In theory, an airplane consumes more fuel on a given trip because
weight is the single most determiner for flight efficiency. Other than the fact
of heading into hurricane force winds or the Jet Stream, those long route runs
affect the profitability on any given trip. Qantas is about to receive its
first 787-9's and they have trimmed the seat count in order to fly those
extended routes in its passenger system. The Qantas advertisers will say more
leg room for a more enjoyable passenger experience having a greater seat pitch
for each seat.
A marvelous sentiment held by Qantas when in fact it’s all about
weight, efficiency and passenger numbers for the long haul. Qantas would like
the most passengers for the longest routes going from Perth to London in 8,960
miles. Note: It’s just under 9,000 miles which the 787-9 was built, but Qantas
attacks the promotion as a passenger opportunity with a "We are offering
more room" campaign.
FAA says this about average passenger weight:
FAA Weight Averages:
The Federal Aviation Administration sets an average weight per
traveler and carry-on luggage to estimate how much weight planes will carry.
According to "The New York Times," the average weight assigned to
each passenger by the FAA is 200 pounds for men, 179 pounds for women and 76
pounds for children under 13. These estimates include 16 pounds per person of
carry-on luggage and averages in the weight of winter and summer clothing.
Not included in this model is the passenger luggage weight for each passenger which can vary from traveler to traveler.
Qantas will be taking delivery with its 787-9's having 236
passengers on its long range 9,000 mile flights instead of having seating with
270 passengers. This gives me another number crunching opportunity for the
significance of Qantas cabin configuration of 236 seats.
If an 787-9 with 236 passengers and half are men and the other
half women it means the airliner has to pack on 118 men X 200 lbs. and another 118
women weighing 179 lbs. with carry-on for the trip. The subset weight for men equals 23,600 lbs. and
for women 21,229 equaling a total of 44,722 passenger pounds including carry-on luggage. Since
this a word problem, the changing dynamic is adding 34 more passengers bringing
the seating total to 270 passengers, which imposes a significant change of squeezing the smaller seat pitch like 31" vs the 236 seat configured economy pitch having maybe a 32" pitch found in economy.
The greater seat load of 270 is 6,443
pounds more with passengers than the Qantas 236 seat configuration. The 36 additional seat adds weight itself and passenger supplies (food) starts declining airplane efficiency in a
hurry. It will increase the weight of a 270 seat configured jet by about an
additional 1,000 pounds over-all vs the 236 seat 787-9. If you added additional
crew members the over-all weight load for 270 seats could rise about 7,500 pounds over
the 236 seat 787-9. The 270 seat configured would take more fuel traveling the same distance, thus
more added weight at take-off. The increased weights all summed up would cause
a 270 seat aircraft each trip to not make money. No luggage weight has been added in for the 236 seat vs 270 seat model for weight cost which add more fuel weight making the 9,000 mile route.
However, for a nominal seat ticket increase for say one hundred
dollars per seat for 9,000 miles, would give the passenger more space for the
same hours of travel. This opens up another word problem for all people still
calculating. A ticket going 9,000 miles may cost $1,000 dollars on average for
each seat and to make it simple. A 270 seat Dream-Liner can offer a $900
average per seat. The 236 seat aircraft will generate $236,000 for its journey.
The $900 ticket in cramped space with 270 seats generate $243,000 of revenue
for the unhappy customers. Increased fuel cost for the flying heavy immediately
erodes the additional $7,000 dollars earned with the stuffed airplane.
The airline stands to make much more money with slight seat price
adjustments for the long haul on a 787-9 that Qantas proposes. To make the
algebra work the formula could look like this. 270x= $236,000. Solution comes
out at about $874 per seat for the same revenue on the 236 seats at $1,000. Once more
fuel and passenger support costs are added, it would make such a 9,000 mile configuration not
feasible for any Airline.