Very interesting thread and very good work WM
! I'd like to join if I may and add some relavent points to the discussion. I've done some scholarship on these issues and have some data to present and I'll get to that as well. One concept that I don't necessarily put much credence in is so called "seats per area" An area density seating model leaves out one very important aspect which is the shape of the cabin or its aspect ratio. For a given same area of cabin a higher aspect ratio fuselage i.e. longer and thinner, will be able to have more seats with the same pitch/size seats. A good example of this is the 777-300ER and A340-500. In operation the seating arrangements are quite close in number despite the fact that there is a notable disparity in cabin area. The A340-500 can hold more rows bringing parity to the cabin usefulness.
To really match cabin density you have factor in the cabin length and width as a determiner of seat rows and abreast seating, the next factor is distrubution of classes and class seat pitch. Throw in galley and crew spaces and then you have the deal just about done. However there is really no substitute for doing actual cabin plans as there are many surprises that abstract geometry won't account for... like doorways...
Take for example the metric of one seat per square meter of cabin area. This measure would put the A380 in at over 550 seats and a 747-8 at 420 or so. This is totally at variance with realistic considerations of seating. Using the same/similar seats, pitch, and class distribution this disparity would never materialize in the real world. While 420 seats could be a realistic consideration for a 747-8 in a premium international configuration with generous percentages of the total seats being buisiness/first class the same would not hold true for the A380. 550 seats on an A380 would require a larger proportion of economy seats to make up the total if the same larger pitch business/first class seating rules are used.
With that said let's use that metric as a standard for the case of simplicity and als use it to measure the differences for more practical arrangements...
Next thing is mission models and weights. This is connected to the first point in this way. lower cabin density, reflected by comparing a standard metric to operational data. In practice lower cabin density means heavier cabin interior items such as seats and galleys are used, albeit in different proportions, to make up the total. As an example on the 777-300ER NH
uses a 247 seat four class arrangement while AC
uses a 2 class 349 seat arrangement. I'm sure it would surprise most to know that the AC
ships are lighter, lower DOW, than the NH
planes. That is because the cabin interiors are heavier for the NH
birds, especially the economy seats. DOW or Dry Operating Weight when we are talking about practical examples of aircraft can vary wildly with manufactures spec or even typical OEW. Those are the weights the OEM's use for quoting public performance figures on and they can be close to what the majority of operators will see or nowhere near them. This makes substantial differences in range performance. Performance quotes are a dubious thing to someone like me when it comes to comparing airplanes. My first question is what is the basis of the results, weights, seating, allowances, etc. Once that basis is established then we can adjust as needed to represent practical situations.
Manufactures basically use three kinds of airplane weights to quote performance. Spec weights, generic operating weight, or typical operating weights. The first two can be wildly off the mark as far as what the majority of operators use but the last, Typical OEW, is usually pretty close to the weights operators will see. Right now there are basically two aircraft that use the manufactures Typical OEW for public performance quotes and those are the A380-800 and the 777-200LR. The weights used for public performance quotes on those aircraft are very close to what operators will see across the board. This makes OEM performance numbers more applicable to reality, but if dramatically lower weights are used, i.e. A340-300, public information can be radically different what operators see in practice.
Quite a mouthful there but getting to my point. With respect to WM
as the pioneering effort here I'll follow his prescribed methods tempered with a little more data and my own insight. The tables I've done are the background data set for the chart done in WM
style. I did include the cast-down data from two mission models, the first being max payload for the 6,000nm segment, and the other being passenger only payload for the same distance. The point of that was to illustrate the cost of carrying additional payload on the passenger aircrafts which would normally be cargo and to put a cost measurement on it. Carrying cargo on a passenger aircraft is usually incidental to the main purpose of the operation but an important revenue generator. The cost of carrying additional payload in terms of aircraft operation is simply the cost of fuel which is detailed in the dataset.
I tried to be as specific and realistic as possible given the contraints of 1 seat per square meter. This necessitated changing cabin appointment levels based on what is used in practical operation so it's not necessarily and apples to apples comparison in that regard. Cabin appointment levels are a significant factor in determining the DOW of each airplane used for the mission models. As I said before The A380-800 vs 747-8 using this metric is a prime example of this. My DOW are operational weights at the cabin seating levels.
I have to add the discalimer that the A350XWB models and 787-10 performance data are highly suspect in my opinion. As far as the Boeing goes the weights I am comfortable with but not the aerodynamics. I think that spec of aircraft without any growth version of the current engines will be hard pressed to make the range figures Boeing wants. On the other hand the Airbus aero looks to be there but the weights are... well very ambitious IMO given the size of the wing, materials and fuselage construction methods.
The A333 is not an airplane capable of the 6,000nm mission model. I have included it at the lower specified range of 5,000nm.
The last factor which is not take into account at the is aircraft price via debt service or lease, and maintenenace. I will update the data to reflect some information that includes other cost of ownership foactors.
Without further delay:
LONG HAUL AIRCRAFT COMPARITIVE FUEL BURN DATASET
LONG HAUL AIRCRAFT SEAT SPECIFIC FUEL BURN BUBBLE CHART
Please feel free to note any need for corrections of typos.