While cursing my bad luck, I noticed that the passenger one row up and across the aisle had an equally deformed tray table. The flight attendant saw immediately upon setting down his drink that it would not stay in place on the slope. She returned to the galley and came back with the aluminum tab she had broken off a pop-top can, and she used it to shim up the cantilevered tray at its main hinge. When she came with my drink I asked for the same mechanical assistance, and she obliged. The fix was just right, and the table was perfectly flat and horizontal even when fully opened across the seat. Thank goodness for shims, and for mechanically inclined flight attendants.
The folding tray table was obviously designed to satisfy a considerable number of constraints, which it does. Thus, it is relatively lightweight, as well as compactable and deployable. These latter two qualities mean it has moving parts that are capable of getting out of kilter. Armrest tray tables clearly have not been designed to take the forces imposed by infrequent fliers wrestling with the puzzle of how the thing deploys and stows, or by frequent fliers who use the table as a crutch for rising out of their seat. Such overloads naturally can and do throw the mechanism out of alignment. All designs have limitations, but not every user respects them.
The case of the airline tray table points out one of the asymmetries of the designer/user interrelationship. The failure of an armrest tray table to deploy into a flat and level surface, perhaps leading to a drink spilling into a passenger's lap, might result in a product-liability lawsuit, with possible career-altering implications for the table's designer. But a passenger who engages in heavy-handed misuse of the table, causing it to be permanently off level when in its deployed position and thus setting the stage for a drink spilling into some future passenger's lap, can simply walk off the plane when it reaches its destination. Neither life nor design is always fair.
That's a great song, TJ. He really nailed a lot of truths in the song. I saw him a couple of years ago at a festival. He still does "Alice's Restaurant." I guess he's stuck with it. I saw him sing it a couple times in the 1970s. That was understandable. But I was surprised he was still singing it 40 years later.
Why not just make the tray from a sturdy piece of corrugated cardbord coated with plastic. Advertise a ski resort on one side and a Maui hotel on the other. Clipped securely to BOTH armrests it would hold more weight than a cantilevered tray, weigh about an ounce, cost 97 cents, and stow in a pocket on the seatback in front of you. A tray with no hinge is harder to break, but if somebody breaks it anyway, the airline gets to sell more advertising.
The lowly fold-out tray table is a pretty amazing piece of design. Besides the basic function, there's numerous secondary requirements. It must be lightweight, strong, and meet flammability requirements. It has to support a certain amount of weight but break away if someone hits it hard without leaving sharp pieces and remain able to be stowed after being broken. It can't have any pinch or "guillotine" hazards and can't fly out of the bin in a 15g foward-aft impact.
I think the airlines' issue with your suggestion, Russell, is that if I'm reading it right, your design would be loose. Yes, it's connected to both armrests when the passenger wants it to be, but if the passenger is putting it back, or doesnt' secure it properly, or whatever, it becomes the airlines responsibility if it goes flying in turbulance.
I had to check the date of this commentary - 2012, not 1965! In the '70s I worked in aircraft seating design. Those First Class seats were a wonder of engineering. Their weight-saving, weight-supporting design were worthy of awards. I'd think the present-day comments would have been unwarranted, even back then. Surely engineering has progressed since...or has it?
The cardboard tray wouldn't weight much more than the plastic plate sitting on it, and unlike the plate, the tray would normally be secured. Even if left unsecured the tray wouldn't be much of a projectile, but adding foam-rubber edging would limit the damage when kids play with the trays. In normal use the edging would also keep cups and plates from sliding off.
This article by Mr.Petroski is a guiding for the young engineer by showing how to clearly express the design functionality. Many a times innovators fail to express the "need" in their statements.
The story of the mechanic pounding the broken table into submission is great! It shows how the human element can be the ultimate enemy of designs of all kinds. I wonder how long it took that tray table to finally be fixed so it could be both gotten out of and put back into the seat arm? Poor maintenance can be worse than no maintenance at all.
I haven't seen significant design improvements in the seating area of airline jets since the mid-1970s. Am I missing something? If anything, the seating area has become more cramped.
On April 21, NASA launched a novel project, putting into orbit three satellites that employ an off-the-shelf commercial smartphone as the control system.
The legacy endpoint devices that control our critical infrastructure (utility systems, water treatment plants, military networks, industrial control systems, etc.) are some of the most vulnerable devices on the Internet.
In a switched-capacitor filter, capacitors and switches take the place of resistors and accurately reproduce the characteristics of continuous-time Bessel, Butterworth, and elliptical filters.
From Dell / Intel® New Paradigms in Design Work Scott Hamilton, vertical market strategist for Dell Precision workstations, 5/2/2013 5
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For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This radio show will show what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.
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