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All the CRJ aircraft from the 100 up through the new 1000 use the antiquated CRT technology for the main primary and secondary displays as well as the ED1 and ED2 displays.

Aren't flat screens a more modern, cheaper and reliable technology? Why aren't there flat screen retrofit units for the older aircraft or flat screens in the newer aircraft?

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    $\begingroup$ If they work, why replace them? Its an added expense with not much benefit. Are you sure that the newer ones don't use LCD technology? It could also be that they have an approved avionics platform and don't want the expense of going through the FAA/CAA approvals again. $\endgroup$ – Ron Beyer Jan 1 '17 at 22:54
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    $\begingroup$ The pictures and videos of the CRJ-1000 I've seen feature LCD screens on the RTUs and FMCDU, but the 6 main screens are still CRT. The old CRT screens are super heavy and require significant cooling. Those familiar with CRJ procedures know about the cooling requirements and associated limitations. I suspect that building these CRTs is more expensive than building LCD screens to replace in terms of the unit. Perhaps certification changes that equation. $\endgroup$ – ryan1618 Jan 1 '17 at 23:51
  • $\begingroup$ @RonBeyer: You replace them now so you don't have to worry about suppliers in 2 years time. The problem is not engineering but logistics. AFAICT, FAA certification is even stricter than medical certification, when I look at the speed of introduction of new technology. $\endgroup$ – MSalters Jan 2 '17 at 8:39
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    $\begingroup$ @MSalters you'd think. In my experience quite often you just buy up all the stock you can get if it looks like a manufacturer will stop production and hope it lasts until you can get a replacement for the entire platform. $\endgroup$ – jwenting Jan 2 '17 at 9:48
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This is just an educated guess, but it was too much info for comments. Maybe someone can come up with a specific answer, but it seems it's probably a certification delay. The CRJ's all use the Rockwell Collins Pro Line 4 avionics suite, which uses CRT's. In 2000 Rockwell Collins introduced the Pro Line 21 suite which uses LCD screens. They have been slowly introducing PL21 retrofits for aircraft with PL4 as they receive STC's. The Falcon 50 and 2000 began getting retrofits in 2008, followed by Beechjet 400A in 2009, King Airs in 2010, Learjet 60 and Gulfstream G100 in 2012, Piaggio Avanti in 2013, then Hawker 800 and Challenger 300 & 605 in 2014.1

My presumption is that the CRJ's have a type cert with the PL4 and they very well may be working on getting a cert with the PL21 or the newer Pro Line Fusion suite. It will certainly become increasingly difficult to find replacement CRT's as there a only a couple of companies still manufacturing them. It seems just swapping display types is not feasible with the PL4 system. The PL21 system was designed to be more flexible so it's easier to integrate improvements in technology.2


1 These dates might be wrong. I'm finding different dates from different sources. For example, Falcons began getting them in the US in 2006 but it didn't receive EASA certification until 2014.

2 http://jetadvisors.com/rockwell-collins-proline-21-avionics/

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    $\begingroup$ True. Certification costs are enormous, and unless an airline is willing to pay for it, the avionics supplier won't do it. If things are working just fine, airlines would rather spend their money on other priorities. People assume because the name sounds cool that it's cutting edge, but most of Avionics is not cutting edge. There are some cool things being developed, but they take time to find their way into flyable solutions, and there is a balance in the retrofit market between a functional status quo and the new features an upgrade could bring. It's really up to the airlines to decide. $\endgroup$ – Kent A. Jan 2 '17 at 14:35
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    $\begingroup$ @KentA. You may be right, since all of the aircraft i mentioned are popular with private owners, whereas there probably aren't too many CRJ private jets. I doubt too many of the regionals will go back and retrofit their fleet. Plus they usually want all their aircraft to be the same. So that part is really pure speculation. It boils down to the older system being designed and certified with CRT's and they prob can't just swap the displays. They can't continue indefinitely, though, because CRT's are disappearing fast. Maybe Rockwell Collins was proactive and bought 40 years with of them :) $\endgroup$ – TomMcW Jan 2 '17 at 17:12
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    $\begingroup$ The big avionics producers do in fact have stockpiles of hardware. They have modern systems running on modern hardware, but their customers are the ones who decide whether they are willing to pay for a retrofit (and the associated certification activities). So the producers buy up and store large quantities of components in order to provide maintenance for as long a time as possible. But you are correct, at some point, replacement parts will be exhausted, and the airline will have to buy a more modern system - and their supplier will be happy to sell their newer stuff to them. $\endgroup$ – Kent A. Jan 2 '17 at 21:27
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I know the exact answer, even if 2 years late.

Firstly, Collins makes their own displays.

Secondly, it was a conscious decision during CRJ700 development to remain CRT, solely for the reason that airlines already had spares supplies of the CRT displays for the CRJ200 fleet. Changing to LCD in the 700, 900, and 1000 would require two different spares supplies for operators of the entire range.

Additionally, it was a cost matter... the PL4 was already certified, and the airlines :

  • want the new plane yesterday, and
  • don't want LCD certification costs passed along to the final price.
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    $\begingroup$ Welcome to Av.SE! $\endgroup$ – Ralph J Jul 21 at 21:57
  • $\begingroup$ Welcome! Your answer sounds very reasonable - do you have any sources to back it up? That would add tremendous credibility. $\endgroup$ – FreeMan Jul 22 at 14:58

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