four engines rather than twins
 

why do freight companies tend to operate four engine aircraft rather than twins, even though they carry the same load ?:confused:

Hull price? Unless buying factory fresh

Which twin carries the same load as a 4-engine?

As a side note, 3 or 4 engine aircraft have better performance figures for maximum loads out of high/hot environments as well as shorter runways than your average 10000+ foot one at the major hubs. Having 3 or more engines also removes the necessity for having/maintaining ETOPS capability.

Also freighters tend to operate to a variety of destinations, some are remote and not well equipped, and in the event of engine problems it is a great advantage (cheaper) for a 4 engine aircraft to 3 engine ferry to a maintenance base.

Because 747 happened to be 4 engine, and MD11 happened to be 3 engine. All other advantages are very much secondary and would never seriously influence decision making, like 3-engine ferry capability etc. Would 747 be twin engined, freight companies would tend to operate twins.

777F just entered the market so in 10-15 years this will change.

The MD-11 and 747 don't carry the same load, though...

The B777 had to have a few modifications to it to be able to carry the same load and be more efficient as the MD-11 like 2 115k thrust engines as opposed to the 2 90k engines on the original -200. The MD-11 has 3 62k engines and as stated above can be easily ferried with one out.

Well thanks people,

Got this question from an interview preparation booklet and I think the above is good feedback...:D

happy flying.

Does anyone actually do 3 engine ferry in 4 engine aircraft these days?

Last attempt I heard of was an "Asian" carrier attempting it and ending up very quickly in the grass:{ (and that was quite some time ago).

BA does regularly with its 747-400s. Once or twice a year.

No big deal.

Captain has to be qualified 3- Eng Ferry, which is a few hours in the sim and a bit of reading.

Only legislative issue is some countries will not allow you to operate from certain airports / runways.

ATB

Pete

Same with CX, maybe once or twice a year, majority have the freighters deliver a fresh engine.

Even DC-6s still 3 engine ferry.

Still 3 engine ferry the Electra on the rare occasion an engine gets toasted.

JetPhotos.Net Photo » G-LOFE (CN: 1144) Atlantic Airlines Lockheed L-188C Electra by Tiago Palla

Actually if you want to compare the 777F with anything, you'd be better off with a 747-400BCF. Both are able to lift around 107 tons, but the 777F can carry the load further. Given a similar load, say 75 tons, the B747-400F will burn 140ish tons on a specific Far East - Europe route. On the same route, on the same day, a B777F carrying the same 75 tons burned 100ish tons. And therein lies the reason why the B777F is the best thing since sliced bread in long-haul cargo, as long as you can live without a nose-door.

Why would you compare a 777F with a 747 conversion? Why not compare it with a 747F?

I'm not so sure that the 777F does all that is claimed for it, now that Thai cancelled their 777F contract with Southern Air...

Also, the new -8 74 burns LESS fuel (over 400 gallons less per hour) than the 777 and carries a significantly larger payload. Not to mention that e-tops does not come into play, and if you loose an engine you sill have 3 over the middle of the pond! If I am going across the Pacific or the Atlantic I want 4 engines thank you very much!!

Cause it makes no more sense than comparing it with the MD11. As for Thai and their relationship with Southern and the B777, I have no idea why Thai pulled out. I know why Air France tried to ditch theirs, and that was poor homework. What I do know is that FedEx cannot get enough of them, and that the experience AeroLogic has had with theirs was, at least partly, the reason why LH Cargo went and bought a few. I also know that the aircraft actually does more than the original brochure numbers, which is quite a surprise indeed. Later iterations have seen further improvements, and it is not unlikely we will see 108 tons payload in the future.

Not sure I buy the bit about the dash 8 burning less than the B777F, would be delighted to be proved wrong if you can post numbers from a reliable source. As for ETOPS, that is quickly becoming irrelevant since all aircraft will have to comply with EROPS requirements. Do agree on the last bit though, but would consider 6 engines if given the choice ;)

Maybe I'm old, but four engines with a PFE onboard is my preference. Nice to have the A&P qualified PFE when you need him for a mechanical at some third world, watering hole charter destination.

Obviously a man with very good sense above!

As for FedEx wanting more 777's, remember that Fedex and UPS both carry small packages for the bulk of their load. Therefor, they cube out the aircraft way before they have to worry about weight.

As for the numbers on the -8, I was in a meeting three weeks ago with the V/P of flight operations. The number that was given is 437 gallons less per hour than the 777 so I think they must know if they are being that specific. Seeing that we have over 20 -8's either on order or optioned, I think that Boeing is giving us real numbers.