Future Technology: Runway Overrun Protection Systems

Runway Overrun Protection Systems

                                             

                                              

Runway Excursion 

This might be a bit off topic, but while looking at Safety nets I came across Runway Overrun Protection Systems (ROPS). Runway Excursion is of serious concern to the Aviation Industry at the moment because occurrences are increasing at a rate greater than the rate of global fleet expansion. Put simply, runway excursion is an incident where an aircraft unintentionally leaves the runway and can occur during takeoff or landing phases of flight – ICAO defines runway excursion as “A veer off or overrun off the runway surface”.  

ROPS shows the position at which the aircraft will stop along the runway (in wet or dry conditions) on the aircraft’s nav display.

The point will move along the length of the runway depending on the systems evaluation of aircraft approach profile, aircraft breaking capability and landing distance available (LDA).

If ROPS predicts a Runway Overrun Occurrence a visual warning is given to the pilot, along with a repeated aural alert: “RUNWAY TOO SHORT”. Research has shown that when pilots are presented with a non-standard situation, their instant reaction is to revert to a pre-programmed response.

In the event of runway overrun it has been found that pilots have often reduced reverse thrust to idle upon reaching 80kts, a standard procedure, rather than reacting to the non-standard situation in front of them. For this reason, the ROPS system gives the aural cue “KEEP MAX REVERSE” if the aircraft is at risk of runway overrun and is approaching 80kts.

Airbus has made their ROPS system commercially available to other aircraft manufacturers in an attempt to combat the number of global runway excursion incidents. 

Today, Main Cause of Accidents is Runway Excursion

A Vast Majority of Overruns at Landing is Preventable

Main Contributing Factors of Runway Overrun at Landing

Auto Brake setting too Low.

Stabilization Not Achieved at 1000/500 ft.

Wind shear at low altitude.

Approach becoming unstable at low altitude.

Long flare.

Long derotation.

Late selection of engine thrust reversers.

Cancellation of reversers at 70kts.

Late/weak manual braking (w/o or after AB disc).

Failure affecting the landing distances.

Runway friction coefficient lower than expected.

Etc.