MAKING IT ALL WORK TOGETHER
At 23.5 inches, the eight wheels of the strategic long range B1B bomber are amongst the largest flying anywhere today. With the brake design, they were first developed by Meggitt in the 1970s. As with most military aircraft, the space within which we had to fit a wheel and brake was limited.
This century, our challenge was to create design that would work harder, for longer, within the same envelope constraints. Today’s modern combat systems and operational requirements have put new demands on the wheels and brakes and advances in material science offered the potential to significantly decrease wear and tear, minimising maintenance downtime.
Like its predecessor, our modernised B1B wheel and brake solution interfaces with one of the world’s more complex landing gears and is based on the skilful interplay of structural design, thermal management and materials technology.
The design includes our latest high performance NuCarb carbon heatsink material. Proven in the field by demanding high-cycle airlines involving frequent take-offs and landings, we expect this to last almost four times longer in service than previous materials. That means 75% fewer removals to maintain eight wheels and brakes—and a quantum leap in operational readiness.
In line with every wheel and braking system challenge we address, we balance weight, life span, life-cycle cost, dispatchability, ease of maintenance, stopping performance and turnaround times to deliver the best solution to the technical performance and operating economics required.
WHAT IT TAKES TO MAKE A BRAKE
- All of them: hydraulic or electric actuation, steel or carbon friction materials.
All the parts
- Wheels, brakes, heatsink, control systems with multiple options and monitoring capabilities
Making them work together
- Our mature system integration capability is based on a simulation and modelling capability using the most advanced techniques available in the industry.
BRAKE CONTROL AND SIMULATION
LANDING IN THE LAB BEFORE THE AIRCRAFT GETS BUILT
When an electrical signal leaves the pedal sensor and enters the controller, hydraulic pressure is unleashed throughout the system starting with valves, progressing to the brakes and setting up torque in the wheels, tyres and the landing gear.
When the tyre touches the runway, those springs could be on the move at over 100 metres per second, generating brake temperatures up to 1700ºC, with loads over, say, 200,000 Newtons and perhaps only 1000 metres in which to stop safely.
If a system doesn’t work, it’s not hard to imagine the landing gear being damaged—worse, breaking off. And given the speeds and loads involved, if a wheel locks up for less than a second, its tyre will blow.
We been in the business long enough to know that effective brake control is down to more than each braking system component meeting its spec. To achieve optimum stopping performance without dynamic instability, they must work in perfect harmony.
We know what to do
A critical part of what makes Meggitt a standout in the field of braking system integration is the simulation capability we’ve pioneered and refined for 40 years over many diverse programmes.
We’ve covered the gamut of commercial transports, business aircraft and military jets—even UAVs—and made it our business to understand anything that could adversely affect braking system performance across all its elements.
To predict how a braking system will perform on the runway, we use key data covering everything from tyre dynamics, fore and aft spring rates and the twist of the landing gear under load and how the aircraft as a whole is loaded. We match this complex array of data to the transfer functions of our parts and simulate takeoffs and landings in our laboratories long before an aircraft gets built.
Our simulation and modelling activity forms the basis of our high quality, highly capable software found in our brake control units. It is also powerful tool that significantly reduces technical risk across all elements. This means more programme certainty and less commercial exposure—advantages that never go out of fashion.
Core system integration services
- Aircraft simulation
- Multi-wheel simulation
- Pitch rotation
- Longitudinal and vertical motion
- Aerodynamic properties
- Landing gear modelling
- Longitudinal and rotational effects of drag force and brake torque
- Twist, bogie pitch and shimmy mode options
- Brake torque modelling
- Tyre modelling
- Dynamic spring and damping rates
- Hydraulics and brake modelling
- System modelling
NO 1 IN HELICOPTER WHEELS AND BRAKES
It takes a Meggitt wheel and brake to safely land—and park—the heaviest lifting Western helicopter on challenging terrain: load and force on raw dirt and sand surfaces.
We designed the tandem rotor Boeing CH47 Chinook’s first wheel and brake in the 1960s, winning every new production contract since with equipment that deftly integrates the design parameters of static torque, parking performance and longevity with low operating cost.
With the strength to absorb unevenly distributed loads, Meggitt wheels help stabilise rotorcraft on descent, backed by brakes robust enough to absorb the impact of rapid vertical landings, with the static torque needed to park these versatile, life-saving machines for long periods on extreme gradients or pitching and rolling aircraft carrier decks.
Meggitt pioneered lightweight helicopter wheels, wheel brakes and rotor brakes in the 1950s. Since then, we have evolved our designs for a variety of platforms from single to multi-disk, pushing braking pressures higher to accommodate greater payloads and utility.
With the strength to absorb unevenly distributed loads, Meggitt wheels help stabilise rotorcraft on descent, backed by brakes robust enough to absorb the impactof rapid vertical landings, with the static torque needed to park these versatile, life saving machines for long periods on extreme gradients or pitching and rolling aircraft carrier decks.
Who we work with
We are the No 1 supplier of wheels, brakes and rotor brakes for world-leading helicopter producers Bell, Boeing, Sikorsky and AgustaWestland.
AgustaWestland Attack, transport
Bell Helicopters Attack, transport
Sikorsky Transport, anti-submarine
INTEGRATING FIGHTER JET LANDING GEAR SUB-SYSTEMS
Meggitt Aircraft Braking Systems was the first to create a landing gear sequencing and brake and skid control unit for a military aircraft. That’s nine subsystems with nose wheels, main wheels and carbon brakes—all controlled by one compact unit.
It is operating effectively in one of the most testing environments aerospace there is—next to the Eurofighter Typhoon’s 27mm Mauser where the system functions after being subjected to the entire spectrum of gunfire vibration.
- Emergency extension monitoring
- Anti-skid control
- Pre-retraction braking
- Park brake monitor
- Gear status indication
- Gear sequencing
- Brake parachute and arrestor hook monitoring
- Weight-on wheels
- Brake pressure metering
Sequencing critical functions
Our unit is as robust as it is safe. Critical functions and the way they are sequenced are split between processes in a push-pull system where events are confirmed by inputs from several sensors. There’s no danger of activating a main gear extension, for example, if the main doors haven’t opened properly.
When you combine nine sub-systems with nose wheels, main wheels and carbon brakes—all controlled by one compact unit—you use less space and less weight and one easy-to-manage system integrator contract.
Dedicated monitoring circuitry and software algorithms don’t just detect faults but tell the pilot and maintenance teams exactly where they are. This advanced system bids farewell to complex maintenance and testing procedures and replacing key components whether they’ve failed or not.
Whatever our customer’s vision of landing gear systems architecture, our demonstrable integration capability is ready to support it.
SYSTEMS FOR UNMANNED AIRCRAFT
NO MAN’S LAND
Meggitt is at the forefront of the European UAV developments as unmanned air vehicles progress towards operational capability in reconnaissance and combat operations alongside traditional military aircraft.
For BAE Systems
In 2006, our electrically-actuated Ebrake® and anti-skid control system became the first to fly successfully on an autonomous UAV. With no pilot to react to landing conditions and control braking, Meggitt delivered a system for EADS that was reliable and responsive enough for safe, remote operation, integrating it with flight controls managed by pre-programmed computers.
In 2006, our electrically-actuated Ebrake® and anti-skid control system became the first to fly successfully on an autonomous UAV. With no pilot to react to landing conditions and control braking, Meggitt delivered a system for EADS that was reliable and responsive enough for safe, remote operation, integrating it with flight controls managed by preprogrammed computers.
MAINTENANCE REPAIR AND OVERHAUL
SEND YOUR PRODUCTS HOME
As the No 1 supplier of wheels, brakes and brake control for military aircraft and an equally strong position in commercial regional and business jets, Meggitt’s MRO services are characterised by two highly complementary features.
Servicing by engineers who designed your product
Military customers outsourcing MRO to us are sending their products home to the brake design engineers that made them. This means they can take advantage of highly informed insights into product behaviour that enables preventative action to be taken, extending the lives of ours―and others’― wheels and brakes.
Competitive military and commercial services
They can also expect highly competitve services. Meggitt’s military aftermarket services are underpinned by long experience servicing an extremely demanding commercial customer base whose operating economics depend on keeping aircraft flying. Meeting these requirements has enabled us to develop slick turnaround processes and logistics support that exceed industry standards.
Meggitt MRO facilities span Asia, Europe and North America.
TOUR OUR SYSTEM HARDWARE
BRAKING SYSTEMS – WHEELS
- High strength fasteners
- Champfered washers
- Multi-run high strength nuts
- Uniform distribution of flange load
- Patented retaining ring design
- Reduced maintenance costs
- Weight savings
WHEELS, BRAKES AND BRAKE CONTROL
Just one of the Meggitt capabilities covered in Meggitt in a Minute, the group’s e-tour.