The cost of simply painting an aircraft can be more than a million dollars. The cost of the biggest passenger aircraft ever– the Airbus A380 – can be more than hundreds of millions of dollars. Aerotime.aero reported that the Lockheed Martin F-22 Raptor had a unit cost of $143 million, making it the world’s most expensive fighter jet. But not all of the exorbitant costs of an aircraft are down to the fact that many aircraft parts have gold in it. And not a lot of people know that gold has become an essential component in modern aircraft.
Image: 4300streetcar | wikimedia Commons
Gold’s exceptional qualities, including superior electrical conductivity, corrosion resistance, thermal conductivity, and malleability, make it suitable for a wide range of aeronautical applications. Gold is employed in critical systems within an airplane and has various functions such as:
- provides secure electrical connections
- prevents signal degradation
- withstands extreme weather conditions
Gold’s unique properties enable it to serve in ways that other materials cannot. Let’s take a look at how this highly prized metal is essential to the design and operation of modern aircraft.
A look at a few characters of gold that makes it plane-worthy
Resilience in extreme environments
Gold resilience to extreme environments is particularly crucial in aviation, where aircraft are constantly exposed to harsh conditions from high altitude (from ground to 43,100 feet in air) to fluctuating temperature (−55°C to over 50°C), pressure (10.1 kPa (1.5 psi) to 101 kPa (15 psi)) and humidity (5% to 60%RH). Unlike many metals that rust and tarnish over a period of time, gold stays intact and shiny even in these conditions. This is because gold has a very strong tendency to remain in its metallic form rather than reacting with the environment.
Photo: Alan Hughes | Wikimedia Commons
Even when it is exposed to acids, humidity, high altitude and extreme fluctuating temperature gold remains unaffected making it perfect metal for long lasting aviation applications. So, when a helicopter flies to the top of Mt. Everest, for example, where the temperatures are low enough to cause white-outs and thinning altitudes to cause hypoxia to pilots, it doesn’t change its chemical composition.
Corrosive resistant
One of the key reasons why gold does not tarnish or rust like other metals is because of its stability. Typically, metals corrode because it shares or loses an electron, but gold’s atomic structure makes it less likely to lose or share electrons in reactions. This high resistance to reaction makes gold incredibly durable, ensuring its beauty and strength in the long run. We see that aircraft are operate in high altitude and fluctuating temperature and humidity. This corrosive resistant is property plays important role in aircraft durability and longevity.
High electrical conductivity
Despite not being as conducive as silver or copper, gold is an excellent conductor of electricity. When we couple this electrical conductivity with its other properties, gold becomes particularly valuable high-end electronics used in an aircraft. Unlike copper or silver, which can wither over time and therefore can lose their conductivity with time, gold takes much longer time to get tarnished and degraded.
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This makes gold a prized metal to be used in the intricate electronics of an aircraft such as:
- flight control system
- onboard computers
- radar systems
The use of gold ensures that electrical signals are transmitted efficiently and without loss.
High malleability
Despite being one of the densest metals, gold is incredibly malleable. This means it can be hammered into extremely thin sheets, called gold leaf, without breaking. Just a single ounce of gold can be stretched into an area of around 10 x 15 foot room. This flexibility is due to gold’s atomic structure, which allows its atoms to slide past each other smoothly, preventing cracks or fragmentation. As a result, components like connectors sensors and circuit boards are coated with gold. Gold is also unique in that it doesn’t form oxides. If it did give way too oxides; it would lose its conductivity.
Amazing reflectivity
Gold is truly remarkable when it comes to reflect and insulate from high heats and radiation. Due to its highly reflective surface, it reflects a large percentage of both heat and radiation, preventing them from passing and affecting the material beneath. For example, gold is used in the insulation of aircraft and its delicate sensors and components from the radiation and interference.
Photo: NASA
An aircraft is exposed to high levels of radiation at cruising altitudes. Gold’s highly reflective surface prevents harmful radiation from penetrating sensitive electronics, shielding vital avionics and sensors from interference. Further, gold also shields crew and passengers from harmful infrared and ultraviolet radiation.
In which parts of a plane can you find gold?
Electrical boards and connectors
As we’ve previously touched upon, gold is a top choice for electronics boards and connectors in aircraft due to its exceptional ability to conduct electricity and maintain signal integrity. Although no conductor has perfect efficiency, gold stands out because of its excellent corrosion resistance and high electrical conductivity. Here are where there are gold-plated connectors in an aircraft:
- Control system
- Onboard computers
- Sensors
Even NASA reported how gold’s amazing properties have made it essential for aerospace:
“Satellite microelectronics that instantaneously relay data around the globe depend on gold components to ensure reliable, corrosion-resistant and static-free performance. The growing use of gold in advanced technologies such as microelectronics, telecommunications, optics, aviation and space has increasingly made gold a vital strategic resource in U.S. technological and economic competitiveness. In 1996, the Mars Global Surveyor blasted off toting a gold-plated telescope mirror, part of a laser device that is to chart the topography of the entire Martian surface over a two-year period.”
Photo: Fil22plm | Wikimedia Commons
Glass shields
High-altitude flights expose aircraft to intense ultraviolet and infrared radiation. To ensure the safety and well-being of both the aircraft and its passengers. The aviation industry uses gold-infused glass shields. These shields effectively block harmful radiation like UV and infrared while maintaining high visibility for the crew and pilots. The gold coating not only serves as a protective barrier against radiation but also enhances the strength and durability of the glass, ensuring the shields remain clear and effective throughout the flight.
Use in Stealth aircraft
Gold is also used in Stealth aircraft to reduce the radiation cross section (RCS) of an aircraft. According to a report by global security.org:
“A window member composed of a transparent resin or inorganic glass with a transparent conducting film such as gold or ITO (indium tin oxide) coated thereon, is used as an electromagnetic wave shield window for stealth aircraft. Applying such transparent conducting film enables, while maintaining transparency to visible radiation, both a radio wave stealth property which scatters radio waves in various directions so as not to be detected by radar, and an electromagnetic wave shield property which prevents harmful electromagnetic waves, except for visible radiation, from invasion into an aircraft.”
Coaxial cables
Co-axial cables, which can be widely used in aircraft manufacture, consist of two or more distinct conductors – one of which can contain gold. According to International Aviation Training, gold is used in co-axial cables in the following way:
“The inner one can be either a solid or a stranded copper wire. According to the conductivity level, it can be plated with tin, silver or gold. The outer conductor, instead, is a fine-braid copper wire tube. The inner and the outer conductors are separated by a layer of insulating material, which can be Teflon or Polyethylene. An outer jacket protects the cables from atmospheric agents and from fluids.”
How much gold is there in an aircraft anyhow?
Depending on the type and usage of aircraft, gold is used in different amounts. For example, an aircraft with a lot of radar and communication antenna uses more gold to reinforce its component than a common commercial aircraft. The amount of gold used also depends on the components where the gold is being used. For example, gold is used more in sensors, connectors and body for goal coating rather than in a helmet, glass shields. The aircraft and satellites generally use gold in small amounts typically 1 to 3 ounces for gold plating. Overall, the amount of gold used in satellites can range from as little as 0.1g to as much as 5kg.
Gold in boards and connector
Gold is present in the computer motherboard, components like ram and connector pins. The gold is usually coated in the component contact site to maintain connection with minimal signal loss and interference. Gold is commonly present in:
- Navigation
- Weather detecting system
- Radar and sensor system
- Advanced data processing unit
- power distribution system
- Relays
Gold in gold plated parts
Gold coated parts consist of a variety of parts from windshields to the main body of the aircraft that need extra protection from the corrosion and radiation.
Gold in foils
Gold foils are used in thermal and reflective coatings that help to manage heat and prevent degradation from radiation. In some aircraft gold is used in radar-absorbing material to help reduce the aircraft radar signature.
Conclusion
All in all, gold is a fabulous material for the aviation sector and can be used in various parts differently. It’s unique physical and chemical properties such as malleability, corrosion resistance and excellent electrical conductivity make it an invaluable material in avionics, electrical connectors and sensors functions. While the cost of the total gold used in an aircraft can be a fraction of the overall cost of the aircraft, gold is almost indispensable in aircraft construction.