Dunlop Aviation develops Do328Jet braking system in ten months

Citation

(1999), "Dunlop Aviation develops Do328Jet braking system in ten months", Aircraft Engineering and Aerospace Technology, Vol. 71 No. 5. https://doi.org/10.1108/aeat.1999.12771eaf.005

Dunlop Aviation develops Do328Jet braking system in ten months

Dunlop Aviation develops Do328Jet braking system in ten months

Keywords: Dunlop, Braking systems, Software

When Fairchild Aerospace Corporation decided to produce a jet version of the already popular 328 Turbo-prop aircraft it selected Dunlop Aviation as its partner for the development of the wheel, brake and braking system. Now, with certification of this 30-34 seat regional aircraft reaching its final stages, production braking units are already being delivered.

To meet marketing requirements it was essential to design manufacture and qualify the "total aircraft braking package" in less than a year. In the event, in May 1998 less than nine months after Dunlop Aviation Braking Systems (DABS) was selected, the first Dornier 328Jet (Plate 2) successfully completed its first flight. Unlike the Dornier 328 turbo prop which has steel brakes, the jet version is equipped with carbon brakes. Providing high performance under heavy braking loads, Dunlop Aviation carbon brakes are also lighter than other materials.

Plate 2 Dornier 328Jet is equipped with Dunlop Aviation brakes and braking system

The Dunlop Aviation digital anti-skid-system is the core of the braking system which already provides excellent braking control on a number of well established aircraft. Its software provides control of the anti-skid variables to provide a more versatile and adaptive system capable of providing required braking efficiencies under a wide range of operating conditions. It is effective at controlling both carbon heat pack based and the older steel pack brakes.

Braking systems data are linked through the EICAS (engine indicating and crew alert system) to provide information used by both the pilot and ground staff for fault finding and maintenance.

As well as hardware the complexities of designing and proving a new electro-hydraulic braking system in such a short time have been faced and mastered. Much of this success is said to be because the company uses an object-oriented methodology which makes it possible to save considerable software development time. Over time the basic elements of a brake management have been identified and these are combined as required to meet the needs of an individual aircraft. Many of them are common to every system, or minor amendments may be required. This means that each element, or object, can be proven in isolation and subsequently brought together to form the complete system.

The individual object library thus compiled also makes possible greater commonality between airborne test and simulation development software.

In the case of the 328-300 (jet) it was possible to reuse 70 per cent of the software developed for the IPTN N250, 100 seat turboprop airliner. Other systems under development using the same approach include the CASA C295 and the BAe Nimrod (MRA4).

Using an ARINC 429 data link it is possible to provide digital cockpit information for the pilot and for fault finding in maintenance. For example, brake temperature information is provided, a secondary check on the effectiveness of the DABS automatic anti-skid braking system.

Undercarriage characteristics have a considerable bearing on brake performance. To be able to take this into account when designing the brake, Dunlop Aviation has made considerable investment in advanced structural dynamics facilities. Another area of considerable investment has been the systems simulation facilities.

One aspect of this is a generic mathematical aircraft model which simulates six degrees of freedom of the aircraft: surge, sway, heave, roll, pitch, and yaw in real time. Various main and nosewheel undercarriage configurations can be selected and suitable stiffness and damping both fore/aft and vertically programmed in. Aerodynamic forces and engine thrust characteristics are modelled for the aircraft during operational manoeuvres. Different tyre to ground characteristics can be selected. These include simulation for icy, wet, dry patches and uneven runway surfaces.

Further details are available from Dunlop Aviation: Tel +44 (0) 1203 666655; Fax: +44 (0) 1203 662294.