I am going to fly on the brand new Delta a321 soon and I am quite excited because these planes are brand new and have all the modern blows and whistles from the passenger point of view.

But I am curious to understand what are the main differences in terms of avionics, cockpit screens, alerts/warnings, safety features, redundancy, systems, etc. between these a321-200s made in 2017-2018 and the older models produced in 1990s and early 2000s?

To the non-professional, the cockpit pretty much looks the same, except maybe some nicer presentation of the weather patterns and LCD screens. But I wonder if the contents of these tools and screens behinds the scenes are much more modern.

There are a few namely-
LCD screens.
Standby horizon, standby ASI, RMI replaced by ISIS (digital)
Old ones had floppy driver for data loading in the center pedestal.
New ones especially Neo's have LED lighting in the cockpit.

StereoTechque wrote:

There are a few namely-
LCD screens.
Standby horizon, standby ASI, RMI replaced by ISIS (digital)
Old ones had floppy driver for data loading in the center pedestal.
New ones especially Neo's have LED lighting in the cockpit.

But all this sounds somewhat minor, considering the 30+ years of progress and innovation. I mean, if you compare a PC or any piece of electronics from the 90s with the one we have today, it's a huge difference. Shouldn't they have more automated monitoring of various parts and more redundancy also?

The crew interface (i.e. the flight deck and everything in it) has stayed much the same for obvious certification reasons.
Pilots who possess an A32x rating need to be able to operate a 1988-built A320 (if there were any left) and a 2018-built A321NEO seamlessly on the same day. The cockpit and its dials, screens and switches are just a way of presenting information to the pilots and allowing them to interact with the airplane. There is little than can be modified without requiring re-certification and expensive additional pilot training and most of the time, it's not required anyway.

You'll find that most of the changes in avionics have happened underneath the cockpit. Many computers and instruments have been upgraded to more modern hardware, software has been updated, all in a transparent way to the flight crew, other than the fact that computer lag after you press a key has decreased significantly...

There been lots of background changes. The FMS has had software updates improving performance and functionality (eg. RNP-AR), EGPWS updates, TCAS updates, GPS Primary input, Autoflight system improvements, Flight Control software updates, better improved Weather Radar. I’m sure there’s lots more.

Not sure if they are called the same on the 320 but I think the Cockpit Door Security System and the Cockpit Door Surveillance System (CDSS) were added/upgraded after 9/11.

Francoflier wrote:

Pilots who possess an A32x rating need to be able to operate a 1988-built A320 (if there were any left) and a 2018-built A321NEO seamlessly on the same day.

The ATR -600 series upgrade is the perfect example of why not to do it. Pilots rated on old ATRs had to do a simulator course to fly the -600. Pilots who do the type rating on the -600 can't fly the older variant at all, unless they do the entire type rating course over again. This resulted in overbooked simulators with month long waiting lists, and airlines sending their crews halfway across the world for that single available sim slot in Singapore or Miami. Now that the -600 is becoming more predominant, operators of older ATRs are having increasing troubles finding crews to fly the old cockpit variants, because more pilots are being type rated directly to the -600.

There were a few changes - one „package“ was EIS 2, which are basically the LCD screens. There were a few changes to the hydraulic architecture over the years and in other systems as well. Since a few years there is a BUSS (Backup Speed Scale) for unreliable airspeed procedures. There are several different weather radars and FMGCs available. The newest weather radar is really nice as it is able to display the weather at any selected level without the need for setting a tilt (it’s even possible to select different levels on the FOs and CPTs side). There is a simpler fuel system since a few years as well on A320s (it’s now more similar to the one used on A321s). Since a few years the Autopilot is able to follow TCAS RAs automatically - I’ve never flown an aircraft with this feature until now but apparently it’s a nice feature for this kind of stressful situation. As you see it’s really only minor things, the most significant in day to day operation is probably the new FMGCs (the old FMGCs don’t have a fix Info Page not the ability to show Abeams when getting shortcuts so it’s a bit annoying to do fuel checks on these...PM will have to select the secondary flightplan to see the waypoints and to do the fuel checks when passing abeam...it’s much more comfortable on the new ones with the abeam function).

[quote="Flow2706"][/quote]
Wow, that's a nice summary. Any idea why the fuel system of A321 with no transfer valves can't be incorporated in the A320?

Flow2706 wrote:

There were a few changes - one „package“ was EIS 2, which are basically the LCD screens. There were a few changes to the hydraulic architecture over the years and in other systems as well. Since a few years there is a BUSS (Backup Speed Scale) for unreliable airspeed procedures. There are several different weather radars and FMGCs available. The newest weather radar is really nice as it is able to display the weather at any selected level without the need for setting a tilt (it’s even possible to select different levels on the FOs and CPTs side). There is a simpler fuel system since a few years as well on A320s (it’s now more similar to the one used on A321s). Since a few years the Autopilot is able to follow TCAS RAs automatically - I’ve never flown an aircraft with this feature until now but apparently it’s a nice feature for this kind of stressful situation. As you see it’s really only minor things, the most significant in day to day operation is probably the new FMGCs (the old FMGCs don’t have a fix Info Page not the ability to show Abeams when getting shortcuts so it’s a bit annoying to do fuel checks on these...PM will have to select the secondary flightplan to see the waypoints and to do the fuel checks when passing abeam...it’s much more comfortable on the new ones with the abeam function).

Did the auto-TCAS thing in the sim a few weeks ago. You just sit there and read the FMA while the PM does radio calls as usual. The experience is rather weird at first.

Beneath the surface, there have been a lot of updates and changes, especially with the FMS. Today's A320s are in a different league to the crappy first gen Pegasus FMS equipped aircraft I first flew, and the new avionics must be capable of monitoring nav accuracy if they're to conform.

The only obvious pointer in our newer A320 aircraft is a red placard in the cockpit which states 'Buss equipped'. You have to delve a little deeper and play around a little to spot stuff like the new weather radar.

Presumably the CPUs have been updated as well. The early aircraft used Intel chips with just a few megabytes of memory

For those interested in the details:

https://aerospace.honeywell.com/en/~/me ... 0_a320.pdf

I would think CPDLC equipment for datalink has been added, at least as an option.

At my airline (probably everywhere else too), the DDRMI is now gone (the old fashioned backup VOR needles). But their is still a cut out in the plastic fascia for it. There is literally an empty hole in the panel.

greg85 wrote:

At my airline (probably everywhere else too), the DDRMI is now gone (the old fashioned backup VOR needles). But their is still a cut out in the plastic fascia for it. There is literally an empty hole in the panel.

It's still available across the whole Airbus lineup. I'm not sure if anyone is buying it though. Probably just Lufthansa.

Elshad wrote:

Presumably the CPUs have been updated as well. The early aircraft used Intel chips with just a few megabytes of memory

More like a couple of hundred KILObytes. If even that.

Only Windows machines need memory to no end to allow faster idling

If you look downstairs in an older A320 you would find most of the boxes are not the same as the ones the planes were delivered with. Many of those black boxes have gone through hardware and software upgrades over the years. Many of those boxes are now the same as the ones in the latest A320 deliveries.

I guess option to not have the floppy drive costs extra.

I just flew a 320 that was manufactured earlier this month and delivered last week from Airbus and the floppy drive is installed with a full set of twenty 3.5” floppies and 15 CD-ROMe stored in the flight deck media storage compartment.

Elshad wrote:

Presumably the CPUs have been updated as well. The early aircraft used Intel chips with just a few megabytes of memory

I'm pretty sure there is a Commodore 64 running everythi......PLEASE WAIT

Woodreau wrote:

I guess option to not have the floppy drive costs extra.

I just flew a 320 that was manufactured earlier this month and delivered last week from Airbus and the floppy drive is installed with a full set of twenty 3.5” floppies and 15 CD-ROMe stored in the flight deck media storage compartment.

Lol, is that for when you need to reinstall Airbus OS?

Kindanew wrote:

Lol, is that for when you need to reinstall Airbus OS?

You'd use a Datasette for that.

Curiosity killed the cat and I was curious to see what was on these floppies and CDs so I lugged an old laptop computer with a floppy drive and CD-ROM drive to work on a trip.

I found it interesting that each floppy disk and CD-ROM contained at most a few files that totaled less than 256kb (not MB) for each disk/CD-ROM.

The entire 20 floppy and 15 CD-ROM set could have been consolidated onto a single CD-ROM with enough room leftover to record a CD album/mix tape.

Flow2706 wrote:

There were a few changes - one „package“ was EIS 2, which are basically the LCD screens. There were a few changes to the hydraulic architecture over the years and in other systems as well. ...

Amazing answer with so many technical details. Thank you!

From the early A320 this is what has been added, some are standard, some are options

ISIS (removed the steam driven altimiter, airspeed, DDRMI)
Digital clock
Predictive wind-shear
T3CAS
ADS-B
EGPWS and terrain pushbutton
Brake fans
Additional centre tanks
VHF/HF/Satellite datalink
DCDU for ATC communications
Auto-Pilot/Flight Director Traffic alert and Collision Avoidance System (AP/FD TCAS)
ATC communications attention getter
RNP-AR, MLS, GLS
Bake to vacate, Runway Overrun Warning (ROW) & Runway Overrun Prevention (ROP) https://skybrary.aero/bookshelf/books/2189.pdf
Advisory runway ahead
Soft go-around
Reversible Back-Up Speed Scale (BUSS)
OANS Onboard Airport Navigation System

Single or dual Head-up display standard (L5) including ROPS, RNP AR 0.1, AP/FD TCAS,runway ahead

VSMUT wrote:

Francoflier wrote:

Pilots who possess an A32x rating need to be able to operate a 1988-built A320 (if there were any left) and a 2018-built A321NEO seamlessly on the same day.

The ATR -600 series upgrade is the perfect example of why not to do it. Pilots rated on old ATRs had to do a simulator course to fly the -600. Pilots who do the type rating on the -600 can't fly the older variant at all, unless they do the entire type rating course over again. This resulted in overbooked simulators with month long waiting lists, and airlines sending their crews halfway across the world for that single available sim slot in Singapore or Miami. Now that the -600 is becoming more predominant, operators of older ATRs are having increasing troubles finding crews to fly the old cockpit variants, because more pilots are being type rated directly to the -600.

That's due to the way ATR designed their training program. They have a -500 to -600 course which is like a week long that allows pilots to fly both. They do not offer a -600 to -500 course. A -600 only rated pilot would have to to an entire -500 course from scratch, which incidentally is probably about 90% similar as the only difference between the aircraft is the cockpit avionics.

LimaFoxTango wrote:

VSMUT wrote:

Francoflier wrote:

Pilots who possess an A32x rating need to be able to operate a 1988-built A320 (if there were any left) and a 2018-built A321NEO seamlessly on the same day.

The ATR -600 series upgrade is the perfect example of why not to do it. Pilots rated on old ATRs had to do a simulator course to fly the -600. Pilots who do the type rating on the -600 can't fly the older variant at all, unless they do the entire type rating course over again. This resulted in overbooked simulators with month long waiting lists, and airlines sending their crews halfway across the world for that single available sim slot in Singapore or Miami. Now that the -600 is becoming more predominant, operators of older ATRs are having increasing troubles finding crews to fly the old cockpit variants, because more pilots are being type rated directly to the -600.

That's due to the way ATR designed their training program. They have a -500 to -600 course which is like a week long that allows pilots to fly both. They do not offer a -600 to -500 course. A -600 only rated pilot would have to to an entire -500 course from scratch, which incidentally is probably about 90% similar as the only difference between the aircraft is the cockpit avionics.

The aircraft is entirely the same, it's just the cockpit that changed. The cockpit OTOH, is as far removed from legacy ATRs as possible. We arent talking an upgrade that keeps everything relatively similar, like 737 classic vs NG, or NG vs MAX. Its completely different. Everything is displayed in new locations, procedures were changed etc.