IDLE & PERF factor on A330

[Ops_Room_Junkie]

Can any Airbus, specifically A330 operators, advise on the following if they know please.


Two issues:
Amending the PERF factor to account for airframe/engine specific deterioration and therefore increased fuel burn from the std. Once the PERF factor has been calculated, who in your airline updates the individual AC FMS?


Amending, updating the IDLE factor to adjust the FM descent profile. If it is thought to be incorrect and the aircraft is descending to early, too late etc.
Once the decision is made to amend from 0 to +4 or visa versa, who actually updates the aircraft FMS.


In my previous airline it was always done, and efficiently, by engineering. I now find myself in a new airline and the suggestion is this should be a flight ops role as the process is stipulated within the FCOM. I see the logic in this but still don't feel comfortable in how it can be controlled if not within an engineering process.


Just wanted a straw poll if that is possible, to see what others are doing and if my fears are unreasonable.


Many thanks for any insights into what others are doing.

[ahramin]

Done by engineering.

Perf factor is shown on the ofp though so if there is a discrepancy we will resolve with dispatch and change it ourselves if necessary.

[Ops_Room_Junkie]

Thanks for that ahramin

[T.R Haychemu]

Yep, Engineering do it.
As you mentioned, in other airlines, the engineers get a ~monthly workpack from planning to check/update the figures for IDLE/PERF. There is an AMM task for exactly this - it's a 2 minute job. (We used to have a sheet that had IDLE/PERF figures for every aircraft in our fleet, in a previous life).

Sadly, the issue you seem to have is everyone in Part M is washing their hands of the responsibility for the IDLE factor. The FCOM states +4 is the default (if it has never been changed) - and this is what it is set to.
As you know, the fleet are set at 0 due to the aerodynamic differences, which is the correct value to use.

So it remains set at +4, the default value because nobody will confirm that 0 is indeed the correct value for that airframe. I suspect the others were set at delivery. :ugh:

All that needs to happen is the 'Airline', Part M/Ops need to produce a sheet of figures. Then this should be distributed by Planning down the the Part 145 engineers in a workpack for them to update the figures. It's simple, shame about the politics involved!

[nitpicker330]

Our Performance engineers monitor the data and issue updates as required.
Our flight plans contain the latest data.
If the Engineers haven't updated the FM we are instructed to update the numbers ourselves when we setup the FM.

[nitpicker330]

A330 FLIGHT CREW OPERATING MANUAL

AIRCRAFT SYSTEMS AUTO FLIGHT - FLIGHT MANAGEMENT

PERFORMANCE - PREDICTIONS



IDLE FACTOR AT DELIVERY If the FADEC A11.4 or a more recent FADEC Standard is fitted on both engines, the IDLE factor set at delivery is +4 %. Otherwise, it is 0 %.

PROCEDURE TO MODIFY THE PERF AND IDLE FACTORS Applicable to: ALL

PROCEDURE TO MODIFY THE PERF AND IDLE FACTORS (ON GROUND ONLY) ‐ PRESS the MCDU DATA key and then the A/C STATUS prompt in order to access the A/C STATUS page. ‐ ENTER the change code in the CHG CODE field. The default value for this code is “ARM” but it is possible to modify it on airline request. The applicable code is then coded: • In the Airline Modifiable Information (AMI) file for aircraft with FMS2 Honeywell or Thales • In the Navigation Database policy file for aircraft with FMS1 Honeywell Legacy. When a valid change code is entered, the IDLE and PERF factors are displayed in blue. ‐ ENTER the new IDLE and PERF factors in the scratchpad separated by a "/". For example: "-2/+1" ‐ PRESS the corresponding key to insert the new IDLE and PERF factors. The new IDLE and PERF factors are displayed in large blue font. Note: Only authorized personnel should take the responsibility to update the IDLE and PERF factors.