Staggered seats might be a solution for a V-shaped aircraft (the Flying V). The cabin longitudinal axis of this airplane has a 26° angle with respect to the direction of flight. When seats are positioned in the direction of flight, they consequently have an angle to the cabin and become staggered. It is unknown whether the comfort of this staggered seat is appreciated. In this study, 117 participants tested the comfort and the privacy experience in this staggered seat compared with a regular aircraft seat. The experiment showed that both comfort and privacy were significantly better in the staggered seats. However, the analysis is based on short-term evaluations, which means that long-term effects still need to be studied and also the effects of groups travelling together need to be investigated.

This study investigates the tactile perceived seat-human interaction of four types of BMW 5-series seats with the same foam properties and contours but different seat cover and seat suspension properties; 38 healthy subjects participated in an experiment rating and ranking the tactile perceived properties of the seats while blindfolded. A discomfort test, a seat characterizing rating on a scale of word pairs, and the overall experience of the seats were examined in four different sitting positions. The results of the experiment were related with the outcome of an objective measurement method: a pressure measurement mat and the measurement tool of Wegner et al. [19]. The study showed that the perception of the surface while interacting with the seat is independent from the sitting position. In contrast, the perception of the hardness and the elasticity of the seat is position-dependent. The results of the seat characterization are in line with the results of the measurement tool of Wegner et al. [19]. Further research is needed to investigate the mutual interdependence of the various measurement points of the measurement tool and to improve the prediction accuracy of the seat characteristics.

BACKGROUND: Selecting the most suitable questionnaire(s) in comfort research for product design is always a challenge, even for experienced researchers. OBJECTIVE: The objective of this research is to create a list of Preferred Comfort Questionnaires (PCQ) for product design to help researchers in the selection of questionnaires for comfort research. METHODS: Fifteen questionnaires that are often used in comfort research for product design were selected as candidate questionnaires. During the Second International Comfort Congress (ICC 2019), 55 researchers and practitioners working in the field of comfort joined together in a workshop to rate these questionnaires individually as well as rank them in groups based on their experience. The criteria of rating and ranking included easiness to answer, easiness for data interpretation, time needed to complete, the need for prior training, as well as mapping the applicable design phases and field of application. RESULTS: The elicited responses related to each questionnaire were analyzed. For comfort research in five proposed application fields and four design phases, the preferred questionnaires were highlighted and categorized into four categories: preferred questionnaire, suitable for less prior training, suitable for fast completion and generally applicable, which led to a list of PCQ for product design. CONCLUSION: We expect that the PCQ list can be used as a useful instrument to help researchers in selecting questionnaires for comfort research in product design.

BACKGROUND: The contrast between a bright computer screen and a dark ambient environment may influence comfort of the users, especially on their eyes. OBJECTIVE: The objective of this research is to identify the optimal desktop lighting for the comfortable use of the computer screen in a dark environment. METHODS: An experiment was designed where seven illumination setups were introduced for the users to perform their leisure tasks on a computer screen. Fifteen healthy subjects participated in the experiments. During each session, durations of the eye blinks, fixations and saccades of the user were recorded by an eye tracker. His/her neck and trunk movements were recorded by a motion tracking system as well. The comfort/discomfort questionnaire, localized postural discomfort questionnaire, NASA task load index and computer user questionnaire were used to record the overall comfort/discomfort, the local perceived physical discomfort, the cognitive workload, and general/eye health problems, respectively. RESULTS: Subjective and objective measurement results indicated that users felt more comfortable with high intensity warm lights using a computer screen. We also identified that the eye fixation durations, as well as the scores of two questions in the computer user questionnaire, have significant negative correlations with comfort. On the other side, the durations of blinks and the scores of three questions in the computer user questionnaire, were significantly correlated with discomfort. CONCLUSION: The warm (3000K) and high intensity (1500 lux) light reduced the visual and cognitive fatigue of the user and therefore improve the comfort of the user during the use of a computer screen.

The pitch and width of airline seats are crucial factors on the comfort of passengers. The aim of this study is to measure the comfort feeling of passengers regarding different widths and together with data from a previous study, to offer suggestions on the aircraft interior design. 311 participants were recruited and were asked to sit in 17-inch-wide and 18-inch-wide aircraft seats in a Boeing 737 fuselage for 10 min, respectively. Questionnaires on psychological comfort and overall discomfort, as well as an additional questionnaire on the discomfort of different body parts, were used to evaluate the comfort and discomfort experience of participants. Experiment results indicated that the comfort scores were significantly higher, and the discomfort scores were significantly lower for sitting in the 18-inch-wide seats than that of sitting in the 17-inch-wide seats. It was also found that rather than the buttock, the shoulders, knees, lower legs and feet contributed significantly to the reduction in overall discomfort by providing more space for movements. Regarding anthropometric measurements, participants with smaller hip-breadth felt more comfort while sitting the 18-inch-wide seat, which highlights the importance of the freedom of movement. By synthesizing the results of a previous study on the relations of the seat pitch and comfort, it was found that given the same amount of additional floor area, widening the seat is more effective on comfort than increasing the pitch. Relevance to industry: This discovery might be useful for the airline industry for a more effective and efficient usage of floor area.

BACKGROUND: Staggered seats are a solution for the Flying-V aircraft, where the cabin's longitudinal axis has a 26 degrees angle with respect to the direction of flight, to compensate for an otherwise oblique sitting position. However, little is known on acceptable pitches in this staggered configuration. OBJECTIVE: The goal of this research is to evaluate the comfort of different pitches for seats that are staggered relative to the cabin's longitudinal axis. METHODS: Two rows of staggered seats are positioned at three different pitches (27, 29 and 31 inches). 53 participants were seated in each setup. For each, a questionnaire was completed including questions on comfort and discomfort, top view photos were taken to analyse postures and physical dimensions were recorded to define passengers' space. RESULTS: Comfort as well as discomfort were significantly different for the three setups. The comfort at 27 inches was seen as unacceptably low. The 29 and 31-inch configurations showed to result in acceptable levels of comfort, comparable to higher-end seating layouts. There were very little complaints about space in lateral direction (elbow and seat width), showing the advantage of having your won armrest and shoulder space in the staggered configuration. Interesting was that at larger pitches more complaints were found for the seat characteristics, probably in the shorter pitch the other discomfort was overruling this. CONCLUSION: The 26-degree staggered configuration offers improvements in shoulder- and elbow-space. The results for the 29- and 31-inch are expected to allow enough design freedom for further exploration of such a configuration for the Flying-V cabin interior.

BACKGROUND: Recent research indicated that an 18′′ ×30′′ aircraft seat resulted in nearly the same level of comfort as a 17′′ ×34′′ seat. However, it took less space in the floor plan. OBJECTIVES: This study explores seat layouts preferred by experts regarding different criteria. Those results of the experts are later compared to layouts produced by computational algorithms to evaluate the advantages of each method. METHODS: Eighty-eight experts in the field of aircraft interior were invited to make a floor plan of a part of a Boeing 777 aircraft where comfort was one of the main goals. Participants worked in groups of 3 and are given the freedom to design a section of the cabin between economy and first-class (5.87 m wide and 3.7 m long), where besides these two types of seats, an old business-class size seat of 20′′ ×36′′ was introduced as well for more flexibilities in design. Computational algorithms were also applied with the same inputs and constraints to generate layouts as a comparison. RESULTS: In total, 29 floor-plans were made, and these plans were analysed to compare against the complexity of the operations, the number of passengers on board, the revenue of the airline, and the width of the aisle. Results showed that 14 groups opted for the economy seats, while the rest utilized a hybrid setup where the business class seats were used in the configuration. These results are compared to the 126 computerized layouts generated. CONCLUSIONS: Among all layouts designed by experts, a combination of 28 18′′ ×30′′ seats and 20 17′′ ×34′′ seats had the highest potential revenue of US$21,984. This floor plan fits the regulations with an aisle width of 0.93 m. The computerized layout had a better outcome in maximizing profit of US$22,416 with 32 18′′ ×30′′ seats and 16 20′′ ×36′′ seats. However, the comfort of such results was to be explored as some seats were rotated 90 degrees.

In order to investigate differences in comfort and discomfort experiences amongst different regions of the world (America, Asia and Europe), a cross cultural study was performed. A questionnaire was sent to participants out in nine countries (Brazil, Canada, the USA, China, Indonesia, Thailand, Germany, Italy and the Netherlands). In total 795 participants completed the questionnaires. All countries score the comfort of a luxurious bed higher than a simple bed, first-class seats higher than economy class and all countries rate the comfort lower when the duration of sitting increases. The study suggests that in the USA and Canada softer beds, hammocks, more luxurious seats and softer pillows are scored as more comfortable compared with the other countries. There are indications that China and Germany prefer a harder mattress than in the other countries. For pillows, the differences between countries are large, which might show that much is influenced by habitude or hesitation to use something new. The Asian countries score the comfort of a brace neck pillow higher, which might be because these participants better realise the benefits better or feel less concerned to wear something that might give the appearance of an orthotic device. Further studies are needed to confirm these suggestions. The study shows that obvious differences are seen in all countries, which makes the construct of comfort internationally comparable. Practitioner summary: In designing and manufacturing globally, it is important to know how different parts of the world experience (dis)comfort. This study did not show large cultural differences amongst nine countries. Some differences emerge regarding pillows, perhaps as differences in sleeping habits play a role. Abbreviations: MANOVA: multivariate analysis of variance; VDA: Vargha and Delaney’s A statistic; USA: United States of America.

This study explores the relationship between seat pitch and comfort, and the influencing factors, like space experience and anthropometric measurements. Two hundred ninety-four participants experienced economy class seats in a Boeing 737 with 28-inch, 30-inch, 32-inch and 34-inch seat pitches. Anthropometric measurements of the participants were measured. Participants completed a questionnaire on comfort (10-scale), discomfort (CP-50) and space experience and the results were analysed using SPSS 25. This study showed a significant relationship between seat pitch and comfort as well as discomfort. Additionally, it was found that the mean rank of discomfort of each pitch size for the middle seat was higher than the window and aisle seat, though seat pitch did affect the (dis)comfort more compared with seat location. It was also found that anthropometric sizes significantly affect the (dis)comfort on smaller pitch sizes, and all space experience questions had a correlation to the pitch sizes.

This research aims to study the effect of seat and/or backrest rotation on comfort and quality of conversation. Different sitting arrangements were tested to study the effect of the seat layout on: 1) (dis)comfort experience; 2) conversation quality and 3) postures. Two seats were arranged in different angles (0° 45° 90° and 180°) at the same distance (1 m) and participants were asked to talk to each other. The participants’ postures were acquired by using cameras and markers on the participants’ body. Questionnaires were used to rate the perceived (dis)comfort and quality of conversation. Results show that 90° configuration scored the best both in overall comfort and quality of conversation; while the 0° configuration scored the lowest in both ratings. A strong correlation was established between high comfort and good quality of conversation.

The percentage of passengers that prefer travelling in groups is increasing. In most vehicles, passengers sit side by side and need to turn their body to be engaged in the conversation with their fellow travellers. However, rotating the body could lead to discomfort which influences conversation quality. The aim of this research is to study the effect of seat configuration on the (dis)comfort experience, conversation quality and posture. Experiments in which participants were asked to talk to each other while sitting at the same distance (1 m) were conducted in four seating arrangements (with seat-belts on), where the angle between the forward directions of two seats were positioned at 0° (side by side), 22.5°, 90° and 120° (almost opposite each other), respectively. Optical tracking has been deployed and the collected data were processed with MatLab^® to acquire postural angles over time. Questionnaires were also used to evaluate the perceived (dis)comfort and the quality of the conversation. Experiment results indicate that the 120° configuration scored the best in the overall comfort and the quality of conversation, but only slightly better than the 90° configuration. Practitioner summary: Seating side by side is not optimal to have a comfortable conversation with your seatmate. To improve comfort and quality of conversation in future vehicles, we tested four seating arrangements analysing the effect of seat layout on (dis)comfort experience. Statistical analysis of objective and subjective data shows the optimal configuration for a comfortable conversation. Abbreviation: LPD: localized postural discomfort; PDF: probability density function; OCRA: occupational repetitive action.

This study explores the relationship between space experience and human anthropometric sizes in different aircraft seat pitch. 294 participants experienced economy class seats in a Boeing 737 with 28 in, 30 in, 32 in and 34 in pitches for 10 min each. The sizes taken were: stature, sitting height, eye height seated, buttock-knee length and popliteal height sitting with shoes. A space experience questionnaire was completed by the 294 participants while sitting in the seat after the 10-min period given to explore the seat. The results show that passengers with a higher popliteal height, a longer buttock-knee depth, a higher eye height sitting and a higher sitting height show more discomfort with reduced pitch then shorter passengers. Eye height did not correlate as good with space perception as was expected.

This study investigates the tactile perceived influence of seat covers. Two identical BMW 3-Series seats are used, one with a leather cover and one with a fabric cover. Thirty healthy subjects participated in an experiment rating the tactile perceived properties of the seats while blindfolded. A discomfort test, a word pair rating and the overall experience of the seats were examined. The study has shown that not only the foam properties and the contour of the seat influences the seat characterisation but also the seat cover material. The leather and the fabric seats were characterised different, but the pressure distribution did not show so much differences. Furthermore, the perceived differentiation of the seats are distinctive for the seat pan and for the backrest. Therefore, further research is needed to investigate other characteristics of the seat like shear force related to various cover properties in combination with different seat components and contour combinations.