Mode Aviation
Reference No. AR201300050
Date reported 23 June 2013
Concern title RNAV approach for runway 21 at Perth
Concern summary

The concern was that when using the PRL transition during the RNAV approach, the flight management system (FMS) tended to cut the corner as the turn is 108 degrees. This left the aircraft high on the final approach profile.

Industry / Operation affected Aviation: Air transport
Concern subject type Aviation: Flight crew

Reporter's concern

The reporter expressed a safety concern regarding the RNAV approach for runway 21 at Perth (Jeppesen 12-3). The reporter stated that when using the PRL transition, certain FMS boxes with predictive turns, in particular the Universal FMS, "cuts the corner" at HAIGH so the GPS sequences early. This disrupts the approach and leaves the aircraft too high to make the final approach profile. The reporter is concerned that a 108 degree turn onto final is excessive.

Operator's response (Operator 1)

Airservices Australia (Airservices) appreciates the opportunity to respond to the reported safety concerns regarding the RNAV approach for runway (RWY) 21 at Perth Airport. Airservices Australia is unable to comment on the specific behaviour of the flight management system (FMS) reported and suggests the issue be raised with the FMS supplier. However, Airservices would like to provide the following information to address the reporter's concern.

The Perth RWY 21 RNAV (with the PRL transition) instrument flight procedure was originally designed and flight validated in November 2001 and published in February 2002. The instrument flight procedure has been revalidated through flight testing twice (October 2009 and September 2012) and redesigned to incorporate changes to the missed approach (March 2009), transition length (June 2009) and the location of the final approach fix (March 2013). This work was completed to ensure the safe and efficient flow of air traffic at Perth Airport. Recently Perth Air Traffic Control has recommended that the RWY 21 RNAV PRL transition be removed entirely as it is rarely used by aircraft approaching Perth Airport. It is anticipated that the removal of the PRL transition from the RWY 21 instrument flight procedure will address the reporter's concerns regarding the final aircraft approach profile.

Regulator's response (Regulator 1)

CASA has reviewed the content of this REPCON and has no comment to make.

Last update 24 March 2014