At CX the 777-200s have the Trent 877, rated at 77,000lb thrust, while the -300s have the Trent 892, rated at 84,000lb thrust. It's essentially the same engine with a different thrust rating. When CX bought the original -300s the engines were rated at 89,200lb thrust, but for certification/contractual reasons we weren't allowed to use the full rated thrust except in emergencies. Later on they 'de-rated' the CX engines so they'll only produce 84,000lb at Max TO. If they paid the dollars I guess they could bump it back up again to the full 89,200lb thrust rating, but for our operation we don't really need it.
The 777-300 was bought by CX as a regional aircraft for bouncing around Asia and was certified with a relatively low MTOW. At typical zero fuel weights, the -200 can uplift more fuel than the -300 before it hits MTOW. The -200 is also lighter, hence the longer range.
For the CX aircraft, the actual fuel capacity of the -300 is much greater than the -200 (137,500kg vs 94,300kg), but even on a ferry flight the most we could uplift in the -300 is about 108,000kg before we hit MTOW. The most we carry in the -300 under normal circumstances is about 50,000kg, usually much less.
Last edited by BuzzBox; 25th July 2007 at 22:48.