There are nearly 500 777s currently in service, not counting orders. The number of A330s and A340s (all series) combined is similar give or take 20 at most (the Airbuses had a 2 year head-start too). At present, 2 versions of the 777 are doing pretty well at holding their own against 6 versions of the A330/A340 family, and bear in mind all 777s are twins! Whatever the 777s future, Boeing is still far from defeat in this sector by Airbus, and don't forget the 744 is still selling too...
If you want specifics, I meant relatively poor part accessibility compared with simpler types like the DC-9 where everything is within easy reach. I'm not Airbus-bashing and I'm merely passing on what I hear from NW
mechanics alike, and as for ageing, aluminium tends to age better than composites.
The A310 is a shrink of the A300 TO AN
EXTENT. The 310 incorporates:
-a radically different tail complete with an extra fuel tank.
-a totally different wing to increase range and fuel efficiency.
-new main landing gear.
Airbus, as I said somewhere else, has gone for a fairly "off-shelf-approach" to aicraft design, as can be seen in the fuselage resemblances between the A333/A343 and A300/310, particularly in the nose, cross-section, tapering of the fuselage near the tail and the fin. All Airbuses descend from the A300B and the A320 whether they like it or not. Boeing's only distinctive mould has been the 707 nose. If you want to link the 310 with the 300, then I'm afraid you also have to consider the 757 and 767 a joint programme too (it sort of was), which achieved phenomenal cockpit commanility, in which case Boeing wipes the floor with Airbus as the Boeing twins have already sold near the 2,000 mark.
Linking is not always accurate. The 767 is a good example, since the 762 you could argue competed with the A310, while the 764 comes close to Boeing's very own 772 and also Airbus's A333. The 767 deserves a separate category for it's narrower cross-section, but with that argument, the A330/A340 cannot compete with the 777.
Every aircraft and every variant is different to some extent, so in my listing of Airbus types, I tried to pair up the widebodies the best I could with their Boeing equivalents, and sometimes there is no right answer. The 752 and A321 are similar enough--airlines have chosen A321s over 757s so clearly they are rivals of sorts, in spite of range differences.
Whatever development costs, my main point is that certain Airbus models have undersold considerably, namely the A343 (let's not mention the A342) and A333. They've been around since 1993 and 1994 respectively, yet there seem to be too few. The A333 doesn't even scratch 200 if you combine those in service with those in the order books. The 744 alone, by contrast, has sold over 650 in 15 years. Granted, the A332 is doing much better, but at the end of the day, what was the point in producing exactly the same aircraft with the choice of 2 engines or 4, when at the end of the day they even produce the same amount of thrust? The option is simply 2 big engines or 4 measly ones, with slight differences in range. I see why you'd describe the A330/A340 as 1.5 types, but personally I believe Boeing offered customers more choice with their 757/767 combo.