News Analysis: The Myopic Marketing Machinations regarding the use of Composite Materials for Aircraft Construction as touted by Airframes and their Mass Media Minions discuss weight reduction compared to Metal Aircraft. While there will be some weight savings between the materials, as well as some design allowances which are more difficult to achieve with Metals, there are some Key Drawbacks which are typically not discussed.
There are Three Main Problems with Composite Civil or Commercial Aircraft: De-lamination, Detonation, and Flammability.
De-lamination: Stress applied to Composite materials can, over time, make the Carbon/Carbon Textile Fabric de-laminate from other conjoining Fabric. De-lamination makes the sturdiness of the Composites ‘disappear’ to the point of being as strong as a piece of soft fabric. As used in the structure of a fuselage or Wing Box, this could be Catastrophic in flight. It no longer has the strength of the fabricated “Vacuum Bagged and Autoclaved ” original structure.
Secondly, Long Term Exposure to Cosmic and Solar Radiation of a Composite Aircraft in High Altitude Flight will eventually weaken the adhesive thereby allowing Fabric De-lamination to occur.
Thirdly, allegedly, the U.S. B-2 Stealth Composite Bomber has had issues over its ‘brief’ life. The U.S. Air Force is presently seeking funding for a replacement of this Vaunted Aircraft. It is too expensive to maintain and has a shorter life expectancy than Metal Aircraft (is what has been reported in the media). The Leading Edges of the Wings need to be constantly examined for Surface Deterioration from flying in the skies with particulates in the air.
The American led Gulf War with Silica Sand particles in the air damaged the B-2’s in their flights from Whiteman Air Force Base in Missouri, U.S.A., to Iraq and back. U.S. Air Force Line Maintenance Personnel were quite chagrined by this reality it has been widely reported. What can Airlines expect of this Composite Behavior in flight that would be different from the U.S. Air Force experiences? The Commercial Airlines will not fly in the Middle East? Hardly.
Detonation: Composite Aircraft cannot land on Airport Runways if they have Landing Gear Failure for example, without detonating the Composites into many Shards (as in an Explosion). Like an Egg Shell that destructs when smashed against something, so too will the underside of a Composite Aircraft have those portions of itself thrown all over a runway. A Metal Aircraft “dents”; a Composite Aircraft “explodes”, in effect.
Flammability: Carbon/Carbon Fabric and Petrochemical Adhesives used to ‘Glue an aircraft together’ are Flammable. The recent Small Battery Episodes causing fire to the Composite Airliners, for which they were grounded for months is a good example of this FACTUAL INHERENT MATERIALS’ LIABILITY. A Small Battery caused extensive aft fuselage damage to an Ethiopian Airlines Aircraft at Heathrow Airport in England. It reportedly took TWO MONTHS for the Airframe to ‘Secretly Repair” the damage. In fact, allegedly NO data as to the Repair Process has been disseminated to the Public nor to other Airlines. Why is that? What does the Airframe NOT WANT potential Customers to know? people ask.
If an Engine Detonation were to occur in flight and hot pieces of the engine (much hotter than a little battery) were to strike the Wing or Fuselage, a fire would be possible. A defective Microwave Oven used in the Galley could overheat, creating a possible fire in the fuselage.
What if the Auxiliary Power Unit were to catch fire and one was flying in such a Composite Aircraft over the Pacific Ocean, far from any airport, at night with a storm occurring below?
Flying into a storm may be hazardous in such a scenario and the greater atmospheric pressure of lower altitude might expand the fire due to more oxygen being present; a possible scenario
METALS IN AIRCRAFT ARE NOT FUEL SOURCES FOR FIRE, Carbon/Carbon Fabrics and the Petrochemical Adhesives ARE; This is not Clever Marketing But Real-World Science.
The Specious Argument of “Weight Savings for Fuel Savings” has a nice sound to it, but ignores the Composite Aircraft Realities of De-lamination, Detonation, And Flammability.
One must ask: “Is Aircraft Safety More Important to Society than Some Fuel Savings to An Airline?” The answer from Men of Good Conscience is “Safety Wins”; For those who choose Fuel Savings, let them enjoy their potential “Fires in the Sky”.
To those who only write about Composite Aircraft Weight Savings, one must ask: “What about Composites’ Liabilities?”
We tell it as We see it; We are beholden to No One.
Reality is the truth.
Reference: http://www.bbc.co.uk/news/business-25833264