Aircraft Seat Research Articles

The importance of different body parts for the (un-)pleasantness of whole-body vibration on an aircraft seat bench

Noise and vibration are two physical factors that can reduce the perceived comfort of passengers during a flight. To reduce the detrimental impact of seat transmitted vibration, it is necessary to understand which body parts and, thus, which corresponding seat parts are relevant for the pleasantness assessment. In this study, 40 participants (19 female, 21 male) rated the pleasantness of sinusoidal whole-body vibrations in the vertical direction while seated on a typical aircraft seat bench and listening to a synthetic broadband aircraft cabin noise over headphones. The vibration signals covered seven frequencies and four vibration levels, and pleasantness ratings were made on a verbally anchored scale. In addition, the participants separately marked those body parts that contributed significantly to their rating and those where they felt a vibration for each of the vibroacoustic stimuli. The results showed that not all body parts at which vibration were felt were also classified by the participants to reduce the ratings significantly, especially at higher vibration levels. A median split of the participants into groups of lighter and heavier participants indicates which body properties might be underlying factors for certain judgments.

A study on the optimal design of UAM seats

The objective of this study is to enhance the efficiency of urban air mobility (UAM) air transportation by determining the optimal design, materials, and processes of seven different manufactured fiber-reinforced plastics (FRP), and to confirm their applicability for next-generation UAM aircraft seats. Structural designs for the aircraft seat models were carried out using carbon fiber-reinforced plastic (CFRP), glass fiber-reinforced plastic (GFRP), and GFRP chop materials, employing Autoclave, Hot-press, and vacuum-assisted resin transfer molding (VaRTM) processes, resulting in a total of seven FRP configurations. It was confirmed that CFRP seats were 50% lower weight than aluminum models, while GFRP seats showed a 30% reduction. Although Autoclave processing resulted in the highest tensile strength at 985[Formula: see text]MPa, VaRTM processing also produced strength levels comparable to Autoclave processing. Structural integrity assessments of the seat models, utilizing the Korean aviation standards (KAS), confirmed that the designed seat models exhibited no failure or deformation under the conditions required by the technical standards. This study provides insights into the potential application of the seven types of FRP materials in the design of aircraft seats, offering weight reduction benefits and meeting the structural integrity requirements outlined by KAS.

Design of a metal additive manufactured aircraft seat leg using topology optimization and part decomposition

PurposeThe lightweight design of aircraft seats can significantly improve fuel efficiency and reduce greenhouse gas emissions. Metal additive manufacturing (MAM) can produce lightweight topology-optimized designs with improved performance, but limited build volume restricts the printing of large components. The purpose of this paper is to design a lightweight aircraft seat leg structure using topology optimization (TO) and MAM with build volume restrictions, while satisfying structural airworthiness certification requirements.Design/methodology/approachTO was used to determine a lightweight conceptual design for the seat leg structure. The conceptual design was decomposed to meet the machine build volume, a detailed CAD assembly was designed and print orientation was selected for each component. Static and dynamic verification was performed, the design was updated to meet the structural requirements and a prototype was manufactured.FindingsThe final topology-optimized seat leg structure was decomposed into three parts, yielding a 57% reduction in the number of parts compared to a reference design. In addition, the design achieved an 8.5% mass reduction while satisfying structural requirements for airworthiness certification.Originality/valueTo the best of the authors’ knowledge, this study is the first paper to design an aircraft seat leg structure manufactured with MAM using a rigorous TO approach. The resultant design reduces mass and part count compared to a reference design and is verified with respect to real-world aircraft certification requirements.

Finite element stress analysis and topological optimization of a commercial aircraft seat structure

In recent years, the Finite Element Method (FEM) has emerged as a cornerstone in the field of seating design, particularly within the aircraft industry. Over the past decade, significant advancements in Finite Element (FE) analysis techniques have revolutionized the seat industry, enabling the creation of safer and more cost-effective seat designs. The accuracy of FE analysis plays a pivotal role in this transformation. In the process of constructing a reliable finite element model, the selection and precise manipulation of key parameters are paramount. These crucial parameters encompass element size, time scale, analysis type, and material model. Properly defining and implementing these parameters ensures that the FE model produces accurate results, closely mirroring real-world performance. Verification of Finite Element Analysis (FEA) results is commonly accomplished through experimental methods. Notably, when the parameters are appropriately integrated into the modelling process, FE analysis outcomes closely align with experimental results. This study aims to leverage the power of FEM in performing static stress analysis and topology optimization of aircraft seats using the SOLIDWORKS commercial finite element platform. By simulating loading conditions, this research calculates static stresses and displacements experienced by the aircraft seat. Through a comprehensive topology optimization study, the weight of the airplane seat is remarkably reduced by up to 30%, while still prioritizing passenger safety. The success of this optimization showcases the potential for substantial weight savings in aircraft seat design without compromising safety standards.

The role of muscle forces in neck comfort for static seating: a pilot study

Aircraft seats play a key role in the competition between aircraft companies seeking to differentiate themselves in terms of passengers’ inflight experience. The seat design process relies on computational and experimental methods based on subjective measures, such as comfort rating questionnaires, and objective comfort indicators of seat-occupant interaction, such as contact pressure distribution and muscle activation. Previous studies around muscle activity for seating comfort assessment have primarily focused on more active scenarios or active systems. As such, there are limited studies about the role of muscle force in normal and relaxed sitting conditions, common in aircraft settings. This paper explores the relationship between activities of the neck muscles, sternocleidomastoid, and upper trapezius, measured from human participants seated sedentarily on conventional business aircraft seats and their perceived comfort with different backrest inclinations. The results show, for normal seating without neck pillow, no significant association is found between the backrest inclination and the neck’s comfort or muscle activation. For general seating across different backrest inclinations, a positive medium correlation between muscle activation and comfort is found in upper trapezius (R = 0.5332, p = 0.0187). This work serves as a pilot study of this new approach of comfort evaluation using muscle feedback in seat designing processes and highlights the posterior’s effect to seating experience in the neck region.

An interval-valued estimation method of aircraft route carbon emission: A function of aircraft seat capacity and route flight time

In this paper, we introduce a novel approach that utilizes aircraft seat capacity and its route flight time to predict carbon emissions for aircraft manufacturers during the aircraft design stage. To address data fluctuations arising from the human-aircraft-environment-management system throughout the production and operation of the future-designed aircraft, we employ the interval-valued data type, replacing the traditional point data type, and construct an interval-valued regression model. Within the parameterized method framework, our programming model incorporates additional constraints to ensure the intersection of each interval-valued sample. This addresses the challenges significant data fluctuations pose, leading to improved fitting performance. Furthermore, the model is demonstrated to satisfy Kuhn-Tucker conditions for solvability, and the obtained regressed parameters exhibit favorable small-sample properties. An empirical study using airline operating data from China validates the prediction effectiveness of the programming model. Finally, based on these predictions, we provide applications and suggestions for decision-makers aimed at reducing CO2 emissions.

The impact of accelerometer location and frequency weightings on the prediction of pleasantness ratings for vertical whole-body vibrations on an aircraft seat bench

Noise and vibration are two physical factors that can reduce the perceived comfort of passengers during a flight. In this application context, vibrations are often measured using accelerometers placed at the seat rail or with a seat pad between the seat surface and the buttock of a sitting person. To develop pleasant aircraft cabin environments, it necessary to know which measurement location best reflects subjective ratings and whether the application of a frequency weighting as proposed in the ISO 2631 standard is beneficial. In this study, 40 participants rated the pleasantness of sinusoidal whole-body vibrations in the vertical direction while seated on a typical aircraft seat bench and listening to a synthetic broadband aircraft cabin noise over headphones. The vibration signals covered seven frequencies and four vibration levels and ratings were made on a verbally anchored scale. The results showed that an increase in vibration level leads to more unpleasant ratings for each of the tested frequencies, independent of the accelerometer position. Although the ISO frequency weighting underpredicts the ratings for high frequencies in both cases, applying it to the seat rail measurements seems to reflect the pleasantness ratings better than the seat pad measurements proposed in the ISO 2631 standard.

CUSTOMER-FOCUSED AIRCRAFT SEAT DESIGN: A CASE STUDY WITH AHP-QFD

Aviation is rapidly expanding and recovering from the pandemic impact driven by the experience economy. This is particularly subject to interfaces such as the aircraft seats, which are getting intense attention as a differentiator in the cabin. The focal point of this paper is to assess and convert customer requirements into what must be done for an optimum aircraft seat. To achieve this, a 2-step analytic hierarchy process and quality function deployment (AHP-QFD) methodology was successfully applied, consolidating product quality characteristics. Then, it leverages a novel scoring method of interdependencies to isolate dependable design variables. Consequently, safety, weight, and durability scored maximum, emphasizing backrest design and alternative composite materials, while test infrastructure was determined as a critical investment component. Furthermore, it is shown how AHP-QFD can be used for product strategy and strategic portfolio management of R&D projects.

A method of aircraft seat dimension design for long-term use by passengers with different body types

To improve the comfort of seat support performance, we proposed a seat dimensions design method. First, an adjustable seat was used to obtain the measurement data of user-selected comfortable seat dimensions. Second, the differences in the measurement data of different body types and riding time variables were analyzed. Third, a compromise treatment method for the different comfort requirements was developed. This method was applied to the design of passenger seats for short-distance flights in China. The lumbar support thickness was significantly different in the time variables, and the seat pan inclination and neck support height were significantly different among body types. We did not find significant differences, however, in seat height, backrest inclination, lumbar support height, or neck support thickness according to time or body type variables. There is one optimal dimension for seat height (430.5 mm), backrest inclination (104.2°), lumbar support height (98.8 mm), and neck support thickness (44.4 mm). However, seat pan inclination (5.8°, 7.2°, and 9.3°), neck support height (582.6 mm and 622.5 mm), and lumbar support thickness (40.6 mm and 48.7 mm) need multiple dimensions to meet passenger comfort requirements. This seat dimension design method provides new ideas to explore the comfort requirements of passengers and addresses the differences in comfortable seat dimension requirements for different body types and different flight durations.

Comfort Influences the Choice Between Airplane and Train Even on Short Distances

High-speed rail might be a solution to reduce energy usage and carbon emissions as rail transport consumes less energy than airplanes. However, in choosing a transport system, time is an important factor in making many passengers choose air travel. This paper studies the reasons why passengers choose a transport mode, and compares the comfort of aircraft and train seats. This study shows that time and costs are the most mentioned factors, but comfort and sustainability can play a deciding role between trains and airplanes on time and cost-competitive travel routes. The train seat is evaluated as the most comfortable, but still, part of the passengers choose the aircraft as the length of sitting on the seat is limited.

Comfort Study of General Aviation Pilot Seats Based on Improved Particle Swam Algorithm (IPSO) and Support Vector Machine Regression (SVR)

Little work has been carried out to predict the comfort of aircraft seats, a component in close contact with the human body during travel. In order to more accurately predict the nonlinear and complex relationship between subjective and objective evaluations of comfort, this paper proposes a prediction method based on the Improved Particle Swarm Algorithm (IPSO) and optimized Support Vector Machine Regression (SVR). Focusing on the problems of the too-fast convergence and low accuracy of the traditional particle swarm algorithm (PSO), the improved particle swarm algorithm (IPSO) is obtained by linearly decreasing the dynamic adjustments of inertia weight ω, self-learning factor c1, and social factor c2; then, the penalty parameter C and kernel function parameter σ of SVR are optimized by the IPSO algorithm, and the comfort prediction of IPSO-SVR is established. The prediction accuracy of IPSO-SVR was 94.00%, the root mean square error RMSE was 0.37, the mean absolute value error MAE was 0.32, and the goodness of fit R2 was 0.92. The results show that the optimized IPSO-SVR prediction model can more accurately predict seat comfort under different angles and backrest tilt angles and can provide reference and research value for related industries. The results show that the optimized nonlinear prediction model of IPSO-SVR has higher accuracy, and its prediction method is feasible and generalizable, meaning it can provide a reliable basis for the prediction of seat comfort under different angles and backrest inclinations, as well as providing reference and research value for related industries.

Research on dynamic comfort maintenance by measuring lower limb edema and seat pressure during simulated seated sleep in flight

Objectives. Seated sleep during flight can bring significant discomfort to passengers. The objective of this research was to study passengers’ dynamic comfort maintenance strategies in lower limb postural shifting during seated sleep in flight. Methods. Studies on seated sleep postures and sitting comfort were conducted. First, 40 participants were recruited to the observational research for collecting typical leg postures during seated sleep. Then, an experiment was conducted with the participants simulating seated sleep in the aircraft seat. The changes in lower limb edema and seat pressure in different postures were measured with a bioelectrical impedance device, near-infrared spectroscopy device and pressure mapping device. Results. Six postures were selected through the observational research. The experiment showed that tissues of the thighs and buttocks suffer alternate higher compression by shifting between the six postures. Lower limb edema is higher when the shanks are forward, while the tissue under the ischial tuberosity suffers higher compression when the shanks are neutral. Conclusion. Six motivations for passengers to shift each sitting posture to achieve dynamic comfort were summarized, which helps obtain alternating rest in different body parts. The suggestion of a leg position adjustment system was also proposed.

A Virtual Sensing Active Noise Control System Based on a Functional Link Neural Network for an Aircraft Seat Headrest

PurposeThe goal of this work is to propose a local Active Noise Control system for an aircraft seat’s headrest. This system should be able to extend the quiet zone beyond the physical microphones that can be placed behind the passenger’s head due to space constraints. Furthermore, the control algorithm should perform efficiently when non-linear phenomena exist during the sound propagation.MethodsA functional link neural network and a computationally efficient Multiple Input Multiple Output approach are used for the system’s implementation. The quiet zone is extended by linearly estimating the acoustic pressure in front of the headrest surface. The main novelty of this paper is the combination of these methods in an attempt to improve acoustic pressure attenuation performance, while keeping computational complexity low.ResultsThe proposed control algorithm has been evaluated through numerical simulations, including Finite Element Method and experimental tests at an aircraft cabin mock-up. The results show that for a real-world acoustic disturbance, a 10 dB reduction in sound pressure level was achieved 10 cm away from the headrest surface. In addition, the attenuation of some harmonics can reach 20 dB and in most cases is bigger than the linear FxLMS algorithm.ConclusionsTo summarize, it has been demonstrated that a multichannel functional link neural network using a simple virtual sensing technique can efficiently attenuate synthesized and real world acoustic disturbances captured in a tilt-rotor aircraft’s cabin. Finally, it can create an adequate quiet zone for gentle head movement while maintaining its stability.

Perception of COVID-19 rapid antigen testing approach prior to flight schedule among air travelers: a questionnaire-based study

PurposeThe COVID-19 pandemic had a huge impact on people's lives, air travel and tourism. The authors explored travelers' perceptions of COVID rapid antigen tests before boarding aircraft, willingness to fly and the precautionary actions for safe air travel.Design/methodology/approachAll the participants were asked to complete the survey while reflecting on their experiences of air travel during this COVID-19 pandemic. The questionnaire consisted of demographic information of the participants and air travel preferences during pandemic. The survey was conducted through Google Form in both English and Arabic language. The link was shared through emails and WhatsApp.FindingsIn this survey, majority had willingness to fly during pandemic. 45.2% preferred to undergo rapid test before boarding, while 41.9% refused owing to no added benefit (23.8%) and nasal discomfort (9.3%) among others. The best indicators to resume safe air travel were COVID-19 vaccination (80.4%), wearing face mask during flying hours (70.8%) and maintain social distancing with aircraft seating (49.6%).Research limitations/implicationsThe findings of the current survey could help the organizations and the biosecurity authorities to act and support accordingly and thus reduce passenger anxiety about resuming the flights, thereby increasing willingness to fly and preparing oneself and the aviation industry for future pandemics.Originality/valueThe findings of the current survey could help the organizations and the biosecurity authorities to act and support accordingly and thus reduce passenger anxiety about resuming the flights, thereby increasing willingness to fly, and preparing oneself and the aviation industry for future pandemics.

Sitting comfort in an aircraft seat with different seat inclination angles

Passengers' comfort experience during flights is important in choosing their flights. The focus of this study is passengers’ perceived comfort in different climbing angles during ascent. Twenty-six participants were invited to experience three inclination angles including 3°, 14° and 18° in a Boeing 737 cabin. The angle of 3° was used to simulate cruising stage and the other two were used to simulate different climbing angles. Participants experienced each setting for 20 min where the perceived comfort, their heart rate variability(HRV), and their body contact pressure values on the backrest and seat pan were recorded with questionnaires, HRV bands and pressure mats respectively. The results indicate a preference of 14° inclination angle resembling the cruising angle (3°) and having the slowest moving speed of the center of pressure (COP) on both the backrest and seat pan.

Analysis of a new standing passenger seat design for commercial transport aircraft

In order to have profitable flight operations, many airlines have used high-density passenger cabin design and arrangement. By doing this, more passengers can be accommodated inside the cabin per flight, hence reducing the overall flight costs per passenger. With conventional aircraft seats, the seat pitch is progressively reduced over the years to accommodate additional passengers into the cabin and this has created high flight comfort issues among the passengers. Reduced seat pitch also means that available legroom at each seat becomes smaller, which leads to discomfort due to inadequate space for many passengers in their sitting positions. For short-haul flights, the standing passenger cabin concept has been explored and proposed to help resolve this issue. Since passengers will require less legroom space in their standing positions, it is possible to have reduced seat pitch (hence more passengers) and acceptable comfort. A proposed standing passenger seat design is studied in this work to establish and support its suitability to be used in the standing passenger cabin concept. Finite element analysis is conducted to demonstrate its ability to fulfill the strength requirements imposed by the aviation authority. Furthermore, several design improvements have also been made to minimize its weight while still satisfying the strength requirements. The final standing passenger seat design has been shown to have adequate structural strength to cope with the requisite 9-g loading and a mass of about 11.7 kg which is lower than most conventional aircraft seats. All in all, this indicates that the proposed standing seat design has a good potential to be applied for air transportation and further supports the future implementation of the standing cabin concept. The final design from this study can be further refined in future studies to improve its characteristics.

Pleasantness ratings for vertical whole-body vibration on an aircraft seat and relevant body parts involved

Noise and vibration are two physical factors which can reduce the perceived comfort of passengers in an aircraft during flight. In this study, 40 participants rated the pleasantness of 28 sinusoidal whole-body vibrations in the vertical direction, which differed in frequency and acceleration level while seated on a typical aircraft seat bench. The results showed significant main effects for frequency and level as well as an interaction of the two factors and an interaction between frequency and gender. Using body-maps, the pleasantness ratings could be linked to those parts of the body that were underlying the judgments. In a second experiment, the same 40 participants judged whether noise or vibration should be attenuated for comfort improvement for the same 28 signals. Logistic regression functions fitted to the results enable an estimate of the percentage of people preferring vibration reduction as a function of frequency and vibration level.

Ergonomics and Aircraft Seats: A Study of Comfort and Well-being for the User

Ergonomics and Aircraft Seats: A Study of Comfort and Well-being for the User

A dynamic strength analysis of wheelchairs based on aviation safety regulations for the purpose of applying as aircraft seats

A dynamic strength analysis of wheelchairs based on aviation safety regulations for the purpose of applying as aircraft seats

Modelling of spinal injury during aircraft seat ejection loads

The primary aim of the present work is to calculate the ejection forces on the spine lumbar vertebra (L1-L5) using Finite element modeling. The critical time of ejection was calculated based on mathematical modelling using ejection parameters such as tail height, aircraft velocity, and aircraft length. The Finite element analysis at a different level of G-Forces was performed with appropriate boundary conditions to simulate seat ejection and stress on the vertebral body is analyzed. The model was validated at the Functional spinal unit level and a multi-level model based on published literature. It was found that the anterior side of the L1 Vertebrae experiences the maximum stress, which justifies the common anterior wedge compression fracture. More stress was distributed on the superior region of endplates than that at the inferior region throughout the lumbar vertebra although the difference in the stress value between the superior and inferior region decreases from L1 to L5. In all the cases cortical bone experiences the maximum stress followed by the endplate and the stress value obtained for Intervertebral Disc(IVD) is found to be 90% lesser than the endplate, which means the initial failure may occur at the vertebral body followed by endplate.