape that fits exactly along the sides of the fuselage as it is the shape is irregular. So the sides would be covered this way starting from the opening of the intake duct at the front of the fuselage till the tip of the rear end. (After covering the whole aircraft and filing them to perfect aerodynamic shape.

We started with the covering the aircraft with monokote)

Fig.60  

Fig.61  

 47  

 

Fixing of landing gears -­‐ After the sheeting of the whole bottom part of the fuselage the area for 3

landing gear wheels and its servos was used. The single front landing gear was placed at right before the nose section.

-­‐ The other 2 landing gears were placed in the fuselage itself on the either

sides rather than on the wing.

Fig.62  

Fig.63  

 48  

 

-­‐ And the servos are made of thick plywood with extra pieces fixed so that it does not leave the support of the landing gear weak making it vulnerable to damage during landing or while experiencing any other high force.

The main components such as speed control, the battery were wired and placed at their respective locations.

Fig.64  

 49  

 

CALCULATIONS:

Wing

Area of A = (18.39 * 25.2)/2 = 231.7 cm2

Area of B = 25.2 * 8.39 = 211.43 cm2

Area of C = 89.46 cm2

Total area = Area of A + Area of B + Area of C

= 231.7 + 211.43 +89.46

= 532.59 cm2 = 0.05326 m2

For both wings = 0.05326 * 2

SREF = 0.1065 m2

Wetted area = 0.21726m2

Fig.65  

 50  

 

Horizontal tail

Area of A = 9.6 * 15/2 = 72 cm2

Area of B = 2.9*15 = 43.2 cm2

Area of C = (3.9 * 15)/2 = 29.25 cm2

Total Area = Area of A + Area of B + Area of C =

= 72 + 43.2 + 29.25 = 144.45 cm2

= 0.01445 m2 * 2 = 0.0289m2

Wetted Area = 0.0289 * 2.04 = 0.0589m2

Vertical Tail

Area of a Trapezium = [(a +b)/2) * h

= (7.2 + 14.5)/2 *15.7

Fig.66  

Fig.67  

 51  

 

= 166.42 cm2 = 0.01664 m2

= 0.01664 * 2 = 0.03328 m2

Wetted Area = 0.03328 * 2.04 =0.06789 m2

Area of Fuselage Cylindrical Part

Surface Area = 2πr2 + 2πrh

= 2*π*(4.9)2 + 2*π*(4.9)*37

= 150.8 + 1139.1

= 1289.9 cm2 = 0.1289 m2

Trapezium Part

Area = (a + b)/2 * h

= (19 +25)/2 * 24

= 528 cm2 = 0.0528 m2

Fig.68  

Fig.69  

 52  

 

Bottom Part

Area = (a + b)/2 * h

= (12.5 +14.5)/2 * 24

= 324 cm2 = 0.0324 m2

Sides

Area = (a +b)/2 * h

= (4.8 + 6.6)/2 * 24

= 136.8 cm2 =0.01368 m2

Area = 0.1368 * 2 = 0.02736 m2

Fig.70  

Fig.71  

 53  

 

Nose

Bottom Triangle

Area = ½ * b * h

= (4.8/2) * 24.8

= 59.52 cm2 = 0.00595 m2

Sides

Area = ½ * b * h

= (6/2) * 25

= 3 * 25

= 75 cm2 = 0.0075 m2

Area = 0.0075 * 2

= 0.015 m2

Fig.72  

Fig.73  

 54  

 

Top

Area = ½ * b * h

= (6.8/2) * 31

= 105.4 cm2

= 0.01054 m2

Cockpit shield

Half Elliptical Cylinder Part

Area = 2πL √(a2 + b2)/2 + 2πab

= 2π*11√[(3.4)2 + (6.8)2]/2] + 2π*(3.4)*(6.8) = 371.55 + 145.26

= 516.81 cm2 = 0.05168 m2

Since it is half

Therefore, 0.05168/2 = 0.02584 m2

Fig.74  

Fig.75  

 55  

 

Half Conical Part

Area = πrs + πr2

=π*6.8*8.3 + π* 6.82

= 177.31 + 145.27

= 322.58 cm2 = 0.03225 m2

Since it is half,

= 0.03225/2

= 0.01612 m2

Top Side Rectangles

Area = a * b

= 35 * 6

= 210 cm2 = 0.021 m2

Fig.76  

Fig.77  

 56  

 

Multiplying by 2,

Therefore, 0.021 * 2 = 0.042 m2

Top tail trapezoidal parts

Area = (a+b)/2 * h

= (3.2 + 4.8)/2 * 14.2

= 56.8 cm2 = 0.00568 m2

Since it is two,

0.00568 * 2 = 0.01136 m2

Bottom Rectangular Parts

Area = a * b

= 3.8 * 49

= 186.2 cm2 = 0.01862 m2

Fig.78  

Fig.79  

 57  

 

Since it is two,

0.01862 * 2 = 0.03724 m2

Bottom Trapezoidal Parts

Area = (a * b)/ 2 * h

= (1 + 5.6)/2 * 51.2

= 168.96 cm2 = 0.01689 m2

Since it is two,

0.01689 * 2 = 0.03379 m2

Total Area of Fuselage = 0.1289 + 0.0528 + 0.0324 + 0.02736 + 0.00595 + 0.015

+ 0.01054 + 0.02584 + 0.01612 +0.042 + 0.01136 +0.03724

+ 0.03379 = 0.439 m2

Wetted area = 0.439 * 2.04 = 0.8955 m2

Fig.80  

 58  

 

Airplane components

GRAPHS4

The graphs that we are going to use are the following

The aerodynamic form factor graph

                                                                                                                         4  Fundamentals  of  Flight  by  Richard  S  Shevell  

Fig.81  

 59  

 

 

 

 

5

                                                                                                                             

Fig.82  

Fig.83  

 60  

 

 

Fig.84  

Fig.85  

 61  

 

6

                                                                                                                         6  Fundamentals  of  Flight  by  Richard  S  Shevell  

Fig.86  

 62  

 

Wing

Wetted area = 0.21726/ Platform area or SREF = 0.1065 m2

Root Chord: 0.338

Taper ratio = CT/CR = 0.086/0.338 = 0.25

Tip Chord : 0.086m

MAC = 2/3 * CR(1 + σ - σ/1+σ) = 2/3 * 0.338(1 + 0.25 - 0.25/1+0.25)

= 0.225m

Weight = 1.21kg = 1.21*10= 12.1N

Wing Loading = Weight/Wing Area = 12.1/0.1065 = 113.61 N/m2

Thickness ratio = 10% = 0.1

Sweptback angle: 400

Tracing from the graph at 40o Swept angle [Put Graph 11.3 page 182]

Form Factor ‘k’ = 1.16

Aspect Ratio (AR) = b2/SREF = 0.72/0.1065 = 4.6

 63  

 

Wing

Fuselage Area 0.439 m2 Wetted Area 0.8955 m2 Length 0.955m Diameter 0.2m Finesse ratio 4.7 Body form factor ‘k’ 1.31 Fuselage diameter/Wingspan 0.28 Induced drag factor ‘S’ 0.84

Horizontal Tail Reference Area = 0.0289 m2

wetted area = 0.0589 m2

Root Chord = 0.16m

Tip Chord = 0.029m

Taper ratio = CT/CR = 0.029/0.16 = 0.18

Planform Area 0.1065 m2 wetted area 0.21726m2 Root Chord 0.338m Taper Ratio 0.25 Tip Chord 0.086m MAC 0.225m Weight 12N Wing Loading 113.61 N/m2 Thickness ratio 0.1 Swept back angle 400 Form factor ‘k’ 1.16 Aspect ratio 4.6

 64  

 

M.A.C = 2/3CR(1 + σ – σ/1+σ) = 2/3 * 0.16(1 + 0.18 - 0.18/1+0.18) = 0.109 m

t/c = 9% = 0.09

From graph 11.3, page 182, Richard Shevell

K = 1.31

Vertical Tail Reference area = 0.03329 m2 = wetted area = 0.06789 m2

Root chord (CR) = 0.145m

Tip Chord (CT) = 0.072 m

Taper ratio = σ = CT/CR = 0.072/0.145 = 0.496

M.A.C = 2/3CR (1 + σ – σ/1 +σ)

= 2/3CR (1 + 0.496 - 0.496/1 + 0.496)

= 0.112 m

t/c = 9% = 0.09

k = 1.31

Reference area 0.03329 m2 Wetted area 0.06789 m2 Root chord 0.145m Tip Chord 0.072m Taper ratio 0.496 M.A.C 0.112 m t/c 0.09 K 1.31

Reference area 0.0289 m2 Wetted Area 0.0589 m2 Root Chord 0.16 m Tip Chord 0.029 m Taper ratio 0.18 M.A.C 0.109 m t/c 0.09 K 1.31

 65  

 

At Cruise condition CL Calculation

Lift (L) = ½ ρV2SCL

At Cruise Condition, L = W

Thrust = Drag

Therefore, CL = 2W/ρV2S

Vcruise = 15 m/s

ρ= 1.2250 kg/m3

S = 0.1065 m2

L = W = 12.1 N

Therefore, CL = 2 * 12.1/1.2250 * 152 * 0.1065

CLcruise = 0.8312

Condition Value Weight 12.1 N Height 100 m Temperature 288.16 K Pressure 101325 N/m2 Density 1.2250 Kg/m3 Kinematic Viscosity 1.4607 * 10-5 m2/s Speed 15 m/s CL 0.8312 t/c 0.1 K (Fuselage) 1.31 K (wing) 1.16 Aspect Ratio (AR) 4.6

 66  

 

Parasitic Drag Coefficient

Wing K = 1.16

CDP = (Cf * k * Swet)/Sref

RN = ( Vo * L)/v

= (Vo * M.A.C)/v

RN = 15 * 0.225/1.4607 * 10 -5 = 231,053.60

For RN > 200,000, the flow is turbulent

Hence, calculations for turbulent flow is adopted

CF = 0.455/(Log RN)2.54

= 0.455/ (Log 231053.00)2.58 = 5.970 * 10-3

C DP = 5.970 * 10-3 * 1.16 * 0.21726/0.1065 = 0.0141

Fuselage RN = ( Vo * L)/v = (15 * 0.955)/1.4607 * 10-3 = 980,694.18

K = 1.31

Cf = 0.455/(Log 980694.18)2.58

CDP = (4.4871 * 10-3 * 1.31 * 0.8955)/0.1065 = 0.0494

Horizontal Tail RN = (Vo * M.A.C)/v = (15 * 0.109)/1.4607 * 10-5 = 111,932.63

For RN < 200,000, we use laminar flow calculation

C f = 1.328/√RN = 1.328/√111932.63 = 3.9693 *10-3

K = 1.31

CDP = (3.9693 *10-3 * 1.31 * 0.0589)/0.0289 = 0.0105

 67  

 

Vertical tail RN = (Vo * M.A.C)/v = 15 * 0.112/1.4607 * 10-5 = 115,013.34

C f = 1.328/√RN = 1.328/√115013.34 = 3.9158 * 10-3

K = 1.31

CDP = (3.9158 * 0678910-3 * 1.31 *0.)/0.03329 = 0.0104

Total CDP = 0.0141 + 0.0494 +0.0105 + 0.0104 = 0.0844

Induced Drag

CDi = CLcruise2/πARe

e = 1/[πARK + 1/(u * s)]

AR = 4.6, u = 0.99, s = 0.84 , k = 0.45 CDp for 350 Swept wings

e = 1/[π*4.6*0.45+(1/(0.99*0.84)]

e = 0.1297

CLcruise = 0.8312

CDi = (0.8312)2/π*4.6*0.1297 = 0.03686

CD = CDp + CDi = 0.0844 +0.03686 = 0.1297

D = ρ * V2 * CD * S/2 = (1.2250 * 152 * 0.1297 * 0.1065)/2

D = 1.9036 N

(L/D)cruise = CL/CD = 0.8312/0.1297 = 6.408

 68  

 

Level Flight Performance

CL(L/D)max = √CDp *π*AR*e

= √0.0844*π*4.6*0.1297

= 0.3977

(L/D)max = √π/2 * b√e/√ CDps = 0.8862 * (4.6√0.1297)/√0.0844*0.1065)

= 0.8862*1.6566/0.2998 = 4.896

Takeoff Performance

VLiftoff = VLo = 1.2 Vstall

V stall = √2w/ ρ*s*CLmax = 21.296 m/s

Therefore VLO = 1.2 * 21.296 = 25.555 m/s

C L to climb = CLmax/(1.2) 2 = 0.7 CLmax

= 0.7 * 0.3977 = 0.2783

 69  

 

Drag at take off

Wing

RN = VoL/v =( VLO * MAC)/v = (25.555 * 0.228)/1.4607 * 10-5 = 437,375.92

RN > 200,000 , therefore turbulent

Cf = 0.455/(log 437,375.92)2.58 = 5.2425 * 10-3

CDp = 5.2425 * 10-3 * 1.16 * 0.21726/0.1065 = 0.0124

Fuselage

RN = Vo *L/V = V Lo *L/v = 25.555 * 0.955/1.4607 * 10 -5 = 1,671,119.21

Cf = 0.455/(log 16711119.21)2.58

= 4.069 * 10-3

CDD = 4.069 * 10 -3* 1.31 * 0.8955/0.1065 = 0.0386

Horizontal Tail

RN = Vo * L/V = VLO * M.A.C/v = 25.555 * 0.109/1.4607 * 10-5

= 190,695.89

RN < 200, 000 : Laminar

Cf = 1.328/√RN = 1.328/√190,695.89 = 3.0410 * 10-3

CDp = 3.0410 *10 -3 *1.31 * 0.021726/0.1065 = 0.0081

Vertical Tail

RN = Vo*L/v = VLo * MAC/v = 25.555*0.112/1.40607 * 10-5 =195,944.41

Cf = 1.328/√RN = 1.328/√195,944.41 = 0.0030

 70  

 

CDp = 0.0030 * 1.31 * 0.21726/0.1065 = 0.0080

Total CDp = 0.0124 + 0.0108 + 0.0081 + 0.0080 = 0.0393

Induced drag CDi = C L to climb

2/πARe

e= 0.1297

C L to climb = 0.2783

C Di = (0.2783)2/π* 4.6 * 0.297 = 0.0413

There is an increase in CDi which could be corrected by ‘ground effect’

Height from ground to wing m.a.c , h = 29cm = 0.29m

Wing span = 4.6

Therefore, h/b =0.29/4.6 = 0.1

Using Graph figure 9.10 on page 152, Richard Shevell “Fundamentals of Flight” (K L)

K L = 0.5

0.5 * C Di = 0.5 * 0.0413 = 0.0206

CD = CDp + CDi = 0.0393 + 0.0206 = 0.0599

D = p* V2 * CD * S/2 = 1.2250 * 152 * 0.0599 * 0.1065/2 = 0.879 N

(L/D)LO = CL/C D = 0.2783/0.0599 = 4.64

 71  

 

Landing Performance V Approach = 1.3Vs = 1.3 * 21.296 = 27.68 m/s

C L = 0.8312

Drag at landing

Wing

RN = VoL/v = VLO * MAC/v = 27.68 * 0.225/1.4607 * 10 -5 = 426,370.92

Cf = 0.455/(log 426370.92)2.58 = 0.0052

C Dp = 0.0052 * 1.16 * 0.21726/0.1065 = 0.0123

Fuselage RN = VoL/v = VLD * L/v = 27.68 * 0.955/1.4607 * 10-5 = 1,678,948.44

C f = 0.455/(log 1678948.44)2.58 = 0.0041

CDp = 0.0041 * 1.31 * 0.21726/0.1065 = 0.0109

Horizontal Tail RN = 27.68 * 0.109/ 1.4607 * 10-5 = 206,553

Cf = 0.455/(log 206553) 2.58 = 0.0061

CDp = 0.0061 * 1.31 * 0.21726/0.1065 = 0.0163

Vertical Tail RN = 27.68 * 0.112/1.4607 * 10-5 = 212,237.96

Cf = 0.455/(log 212237.96)2.58 = 0.0061

 72  

 

CDp = 0.0061 * 1.31 * 0.21726/0.1065 = 0.0163

Total CDp = 0.0123 + 0.0109 + 0.0163 + 0.0163 = 0.0558

Induced Drag CDi = CL/πARe

e= 0.1297

C L =0.8312

CDi =(0.8312)2/π* 4.6 * 0.1297 = 0.0368

CD = CDp + C Di = 0.0558 + 0.0368 = 0.0923

D = pV2CD S/2 = 1.2250 * 152 * 0.0923*0.1065/2 = 1.3546

(L/D) = CL/CD = 0.8312/0.0923 = 9.00

Maneuvers

Turning Performance

V = 15 m/s

θ = 60o

g = 10 m/s 2

n = 1/Cosθ = 1/Cos60 = 2

Level Turn

 73  

 

Radius of turn (r)

r = V2/g√n2 – 1) = 152/10√(22 -1) = 152/10√3 = 12.9m

Angular Velocity (ω)

ω= g√n 2 – 1/v = 10 * √3/15 = 1.15 m/s

Vertical Turn Pull up Radius of turn (r)

r = r 2/g(n-1) = 15 2/10(2-1) = 22.5 m

Angular velocity

ω= g(n-1)/v = 10(2-1)/15 = 10/15 = 0.66 m/s

VERTICAL TURN PULL DOWN

Radius of turn (r)

r= v 2/g(n+1) = 152 /10(2+1) = 7.5m

Angular velocity

ω = g(n +1)/v = 10* 3/15 = 2 m/sθ

Vertical turn Radius of turn r

r = v2/gn = 152/10*2 = 11.25 m

Angular velocity (ω)

ω= gn/v = 10 * 2/15 = 1.33 m/s

 74  

 

Centre of Gravity:

The reference is taken as 10cm from the Ducted fan.

The weight and distance of each component is mentioned in the table.

Object Weight(kg) Arm + Reference(m) moment

Tail 0.095 0.03 + 10 0.95285

Fuselage 0.343 0.55 + 10 3.61865

Wings 0.250 0.33 + 10 2.5825

Landing gear 0.117 0.15 + 10 1.18755

Servo box 0.040 0.34 + 10 0.4136

Speed Control 0.066 0.17 + 10 0.67122

Ducted fan 0.088 0 + 10 0.88

e-poxy 0.100 0.001 + 10 1.0001

Motor 0.106 0.05 + 10 1.0653

Total 1.205 91.61 12.37177

To find the center of gravity the moment is divided by the weight.

Centre of Gravity = Moment/Weight = 12.37177 / 1.205

= 10.267

So the center of gravity for our aircraft is 10.267 from our ducted fan.

 75  

 

FORMULAE USED in calculations throughout the report  

• Area of triangle = (b*h)/2

• Area of Trapezium = [(a+b)/2]h

• Area of rectangle = (length x breadth)

• Surface Area of cylinder = 2πr2 + 2πrh

• Surface area of elliptical cylinder = 2πL √(a2 + b2)/2 + 2πab

• Surface Area of cone = πrs + πr2

• Taper ratio = CT/CR

• MAC = 2/3 * CR(1 + σ - σ/1+σ)

• Wing Loading = Weight/Wing Area

• Aspect Ratio (AR) = b2/SREF

• Lift (L) = ½ ρV2SCL

• CL = 2W/ρV2S

• CDP = (Cf * k * Swet)/Sref

• RN = ( Vo * L)/v

• CF = 0.455/(Log RN)2.54

e = 1/[πARK + 1/(u * s)]

CDi = CLcruise2/πARe

• D = ρ * V2 * CD * S/2

• (L/D)cruise = CL/CD • CL(L/D)max = √CDp *π*AR*e

 76  

 

• (L/D)max = √π/2 * b√e/√ CDps

• V stall = √2w/ ρ*s*CLmax

• D = pV2CD S/2

• Centre of Gravity = Moment/Weight

 77  

 

Troubleshooting

After testing the plane we had a problem with the following things:

Landing Gear

We were told that the landing gear was too high and needed to be made lower

otherwise the aircraft won’t move straight. We decided to try it out anyway, but as

expected the plane didn’t move straight and turned over.

Battery

The battery was fine, except that it needed to be charged on the day of the test flight.

Fig.87  

Fig.88  

 78  

 

Speed controller

The speed controller was not working, due to an internal problem

Remote Control and receiver

The remote control that we used wasn’t working as it had an old system and had a

glitch, so it was difficult to configure. Hence there was interference between the receiver

and remote control.

Fig.89  

Fig.90  

 79  

 

Engine

The engine was working perfectly and gave us no problems

Fixing the problems:

We managed to fix all the problems within 3 days:

Landing Gear

We removed the existing landing gear and put lower ones instead. After testing it the

plane moved properly and was able to take off.

Speed controller

We had to replace the current speed controller and buy another one. Though it was

expensive we had no other choice.

Remote control

 80  

 

We had to also get another remote control and receiver for the aircraft

Overall, the problems were not many and were easily fixed as there was no major

damage on the aircraft. This is because the plane did not crash or anything and we

were not able to fly it during the test flight, now that the problems have been rectified the

aircraft is ready to fly.

Fig.91  

 81  

 

Safety and Risk Assessment7

• When working with glue, accelerator or acetone, remember that they are toxic

and hazardous materials. Follow all guidelines and precautions accompanying

these materials. It is easy to become complacent, as the hazard is not

immediately obvious.

• Always wash hands after working with glue materials. Keep glue, accelerator and

acetone away from the eyes. Safety glasses are recommended. Avoid rubbing

the eyes, and keep the hands away from the face when working with these

materials

• If power tools are used, eye protection, instruction in the safe use of the tools and

proper supervision should all be considered prerequisites.

• If not flying at a club field, make sure the site you choose is adequate and

appropriate ,not too small an area and not too close to people, animals, trees,

power lines, buildings, roads, etc. Also find out if there are any local ordinances

that prohibit flying RC airplanes in public spaces.

• When working with a hand cutter make sure not to apply big forces as it might

lead to hurting your hand.

• Unless your radio system is 2.4GHz, use a frequency checker or some other

method of frequency control before turning on your transmitter. Having two or

more people flying RC airplanes on the same frequency does not work; if you

interfere with another pilot’s frequency, you will cause an accident.

• Never ever keep your hands close to the engine propeller blade it can cut

anything with the speed of 17,000 rpm.

                                                                                                                         7  http://www.rcplanesandcopters.com/flying-­‐rc-­‐airplanes-­‐safety-­‐tips/  

 82  

 

• Don’t try flying RC airplanes in “adverse” wind conditions. Depending on your

model, that could be anything over 10-15 mph. Know your plane’s limitations and

if unsure about wind speed, wait for another day.

 83  

 

REFERENCES

1.  http://www.bruceair.com/aerobatics/aerobatics.htm

2.  http://www.moneysmith.net/Soaring/soaring4.html

3. Fundamentals  of  Flight  by  Richard  S  Shevell

4. http://www.oakdaleaircraft.com/f35_manual/f35_edf.pdf

5.  http://www.rcplanesandcopters.com/flying-­‐rc-­‐airplanes-­‐safety-­‐tips/

 84  

 

Conclusion

We have learned a lot of things from this project, the most important thing that we have

learned is how to construct an RC aerobatic aircraft. We have also learned the basics of

flying a RC aerobatic aircraft and have a better understanding of the different designs of

airplanes.

In this report we have described the assembly and construction of the aircraft in great

detail. We have also included pictures of the different stages of the construction to give

you a better understanding on how we made the aircraft. We have also included the

parametric design of the aircraft, Gantt chart and mission. In addition, we have included

the cost analysis as well as the manpower hours of each member in the group. We

have mentioned the different materials and tools used during the project and the

product specifications as well.

AutoCAD was used to help us with the design of the model, the 3D design of the model

gave us a proper idea of how to construct the aircraft, the AutoCAD designs have been

included in this report.

The second part of this assignment contains all the calculations of the aircraft, this

includes all the maneuvers calculations etc. Lastly, we described the troubleshooting of

the aircraft that talks about the problems faced during the test flight and how to rectify it.

The report ended with a few points about safety and risk assessment.

Overall we learned a lot from this project, it took a lot of hard work and commitment, but

in the end our hard paid off and our project was successful.