Design of a Neurodiverse Accessible Airplane Cabin
Design of a Neurodiverse Accessible Airplane Cabin
Design of a Neurodiverse Accessible Airplane Cabin
In Collaboration with the Boeing Company
Team Members: Erin Quick, Ruby Hernandez, and Morana Lundquist
Role: Project Manager (.5 of year), Responsible for Overall Headrest Design and Additional Design Recommendations, and Co-Author of all other work
2023 - 2024 Academic Year
Problem
We initiated our project by researching a range of Neurodiverse conditions and how they may impact flying accessibility and experience. Using this knowledge, we developed and conducted an IRB-approved survey and interview series.
The study found that the three most common issues when flying were seating (86% of respondents), cabin sound (68%), and sleep (66%). Respondents also described airplane travel most often as ‘stressful’ or ‘overwhelming’, and 44% said they avoided it. Our interviews found that, in general, interviewees felt overstimulated and experienced heightened sensory overload while flying.
Concept Generation and Selection
Taking the findings from the survey, interviews, and our literature review, we developed a web of concerns that summarized the breadth of accessibility issues within the cabin (see above). We then developed 64 concepts targeting the entire range of issues.
Key Design Requirements
Provided by Boeing and selected from FAA regulation
Fit within the typical seat dimensions of a Boeing 737
Adheres to flammability codes (FAR 25.853)
Weighs less than two pounds
Material Composition
We iteratively developed our material composition, which integrates an aluminum hexagonal cell sandwich panel with external absorbing layers.
This final material composition design utilizes the absorbing layers to absorb external sound and the sandwich panel layers to trap traveling sound waves within the headrest.
Passanger Interaction
Overall Headrest Shape
Baseline Modeling
Experimental Data Collection
Goal: Collect baseline data to match the COMSOL model
Setup: Headrest and microphone in room center, a speaker in each corner inputting 85 dBZ
Collected: Max 85 bBZ at headrest center
Shape Development
I used a material reduction technique to develop the ideal headrest shape, starting with a ‘full’ design and progressively removing material. The theory being that maximum noise reduction would occur with the ‘full’ design, and any adjustments would try to maintain that reduction.
Once shape development was completed, I integrated the appropriate material thickness and absorption coefficient from the material composition to the design.
Additional Design Recommendations
Although work has been done to increase accessibility for physically disabled passengers on commercial aircraft, little has been done to improve accessibility for neurodiverse passengers. With an upper estimate of 20% of the world’s population being neurodiverse, this leaves significant room for improvement. As such, for my senior capstone project, my team and I worked with the Boeing Company to design accessibility improvements for neurodiverse passengers within a commercial airplane cabin.
Background and Motivation
Moving through multiple rounds of evaluation, we determined that developing a Noise-Reducing Headrest would be the most favorable design direction.
Some designs would be very impactful but did not warrant a year-long project. These were sorted into ‘Additional Design Recommendations’.
Design Direction
The Noise-Reducing headrest impacts all three (seating, cabin sound, and sleep) of the most prevalent issues respondents noted regarding flying. It combines concepts from the Reduced Sensory Overload Categories of Sound, Sight, and Increased Spacing. The way in which we intended to address these issues was by targeting the areas of noise reduction, comfort, and privacy through changes to material composition, overall shape, and user interaction.
Design Goals
We looked at the web of concerns to identify overarching issues and developed three key questions...
How can we reduce sound heard by the user?
How can we increase user comfort?
How can we increase the user’s sense of privacy?
Design Development
We then broke the design into Material Composition, Overall Headrest Shape, and Passenger Interaction. The resultant designs are outlined below. As I was responsible for the overall headrest shape, that development process is described more deeply.
Initially, we generated numerous ways a passenger could adjust their headrest (left). Using decision matrices, we determined a release button would be most effective as it was similar to the recline button on the seat, so users would be familiar with the function, and it easily allowed for ‘locked’ positions, which would better support a user's head.
The final design allows for three positions, seen to the right, and only requires the user to press a button to adjust their position.
We tested Nomex, Melamine Foam, and Confor Foam as the absorption layer using acoustic modeling.
The headrest with Nomex decreased sound pressure levels most, with a 0.77 total sound absorption coefficient.
To ensure that the acoustic model matched reality, we completed baseline modeling. We gathered experimental data, which I mapped onto a COMSOL acoustic room model. For testing, we used typical noise levels within an airplane and a current standard airplane headrest.
COMSOL Acoustic Model
I started by investigating precedent work like noise-canceling headphones, childrens car seats, fighter pilot headrests, and Formula One headrests.
Same dimensions as testing room
85 BZ input from speakers
50 dBZ input on walls to account for ambient noise
Peak Noise = 85 dBZ (current headrest noise)
Because the peak noise in the acoustic model matched reality, I was confident that design efforts within the acoustic model could then be recreated in reality.
For each phase, I altered the cross-sectional shape of the headrest to maximize noise reduction. In the final phase, I adjusted the shape until sound reduction was maximized, while still ensuring passenger comfort and headrest usability.
Horizontal slice at ear level, red indicated higher dBZ, blue indicates lower dBZ.
Maximum noise level of 65 dBZ at ears. This is a 20 dBZ drop from the current headrest and corresponds to a 75% perceived noise reduction.
Because the need for neurodiverse passengers is highly individualized, we recognized that there was no one-size-fits-all solution. As such, we also presented Boeing with a collection of additional design recommendations that could further improve accessibility. A selection of these recommendations are summarized below by genre.
Integrated Final Design
The final design utilizes a layered material composition and unique shape to reduce the sound heard, as compared to the original headrest, by 75%.
The headrest shape reduces the user's peripheral vision field, creating a sense of seclusion and privacy while still allowing the use of the IFE system.
The adjustable locking wings allow for passenger customization and reliable head support when sleeping; the material composition is cushioned, increasing passenger comfort.
Validation and Future Work
The next phase of the project is to move into validation. Boeing is currently testing the design from a regulation standpoint. From my team’s end, we would want to return the headrest to our original users for their feedback. From there, we could apply the feedback and make design adjustments.
We could also work further into reducing the horizontal (from shoulder to shoulder) profile and overall weight of the design while not interfering with comfort or noise reduction of the original design.