I have recently come across threads about Thompson seats with staggered seating. In theory, these seats would convert a 7-abreast B767 to 8-abreast Y with staggered seating. Likewise, 8-abreast A332 could become 9-abreast Y. It is my understanding that Delta is converting some of its 767s to 8-abreast staggered with Thompson seats.
If the staggered seats turn out to be acceptable, and become the norm, then Boeing could design its 737 replacement as a twin aisle 7-abreast with staggered seating. I will use B739ER as the base model to carry out the financial case for such a replacement.
Note below cabin dimensions for the 739ER and the 739RS(twin aisle, CFRP, new engines):
Fuselage Length 138.16 feet
Cabin Width 11.58 feet 14 feet
No. of single class seats 215 245
The 739RS would only need 14 feet in cabin width to accomodate two aisles with 2-3-2 staggered seating. I hope Keesje will come up with graphics to illustrate this point. The fuselage length of the replacement will remain the same.
Note below a summary of estimated technical specifications for 739ER and 739RS.
OEW 98,495 112,000
MTOW 187,700 204,000
MZFW 149,300 169,000
MSP 50,805 57,000 (Max. Structural Payload)
Range 3,200 3,500 (Max. Design Range in nm)
Wing size 117 ft.(w/winglets) 125 feet
The 739RS can carry its max. payload to 2,900 nm.
For a 2,000 nm mission,
737ER burns 3,877 gallons of fuel, carries 5,655 lbs. cargo, GSM .0090
739RS burns 3,314 gallons of fuel, carries 5,550 lbs. cargo, GSM .0068
739RS saves about $2,200 in fuel costs.
739RS may earn $4,200(30Y seats X 70% LF X $200) more in seat revenue.
The net advantage to 739RS is about $6,400 per trip--about $7 million annually.
If my estimates are fairly accurate, then a twin aisle with two different wings could be utilised to replace both 737/757 and 767 series. The smaller 125 feet wide wing would be on the 738/739/752 replacement, and the larger 160-170 feet wing would be on the 767 replacement.
For the series with the smaller wing, the shortest fuselage length would be 130 feet(current B738 length), and the longest would be 155 feet(current B752 length). The single class seat count would range from 195 to 260, and the range would be around 2,800-3,500 nm.
For the series with the larger wing, the shortest fuselage length would be at 160 feet and the longest would be at 200 feet, providing replacements for 762/763/764. The single class seat count will range from 280 to 400, and the range would be around 5,800-6,800 nm.
Looking forward to your comments/feedback.