Blog Layout

The Story Of Seals In Modern Day Aircraft

Cliff • June 19, 2020
EE-002-aircraft pushing the limits of engineering (1)

In the last century, commercial air travel has transformed the way we see the world.

What were once far flung, distant lands can now be reached in under a day from anywhere across the globe. And the popularity of air travel only continues to grow.

It’s predicted that the number of airplanes in the sky will double by the year 2032 . That means in addition to the demand for more planes, the demand for faster, safer, and more reliable aircraft is driving the performance of new planes to levels never before seen or imagined.

Needless to say, the Wright brothers would be impressed.

But reaching the performance goals required by modern day aircraft designers and manufacturers is no easy task. New aircraft need to be lighter, more fuel efficient, and cheaper to fly than previous generations of planes.

The challenge lies in achieving a high performance, while maintaining a supreme degree of reliability and safety. There are a number of components that help to assure safety, and seals are one of the most important.

But what happens when a part fails to live up to the standards required by the aircraft industry? Disaster can start with just one faulty component.

What Happens When An Aircraft Component Isn’t Perfect?

Sometimes, the failure of a small component can initiate a sequence of events ending in catastrophic failure — like the Qantas flight QF32 taking off from Singapore in 2010.

A small stub pipe carrying lubricating oil to a bearing was machined by the manufacturer with unequal thickness, leaving it misaligned and fragile. When it broke, it leaked oil, which caught fire and softened the spinning turbine blades.

As a result, the turbine blades disintegrated and tore the engine apart. Shrapnel then punched holes in the wing, damaging spars and severing a main fuel line.

This example of a seemingly negligible issue — that of a slight difference in thickness — highlights just how crucial perfection is in the design and manufacturing of parts for use in aircraft.

Fortunately, the pilots managed to turn the plane around and land safely. But this easily could have been a far more dangerous and disastrous situation.

Modern Aircraft Performance Demands

When it comes to the cutting edge in aircraft design and development, aviation consultant and former National Transportation Safety Board member John Goglia claims that “we are pushing the technology faster than at any time in the past.”

The complexity of new aircraft is ever-growing. Elaborate electronics, fine trim systems, hydraulic-assisted control surfaces and improved engine mechanics all require precise components in order to function.

Even an old Boeing 737 would have had an extensive list of upgrades and part replacements in its life.

The industry now requires ever-extended lifespans and longer maintenance intervals for components such as flap actuators.

These demands of modern day aircraft may seem intimidating to some. But here at Eclipse Engineering , we meet these kinds of expectations every day with our custom seal design and manufacturing.

With precision engineering, use of the proper materials, and extensive, thorough testing, we’ve become a go-to firm for the aerospace industry’s seal needs. Our seals were even used on the Mars Rover !

Eclipse Seals’ Role in Aircraft Construction

Aircraft require a plethora of seals to contain pressurized fluids, exclude contaminants, retain lubricants and keep the body airtight. High-quality materials are essential to deliver these functions reliably.

We use high-specification elastomers in the creation of all our airframe seals, O-rings and molded parts in order to meet these demands.

One crucial aircraft component in which seals are essential are the hydraulic systems that control the brakes, suspension, flap actuators, landing gear and more. These systems undergo extreme amounts of stress, especially during take-off and landing.

The seals we create for aircraft hydraulic systems are made of durable polytetrafluoroethylene, otherwise known as PTFE, or by its household name of Teflon . This is the same stuff that makes your pots and pans non-stick.

It’s the low-friction property that makes Teflon the perfect choice for seals in hydraulic systems in airplanes. In this application, PTFE outperforms and is more dependable than any other material out there.

Achieving Ultra-Reliability with Eclipse

As the aerospace industry continues to rapidly develop, it will rely on quality suppliers to support it. A new aircraft usually takes about five years to develop, with a myriad of components to be designed and engineered along the way.

Increasingly advanced solutions are a necessity, and they’re under-girded by the most stringent quality regime of any industries.

It takes the highest quality parts to maintain efficient and safe operation. Precision and accuracy are critical, with machining tolerances getting tighter and tighter with each passing year.

Eclipse Engineering has in-depth experience with the rigorous demands of the aerospace industry, and offers a range of reliable top-quality seals for aircraft and ground-based aviation systems. These include spring-energized aerospace seals , elastomer-energized PTFE seals , and high performance elastomeric seals and O-rings .

The governing AS9100 quality standard specifies extensive requirements for product risk, documentation and product traceability, and it’s something we take very seriously . Thanks to these governing standards that we adhere to, if there is a sealing problem (something that is a very unlikely event), manufacturing can be traced back to the exact second of production, the machine, and the operator, assuring full accountability.

Looking for custom crafted, best-in-class seals for aircraft or ground-based aviation systems?

By Doug Montgomery November 25, 2024
Eclipse has engineered sealing solutions for applications all over the planet and in a plethora of environments. From the bottom of the ocean to orbiting the earth, Eclipse is challenged by the unique conditions in each application. Whether it be extreme temperature and pressure or severely caustic or abrasive media, Eclipse has a solution for most every sealing problem. One distinct environment presents a particularly challenging set of circumstances for seal design – high radiation. Eclipse’s primary seal material choice for many applications is PTFE and PTFE blends. With all the wonderful attributes PTFE possesses as a seal material, radiation resistance is not one. In high radiation environments PTFE’s properties can degrade to essentially rule it out as a suitable material. The options for effective sealing materials that are also radiation resistant becomes very limited. The seal designer is therefore confronted with creating a seal that is expected to perform in every way a typical PTFE seal operates, out of materials that are not as favorable to sealing. This is where Eclipse’s engineering experience and expertise in seal design come to the forefront. The Client's Issue Eclipse was approached by a customer that was looking for a seal solution for a sensor used in a nuclear application. It would be operating in an environment with both high temperature and high Gamma radiation. Operating Conditions:
 Reciprocating Rod Seal
 Rod Diameter: Ø1.000
 Stroke: 1.5”
Cycle Rate: 2-4 cycles per minute
 Media: Air, Salt Water Mist
 Pressure: 100 PSI
 Temperature: 70° to 450°F
 Gamma Radiation Exposure: 10^6 rads
By Doug Montgomery November 14, 2024
Technological advancements in the area of robotics have led to more and more life-like creations existing only in works of science fiction a few decades ago. Development in autonomous logic processing and sensing allows bipedal robots to walk over uneven ground, up and down stairs, open doors and carry loads. Fast response to dynamic and unpredictable real-world environments is critical for the future use of robots in true-life service and practical employment in the years to come. While software and sensor development remain the primary focus of most research, the physical mechanics of next-gen robotics are also continually progressing. Physical components and control systems such as hydraulic pumps and cylinders, servo motors, and structural members are under pressure to continually be lighter, stronger, more efficient and less expensive. Increased demands on the physical components facilitate the need for innovative solutions in design and material usage. Advancements in construction and technology have spilled into all areas of robotic mechanisms and the many seals located throughout the system need to meet the challenges of tomorrow. Eclipse has been at the forefront of this research and has developed innovative solutions pushing the boundaries of conventional sealing devices. MicroLip™ by Eclipse is a prime example of most demanding applications forging new technologies in the sealing world. The Client's Issue Eclipse was approached by a leading robotics company looking for a sealing solution operating under a challenging set of conditions. While many components of tomorrow’s robotics are now controlled and actuated by servo/stepper motors and various electronic devices, the heaviest and most powerful movements are still driven by traditional hydraulics. The constant demand for more powerful hydraulic actuation in ever deceasing size and weight requirements has put tremendous strain on component design. But if robots are to progress to the point where they are usefully employed in the world, high power in a compact design is necessary. A robot, for example, used to survey and assist in a disaster zone too unstable for normal rescuers, must fit through doorways and over obstacles yet still be physically strong enough to render assistance. Large hydraulic systems are capable of moving extremely heavy loads but size and weight constraints of a humanoid size robot limit potential. The robot’s internal power supply to drive all components is also a limiting factor. Our client was developing a new hydraulic pump to drive all major motion aspects of their robotic systems. Their main objective was to minimize the pump’s physical size as much as possible while increasing output and improving power consumption efficiency. This means higher pressures and speeds on increasingly smaller and lighter components. Application Parameters: Shaft Diameter: Ø9.5mm Seal Housing Envelope: 5mm radial cross-section by 6mm axial width Rotational Speed: 3,500 RPM nominally; 6,000 RPM max Operating Pressure: 125 PSI min, 225 PSI nominal, 350 PSI max Surface Finish: 0.04µm Media: Hydraulic Oil While the above combination of pressure and speed might present difficulties for any conventional seal alone, the client’s extremely small physical envelope to house the seal further complicated the matter. If that wasn’t enough, the application presented the additional sealing challenge of up to 0.003” [0.08mm] of shaft runout. As part of the downsizing of all components in the pump, shaft support bearings were minimized leading to the possibility of runout. The wobbling effect of the shaft creates problems as the sealing lip has follow a moving, uneven mating surface, therefore potential leak-paths are created. Wear life can also be compromised due to higher concentrations of uneven loads. The combination of high pressure, high speed, high runout and minimal gland size present a worst-case scenario for a typical seal. Unsurprisingly, the client faced leakage of hydraulic fluid after only short periods of service with any conventional seal they had tested. Eclipse knew the had the perfect solution for this application. One developed to handle such extreme rotary sealing conditions: MicroLip™.
By Doug Montgomery October 14, 2024
How Eclipse reverse-engineered custom PTFE gaskets to restore a brewery’s historic equipment, ensuring leak-free connections and consistent, quality beer production.
By Doug Montgomery September 10, 2024
Custom piston seal rings by Eclipse enhance compressor performance, offering dry-run capability and extended wear life without hardware modifications.
Share by: