A350 XWB will have as standard the runway overrun protection system (ROPS) to avoid the most common type of airline accident.

ROPS represents a major contribution to increased safety, and will be fitted as standard to the A350 XWB. It will be also available as a retrofit to all Airbus aircraft.

This system will warn the pilots, during approach, of the risk of runway overrun. This is the most common type of airline accident, occasionally fatal but almost always damaging to the aircraft.

ROPS is an avionics solution that compares aircraft energy state and landing performance against the runway end throughout the short final approach to the aircraft’s eventual stop. It issues warnings to pilots on final approach, if the runway length from the projected touchdown spot is too short, aiding them in making the decision to go around. Once the aircraft has touched down, ROPS warns if heavier braking and reverse thrust are required to stop the aircraft within the confines of the runway.

ROPS provides the pilots, during approach, with a visual display of where the aircraft will stop on the selected runway in both dry and wet conditions if the aircraft carries out a standard stabilized approach at the correct speeds. If the runway is too short, the stop lines show beyond the end of the runway, and the pilots receive spoken and visual warnings.

This GPS-linked function is active in real time, so if the pilots approach to fast or too high, or land too far down a runway that originally showed as sufficiently long, the visual information about stopping positions is continually adjusted and warnings are activated if necessary.

click the image to watch a demo-video

The crew can call up an image of the desired runway layout on to the navigation display to designate the runway required (Toulouse Runway 14L, for example). The pilots then designate the runway by using their keyboard cursor control unit to place the magenta chevrons over the threshold of Runway 14L and click. Seconds later, the magenta crossbars across the runway show where the landing roll would come to a full stop if the runway were dry, and the second - further on - if it were wet. If the runway were too short the crossbars would be in the overrun.

When ROPS provides the stopping point designators early in the approach, it assumes you will fly a standard profile at standard reference speeds, crossing the threshold at 50ft (15m) and putting the aircraft down in the touchdown zone. But if the aircraft is high and fast on approach, the ROPS knows, and the stopping point designators move away down the runway.

 click the image to watch a demo-video

 While the safety enhancement aspect of ROPS cannot be overlooked, there is also a cost-saving implication.

The ROPS has been developed from the A380's "brake-to-vacate" (BTV) capability, whereas BTV itself will be optional on the A350 XWB. BTV is a programmable braking control system which, if set before landing, provides automatic braking to slow the aircraft evenly to enable the crew to turn off the runway at a chosen exit, potentially reducing runway occupancy time. BTV would be particularly useful when landing in marginal visibility.

 

Based on article “Airbus To Offer Runway Protection System for Its Aircraft” published in AINOnline