143 metres
143 metres???
What are they doing with 143 metres? Even Beriev-Be-2500 finds 122 metres or so quite enough!
I can understand why Concorde likes to have a slender fuselage and long nosecone. The result is that Concorde is about 62 m long and has 25 seat rows at 4 abreast. She is considerably longer than E-190 (which has a similar passenger cabin) and matches the length of MD-11 (which accommodates 410 seats).
Now, L-2000 and Boeing 2707 target near 300 seats. L-2000 specifies 5 seats abreast, and is actually a couple of cm narrower than DC-9. 60 rows of 5 abreast would take up more space than the 172 seats of MD-80. L-2000 is supposed to be 85 m or so.
Various B-2705, Boeing HSCT, MD HSCT, Airbus AST and JAXA NEXST projects talk of 300 seats, too - and they think they need 90...104 metres. It would cause some problems with fuselage bending strength and tailstrike clearance, plus a nuisance at taxiways and gates...
But 143 metres? Where does it go? With 300 passengers?
If an airport can handle 150 m long planes, how many seats do you think should go on, say, an Airbus 380-1800 stretched to 141 m length?