posted on Jun, 13 2011 @ 03:12 AM
reply to post by kondor
It's great that you have taken an interest in so many threads but exactly what is your point in posting so many of these performance tables on at
least three threads I have just read? You haven't said anything else, just posted the tables so what is the point? If you have one I would just like
to know what it is.
You need to realise also that many of the quoted numbers are very subjective as different sub variants of aircraft and conditions will produce very
different results, so using them to rank any aircraft performance metric is fraught with danger. For example on the thread where you listed airliner
performance data two numbers stand out as examples. Passenger numbers and weights. There have been several variants of the 747 that have greater
numbers of seats than just about any inservice variant of the A-380 so it could be argued that the 747 has a greater seat count, see my point?
Empty weights is another. I can tell you from my own experience of carrying out aircraft re-weighs (in this case both the 747 and A-380) that no two
aircraft are the same, even when they have rolled off the production line sequentially to each other, there are always differences, sometimes small,
Same goes for other performance measures like fuel capacity and range, both of which are highly dependent upon physical characteristics and
atmospheric conditions. For example the difference in maximum fuel capacity of the 747-400ER based on nothing more than the highest and lowest fuel SG
(Specific Gravity) in the aircraft refueling manual is around 10,000kg's, hardly a small amount you will agree and one which will affect maximum range
by a few hundred nautical miles. This principle was used by Qantas and Boeing to set a world record when the airlines first 747-400 was delivered in
1989 non-stop from London to Sydney on a flight that was 11,185 miles, far more than the standard quoted range as you can see. It was achieved by
placing the aircraft in a heated hangar and then filling the tanks to the brim with a high density fuel that was basically just chilled and left
outside in the cold night air, the combination of chilled fuel and warm (thus increased volume in the tanks due to thermal expansion) aircraft
increased the amount of fuel carried. Coupled with no revenue passengers and only around 20 people on board saw this range achievable.
As I said it's great you are taking an interest but I would just like to understand the point of the data, and hope you understand that the
information is really only good as a rule of thumb measure.
edit on 13-6-2011 by thebozeian because: Because I can..