Desciption of modification RUAG EASA approved modification consists of the following: 

• Replacement of the existing EGPWS MK VIII with an EGPWS MK V with software status -228-228, re-using the interfaces and wiring from the MK VIII. This is necessary, as the MK VIII cannot be upgraded to RAAS.
• Activation of RAAS functionality by a software activation key (RAAS is already part of EGPWS software -228-228).
• Installation of a Reloadable Configuration Database (RCD) containing global and a/c specific configuration options such as voice gender, units for distance, individual alert on/off, etc.
• Installation of a “RAAS OFF” switch in the centre pedestal to give the pilot the possibility to mute the system.
• All previous EGPWS functionality will be retained.

RAAS -  Runway Awareness and Advisory System The Honeywell Runway Awareness and Advisory System (  RAAS) offers significant safety enhancements for aircraft equipped with Honeywell’s Mk V Enhanced Ground Proximity Warning Systems (EGPWS). 

Honeywell’s Runway Awareness and Advisory System is a software enhancement hosted in the EGPWS Unit. 
RAAS uses GPS position data and the Honeywell EGPWS Database to provide aural advisories that supplement flight crew awareness of position during ground operations and on approach to landing. EGPWS protection and operation is unaltered by the addition of RAAS. 

RAAS installation is accomplished via an enabling “key” and loading a configuration database.  The installation requires that:  - the EGPWS has a source of GPS data,  - Terrain Database version 435 or later, and  - RAAS Configuration Database (RCD) is loaded. 

When enabled, RAAS operates automatically, without any action required from the flight crew. RAAS availability can be verified by performing an EGPWS self test.

 
EGPWS MK V - Enhanced Ground Proximity Warning Systems MK V

The EGPWS MK V provides the same altering algorithms and offers all the functionality of the MK VIII system it is replacing.  Moreover, the MK V offers the upgrade possibility to RAAS and provides a more comprehensive set of interfaces. It is designed for installation in “digital” aircraft.  Compared to the MK VIII, the MK V it is slightly bigger in height and depth and mounts on a 2 MCU Arinc 600 tray. The unit is configured via pin strapping opposed to the configuration module of the MK VIII. All wiring interfaces from the previous OEM installation will be re-used.