Thales vs Honeywell vs Rockwell Collins on the A320 series

[divinehover]

Is there a difference between the different MCDU manufacturers in terms of the presentation to the pilot? In other words, Would a pilot who flys a Honeywell equipped aircraft see any difference should he/she now get into a Thales (or RC) equipped aircraft.

My company is in the process of negotiating to equip some new orders but it appears the best deal isn't from the supplier we have been using all along. I was wondering what impact it would have on the pilots should we change suppliers for the new airframes arriving in the future.

[Endeavour]

bmi flies a fleet of A319/A320/A321/A330 aircraft, equipped with a mix of Honeywell Legacy, Honeywell Pegasus and Thales Flight Management Systems. The differences between them, from a users perspective, are relatively minor. By design, if you can use one then you shouldn't have a problem operating another. When the Thales equipped aircraft were introduced at bmi, only self briefing was required.

[Cardinal]

The Thales box requires that you "Insert" a Direct-To. The Honeyell box launches off towards the waypoint as soon as you LSK it.

[divinehover]

Thanks. Apparently Honeywell is at the end of the development cycle for their product where RC and Thales still have some development to come which makes them more attractive.

[oceancrosser]

divinehover, do you mean Honeywell is not going to offer any more upgrades to its system? Seems strange considering AB is trying to extend the life of the A320 series for another 15 yrs at least with the NEO.

[divinehover]

I've been told the Honeywell product is at the end of it's development life cycle whilst the others have some time to go. This is apparently effecting managements decision as to whether we should stick with Honeywell (currently in our A320, A330 and A340's) or move to another product. I really can't verify how much fact is in that statement as I'm not involved in those negotiations.

[underfire]

There is typically little difference to the pilot.

However, there are significant differences in the internal avionics, and the associated combinations of different manufacturers equipment.

Depending on where you are operating, you may/may not have experienced the differences, especially if you are flying RNP procedures or terrain challenged areas.

As an example, you have been flying an A320 with HW avionics on a terrain challenged final approach with no issues. You fly the exact same approach with Thales avionics, and you get a prox warning.
(internally, the HW box uses a 400'ROC at the FAF, while Th uses a 500' ROC)

If you are paying way to close attention, you will notice subtle alt difference. The boxes use different models of the Earth for the cal. While one lays a simple grid over the Earth with a lookup feature at the lat/long, the other uses the geiod with a calc per lat/long.

With A320 RNP..HW, no problem, Thales problem. Internally HW box accepts at/above alt at waypoints without issue. On the other hand, the 320 with TH, will cross the waypoint fine, then porpoise down to the next waypoints at/above alt, thinking its the min seg alt. The first TH equipped 320's had quite the issues on the RNP flight val. Imagine our surprise...

Unfortunately, the coding that fixed the TH issue, did not work on the HW equipped ac.

Long story short...many differences in the calcs...perhaps little difference to the flight deck.

Interesting to note that while HW has the GBAS cert, they do not manufacture a GBAS capable MMR. So to use the HW GBAS system requires the RC MMR on the ac, which is another reason you dont see HW pushing SmartPath too hard.
I was always confused by this, I kept asking, why dont you create a HW GBAS MMR?!?!?