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Boeing 747s are back in demand as workhorses of global shipping
- tesseract 8y agoSuitability for conversion to freighter service was actually one of the original design goals for the 747! But back then, the assumption was that passenger airlines would be transitioning not to twinjets but to supersonic planes.
- Steve44 8y agoI saw a programme about this a little while ago. That's why the cockpit and crew area is high, it allows a larger flat load area.
- dingaling 8y agoWhen Boeing stretched the upper deck for the -300 and subsequent passenger models there was resistance from the freight operators because the floor beams intruded into the main-deck volume. Not so much as to affect passengers but enough to restrict positioning of cargo. So all built-as-freighter models retain the short-deck with short hump, right up until the latest 747-8F being built today. Even though, counter intuitively, the long hump has less drag. That's also why retired long-hump passenger versions are less valued for conversion to freighters. There is no approved type mod to hack off the long hump and its structure.
- howard941 8y ago> the long hump has less drag. Does that translate into less lift?
- djrogers 8y agoNo, planes are not designed with a significant amount of lift from their bodies (excepting lifting-body aircraft like the B2). The primary goal for the body design is to reduce drag, and let the wings produce the lift.
- FabHK 8y agoI assume the fuselage drag is mostly parasitic (=wasted) drag, not induced (=lift-generating) drag.
- Steve44 8y ago> Even though, counter intuitively, the long hump has less drag. Not directly related but readers may be interested in the Area Rule. This is more aimed at trans and super sonic flight so I don't think that applicable to the 747. Basically the whole area cross sections down the length of the plane needs to be smooth so when it's punching a hole in the air the compression ( volume displacement ) around it is even and this reduces drag. The generally do this by narrowing the fuselage at the places the wings and external engines are. The Blackburn Buccaneer is a good example. https://modelingmadness.com/review/viet/gb/cjabuc2b.jpg https://modelingmadness.com/review/viet/gb/cjabuc2b.jpg This looks like a decent starting point, http://www.aerospaceweb.org/question/aerodynamics/q0104.shtml http://www.aerospaceweb.org/question/aerodynamics/q0104.shtm...
- compton_effect 8y agoAlso airlines are moving from the hub and spoke model to the point to point model. So the need for 747's and especially A380's for passenger service has gone way down. Plus both those planes just aren't as efficient as twinjets. In fact, it was partly the high fuel consumption of the early 747's that eventually led to Pan-Am's bankruptcy.
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- pintxo 8y agoIf I read it correctly, the original design was for an AF cargo plane, actually. As the AF dropped the Boeing proposal, airlines asked for a larger plane, and Boeing converted the freight design into a passenger plane. So no wonder, you could so easily convert it into a cargo plane.
- gsnedders 8y agoAFAIK, relatively little was shared between the proposed Boeing transport and the 747. Certainly there are influences: the cockpit and the nose door are the biggest ones. I think little else was carried over, given very different mission profiles. (The winner of that competition was the C-5 Galaxy.)
- em3rgent0rdr 8y agomakes sense...economical decision.
- consumer451 8y agoAs long as fuel prices don't jump, right? What a crazy business.
- joelthelion 8y agoAn air cargo surge is just what we need when the planet is warming at unprecedented rates and we have just crossed the 400ppm boundary...
- sho 8y agoPlanes are an easy target because they're so big, but the industry as a whole is hyper-focussed on efficiency. If you want to rail against emissions, don't look at the plane, look at the endless procession of single-occupancy 2 ton cars the plane is flying over. And you can get a lot of parcels on a plane like the 747F. Amortised by unit the emission numbers are in fact very good. It's almost certain that your last fast food run or uber trip used much more gasoline than it took to get your last parcel all the way from China. But why let the facts get in the way of some good old righteous outrage!
- joelthelion 8y agoYou're comparing things that aren't comparable. Of course single occupancy cars are inefficient, but that shouldn't obscure the fact that long distance transportation is a major source of emissions that should be severely limited. The fact that the industry is efficiency focused is also irrelevant at best, because they are high emitters in spite of it.
- briandear 8y agoOk so stop buying things and do your part. The globe isn’t warming as much as you think.
- shoo 8y agoit seems like people in countries like mine (rich, western) find it very easy to blame the supply side of the equation rather than the demand side of the equation -- e.g. companies are to blame for wrecking the environment because they ship stuff in planes to save money / save time. but the general public are also to blame as the source of demand. what might make a huge positive difference for the environment would be rolling out policies to help reduce population growth (or the absolute population count) of people such as myself with relatively affluent polluting lifestyles, but we might have to wait until there is mass suffering right here right now due to environment reasons across many countries with political power before there is substantial change.
- snake_plissken 8y agoWas listening to Bloomberg Radio this morning and Tom Keene brought this up randomly...I was surprised to hear only ~1500 were ever built; seems like a low number for a plane that's been around since the 1970s. One thing I have always wondered about tho is, where are the relatively short domestic route (2-3 hours) where a 500+ person 747 would make sense? It's almost like airlines need the inverse for which this plane was made. Same goes for the A380.
- tesseract 8y ago> where are the relatively short domestic route (2-3 hours) where a 500+ person 747 would make sense SE Asia and Japan, mostly. The 747 was never intended for domestic US routes - Pan Am, the launch customer, only had international routes.
- jpatokal 8y agoOn a related tangent, there was a general expectation that the A380 superjumbo would find a lot of customers on core domestic routes between Chinese and Indian megacities like Beijing-Shanghai, Mumbai-Delhi, etc. Aside from the odd filler hop between long-haul flights, this has entirely failed to materialize: there's tons of traffic between these cities but the vast majority is single-aisle 737/A320.
- dx034 8y agoIt's similar to NYC-LAX or NYC-SFO. Airlines realised that passengers prefer 10 flights a day with a small plane rather than 4 a day with a large plane. Boarding/deboarding is faster on single-aisle planes and it gives more flexibility on travel times. Operating costs for large planes are also not lower, as long as you can get landing rights. So apart from a few overcongested airports (e.g. London Heathrow), there's really no reason to use a large plane if you can use a small one instead.
- tesseract 8y agoPlus, more flights on smaller planes gives finer granularity in tuning the number of seats flown per day to match the demand for that route.
- omegant 8y agoAlso four engines are a must if you operate long haul from hot and high airports like Mexico, Bogota or Quito. Due to engine failure performance requirements a twin engine needs to cut back almost half the traffic load(cargo and passangers) to be able to take off within the tables. Once they have to retire 747 and A340 airlines din't really know what to do in those airports. New hot and high versions of the twin engines are being studied, but they have failed to meet the expectations previously.
- sho 8y agoDon't forget the MD11, also a favourite of the cargo operators due to having plenty of spare thrust for hot and high ops. Although it's also a truism that high altitude locations don't generally have a lot of heavy things to export. AFAIK Quito's main outgoing cargo is cut flowers...
- omegant 8y agoMexico main cargo are avocados for Europe, Bogota fruis and flowers too. There isn't enough cargo offer for the demand that exists now a days. We are leaving cargo behind every single flight between these airports and Madrid.
- russdill 8y agoI love how planes like the 747 can attach an extra engine to ferry it around. https://www.flightradar24.com/blog/wp-content/uploads/2016/01/62014_1283325243.jpg https://www.flightradar24.com/blog/wp-content/uploads/2016/0...
- amorphid 8y agoWendover Productions did a great video YouTube on overnight shipping that goes into the use of old planes for shipping cargo. [1] . The short version is that cargo planes spend most of their time sitting around, usually much less time than an equivalently sized passenger plane. [1] https://youtu.be/y3qfeoqErtY https://youtu.be/y3qfeoqErtY
- dx034 8y agoAlthough due to its size, 747F are usually used at a higher percentage of the time. The large freighters (7437, 777) are mostly used between hubs and for long-distance routes. That's why having fuel efficient planes (e.g. 747-8) makes sense. What Wendover describes are cargo planes serving hubs, those often only fly 1-2 returns a day, so having a very cheap plane with higher consumption is worth it (e.g. A300).
- mrpippy 8y agoThe title is a bit clickbait-y: passenger 747s were retired by the US airlines last year, and are not coming back. Passenger to freighter conversions (the BCF, Boeing Converted Freighter) are also not restarting. And, it’s highly unlikely there will be any new passenger 747s manufactured.
- ghaff 8y agoThe headline isn't really wrong. According to the article, they're not being retired at the rate which seemed likely--because of freighter demand (at least so long as fuel prices stay relatively low). But, for someone no familiar with 747s, the headline does seem to imply that this unexpected use was discovered for them--which, of course, isn't the case.
- thedogeye 8y agoFun fact: The loadmaster and maintenance workers on Flexport's 747 freighter fly back and forth on the plane 20 days per year, sleeping in the old first class seats in the upper deck. That is real skin in the game. The plane began service as a passenger plane for Japan Air in the 90s. I better its safer than most modern planes with those guys living up there taking care of her.
- hueving 8y ago>I better its safer than most modern planes with those guys living up there taking care of her. Not likely. Planes don't usually crash from maintenance neglect. We are at a point where it's multiple simultaneous failures caused by something unforseen, not lazy maintenance.
- CaptainZapp 8y agoIt's called the Swiss Cheese Model and doesn't only apply to aviation accidents. https://en.wikipedia.org/wiki/Swiss_cheese_model https://en.wikipedia.org/wiki/Swiss_cheese_model
- joshgel 8y agoDoctors use this model for evaluating/trying to prevent medical errors as well
- FabHK 8y agoThere's an excellent book, The Checklist Manifesto by Atul Gawande, that explains several transfers from aviation best practices to hospital best practices (primarily checklists and CRM, crew resource management). Captivating read if you're interested in aviation and not dying needlessly in hospital.
- Steve44 8y agoPossibly from the same source but one useful thing I learned was to do with check lists. Rather than ticking a box to say how many scalpels you used, is the tyre pressure OK etc etc you write down the number. The persons doesn't just say yes OK, they write down the pressure. That [generally] ensures they have actually measured it and got a real value.
- czep 8y agoEconomically, older cargo types can make a lot more sense than a new plane. With the 744 no longer in production, a used model with another 15 years of use at $50mn is a better investment than a new 748 at its $400mn list price. Well-capitalized wet lessors like Atlas can afford to invest in new frames, but if you're a startup or a primarily passenger airline looking to branch out into a few cargo routes, you can't necessarily afford to buy new. A similar trend occurred with the MD-11. Only a hundred or so frames exist, the last one built in 2000. As a passenger airplane, it was not great: high deck angle in cruise, noise, and of course poor fuel burn compared to projections. But for freight, its nearest competitor is the 77F. A few years ago when I was looking into this, a used MD11 frame would go for around $3mn. With a D-check you could have it flying again for an all-in cost of maybe $10-$15mn and it would last another 10 years. The 77F lists for around $200mn. Thus, even though the M11F is far less efficient than the 77F, it would be 10 or more years before the fuel costs would make up the difference in initial outlay. This is why the MD-11s are still flying. Passengers prefer new planes, but cargo doesn't complain!
- gsnedders 8y agoLikewise, this is why there are still freight companies flying (older) aircraft with a three-man crew, including a flight engineer (or four with a loadmaster). Yes, you have to pay an extra crew member… but the initial outlay can be much lower.
- dgemm 8y agoOvernight cargo carriers like FedEx additionally have economics that make this worthwhile. Those planes might typically make only two flights in a day, one to a hub in the evening and one from the hub in the morning. The efficiency of modern planes is only worth the price if you fly them constantly.
- borkt 8y agoMy father in law just switched to the triple 7 after a few decades on the MD-11 out of Anchorage. He loved the plane but even with the top spot on seniority the routes kept getting reduced making the 777 more desirable. He often commented that ATC always did a poor job of accounting for their higher approach speed when placing them into the lineup, as they about every other plane out there can fly much slower.
- alex_duf 8y agoI wonder what's the carbon footprint per kg compared to a boat?
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- jandrese 8y agoInterestingly enough, per-passenger the CO2 emissions are almost certainly better for the ship, but sulfur, particulate, and other emissions may be much worse.
- dsfyu404ed 8y agoyou probably want per kg per mile since takeoff is going to disproportionately affect emissions on shorter flights.
- alex_duf 8y agofair enough
- stcredzero 8y agoNot an aeronautics expert, but my understanding is that the 747 design sits on a local maximum, with regards to figures like wing loading. The A380 deliberately gets bigger by aiming for a less ideal design. Its wing loading is a bit high. I suspect that this tends to make it less suitable for cargo than the 747.
- TylerE 8y agoWing loading is a complicated thing... higher wing loading will increase takeoff and landing speeds a little bit, but it also generally makes for a smoother ride in flight.
- stcredzero 8y agoSmoother ride isn't as high a priority for cargo. Better fuel efficiency and ease of operations are more important there.