Date: 30 Apr 97 03:19:08 From: "Alvin W. Law" <firstname.lastname@example.org> Organization: Oracle Corporation, Redwood Shores, California References: 1 2 3 4 Followups: 1
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M Carling wrote: > > email@example.com wrote: > > According to Boeing's web page, the range for the heaviest 777-300 > > is 6500mi, and the 747-400 range is 8290mi. I imagine the range for a > > 777-300X will be about the same as the 747-400. Given the 777's much > > lower operating costs, what would then be the advantage of > > operating the 747-400 (as opposed to the 777-300X)? > > While Boeing's web page claims 8290 miles for the 747-400, this is > wildly optimistic. The longest non-stop route that anyone has been able > to fly in both directions is United's ORD-HKG service at 7786 miles, > which can only be flown during the summer, and is severely > weight-restricted (301 seat configuration versus the usual 420 seats, > and no cargo). > > On the other hand, Boeing's claim of 8225 miles for the 777-200IGW > appears to be very conservative. I believe it is Boeing's official > policy that the 747-400 has greater range than the 777-200IGW, though > the evidence seems to suggest that the 777-200IGW has a range of at > least 500 miles more than the 747-400. Pardon my ignorance here but I have a question regarding aircraft ranges as published by airframe manufacturers for promotional purposes. As many of the so-called ultra-long haul routes are trans-Pacific which are heavily affected by the strong westerly wind, what kind of guidelines are the airframe manufacturers using to calculate the maximum range? Here are some of the permutations I can think of: - full loaded pax vs. fully loaded pax and cargo - uni-directional vs. bi-directional - w/ head / tail wind vs. w/o head / tail wind I've flown on fully loaded 747-400s for 15+ hours non-stop. Assuming no head winds, a range of 8,000+ miles is certainly achievable, at least theoretically. And while the longest bi-directional non-stop 747-400 route is ORG-HKG at 7786 miles as stated, it is limited by the westbound segment. The eastbound flight (HKG-ORD) certainly is capable of handling a larger payload or a longer range during summer, and even more so during winter. I think a 747-400 can quite possible handle HKG-JFK with a full load during winter months.