Karnage
I-am-a-pirate. I do not need credentials!
I'd really like to see the raw data they used to come up with the supposed width of the seats in years past, especially for narrow bodies. 737 fuselages haven't gotten any wider since 1967, and I doubt that there were any operators still flying them in 5 abreast configuration by the early 1990s. If anything, there's more elbow room on newer models thanks to thinner insulation and re-contoured sidewall panels. While I agree that seat pitch and leg/knee room has been decreasing steadily over the last 10 years, I would argue that it's not a matter of seats getting narrower but the fact that 65% load factors and empty middle seats are no longer the norm that has led to a perceived narrowing of seats, at least in narrow bodied aircraft. After all, if Southwest's seats have gotten 2" narrower over the years, why aren't the aisle's 12" wider? AFAIK Southwest has always been 6 abreast so where'd that extra room go, it's not like their planes got narrower.
On wide bodies, it is more than just perception, airlines going from 9 abreast to 10 abreast in 777s and switching from 8 abreast to 9 abreast in the 787 are using narrower seats.
Seat pitch comparisons, measuring the distance between one point on a seat to the same point on the seat in front of it, have the benefit of being a standardized measurement across different airplane and seat manufacturers. Seat width doesn't. Some measure between armrests. Some between armrest centers. Others measure the width of the seat cushions, others the seat backs which may or may not have a gap to allow for the armrest to be raised up.
Here's what I could find per the various manufacturer's Airport Planning Manuals (coach seating). All measurements are between armrests.
4 Abreast:
ATR: 16.8"
CRJ-200: 17.3"
Dash 8: 17.3"
ERJ-145: 17.3"
ERJ-170: 18.0"
5 Abreast:
DC-9: 17.9"
6 Abreast:
A320: 18.0"
707: 16.5" to 17.3"
727: 16.5" to 17.3"
737: 16.8" to 17.8" (737-100)
737: 17.0" "typical" (737-200 through 737-900)
757: 17.0" * (Only lists a 59" total width of 3 seat unit, same as shown in 737 data.)
Wide bodies:
A330: 18.0"
747: Only lists total width of various 2,3, and 4 seat units and I'm too lazy/tired to parse them all.
767: 18.0" between armrests*. (42" total width 2 seat unit, 62" 3 seat unit.)
777: 17.0" to 18.5" (10 abreast and 9 abreast respectively)
787: 17.2" between armrests*. (59.6" total width for 3 seat unit used in 9 abreast, doesn't give width for 8 abreast)
*Boeing is fairly consistent in assuming a 2" wide arm rest from the 737 onward.
