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Super Payloads
A big picture look at the giants of air cargo |
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Written by Fred Petrie
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 What is the definition of a large freighter? Some sources use a
65-tonne structural payload as the minimum size. I prefer to look at
their use, and focus on transoceanic services. That can include a few
narrow-body types, like the B707 and the many DC- 8s still in service,
but these are close to final retirement. We can then make the cutoff at
widebodied types like the Airbus 300 (used by Canada’s military as the
CC-150 Polaris), the Boeing 767 and the DC-10/MD-11 line. These will
all carry 50 tonnes or more, over 100,000 pounds. A new freighter
version of the B777 is the next big thing in this ‘small’ large
freighter category, and a freighter version of the Airbus 330 is likely
not far behind.
Stepping
up to the 100- tonne payload, the B747 is the dominant large freighter
in service today. Eastern bloc freighters like the Antonov 124 carry an
even larger payload but are limited in numbers.
The next
generation is imminent. Where freighter aircraft have often been
converted after 15 to 20 years of passenger service, the next
generation is being developed concurrently, led by the giant Airbus 380
launching with both passenger and freighter versions. The latest Boeing
response, the B747-8, will also be developed in both configurations,
while adding the latest technologies developed in the B787 Dreamliner
program. Indeed, a bit of trivia that I only discovered in researching
this piece was that the B747 was first conceived as a freighter for
military airlift, hence the cockpit above the main deck. But Boeing
lost that competition to Lockheed which went on to build the C-5 Galaxy
(whose civil version failed to sell). Boeing than applied its design
work to launch the world’s first ‘Jumbo Jet’ (and really won!).
But
these last few generations of air freighters have been evolutionary,
still using the same subsonic, turbofan, pressurized aircraft
configuration designed for passengers first. Our report will close by
introducing two diferent concepts for giant air freighters, if not
tomorrow, perhaps yet in the future.
The table summarizes the
key parameters for the freighters highlighted in this report. Some of
the numbers are extracted from tables and others are estimated; some
are incomplete (e.g., where only main deck volume was given) and
various models differ for engine types and other variations. But they
serve the purpose of illustrating comparative sizes and capabilities.
The table also suggests another classification starting with widebodied
aircraft having a 50- tonne payload that are capable of trans-ceanic
hauls but may also be used for larger routes domestically. The ‘Jumbo’
long-haul freighters carry more than 100 tonnes while the larger
next-generation freighters are going to offer 150-tonne payloads.
The
Airbus A300 is already 30 years old but it was not until Fedex’s launch
order in 1991 that it was first produced as a freighter, the 600F
(ordered by UPS as well); it continues as a production model on a
‘build-to-order’ basis. It has been around long enough that conversion
models are also prevalent. An interesting variation is the A300-600ST
Beluga developed to replace the Super Guppy to transport Airbus’s own
fuselage sections for final assembly in Toulouse. With a fleet of five,
a subsidiary also charters them for outsize special cargo hauls; I had
an opportunity to get up close at the 2003 Air Venture show.
The
A310, an updated A300, has also been converted to freighters, again
with Fedex as a lead operator, but the A310 has not been made since
1998.
Similarly, Boeing developed its B767 freighters in 1993
after it had been in passenger service since 1982; due to its slightly
smaller fuselage diameter not accommodating standard unit load devices
(ULDs), it is used mainly as a package freighter by the integrated
carriers.
The DC-10 and its MD-11 successor have proven very
popular as freighters. The initial DC-10-10 was offered as a
convertible but had limited sales; only the DC- 10-30AF was delivered
as a dedicated freighter. Last produced in 1988, most DC- 10s have now
been converted to freighters. The MD-11 replaced the DC-10 in 1989 and
the first two were freighters for Fedex (who else?). Like the latest
designs, the MD-11 was offered as a freighter (as well as a
convertible) from the beginning. Air Canada, which retired its own DC-8
freighters years ago, has gotten back into the allcargo market by
leasing three MD-11Fs from World Airways. While 200 MD-11s were
produced, they have proven so popular as freighters, with an apparent
ideal combination of payload and range for many markets, that several
carriers are searching for them without success, as even most passenger
models have by now been converted.
Before getting into the
ubiquitous B747, special mention is due the Antonov 124. It is the one
aircraft in the table that was designed from scratch as a freighter.
While it was first developed for military strategic airlift, it is in
significant, if not yet widespread, use in civil markets today. While
used more in the eastern bloc, UK companies like Skylink and Air Foyle
market for Antonov operators including Air Foyle’s partnership with
Antonov Airlines. The Canadian link, as noted in my previous report on
DND airlift, is that the AN124 has been de facto Canada’s strategic
airlifter for the past dozen years. There has been a presumption that
they would never see widespread use in the west due to the prohibitive
cost of Transport Canada/- FAA/JAA certification. But foreign-certified
aircraft and carriers can get a Foreign Air Operators Certificate to
operate into and out of Canada. There is an Uzbekistan company
operating between Miami and Caribbean points using Antonov aircraft.
Look at the numbers – it is bigger than a B747 and is designed for
cargo, especially outsized freight. And while the C5 may post similar
numbers, it was never sold for civil use.
The B747 is the
dominant long-haul large freighter aircraft today, and while developed
for passengers, it was at least conceived as a freighter. It entered
service in 1970 and the first 200F was delivered in 1972. Due to its
length of time in service, a great many of the ‘Classics’ have also
been converted to freighters. But only the 200F and now 400F have the
nose cargo door for straight-in loading. As civil aircraft, they have
never been operated without ground support for loading although there
was once a design for a ‘kneeling’, self-unloading version (like the
Antonov).
Launched in 1985, the B747-400 is the current
production model; the first 400F was delivered to Cargolux in 1993.
Even though it is larger than the 200F, it incorporates weight and fuel
saving technologies that make it lighter, giving it more payload and
range. Boeing claims that half of the world’s dedicated air cargo is
flown in B747s. (Boeing also claims 95 per cent of the world’s
long-haul dedicated cargo capacity, but then it is including Douglas
and McDonnell-Douglas aircraft since it merged into Boeing, and, I
expect, excluding eastbloc aircraft.)
What is coming on the
horizon? With a new generation of technology every ten years, the B-777
has been with us barely ten years. With almost as much payload as a
B747 classic, more fuelefficient with only two engines to feed, and
long range, operators are not waiting for retirees from passenger
service for conversion. Boeing launched the B777 Freighter in May 2005
with an order from Air France. Given the demand shown by carriers
searching for MD11s to convert, the B777F is bound to enjoy sales.
Boeing
is not likely to be as successful with a civil version of the C-17
Globemaster. A Google search shows it last being proposed in 2000.
There are security restrictions with its classification as military
technology, not to mention that its numbers are not competitive with
the civil models available.
The Antonov 225 Mriya (Dream) is
under the nextgeneration section because it is the world’s largest
aircraft and there is only one. First flown in 1988, it was designed to
carry the Russian Buran shuttle and other external loads up to 10
metres in diameter and 70 metres long, weighing up to 250 tonnes. After
the collapse of the Russian space program in 1991, it sat neglected
until 2000 when it was restored, making its first commercial flight in
January 2002. While a second or even a third may be built, it will
likely remain a very special-use aircraft.
Having dispensed with
the pretenders, we turn to the most exciting development in air
freighters, the A380F. While Boeing watched, Airbus took the lead in
the two-horse global race of aerospace giants. Airbus took the
traditional ‘bigger is best’ approach to airliner economics – economies
of scale produce the lowest (seatmile) cost. Airbus claims a 15- 20 per
cent saving over the B747-400, including 12 per cent less fuel per
seat. With three decks of cargo capacity, the Airbus 380 is so large
that airports are having to make modifications to their facilities.
Meanwhile,
Boeing “sat in the weeds” with its (apparently) more modest strategy of
keeping the next generation smaller, relatively speaking. What emerged
was the B787 Dreamliner, continuing a strategy of incremental
cost-saving technologies – more composites for less weight, leaner
manufacturing, and ever more efficient engines. But rather than abandon
the ‘jumbo’ sector to Airbus, and after some false starts, Boeing
launched the B747-8 family just last November. And the B747-8 was
launched on orders for freighters – ten for Cargolux and eight for
Nippon Cargo. As the next round in oneupmanship, Boeing is claiming
that the B747-8 Intercontinental will consume 14 per cent less fuel per
passenger seat and offer a 6 per cent lower seat-mile cost – while
fitting within today’s airport infrastructure. Boeing has also just
announced that it will build its own Beluga, a B747-400 “Large Cargo
Freighter” with a bigger fuselage (1,800 cubic metres!) and a ‘swing
tail’ to transport large B787 components for final assembly. Like
Airbus, Boeing expects it will also offer its three B747-400LCF for
charters when not required by the B787 line.
How much longer can
this game of technological leapfrog go on between Airbus and Boeing? I
cannot say, but I do know that there will be diminishing returns until
someone comes up with a revolutionary technological leap. What might
that be? The best that has been proposed for a very high payload cargo
aircraft is a blended wing body or flying wing. These would give
similar performance to today’s freighters, with jet speeds and
altitudes. But thinking outside the box (way out!), here are two
different approaches:
First, someone, somewhere, someday will
start with a blank sheet of paper and design a flying machine strictly
for freight. Global freight today is containerized. The L500, the
proposed civil version of the C5 Galaxy was going to carry
standard-size containers but only special lightweight aluminium ones
that would need to be stacked on top when caried by a train or ship.
Our hypothetical flying machine would carry the same containers you see
on ships, trains and trucks. That implies a very large size to spread
the cost of that weight penalty. But who says freight needs to fly at
40,000 feet at 500 mph? Perhaps our future freighters should be ‘low
tech’. That could mean a big high-lift wing versus a high-speed swept
one, and big fans, likely turned by diesel engines on biofuels, rather
than turbofans. And it would not be pressurized. Ceiling would be
20,000 feet tops and cruise speed 250 knots at best – but it would haul
a million-pound payload in 24 standard containers. We will leave
technical details like the landing gear to a future piece.
Tonne-kilometre costs would still be higher than land modes but a
target would be one quarter of current air freight costs.
As
long as we are exploring low-tech approaches, turn the clock back even
further for an already proven technology – airships. The giant
Zeppelins of the 1920-30s proved the economy of carrying large payloads
long distances Everyone who hears this immediately yells “Hindenburg!”
but that accident was from highly flammable paint and dope on cloth
fabrics, and while most airship proponents today use helium, hydrogen
is even lighter and really quite safe. The designs on the boards today
incorporate modern technology in materials and power plants, and even
pioneer liftingbody approaches. Dr. Barry Prentice at the University of
Manitoba has organized three conferences on airships over the past five
years. Prentice sees them as the solution to northern transportation
where the environment is delicate and the cost of roads prohibitive.
Air
cargo is high value and often perishable; it absolutely must get to its
destination as quickly as possible, with complete reliability. Federal
Express and UPS and other integrators have built empires on this market
need. In today’s global village economy, those needs will continue to
grow. The A380F and the B747-8F, along with a fleet of B777, MD11 and
other freighters converted from retired passenger airliners will evolve
and grow to meet that market But what about the vast quantity of goods
traded around the world, shipped in containers, to meet just-in-time
manufacturing or the next fashion trend – will more of that ever go by
air? That may need to wait for a revolutionary airborne craft.
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