Aircraft engineering is the discipline that deals with the design, manufacture and maintenance of aircraft. In the UK, the aerospace industry has an annual turnover of £35 billion and provides over 120,000 jobs. As government spending is set to increase in this sector, aerospace is an industry with great potential.
The importance of aircraft engineering & maintenance is undeniable. From passenger and cargo transportation to crop dusting and aerial photography, aircraft play essential roles in the modern world.
Main Reasons for Aircraft Maintenance
The aircraft repair and maintenance industry in the UK is estimated at a value of £5 billion; growing at an average rate of 1.9%. This growth is accounted for by increasingly innovative technologies, such as adhesives, that are allowing better maintenance techniques. Aerospace manufacturers and repair companies are able to place themselves at a competitive edge by utilising these techniques.
Aircraft maintenance, through carrying out preventive and corrective services, aims to:
- Maintain optimal aircraft safety and airworthiness
- Maximise aircraft availability so it can meet its planned schedule
- Prevent breakage of expensive components
- Reduce running costs of aircraft
Aircraft maintenance needs to be carried out due to:
- Wear and tear
- Mechanical damage as a result of impacts
- Chemical contaminations and leakages
The factors that affect the extent to which an aircraft requires maintenance range from:
- Material selection
- Component finishing and assembly
- Operational environments
- Maintenance programs
Main Components of an Aircraft
The engine is the main source of thrust of an aircraft. It contains cylinders, fans, and pistons which work together to generate power. These components are essential to optimising the lifespan of an aircraft, so ensuring that premium adhesives are used boosts efficiency and cost management in the long-term.
The landing gear is an essential part of the aircraft as it facilitates take-off and landing. It contains wheels, shock absorbers and steel parts. These components are under constant work, and unproper performance can cause catastrophic issues.
The fuselage is the main tube running in the middle of an aircraft, holding the passengers, as well as connecting every other part of the aircraft. Opting to use a high performance adhesive to add extra structure and strength alongside traditional fastening methods. As aerospace and aircraft continue to evolve and bring new technologies, utilising the characteristics of reliable structural adhesives will help to continue innovation in greener air travel and new aircraft.
The wings of an aircraft are responsible for producing the lifting force required to lift off the ground.
The tail controls the stability and direction of the aircraft. It contains the rudder, which steers from left to right, and the elevator, which controls the up to down motion. Due to the rudder and tail being under constant work, ensuring only high performance adhesives, lubricants and sealants are used is essential to cutting future maintenance costs and time; allowing aircraft to stay in operation with limited requirements for maintenance and repair.
Aircraft Bonding Applications
Within aircraft, there are many applications for which adhesive bonding is a great solution. Here we describe a few of these applications that are shaping the future of aircraft manufacturing and maintenance.
Manufacturers of aircraft can ensure the maximum structural integrity of aircraft components by providing strong bonds between composite sub-panels. These applications require adhesives of great chemical resistance and excellent mechanical performance to allow for premium performance over the long-term.
Metal honeycomb bonding
Metal honeycomb “sandwich panels” are used in aerospace applications due to their extreme rigidity at a low weight. They can be used as a mesh structure, within aircraft, to reduce or increase wind turbulence. Bonding honeycomb panels can be a difficult process, but offers dramatic performance enhancements that can help to shape the future of green air travel.
Surface and lightning strike protection
Adhesives and sealants can be used as protective layers which enhance the surface quality of aircraft components. This provides protection from lightning strikes, wear and tear, and corrosion. The lifetime of honeycomb and composite panels can also be extended through this process; allowing for a longer, more reliable lifespan of new, innovative aircraft.
Adhesives for Aircraft Engineering & Maintenance
Adhesives offer many advantages over mechanical fasteners, especially in aerospace applications. These include:
- Weight reductions – allowing a greater lifting force and improving aircraft efficiency.
- Efficient applications – allowing fast and easier repairs and maintenance.
- Great aesthetics – adhesives won’t rust or form lumps, unlike mechanical fasteners or welds.
- Reduced cycle time – adhesives provide quick solutions, allowing greater production rates.
- Lower manufacturing costs – labour costs are massively reduced through adhesives shortening the cycle time.
- Flame retardancy – adhesives can provide flame retardancy properties; essential in aircraft.
- Sustainability – adhesives reduce carbon footprint by requiring less energy to produce and apply.
Huntsman provides many epoxy and polyurethane adhesives that provide all of these characteristics. Specifically, Huntsman adhesives possess low flame, smoke and toxicity characteristics which are requirements for the FAR 25.853 regulation; a required specification for materials used in large commercial aircraft. These can be used for panel bonding, component bonding and structural repairs.
“I have certainly used Araldite 420 A/B and Araldite 2015-1 in aerospace applications and they are fantastic composite bonders. They are also used for insert potting i.e. bonding fastenings into panels.” – John Gallagher, Antala’s Huntsman Representative.
List of Adhesives
Our recommended range of Huntsman adhesives for aircraft engineering & maintenance are:
Araldite 2011 is a two-component epoxy adhesive with good resistance to dynamic loading. It has been used in many Airbus applications, including Airbus AIMS 10-04-020, Airbus ASNA 4049 and Airbus ABR 2-0179.
Araldite 2013-1 is a two-component epoxy paste adhesive particularly suitable for vertical applications. It has been used in the Fokker TH5.937 aircraft application.
Araldite 2015-1 is a two-component epoxy paste adhesive designed to bond GRP, SMC and dissimilar substrates. It is thixotropic and non-sagging up to 10mm thickness.
Araldite 420 A/B is a two-component epoxy adhesive ideal for bonding metal, honeycomb and fibre-reinforced composites. It provides great shear and peel strength and forms a uniform bond line required in high-stress areas. It has been used in Airbus, Boeing and Meggit bonding applications.
In addition to the examples discussed, drones and UAVs are other forms of aerospace applications which can benefit from adhesives. We explore the use of adhesives in drones and adhesives extensively in our article here.