Story ID: 
Crane really puts brakes on
By: Bernard Fitzsimons
Caption: Crane Aerospace & Electronics is here (Hall 5 Stand G17) celebrating its selection by EADS CASA to supply the braking and antiskid system for the Airbus A4
Word Count: 691
Crane Aerospace & Electronics is here (Hall 5 Stand G17) celebrating its selection by EADS CASA to supply the braking and antiskid system for the Airbus A400M and taking the opportunity to showcase an innovative range of components and subsystems that combine sensor and electromechanical technology.

Previous generations of Crane's braking controls are on every Boeing commercial aircraft and most of its military airframes, group vice president Ron Kato said here Saturday, but the fifth-generation system for the A400M is the company’s first brake control for an Airbus type.

Kato attributes the breakthrough to the technology Crane was able to bring to the table. “Our system has improved performance over anything else in the industry in terms of weight, stopping performance and reliability,” he said.

The Mark V digital brake-by-wire system has full digital redundancy plus a third layer of analog control redundancy, and the brakes themselves are hydraulically redundant, with primary and alternate braking hydraulics. Integrated to the aircraft modular avionics and incorporating all the components for brake control, antiskid, automatic braking and brake temperature monitoring, the Mark V systems typically provide better than 95 percent braking efficiency. 

The A400M contract represents an expansion to the range of Crane products already used by Airbus aircraft, Kato said. They include the proximity sensors used to monitor landing gear extension and retraction and engine components on every engine used by the Airbus range.

The braking system typifies the evolution of Crane's products from components to systems as aircraft avionic architectures have moved toward the use of remote data concentrators and distributed controls. “The process started in the regional airliner world with the Honeywell Primus Epic and is blossoming now in the large commercial world,” he said.

Kato hopes the A400M contract will position Crane to supply the brake controls for the A350 when that aircraft’s systems are defined. Another Mark V type system with additional features such as the integration of tire pressure sensing has been selected already for the 787: “The A400M and the 787 were both very heated competitions so I believe we are well positioned for the A350,” he said.

Yet another technology Crane hopes to sell to Airbus for both the A350 and the A380 is an on-board weight and balance system that uses sensors in the landing gear struts to measure the weight and its distribution as an airplane is loaded and calculate the actual center of gravity.

Compared with calculations based on average passenger and baggage weight, the benefits of the AirWeighs system would include fuel and payload optimization, plus major safety benefits on smaller aircraft, Kato said. The system is retrofittable, and Crane is discussing its application to U.S. Air Force C-130s with the U.S. government.

Another technology Crane is working on for the A350 and subsequent platforms involves using wireless technology allied to both passive and active sensors. An example is the SmartStem tire pressure sensing system. A replacement for the existing inflation stem, SmartStem incorporates a sensor to measure inflation and compensate for weight, tire wear and temperature and can be interrogated by a hand-held radio frequency reader. Advantages would include increased tire life and braking efficiency and avoidance of the safety hazard represented by underinflated tires.

For the A350, Crane is proposing to take the idea further by using wireless communication between stem and a sensor in the wheel hub. The readings would be fed from the hub to the wired avionic bus to provide a cockpit indication of actual tire pressure.

Inside the cabin, Crane’s products include premium seat actuation and recline systems. Here again, the company is expecting to add sensing to the electromechanical devices: its P56-55000-00 actuator has a radio frequency identification device that can be used to measure the health of the in-seat actuation system as part of the aircraft health monitoring strategy.