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-   -   All metal livery Cargo planes (https://www.pprune.org/tech-log/444643-all-metal-livery-cargo-planes.html)

Vibes 4th Mar 2011 16:39

All metal livery Cargo planes
 
Hi folks,

I would like to seek your opinion as to why do certain 744 cargo planes come in an all-metal livery i.e Cathay,JAL?Is it due to the fact that doing so might be able to save a significant amount of weight which translates to better fuel economics?

Best Regards,
Vibes

spannersatcx 4th Mar 2011 17:16

That was the plan but it costs more to maintain them that way, so now the paint is left on again.

sb_sfo 4th Mar 2011 17:18

JAL had one classic freighter in bare metal as an experiment, and didn't strip any others. However, when the 400Fs arrived, they were bare metal. The -400BCFs were painted.

Bare metal does save some weight, (I've heard up to 600 pounds) but whether that is significant is up to argument. Due to skin color variations, they look better if they are matched by Boeing when built, rather than pick one at random and strip it.

rotornut 4th Mar 2011 17:49

I read somewhere that the weight of paint on a 747 is around 375 kg..

barit1 4th Mar 2011 21:10

I've heard pros and cons. Paint can act as a filler, smoothing skin joints for some advantage in profile drag. Whether this overcomes the weight difference - who knows?

Turbine D 4th Mar 2011 23:09

To Paint Or Not
 
To paint or not paint the fuselage is open to debate. The paint does add weight to the aircraft, depending on size, 300 to 600 pounds. If the aircraft remains unpainted, the aluminum skin, typically, Aluminum alloy 2024 (Aluminum & copper) - Good fatigue performance, fracture toughness and slow crack propagation rate, will oxidize over time, giving the appearance of not being well maintained. American Airlines has an unpainted fuselage fleet, but polishes their aircraft to keep them bright and shiny. Some claim the cost to do this outweighs the cost to have a painted fleet, eliminating the fuel savings advantage. So for pure cargo freighters, if you don't care about appearance, unpainted planes will save fuel in the long run, but, will not look very nice as the aluminum ages (oxidizes). Note: The wings are painted and use a different aluminum alloy than the fuselage for various reasons.

Turbine D

bearfoil 5th Mar 2011 00:12

I had a friend who had a Swift. He was obsessive about the Shine. He crashed and burned on TO at Tahoe a few years back. We missed him at the coffee shop due all his rubbin' and burnishin'. In the scheme of things, Shiny is not a priority.

Aluminum? They still build A/C out of Aluminum?? Paint the resin, or lose it to the Tap Man. (Preferably White, cuz SPF 100 is expensive).

bear

stickyb 5th Mar 2011 06:52

From the Horse's Mouth
 
Cathay Pacific “silver bullet” freighter takes to the skies

17 May 2006


Cathay Pacific Airways’ first “silver bullet” freighter, stripped bare of most of its paint, goes into service tomorrow (Thursday) as part of an innovative airline initiative that asked staff for ideas to cut spiralling fuel costs.

Less weight reduces aircraft fuel burn. The polished silver fuselage makes a Boeing 747 about 200 kg lighter and will shave about HK$2.8 million from the airline's annual fuel bill when implemented across the 14-strong freighter fleet. Virtually the entire aircraft body has been stripped bare, with the exception of the tail and a strip along the aircraft’s nose to maintain the airline’s identity.

Ultimately all 14 freighter aircraft in the Cathay Pacific fleet will undergo the transformation. They will get the new look when they undergo a scheduled maintenance overhaul over the next couple of years. The full livery on passenger aircraft will remain unchanged.
Cathay Pacific ?silver bullet? freighter takes to the skies

john_tullamarine 5th Mar 2011 09:03

Less weight reduces aircraft fuel burn

... and equals more payload (unless there is some payload limitation preventing that) = more revenue = same fuel burn ?

Marketing hype and increased maintenance costs.

lynn789 11th Mar 2011 21:12

I read that howard hughes had an unpainted DC4 that was seldom flown and always left outside
eventually the new owner had to spend a fortune on its severe metal corrosion
I guess air pollution in the parking area would need to be taken into account

Jinkster 12th Mar 2011 10:13

American Airlines are silver - always wondered whether that was the metal or the paint!

HazelNuts39 12th Mar 2011 14:29


American Airlines has an unpainted fuselage fleet, but polishes their aircraft to keep them bright and shiny.
That policy means that the sheet metal used for the manufacture of their airplanes is made to special order, and expensive measures apply to protect those skins during manufacture.

Regards,
HN39

glhcarl 13th Mar 2011 00:34


That policy means that the sheet metal used for the manufacture of their airplanes is made to special order, and expensive measures apply to protect those skins during manufacture.
The only "special skins" American Airlines required were those used on their A300-600's because Airbus does not used Alclad skins. If you look back their first AA A300's were painted gray and looked like c..p. American made Airbus change to Alclad skins for the remainder of their order.

Boeing uses Alclad skins on all their models (except the 787), regardless if they are polished or painted.

All aircraft skins are protected during the manufacturing process to prevent scratches as scratches can lead to corrosion and or fatigue cracks.

Lots of information on Alclad aluminum on the web but basically it is a thin layer of pure aluminum applied to both sides of aluminum sheets. The pure aluminum makes up approximately 10% of the total sheet thickness and provides corrosion protection.


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