|Quoting AirlineCritic (Reply 2):|
But as a general rule, a.net is overly focused on fuel consumption performance
I could not agree more. A.net is fascinated with fuel burn, so there are many threads about it.
Airlines purchase airplanes factoring in total ownership and operating costs. There are many factors involved that A.net completely ignores since if you read threads, you'd think all orders are based on fuel burn, CEO opinion on A vs B, and deep discounts "airplane sold at a loss".
In reality it is quite a complex process. The calculations involved in making a decision involve many factors.
Fuel burn is very important, but it is only part of a weighted decision process. Also, you can't say the A320 is 5% more efficient than the 738 and base any calculations on that. Trip vs per seat fuel burn numbers are important. A 10 seat capacity difference makes the a big impact. So while one might have better trip costs, one has better per seat costs, which is what the airline is usually looking at more closely (but not always). The operating environment also matters. Short trips vs long makes a big difference. You also have to include takeoff performance in because an airplane can have great MTOW fuel burn numbers, but they are meaningless if an airplane is operating 500 mile hops or if their main hub only has a 7,000ft runway and is TOW limited. There's no one airplane is more efficient than the other argument. It depends on the specific operating environment and conditions of the airline.
Acquisition cost is also important, but it also goes beyond purchase price. What are leasing rates? What is the depreciation? Leasing companies are only interested in the most popular models. Part of the reason why new airlines aren't ordering the 73G or A318 or A319 is that leasing companies don't like them because they are more of niche players and are harder to resell. Leasing companies charge extra for airplanes that are hard to sell, which is why Boeing capital had to finance most 717s since the leasing companies avoided them.
Maintenance is an important factor since it is about 8% of the operating cost of the airplane. Scheduled and unscheduled is important. Both Boeing and Airbus roll up the total scheduled maintenance costs over the lifetime of an airplane (depends on customer & operating environment). The difference between a 737 and A320 is about 10%. They also look at historical dispatch reliability numbers as each percentage point of airplane out of service and delays & cancellations has a negative impact on cost.
Crew training, maintenance support, and other add on features can also make or break a deal.
So in the end it is a weighted score of many factors. Whenever I see threads talking about fuel burn, deep discounts or CEO opinion, I cringe since I know I am reading opinions which are often uneducated.
If you have never designed an airplane part before, let the real designers do the work!