Aircraft Seat Research Articles

Access improvement to aircraft passengers' hand luggage

Efficient use of space and passenger comfort in aircraft interiors are major issues. There is not much research available about the flying experience regarding passengers' personal belongings. The objective of this study is to explore concepts within the current aircraft seats which improve the passenger experience related to their personal belongings like wallets, mobile phones and laptops. Through on-site observations, interviews and online questionnaires, data regarding the number of personal belongings taken into the airplane and opinions about access to hand luggage were gathered. These data were used to develop different concepts to optimize the aircraft interior, which were evaluated by passengers. Almost every passenger carries a phone (88%), wallet (94%), travel documents (98%) and keys (76%) with them and they like to have these stored close by. Passengers rate the concept that provides integrated storage in the tray table of the aircraft seat the best. Extra storage possibility in the table-tray seems a promising solution according to the passengers.

Enhancing the travel experience and delivering great customer service at Gerald R. Ford International Airport

What motivates passengers to travel through our airport? We know travellers rant about tiny aircraft seats, lost luggage and the ticket prices before they travel, but there are ways we can entice them to fly out of the Gerald R. Ford international Airport in Grand Rapids, Michigan to keep them coming back time after time. When big city airports lose the grasp of why we fly, we bring travelers back in. In this paper, we examine some of the reasons we’ve been successful in Grand Rapids with customer service at our airport, and ways you can work to make the airport friendlier, more comfortable and welcoming. We’ll dive into the reasons social media at our airport has grown, ways one can take a small holiday and turn it into a customer service outreach, and some of the ambassadors – both humans and dogs – that have enhanced our customer service experience at GFIA

Development of an updated tensile neck injury criterion.

Ejection neck safety remains a concern in military aviation with the growing use of helmet mounted displays (HMDs) worn for entire mission durations. The original USAF tensile neck injury criterion proposed by Carter et al. (4) is updated and an injury protection limit for tensile loading is presented to evaluate escape system and HMD safety. An existent tensile neck injury criterion was updated through the addition of newer post mortem human subject (PMHS) tensile loading and injury data and the application of Survival Analysis to account for censoring in this data. The updated risk function was constructed with a combined human subject (N = 208) and PMHS (N = 22) data set. An updated AIS 3+ tensile neck injury criterion is proposed based upon human and PMHS data. This limit is significantly more conservative than the criterion proposed by Carter in 2000, yielding a 5% risk of AIS 3+ injury at a force of 1136 N as compared to a corresponding force of 1559 N. The inclusion of recent PMHS data into the original tensile neck injury criterion results in an injury protection limit that is significantly more conservative, as recent PMHS data is substantially less censored than the PMHS data included in the earlier criterion. The updated tensile risk function developed in this work is consistent with the tensile risk function published by the Federal Aviation Administration used as the basis for their neck injury criterion for side facing aircraft seats.

Emopad: An Affective Gamepad

Affective Systems have been used in different applications, such as stress monitoring in aircraft seats and managing sensitivity in autism spectrum disorder. Although many scientific progresses have been made there are many computational challenges to be overcome in order to embedded affectivity into traditional user interfaces. For example, context-sensitive algorithms, low-complexity pattern recognition models and hardware customizations are requirements to support the simplification of user’s experience becoming more intuitive, transparent and less obstructive. In this paper an affective gamepad is presented. This acquisition system has been developed to improve user’s biofeedback when they are playing games on Microsoft Xbox or Sony PlayStation. The preliminary version of Emopad is able to capture Galvanic Skin Response (GSR), Temperature, Force, Heart Rate (HR) and its variability (HRV) by photoplethysmography (PPG) sensor while complementary algorithms are executed to filter noise, recognize interests patterns and classify events related to user’s emotional states. All processing phases are embedded into Emopad, and they explore microcontroller’s dynamic power management. Emopad has been developed to deal with energy-efficient and platform-independent requirements. Concerning to this paper’s aim, the acquisition systems development is highlighted. Also, the sliding window-based algorithm is presented and evaluated. It has been applied after sampling in GSR, Force, Temperature and HR signals to detect events related to emotional responses. The success of affective gamepads can lead to a paradigm shift, because traditional consoles can be configured to work as Point-of-Care technologies. Consequently, they can receive, process and transmit physiological data and events related to clinical conditions about their users.

Aircraft Seat in- and Egress Differences between Elderly and Young Adults

An aircraft interior should be adjusted to the needs of elderly, but research data in this area are limited. Especially, in- and egress could be an issue. In this paper differences in strategies between elderly and students are studied in a mock-up by analyzing video recordings of the in- and egress in seat rows. It shows that elderly take significantly more in- and egress time, especially for the non-aisle seat. Elderly also use more often support by touching arm rests and backrests. The in- and egress of PRMs could be improved to give the right support, perhaps by redesign and to assign PRMs to special seats.

Identifying patent conflicts: TRIZ-Led Patent Mapping

This paper presents a novel method of patent mapping for visualising conflicts between patent claims that incorporates the Theory of Inventive Problem Solving (TRIZ). The method uses TRIZ engineering parameters as the criteria for evaluating dissimilarities between patent claims, producing a visualisation based on Multi-Dimensional Scaling (MDS) that can be compared with legal judgments.The advantages of the method are that it (a) reduces evaluation complexity by transforming claim-to-claim comparisons into claim-to-criteria comparisons, and (b) provides a means of comparing judgment standards between different legal authorities in mechanical engineering terms. Reliability and validity of the method are tested through focus groups using a case study on aircraft seats. The scope of the method is limited to the field of mechanical inventions.

Measurement of a cost function for US airlines: restricted and unrestricted translog models

This paper continues and expands several themes from previous studies of commercial airline cost functions. A well specified industrial cost function reveals characteristics about the market players, such as economies of scale and the cost elasticities with respect to operational styles. Using a translog specification, and its restricted first-order form, this paper updates previous parameter estimates, reworks the experimental design, and gives new analysis to describe the spectrum of choices facing airline firms in recent years. The translog model in this paper allows the energy cost share to interact with other variables and illuminate what factors may exacerbate cost sensitivity to energy prices, an advance in this specific area of interpretation. The result shows that fuel cost shares tend to be higher with older equipment, smaller fleet sizes, and to be increasing in aircraft size and seating density. The restricted first-order model indicates that older aircraft designs are more costly to operate, even accounting for operational style. This may imply that airlines with poorer access to capital suffer a cost disadvantage, particularly during a fuel spike - also a new contribution of the paper. Finally, the first-order model does not reject constant returns to scale (CRS) for fleet expansion, or increasing returns to scale (IRS) in aircraft size, which are the expected results.

Certification by analysis and simulation validation

Modelling and simulation is increasingly being used to represent occupant behaviour of human subjects and anthropomorphic test devices. Future trends are towards the application of certification by analysis whereby a product, such as an aircraft seat, can be partially certified through analytical means. A robust and objective method to discriminate different features of the model comparison is needed to determine model validity so that the certification authority can objectively determine the model acceptability. Expert opinion could introduce bias and lead to inconsistent results. In any testing, there is some inherent uncertainty and variation in the measured responses that affects the baseline comparison data. Each individual response should be treated as a separate case. A method derived from Sprague and Geers was developed and applied to occupant models of seat simulations. Using test data, acceptable error levels were calculated that represent the uncertainty and provide consistent and objective results.

Manikin families representing obese airline passengers in the US.

Aircraft passenger spaces designed without proper anthropometric analyses can create serious problems for obese passengers, including: possible denial of boarding, excessive body pressures and contact stresses, postural fixity and related health hazards, and increased risks of emergency evacuation failure. In order to help address the obese passenger's accommodation issues, this study developed male and female manikin families that represent obese US airline passengers. Anthropometric data of obese individuals obtained from the CAESAR anthropometric database were analyzed through PCA-based factor analyses. For each gender, a 99% enclosure cuboid was constructed, and a small set of manikins was defined on the basis of each enclosure cuboid. Digital human models (articulated human figures) representing the manikins were created using a human CAD software program. The manikin families were utilized to develop design recommendations for selected aircraft seat dimensions. The manikin families presented in this study would greatly facilitate anthropometrically accommodating large airline passengers.

Explicit dynamic formulation to demonstrate compliance against quasi-static aircraft seat certification loads (CS25.561) – Part II: Influence of body blocks

Loading an aerospace and automotive seat statically through lap or body blocks is a complex and highly non-linear problem, as the key numerical challenge is to replicate the contact and slipping kinematics between seat, lap block and belt. In addition, severe element distortions and unexpected contact between parts can occur due to the large deformations involved, which result in implicit solvers struggling to find a converged solution. This paper focuses on the use of an explicit Finite Element Analysis (FEA) solver (LS-DYNA3D) for an aircraft seat subject to Certification Specifications CS25.561, although the ideas presented are equally applicable to automotive seat designers. Explicit codes are better able to overcome contact convergence issues and are often used with appropriate damping to achieve a quasi-static solution. This paper reviews the methodology presented in Part I, whereby issues relating to damping, mass and time scaling are outlined in order to overcome the high computational time step costs (Courant-Friedrichs-Lewy (CFL) condition), together with the procedural and error checks required to ensure a quasi-static response. This paper extends the methodology by considering load cases that use lap blocks, such as ‘forward 9g’ and ‘upward 3g’ certification requirements. Alternative modelling approaches to represent the loading mechanism and effect of lap block mass on solution accuracy are discussed. This paper concludes with a verification framework that outlines the quality checks on various model energies and their ratios, where the numerical results are validated against test in terms of displacements and seat kinematics. Thus, ‘Part I’ and ‘Part II’ cover all elements related with the application of an explicit dynamic integration scheme to demonstrate static seat compliance, and together, form a clear framework to assist a Computer Aided Engineering (CAE) analyst involved in applying an explicit integration scheme to solve non-linear quasi-static analyses.

Explicit dynamic formulation to demonstrate compliance against quasi-static aircraft seat certification loads (CS25.561) – Part I: influence of time and mass scaling

A finite element model of an aircraft seat subjected to static certification loads (Certification Specifications CS25.561) involves material, geometric and contact non-linearities. Implicit algorithms can model the physics of such problems appropriately but suffer from shortcomings such as significant finite element modelling efforts, high disk space and memory requirements and unconverged solutions. Explicit finite element schemes offer a more robust alternative for convergence for quasi-static loadcases but may come at an even higher computational cost as smaller solution time steps are required, in addition to unwanted inertial effects. A methodology to apply an explicit formulation for simulating static certification loading for an aircraft seat-structure is presented and validated in this article. The first part reviews the design novelties of the triple seat-structure considered, the safety regulations used in aircraft seat certification. The key theoretical aspects of an explicit solver are presented, together with the numerical challenges faced when applied to solving quasi-static problems. Time scaling, mass scaling and damping are common approaches to assist in artificially reducing the computational time but previous articles provide little insight into how to apply these techniques correctly and the level of checking that is required to ensure the quality of the results are unaffected by these modifications. The main focus of this article is to clearly define the procedure to establish appropriate factors for mass scaling, time scaling and damping. Quality checks, such as ratio of kinetic energy to internal energy and their time-histories have been investigated to ensure a quasi-static solution. finite element analysis results are validated against experimental testing for the 8.6 g downward loadcase. Parameters such as kinematic behaviour and deflections at key locations been used for comparison. An acceptable level of correlation between finite element analysis results and physical tests validates the proposed methodology, which will be extended in a future article (Part II) to consider additional contact complexities with the inclusion of body blocks.

Piled-up configuration design of decelerators in drop test for aircraft seats

To ensure the safety of aircraft seats, it is mandatory to perform a dynamic test under an acceleration pulse prescribed by the Federal Aviation Administration. This paper proposes a design method for a decelerator. The design involves the piling up of paper sandwich panels for use in a drop test. First, a quasi-static compression test of paper core sandwich panels was conducted to examine the displacement–load curve, from which the absorption energy of the panels was deduced. Then, a piled-up configuration of panels was designed via a method based on the rigid, perfectly plastic, locking model proposed by Reid and Peng—in which the dynamic effect of the panel is considered when the core height is constant or variable—under the assumption that the decelerator crushes in descending order starting with the upper panel. Second, a drop tower test was conducted to determine whether the designed decelerator achieves the required acceleration pulse. The results of the proposed method were compared with those of the decelerator design method by Shoji et al. based on the dynamic absorption energy of the panels. The test results indicate that decelerators designed with the proposed method—based on the absorption energy derived from a simple static compression test and employing the effect of dynamic crushing—can produce identical results to those designed with the method by Shoji et al., which is based on the absorbing energy derived from a complicated dynamic compression test.

Total Design of Active Neck Support System for Economy Class Aircraft Seat

Travel by air with long hours will create discomfort feeling for aircraft passenger especially economy class aircraft passenger. Long hour air travel will create physiological stress on aircraft passenger. It may due to seat space limitation, noise, vibration, cabin humidity as well as seat comfort. Seat comfort is a subjective feeling that related to psychological aspect of aircraft passenger. The current aircraft passenger seat is equipped with a passive function where the passenger themselves needs to adjust the seat for comfort seating position. The aircraft passenger will not able to adjust the seat when the aircraft passenger is in the low activity condition. The active seat support system was developed to support the aircraft passenger actively. The first prototype of active seat support system is focus on neck section. The head position of the aircraft seat was embedded with the system to detect the head position of the passenger. During the development of the active seat support system, total design technique was used. Five conceptual designs were generated for selection. To determine the final design of active neck support system, the matrix evaluation method was used. The weight of the concept was obtained through weight analysis.

Centrifuge-Induced Neck and Back Pain in F-16 Pilots: A Report of Four Cases

Early in their careers, as an important part of their training to become fighter pilots, pilots undergo centrifuge training in order to learn effective anti-G straining maneuvers (AGSM) and to test their G tolerance. The exposure of pilots, especially early in their careers, to training that could lead to injuries should be avoided. This is a report of four cases of neck pain experienced during G-tolerance training, some of which may have caused ongoing problems for the pilot. Four cases, describing four different injuries experienced during G-tolerance training, are presented, including the history of the incident, radiographic description, and physical examination. Three main questions were identified in regards to the training of fighter pilots in centrifuges: 1) should the seat be positioned to imitate a specific aircraft's seat? 2) should the pilot wear a helmet and a mask? 3) what is the appropriate amount of head support? Based on the four cases reported it is recommended that pilots should be given the best possible conditions concerning neck support and load on the neck and the back for G-tolerance testing. Training the pilot in an anatomical neutral sitting position, without a helmet, and with maximal neck support minimizes head movements in cases of conscious or unconscious loss of muscle control. To test the stability of the neck in a setup similar to the environment where the pilot is going to operate, the pilot should be given the opportunity to prepare himself or herself accordingly in advance.

Use of Euler parameters for the evaluation of ATD head trajectory from angular rate sensor and accelerometer data in aircraft seat certification testing

As part of the requirements of the US Federal regulations and the Society of Automotive Engineers (SAE) Aerospace Standard 8049B, when testing of the seat and adjacent parts of the aircraft may be impractical or unknown to the seat designer and cannot be determined if head contact is made, the head strike path and head velocity shall be documented. The head strike path, also known as head trajectory, is normally measured using software specifically designed to complete a photometric analysis from the high-speed video of the dynamic impact event. A procedure is presented in this paper to use accelerometers and angular rate sensors in the head centre of gravity (CG) location of the anthropomorphic test device (ATD); the head trajectory can be evaluated by using an algorithm utilising Euler parameters to transform the local accelerations into global accelerations. This can then be integrated to achieve global velocity and global displacement. The algorithm utilised to calculate the head trajectory provides results similar to a head trajectory by photometric analysis and can provide those results much quicker and independently of operator influence. It can also provide results without the need for interpolation due to the visual loss of a tracking target.

Adaptive Body Support System for Aircraft Seat

The development of new technology enables the comfort service becoming an important requirement in the air travel industry. Long haul air travel may cause different physiological and psychological discomfort of aircraft passenger. Most of the aircraft company treats the passenger comfort as a main priority for the user’s acceptance of their airline. In order to improve the aircraft passenger body comfort during long haul air travel, an adaptive body support system was developed and embedded in the economy class aircraft seat. In this paper, we describe the development of adaptive body support system.

Simulation Design Approach for the Selection of Alternative Commercial Passenger Aircraft Seating Configurations

Loading strategies for commercial passenger aircraft have been a subject of recent study among air transportation research analysts. A fundamental assumption in the majority of these studies is the fixed configuration of passenger seats. Previous studies have focused on analyzing different strategies in an effort to reduce passenger loading time. This study takes a more proactive approach to the passenger loading process by starting with the design of the aircraft seating layout itself. Simulation analysis results indicate that alternative designs can result in loading time reductions between approximately 9–44%.

Lumbar load attenuation for rotorcraft occupants using a design methodology for the seat impact energy-absorbing system

Abstract Aircraft occupant crash-safety considerations require a minimum cushion thickness to limit the relative vertical motion of the seat-pelvis during high vertical impact loadings in crash landings or accidents. In military aircraft and helicopter seat design, due to the potential for high vertical accelerations in crash scenarios, the seat system must be provided with an energy absorber to attenuate the acceleration level sustained by the occupants. Because of the limited stroke available for the seat structure, the design of the energy absorber becomes a trade-off problem between minimizing the stroke and maximizing the energy absorption. The available stroke must be used to prevent bottoming out of the seat as well as to absorb maximum impact energy to protect the occupant. In this study, the energy-absorbing system in a rotorcraft seat design is investigated using a mathematical model of the occupant/seat system. Impact theories between interconnected bodies in multibody mechanical systems are utilized to study the impact between the seat pan and the occupant. Experimental responses of the seat system and the occupant are utilized to validate the results from this study for civil and military helicopters according to FAR 23 and 25 and MIL-S-58095 requirements. A model for the load limiter is proposed to minimize the lumbar load for the occupant by minimizing the relative velocity between the seat pan and the occupant’s pelvis. The modified energy absorber/load limiter is then implemented for the seat structure so that it absorbs the energy of impact in an effective manner and below the tolerable limit for the occupant in a minimum stroke. Results show that for a designed stroke, the level of occupant lumbar spine injury would be significantly attenuated using this modified energy-absorber system.

Aircraft seating comfort: the influence of seat pitch on passengers’ well-being

One of the most important factors influencing aircraft seating comfort in economy class, is legroom. In an airline interior mock up, with the ability to adjust the seat pitch in a range of 28 inches to 43 inches, a study to investigate the influence of seat pitch on passengers' well-being was conducted. In a pre-study, aspects of subjective postural sensations and spatial perception were identified, and a questionnaire was developed. In the main study, 30 subjects rated at different seat pitch settings the spatial perception and the ability of adopting and changing sitting postures. As a result a functional relationship between overall well-being, the subjects' anthropometry and seat pitch was developed. Furthermore it was identified, that there is a maximum overall well-being at a seat pitch of 34 inches to 40 inches, depending on the passengers' anthropometry. A further enlargement of seat pitch, led to a reduction of well-being.

Chosen postures during specific sitting activities

This research study analysed the interaction between people's postures and activities while in semi-public/leisure situations and during transportation (journey by train). In addition, the use of small electronic devices received particular emphasis. Video recordings in German trains and photographs in Dutch semi-public spaces were analysed using a variation of Branton and Grayson's (An evaluation of train seats by observation of sitting behaviour. Ergonomics, 10 (1), (1967), 35–51) postural targeting forms and photos. The analysis suggests a significant relationship between most activities and the position of the head, trunk and arms during transportation situations. The relationship during public situations is less straightforward. Watching, talking/discussing and reading were the most observed activities for the transportation and leisure situations combined. Surprisingly, differences in head, trunk, arm and leg postures were not significant when using small electronic devices. Important issues not considered in this study include the duration of the activities, the gender and age of observed subjects and the influence of the time of day. These are interesting issues to consider and include for future research. Statement of Relevance: This study shows what activities people choose to carry out and their related postures when not forced to a specific task (e.g. driving). The results of this study can be used for designing comfortable seating in the transportation industry (car passenger, train, bus and aircraft seats) and semi-public/leisure spaces.