The document discusses the selection and analysis of a landing gear design for an unmanned aerial vehicle to compete in the SAE Aero Design Series competition. It describes different types of landing gear configurations, including tail wheel, tandem, and tricycle types. It then details the selection of a tricycle-type landing gear for the specific unmanned aerial vehicle due to its ease of ground operations. A finite element analysis was performed on the selected landing gear design to analyze deformation and stresses under expected landing impact forces, with the results showing a factor of safety above 2, indicating a safe design.

1. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print),
ISSN 0976 – 6359(Online), Volume 6, Issue 2, February (2015), pp. 10-18© IAEME
10
SELECTION AND ANALYSIS OF THE LANDING GEAR
FOR UNMANNED AERIAL VEHICLE FOR SAE AERO
DESIGN SERIES
Jigar Parmar
UG Student, Department of Production Engineering, Fr. Conceicao Rodrigues College of
Engineering Fr.Agnel Ashram, Bandstand, Bandra (W), Mumbai, Maharashtra, India.
Vishnu Acharya
UG Student, Department of Information Technology Engineering, Fr. Conceicao Rodrigues College
of Engineering Fr.Agnel Ashram, Bandstand, Bandra (W), Mumbai, Maharashtra, India.
Dr. JayaramuluChalla
Professor of Production Engineering, Fr. Conceicao Rodrigues College of Engineering
Fr.Agnel Ashram, Bandstand, Bandra (W), Mumbai, Maharashtra, India.
ABSTRACT
UAV-Unmanned Aerial Vehicle commonly known as Drones are extensively being used
these years. Today drones are used in various applications like Military, Commercial Cargo
Transport, and 3-D Mapping etc. For supporting the weight of the plane, and shock absorption
functions, landing gear design is highly essential.
Society of Automotive Engineers (SAE) conducts ‘Aero Design Series’ competition annually
in the United States of America (USA). This papers explains and gives details about the landing gears
and significance of selecting the optimum one for the respective plane required to compete in the
challenge. The gears were selected on various factors and methods depending upon the design and
the load bearing capacity of the UAV.
Keywords: Aero, Analysis, Landing gear, SAE, UAV
INTERNATIONAL JOURNAL OF MECHANICAL ENGINEERING AND
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ISSN 0976 – 6340 (Print)
ISSN 0976 – 6359 (Online)
Volume 6, Issue 2, February (2015), pp. 10-18
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2. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976
ISSN 0976 – 6359(Online), Volume 6, Issue
I. INTRODUCTION
SAE International conducts “Aero Design Series” competition annually in USA. Depending
upon the event objectives there are three classes in the
class. The objective of the Advanced
efficient aircraft capable of accurately dropping a three pound (3 lb) humanitarian aid package from a
minimum of 100feet off the ground.
As the build UAV was approximately 29
designed.
Landing gear is a very major component in any UAV. The landing gear provides a stable
support for the aircraft at rest on the ground. During landing, it acts as shock absorbent mechanical
structure to absorb and transmit
majority of impact energy is dissipated. Landing gears also act as brakes during the motion of the
UAV on the runway.
For building the most efficient UAV for th
with techno economic feasibility of the landing gear was to be designed and fabricated.
The types of landing gear are as follows:
• Tail Wheel Type (Tail- Dragger)
• Tandem Type (Bicycle Type layout)
• Tricycle Type
II. LANDING GEAR
A. Tail Wheel-Type
Tail Wheel-type landing gear is an arrangement in which the main gear is attached to the
UAV slightly forward to the center
the tail portion. This type of design is also called the conventional gear or Tail
kind of landing gear results in giving the angle of the fuselage as
propellers to recompense for the underpowered
wheel type landing gear.
Figure
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976
6359(Online), Volume 6, Issue 2, February (2015), pp. 10-18© IAEME
11
SAE International conducts “Aero Design Series” competition annually in USA. Depending
upon the event objectives there are three classes in the competition-Advanced, Regular and Micro
The objective of the Advanced Class of SAE Aero Design Series was to
efficient aircraft capable of accurately dropping a three pound (3 lb) humanitarian aid package from a
minimum of 100feet off the ground.
he build UAV was approximately 29pounds, a strong and efficient landing gear was to be
major component in any UAV. The landing gear provides a stable
est on the ground. During landing, it acts as shock absorbent mechanical
ucture to absorb and transmit these loads to the stronger part of the UAV (fuselage) so that a
majority of impact energy is dissipated. Landing gears also act as brakes during the motion of the
For building the most efficient UAV for the competition a high strength
of the landing gear was to be designed and fabricated.
types of landing gear are as follows:
Dragger)
Tandem Type (Bicycle Type layout)
type landing gear is an arrangement in which the main gear is attached to the
center of gravity and so another gear is required to support the UAV at
the tail portion. This type of design is also called the conventional gear or Tail
kind of landing gear results in giving the angle of the fuselage as such, which allows t
propellers to recompense for the underpowered engines. Figure below shows the
Figure 2.1 Tail Wheel Configuration
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print),
© IAEME
SAE International conducts “Aero Design Series” competition annually in USA. Depending
Advanced, Regular and Micro
Class of SAE Aero Design Series was to design the most
efficient aircraft capable of accurately dropping a three pound (3 lb) humanitarian aid package from a
pounds, a strong and efficient landing gear was to be
major component in any UAV. The landing gear provides a stable
est on the ground. During landing, it acts as shock absorbent mechanical
these loads to the stronger part of the UAV (fuselage) so that a
majority of impact energy is dissipated. Landing gears also act as brakes during the motion of the
high strength, light weight coupled
of the landing gear was to be designed and fabricated.
type landing gear is an arrangement in which the main gear is attached to the
of gravity and so another gear is required to support the UAV at
the tail portion. This type of design is also called the conventional gear or Tail-dragger gear. This
such, which allows the use of long
shows the layout of the Tail-

3. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print),
ISSN 0976 – 6359(Online), Volume 6, Issue 2, February (2015), pp. 10-18© IAEME
12
B. Tandem Type
Tandem landing gear is the arrangement in which the main gear and the tail gear are aligned
on the longitudinal axis of the UAV. Most UAVs have only the main gear forward with the tail
having a skid under it. Usually it is arranged in a bicycle type layout and sometimes the wings may
have small wheels attached to them to ensure optimum balance and stability. This type of landing
gear allows high flexibility of the wings. Figure 2.2(a) and 2.2(b) shows the layout of tandem landing
gear.
Figure 2.2 (a) Front View of Tandem Type Layout
Figure 2.2 (b) Top View of Tandem type layout
C. Tricycle-Type
The Tricycle-type landing gear comprises of a tricycle like layout with one wheel in front,
called the nose wheel and two or more wheels at the back. The basic arrangement of this type of
system is shown in the figure2.3. The main wheels are usually joined to a wing structure or fuselage
of the UAV. They can vary in number and location. The wheels improve stability and also provide
safety in the case of malfunction of one wheel. The nose wheel allows the UAV to change directions
during ground operations. The Tricycle-type landing gear is the most commonly used landing gear
due to the ease at which ground operations can take place when implemented in a UAV.

4. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976
ISSN 0976 – 6359(Online), Volume 6, Issue
Figure
III. DETAILS
A. Tail Wheel-Type
In the tail- wheel Configuration the
support most part of the UAV and are usually la
controlling direction and supports the latter half of the UAV. This type i
having large propeller diameter and need higher ground clearance. This type of an arrangement has
its advantages and disadvantages as follows:
Advantages:
• This type of configuration reduces the overall weight of the UAV
• It Increases the directional stability of the UAV.
• The damages due to ground operations on unpaved and rough runways are reduced.
• The overall parasitic drag is reduced as it has an inclined configuration.
Disadvantages:
• Difficulty in steering the UAV
latter half of fuselage.
B. Tandem type
This type of landing gear arrangement is similar
gear on the fuselage aligned on the central axis of the UAV to support
wheels attached to the wings to maintain stability
slender and long fuselages which
advantages and disadvantages are mention
Advantages:
• The overall Weight of the UAV is considerably reduced.
• The induced drag on the UAV is reduced.
• It Allows the UAV to have high as
created.
Disadvantages:
• Take-off and landing operations of the UAV become
• UAV might get damaged if airstrip is uneven while landing.
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976
6359(Online), Volume 6, Issue 2, February (2015), pp. 10-18© IAEME
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Figure 2.3 Tricycle-Type Configuration
wheel Configuration the main landing gear usually consists of two wheels which
support most part of the UAV and are usually larger in size. The gear mounted
controlling direction and supports the latter half of the UAV. This type is usually used in UAVs
and need higher ground clearance. This type of an arrangement has
ts advantages and disadvantages as follows:
reduces the overall weight of the UAV.
It Increases the directional stability of the UAV.
damages due to ground operations on unpaved and rough runways are reduced.
overall parasitic drag is reduced as it has an inclined configuration.
Difficulty in steering the UAV and probable ground looping due to center
This type of landing gear arrangement is similar to that of a bicycle with the
gear on the fuselage aligned on the central axis of the UAV to support its weight.
the wings to maintain stability. It is specially used in case
slender and long fuselages which cannot support Tricycle type and Tail-wheel type landing gear. Its
advantages and disadvantages are mentioned below.
Weight of the UAV is considerably reduced.
on the UAV is reduced.
UAV to have high aspect ratio wings with low angles of attack where
landing operations of the UAV becomes difficult and unstable.
UAV might get damaged if airstrip is uneven while landing.
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print),
© IAEME
usually consists of two wheels which
rger in size. The gear mounted to the tail helps in
s usually used in UAVs
and need higher ground clearance. This type of an arrangement has
damages due to ground operations on unpaved and rough runways are reduced.
of gravity being in the
to that of a bicycle with the main landing
its weight. It usually has
in case of UAVs which have
wheel type landing gear. Its
pect ratio wings with low angles of attack where high lift is
difficult and unstable.

5. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print),
ISSN 0976 – 6359(Online), Volume 6, Issue 2, February (2015), pp. 10-18© IAEME
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C. Tricycle-type
The tricycle type landing gear arrangement works just as a tricycle. The main landing gear
that is located at the latter half of the UAV usually supports most of the weight of the UAV and the
nose landing gear located at the nose of the UAV is used to steer the UAV in the required direction.
This is a very frequently used landing gear arrangement as it helps in easy maneuvering of the UAV.
Some of its advantages and disadvantages have been mentioned below:
Advantages:
• It allows the UAV to brake faster without the UAV nosing over.
• Ground-Looping of UAV is prevented due to optimum location of center of gravity.
• Evenly distributed weight of UAV increases stability and ensures safety.
• Cross winds do not affect the UAV.
• Easy maneuvering.
Disadvantages:
• The drag is significantly increased.
• Weight of the UAV is slightly more.
• The nose gear is damage-prone as stresses induced on it are high.
IV. Practical Setup
A. Geometrical Model
The Mechanical Analysis was done on Finite Element Software Ansys Workbench 14.5
Module. Several models were considered for the landing gear and the model selected for the UAV is
shown below, it has straight ends.
Figure 4.1 Model Selected

6. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print),
ISSN 0976 – 6359(Online), Volume 6, Issue 2, February (2015), pp. 10-18© IAEME
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B. General Assumptions
Assumptions made during the Analysis for the gear are as follows: The frictional force
developed between the contact of the wheel and the ground surface was neglected, as the rolling
resistance of the wheels which we used was negligible. The tangential force developed by the inertia
force, the moment produced by the vertical load times the horizontal distance from the center of
gravity to the gear was neglected as the wheels were placed equidistance from the center of gravity of
the gear. The weight of the UAV was considered to be 12kgs (29 pounds).
C. Landing conditions
The landing gear was analyzed assuming that the UAV would land between 3 to 6m/sec. As
the Impact force is a function of vertical velocity, the impulse momentum equation is given by,
F ∆t = mܸ௙
Where, F = Impact Force in Newton
∆t = Impact time
m = weight of the UAV
ܸ௙ = vertical velocity
Assuming the impact time to be 0.5 seconds, range of impact load with respect to the velocity
are tabulated below,
Table 1: Velocity and Impact Force
D. Boundary Conditions and Constraints
The material assigned to the landing gear was a grade of 6061-T6 Aluminum. Material
properties are shown in below table,
E. Material Properties
Table 2: Material Properties
Material Al 6061-T6
Modulus of Elasticity 68.9Gpa
Yield tensile Strength 276 MPa
Ultimate tensile Strength 310 Mpa
Break Elongation 12%
Fine meshing done on the structure gave 5948 Elements and 12548 Nodes.
Velocity(m/sec) Impact Force(N)
3 72
3.5 84
4 96
4.5 108
5 120
5.5 132
6 144

7. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print),
ISSN 0976 – 6359(Online), Volume 6, Issue 2, February (2015), pp. 10-18© IAEME
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F. Mechanical Constraints and Loads
The top surface of the landing gear, a fixed support was imposed, between the landing gear
and fuselage (shown in blue color). Thus the displacement of the top surface in all the directions
becomes null.
The UAV weight in Newton was put in vertically downward direction at the top surface of the
gear from its center. The impact load was applied at the bottom of the gear along the positive y-
direction.
Figure 4.2 Loading Constraints on Ansys
V. RESULTS
The model was solved according to the respective loading conditions. The total deformation
and the Von Mises Equivalent stress is shown in the following table for the different values of impact
loading. Factor of Safety was calculated as,
Factor of Safety = Ultimate Strength / Allowable Strength
Calculated values of factor safety compared to the Ultimate Strength of the material is also shown.
Table 3: Calculated Factor of Safety
Impact Force
(N)
Total Deformation
(mm)
Von-Mises Equivalent
(MPa)
Factor of Safety
72 9.36 73.4 4.2
84 10.9 85.6 3.6
96 12.4 97.9 3.1
108 14.0 110.1 2.8
120 15.6 122.4 2.5
132 17.16 134.6 2.3
144 18.7 146.8 2.1

8. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976
ISSN 0976 – 6359(Online), Volume 6, Issue
Figure
VI. CONCLUSION
The landing gear configuration was analyzed in Ansys Workbench 14.5
landing conditions were considered using various
Impact loads were above 1, implying the material select
The factor of Safety ranges from 2.1 to 4.2 leading to more conservative and safe design.
The gear was chosen considering various parameters.
payload bay was over 29 Pounds,
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976
6359(Online), Volume 6, Issue 2, February (2015), pp. 10-18© IAEME
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Figure 4.3: Total Deformation
igure 4.4 Von-Mises Equivalent Stress
Figure 4.5 Practical Setup
The landing gear configuration was analyzed in Ansys Workbench 14.5
s were considered using various landing speeds. The factor of safety
Impact loads were above 1, implying the material selected was acceptable to manufacture the model.
from 2.1 to 4.2 leading to more conservative and safe design.
The gear was chosen considering various parameters. As the weight of the UAV including the
payload bay was over 29 Pounds, tandem wheel type was rejected. As the build
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print),
© IAEME
The landing gear configuration was analyzed in Ansys Workbench 14.5 Module. Different
landing speeds. The factor of safety rendered for all
ed was acceptable to manufacture the model.
from 2.1 to 4.2 leading to more conservative and safe design.
As the weight of the UAV including the
. As the build UAV was a high

9. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print),
ISSN 0976 – 6359(Online), Volume 6, Issue 2, February (2015), pp. 10-18© IAEME
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winger and covered with MonoKote, mounting wheels on the wings wasn’t feasible. The
configuration chosen was conventional gear or the tail-dagger type over the tri-cycle type, the
following table shows the comparison,
Table 4: Comparison of Tail-Dragger and Tri-Cycle
A complete model of the gear was designed and fabricated for the UAV. Apart from
conforming to the design requirements of ‘SAE Aero Design Series’, the landing gear is a reliable,
lightweight and high strength unit which can be mounted easily on the UAV. It proves to be an
invaluable tool for assisting the flight and mission requirements of the UAV.
VII. ACKNOWLEDGMENT
The authors wish to thank Mr.D.S.Sudhakar, Dr.V.S.Bilolikarand Mr. Jay Boradefor their
guidance and technical support. This work was supported in part by a grant from Fr.Conceicao
Rodrigues College of Engineering.
REFERENCES
1. About SAE AERO International, https://www.sae.org/about/
2. Tail Wheel-type -https://www.faa.gov/regulations_policies/handbooks_manuals/aircraft/amt_
airframe_handbook/media/ama_Ch13.pdf
3. Tandem Type – http://www.biplaneforum.com/Three-Popular-Landing-Gear-Designs.html
4. Tail Wheel-type – AkhileshJha “Landing Gear Layout Design for Unmanned Aerial Vehicle”,
14th National Conference on Machines and Mechanisms (NaCoMM09),NIT, Durgapur,
India, December 17-18, 2009
5. Analysis - Amit Goyal, “Light Aircraft Main Landing Gear Design and Development”,
International ANSYS Conference Proceedings, 2000
6. D.W. Young, “Aircraft Landing Gears – Past Present and Future” Proceeding of IME, Vol.
200, No. D2 PP 75-92, 1986
7. R.H. Mallett and P.V. Marcal, “Finite Element Analysis of Non-linear structures,” JstDiv.,
Vol. 94, No. ST9, 1968, PP. 2081 – 2105.
8. M. H. Sadraey, Aircraft Design: A Systems Engineering Approach, Wiley, 2012.
9. Ramesh Kamath, Siddhesh Nadkarni, Kundan Srivastav and Dr. Deepak Vishnu Bhoir, “Data
Acquisition System and Telemetry System For Unmanned Aerial Vehicles For SAE Aero
Design Series” International journal of Electronics and Communication Engineering
&Technology (IJECET), Volume 4, Issue 5, 2013, pp. 90 - 100, ISSN Print: 0976- 6464,
ISSN Online: 0976 –6472.
10. Mr. Prithvish Mamtora, Mr. Sahil Shah, Mr. Vaibhav Shah and Mr. Vatsal Vasani,
“Unmanned Aerial Vehicle (UAV)” International journal of Electronics and Communication
Engineering &Technology (IJECET), Volume 4, Issue 5, 2013, pp. 187 - 191, ISSN Print:
0976- 6464, ISSN Online: 0976 –6472.
Tail-Dragger Tri-Cycle
Drag Less More
Propeller Clearance More Less
Overall Weight Less More
Stresses Induced Moderate More
Ground Looping Tendency More Less