Mode Aviation
Reference No. AR201300028
Date reported 22 April 2013
Concern title Non-synchronised flight management systems
Concern summary

The concern related to the use of dual flight management systems (FMS) which are not fully synchronised resulting in the flight crew operating in a head down state at critical phases of flight or undesired power states.

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

Reporter's concern

The reporter expressed a safety concern regarding the use of dual flight management system (FMS) which are not fully synchronised.

Some FMSs are "cross fill enabled" which is an independent mode of operation where the flight plan legs page only is pushed to update the offside FMS. The reporter stated that the interaction and co-ordination required to update both of the FMSs at critical phases of flight is complex and frequently forces both pilots to operate in a head down state. The pilot-not-flying frequently has to reach across the power / condition lever quadrant to update the second FMS which has led to both reported and unreported events of undesired power states.

Additionally, as the cross fill is limited, many other actions have to be duplicated on both FMS control display units at critical phases of flight. This arrangement leaves the operation open to errors and removes the added safety of having a FMS.

The reporter commented that as the company is profitable and expanding there is no excuse. To neglect it would be a matter of organisational complacency.

Operator's response (Operator 1)

We are pleased to provide a response to this issue as it is something we are well aware of. In considering our response we have reviewed occurrence data for the last three years, our current procedures and future plans for upgrade:


A review of all investigations conducted in last 3 years, does not indicate the non-synchronised FMSs as a contributing safety factor. Additionally, there are no historic reports from pilots identifying non-synchronised FMSs as a safety concern.

Current procedures

Current procedures regarding the use of non-synchronised FMSs are well established since the introduction of the aircraft, and any hazards relating to their use have been assessed and mitigated. Furthermore the procedures are continuously improved through experience, consultation with the manufacturer and other airline operators to ensure "best practice" is implemented. This includes thorough checking of both FMSs when changes to flight plans are made, as well as allowing opportunity for the pilot flying to make simple selections on the on-side FMS to avoid inadvertent touching of levers, switches, or buttons.

The primary focus is to maintain situational awareness of both pilots and in particular the pilot flying; accordingly the pilot monitoring role is management of both FMS.

Future plans for upgrade

Of the aircraft in our fleet, 7 of these already have a factory installed upgraded FMS installation that includes synchronisation of both FMS. An upgrade programme was approved for the remaining aircraft in late 2012. The upgrade will commence in the third quarter of 2013.

We appreciate the report and would ask the ATSB to relay to the reporter that we are more than happy to answer any questions regarding this or any other matter by simply liaising with our Flying Operations management team.

Regulator's response (Regulator 1)

CASA has reviewed the REPCON and is satisfied with the operator's response. CASA will continue to engage with the operator while they work with the aircraft manufacturer.

Last update 24 March 2014