Runway Awareness and Advisory System (RAAS)

Introduction

Runway Awareness and Advisory System (RAAS) is a Honeywell computer system development aimed at the providing flight crew with information regarding the relative position of their aircraft to the runway of the aerodrome that they are operating at. In addition to utilisation of Global Positioning System (GPS) and onboard sensors, RAAS combines the airport geographical layout information stored in the database of the Enhanced Ground Proximity Warning System (EGPWS) to oversee the movements of the aircraft around the aerodrome. Voice announcements are activated when the aircraft is perceived to have reached crucial intersections, such as alerts when approaching an active runway or lining up and moving on a taxiway at more than 40 knots. During take off run, approach and landing, RAAS also informs the flight crew of the remaining runway length. The RAAS may also be programmed to alert flight crew of their incorrect intrusion into a protected area meant for aircraft landing and takeoff, wrong runway usage as well as potential surface dangers.

Human Factors Relation

1) Increase Situational Awareness

Flight crew is able to have a clear comprehension of their exact location as well as important information of the runway in use. For instance, if they accidentally line up on a taxiway for takeoff instead of the departure runway, the RAAS would have informed that they are on a taxiway instead of the designated departure runway. They may also undertake earlier actions in anticipating the usage of a shorter runway.

2) Prevent Hazardous Incidents

This would have prevented incidents when aircraft actually mistook taxiways for runways and executed takeoffs or use a closed runway for landing. The probability of such accidents is greater when visibility conditions are poor and/or a lack of aerodrome movement radar. In 2000, a Singapore Airlines B747-400 took off on a closed runway used as a temporary taxiway and crashed into construction machines in low visibility conditions. If the RAAS had been in use at the point of the accident, it would have alarmed the flight crew that they were in the wrong runway and the presence of surface hazards. Out of the 170 people aboard, 83 were killed and another 71 were injured.

Likewise, runway incursions could be avoided when the RAAS alerts the flight crew that they are entering an active runway. In July 2010, an Antonov AN-124 entered the active departure runway while an Airbus A330-300 was commencing its takeoff run. Fortunately, as the Antonov AN-124 entered the runway at the other far end of the runway, a catastrophe was avoided.

References

Honeywell. (2010, May 24). Product description: SmartRunway/SmartLanding. Retrieved 27 August 2010, from http://www51.honeywell.com/aero/common/documents/egpws-documents/raas-documents/SmartRunway_SmartLanding_description.pdf.
http://www.skybrary.aero/index.php/Runway_Awareness_and_Advisory_System_(RAAS)
http://aviationknowledge.wikidot.com/asi:singapore-airlines-flight-006
http://aviationknowledge.wikidot.com/aviation:runway-incursion:clear-and-present-danger

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