Challenges of Designing Landing Gears for Aircraft

Discuss about the Upgrading and Optimization of Landing Gears.

The landing gear supports the aircrafts above the ground as it keeps sufficient clearance between the ground and the aircraft in order to support the external parts such as weapons and fuel tank. During the process of aircraft design, the landing gear poses many challenges to the design team. Depending on the distance, centre of gravity, the angle with the tip- of the tail, the aircraft weight, shock absorbers and the tires must be of certain specifications and size in order to allow effective landing and taking off of the aircraft. In addition, if the landing gear is designed to retract, therefore it has to be able to fit within the structure which is existing of the newly designed aircraft. In most cases, it is very rare for the structure of the aircraft to be modified to accommodate the newly designed landing gears Jocelyn Pritchard (2011).

Although the planning Mechanism Assembly allows the main landing gear to suit into the limited space of the wheel well, there are other challenges that surfaces. The planning Mechanism Assembly becomes one of the weakest parts of the landing gear which is resulted in consistent failures. The planning Mechanism Assembly failures generally occur upon touch down or shortly after touch down, and in most cases, it could occur either on the right or left main landing gear. Generally, failures of the planning Mechanism Assembly are attributed to the collapsing of the joining link or the planning link with the signs of the bell crank assembly contact. In the process of failure, the axle lock links unlock resulting to the key wheel deplaning from the main landing way result to loss of direction at very high-speed Yuanyuan et al. (2017).

The main aim of this research is to evaluate the effectiveness of upgrading and optimization of landing gears of aircraft to minimise the danger of planning Mechanism Assembly failure.

The following objectives are set in order to assist in achieving the main aim of the research management:

• Evaluate static hold downforce in the rigging of the landing gear.
• Determine the rise of the bell crank breaks and the pinhead.
• Evaluate the aircraft grand handling at different ground speeds
• Evaluate the lots on the connecting and planning links in many landings which include full stop, touch and arresting cable engagement and cable overrun.

The findings of the research will be of great significance for the design team of aircraft. They will be able to know the type of landing gears to use for a particular type of air crafts, and the findings will give them a better understanding on how to upgrade and optimization of landing gears of aircraft to minimise the danger of planning Mechanism Assembly failure is done (Gudmundsson, 2013).

Planning Mechanism Assembly Failure and Its Challenges

This research will mainly focus on the upgrading and optimization of landing gears of aircraft to minimise the danger of planning Mechanism Assembly failure. A detailed literature review will be carried out to gain a better understanding of the upgrading and optimization of landing gears. After various other methods will be used to gather information related to the topic of study. Computer simulations and mathematical models will also be used as techniques to carry out the research.

The secondary sources that will be used must be containing content related directly to the upgrading and optimization of landing gears. The research will not focus on other topics apart from upgrading and optimization of landing gears of aircraft to minimise the danger of planning Mechanism Assembly failure

The landing gear in aircraft is used to control the aircraft during the landing, take-offs and other ground operations. Due to the roles which the landing gears play in the operations of the aircraft.it must have the ability to resist the other forces associated with loads of the aircraft. The landing gears play a very vital role in supporting the aircraft above the ground to enable it to keep sufficient clearance between the ground and the surface of the aircraft Zhang et al. (2010).

Depending on the requirement of the aircraft, the landing gear may be retractable in order to reduce the radar cross-section or limit the additional drag during the flight. The landing gear must have the right size of the shock absorbers and the tires in accordance with the weight of the aircraft, and if it is retractable, it must fit into the wheel well without any struggle.

The landing gear must properly position in order to allow the aircraft to rotate without necessarily affecting the tail which might be on the ground during take-off or landing.

The landing gears are grouped according to the arrangements or according to their operational management (Torenbeek, 2013).

Arrangements of landing gears.

1. Conventional landing gear
2. Tandem landing gears

• Tricycle-type landing gears

Conventional landing gear is also referred to as Tail wheel-type it is was applied in most of the early aircraft. In this arrangement the main gear is located at the forward centre of gravity, due to that, the tail is forced to have support from the third wheel assembly. This type of arrangement allows the aircraft to slow down upon landing and at the same time offer stability. The subsequent fuselage angle, when the aircraft is fixed with the tail wheel landing, allows the application of large propellers which are mainly used to compensate for the traditional underpowered engines (Peery, 2011).

Objectives for Upgrading and Optimization of Landing Gears

The maximised authorization of the forward fuselage which is usually provided by this type of landing gears. In the modern time, the aircraft are manufactured with this type of landing gears because of the reasons mentioned above and weight savings accompanying the light tail wheel-type landing gears. As shown in the figure below.

Very few aircraft are designed with these landing gear arrangement. As the name suggests this type of the landing gears has the tail gear and the main gear aligned with the longitudinal axis of the aircraft. The sailplanes in most cases use this type of the landing gears arrangement Fletcher et al. (2012). A few military aircraft bombers such as the B-52 and the B-47 uses the tandem gear. In general, having the gear only under the fuselage facilitates the application of flexible wings as shown in the figure below.

This is the arrangement of landing gears which is commonly used. It is usually made up of the nose gear and the key gear. Tricycle-type of landing gears is used in large and small aircraft. There are many benefits which are associated with this arrangement such as:

• Permits more forceful application of brakes without the nosing over when braking. This enables landing at high speed.
• Visibility from the flight deck is enhanced particularly during ground manoeuvring and landing.
• Prevents ground-looping of the aircraft Guo and Yamamoto (2016).

The landing gear must be able to control the impacts which are created by the forces besides offering support to the aircraft. This is usually carried out in two ways. First the shock energy is changed and then transferred through the airframe at a different time and rate than the single strong impact. Then the shock is immersed by changing the energy into heat energy Yuanyuan et al (2017).

Research methodology is characterized as a deliberate methodology that guarantees the analyst to assemble appropriate data or to embrace examination relating to the topic of research by utilizing diverse research strategies. The aim of the proposed research is to investigate the upgrading and optimization of landing gears. The objectives were set in order to assist in achieving the main aim of the study .Due to that, it was essential to have an overview of the upgrading and optimization of landing gears .It was of great importance to understand the main principles upgrading and optimization of landing gears. Various methods were used to obtain the data during the process of the study such as;

Various practitioners who are involved in the design of the aircrafts were interviewed on various issues which are related to the design of landing gears. Questions which were relating to the topic of study will be used during the interviews.

Types of Landing Gear Arrangements

Questionnaires will administered using both electronic media such as email and the field administration. The questions which will contained in the questionnaires will be relating direct to the topic of research. The questions were straightforward to enable the respondent to respond without any challenge.

There are many benefits which are associated with the use of questionnaires to collect data some of them include;

• Questionnaires are cost-efficient
• Faster to obtain results
• No specific skills or knowledge required to handle
• They allow scientific predictions and analysis
• It is easier to cover all the aspects of the topic of research

Disadvantages of using questionnaires

Even though the questioners have lots of benefits they also have some setbacks such;

• Some of the respondents may be dishonest resulting in inaccurate data.
• The challenge of understanding and interpretation
• Some of the questions might be a challenge to the respondent to analysis
• Some of the respondents might be having a hidden agenda
• Some of the questions can be skipped thus leading inadequate data.

By conducting the literature review, the author could pass the knowledge about the topic of research, and it would include the main features of a topic. This research approach is of great importance in achieving the objectives and aims of the research. This research approach is also very helpful in attaining all the objectives and aims of the research such as to have a summary of designing and optimization of landing gears, to evaluate the various principles behind upgrading and optimization of landing gears. The main reason behind the selection of this research methodology is to give detailed knowledge about upgrading and optimization of landing gears. This research methodology also gives the knowledge about the various scholars and who had previously carried research on the topic. The literature review that was carried out gave the detailed knowledge on upgrading and optimization of landing gears.

Various mathematical models will be used during the research. Mathematical models regarding the upgrading and optimization of landing gears will be developed.

Advantages of using mathematical models

Some of the advantages of using mathematical models include:

• They are easy and quick to produce
• They can be able to simply a more complex situation
• They7 can greatly help in enhancing our understanding of the real world variables.
• They make it possible for the predictions to be made
• They can assist in providing control as in the case of aircraft control (Mitragotri et al 200).

Limitations of using mathematical models

• Most of the mathematical models are a simplification of the real problem and in most cases does not include the aspects of the problem.
• The mathematical models might only work in certain situations.

Various computer programs and simulations will be carried out to determine the aspects of upgrading and optimization of landing gears.

Benefits of Computational methods and simulation

• Computer simulation can avoid danger and loss of life
• The different conditions can be varied and the outcome of evaluated
• Computer simulations can be sped up so that the character can be studied easily and quickly for a long time
• The simulations can be slowed down to study the behaviours more closely
• Simulation is more cost-effective

Disadvantages of Computational methods and simulation

• In simulation it can be very hard to measure how one factor affects another in order to make initial measurements
• For one to carry out simulation he/she requires a deeper understanding of the subject

The research approach proposed is intended on utilizing literature reviews, interviews, and survey and computer simulations to carry out the research. Computer simulations and literature review encourages a researcher to keenly examine the information relating to a particular setting that is a specific topic of research. Additionally, literature review which is Usually referred to as secondary sources allows a researcher to pick up top to bottom information and illustrate the aspects of a proposed research topic. For the given research project it is suitable carrying out various computer simulations on upgrading and optimization of landing gears. With that it can be possible to get the clear idea of what is happening in real situations.

The research is to be carried out in 65 weeks and the timeline for the research is as follows.

Period/Duration	Activity
Week 1 – 9	Identify the collaborators, mentors and other stakeholders who can assist in the research process. Acquire informal critique from the collaborators, mentors regarding the merits and demerits of the study topic.
Week 9 –  16	Carry out a thorough literature review of the topic of study to identify the various gaps in the experts in the field and knowledge in general and to obtain detailed knowledge regarding the topic of research.
Week 17-25	Come up with specific aims and study objectives based on the conclusion and results obtained from the literature review.
Week 26-35	Come up with the design of the study having the best approach that will facilitate efficient collection of data on the topic of research and ensure that the research is successfully carried out.
Week 36 –  41	Refine the study questions after the consultation with the mentors and collaborators in order to flesh out the protocol and at the same time create a proposal.
Week 41- 47	Start to drafting the proposal budget to ensure that the project aims can be met without any challenge Obtain the necessary advice from the colleagues/guardians  and the sponsor sources Identify the potential reviews of the work to ensure that they are in constant touch
Week 48- 55	Start writing the proposal draft Put the proposal aside for some time and then I will start editing I will employ the outside reviewers who I identified initially  proofread my work and give the appropriate comments
Week 56 – 60	I will rewrite and re-write the proposal as per the comments of the external review. the process will continue until close to the submission dates of the proposal I will finalize the proposal budget with a well-defined and detailed justification
Week 61 –  64	I will write the abstract and summary of the research
Week 65	Have a face-to-face meeting with the mentor’s /supervisor in order to get as much feedback as possible.

Conclusion

In conclusion, the landing gear in aircraft is used to control the aircraft during the landing, take-offs and other ground operations. Due to the roles which the landing gears play in the operations of the aircraft.it must have the ability to resist the other forces associated with loads of the aircraft. The landing gears play a very vital role in supporting the aircraft above the ground to enable it to keep sufficient clearance between the ground and the surface of the aircraft. There is need to design and optimize the landing gears in order to archive better performance

References

Fletcher H., Griffis J. and Major C. (2012), Airport Upgrading Versus Landing Gear optimization. Transportation Engineering Journal of ASCE. 102(2), pp.  313-329

Gudmundsson, S. (2013). General aviation aircraft design: Applied Methods and Procedures. Butterworth-Heinemann.

Guo Y. & Yamamoto K. (2016), experiment study on Aircraft Landing Gear Noise. Journal of aircrafts.43 (2), pp. 306-317

Jocelyn Pritchard. (2011), overview of Landing Gear Dynamics. Journal of Aircraft, 38(1), pp. 130-145

Mitragotri, S., Anissimov, Y. G., Bunge, A. L., Frasch, H. F., Guy, R. H., Hadgraft, J., … & Roberts, M. S. (2011). Mathematical models of skin permeability: an overview. International journal of pharmaceutics, 418(1), 115-129.

Peery, D. J. (2011). Aircraft structures. Courier Corporation.

Torenbeek, E. (2013). Synthesis of subsonic airplane design: an introduction to the preliminary design of subsonic general aviation and transport aircraft, with emphasis on layout, aerodynamic design, propulsion and performance. Springer Science & Business Media

Yuanyuan  l., Shunguang S. and Chunjie W. (2017), Multi-objective optimization on the shock absorber design for the lunar probe using no dominated sorting genetic algorithm II. International Journal of Advanced Robotic Systems. 14(4), pp. 236- 376

Zhang W., Zhang Z., Zhu Q. & Xu S.(2010) Dynamics Model of Carrier-based Aircraft Landing Gears Landed on Dynamic Deck. Chinese Journal of Aeronautics. 22(4), pp. 371-379