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jgilbert20
Topic Author
Posts: 4
Joined: Sun Jun 11, 2017 11:19 pm

Details on a 747-200 CDU (retro!)

Sun Jun 11, 2017 11:38 pm

I am a retro-computing hobbyist and I recently acquired a "Control Display Unit" following from ebay. This was taken from a now-retired NW aircraft.

Image

I've managed to get the unit's LED display up and running with some careful electronics hacking. I can now make it display whatever I want and also detect which key presses are made. I faked the following 4 lines of text using a freescale ARM processor and some of the transistors I salvaged from the part itself.

Image

I'd really like to set it up as a demo to show aviation enthusiasts what the actual device would look like and do.

Can anyone point me at photos of the device operational or some pointers on what it actually did, and how to use it? I would love to find a manual and recreate a few of the functions to serve as some inspiration for others.

The plane it was originally from:

https://www.planespotters.net/airframe/Boeing/747/22389/N628US-Northwest-Airlines

This is a control display unit (CDU) used on Boeing 747 aircraft and possibly other types as well. This one has a parts tag showing removal from N628US on 5/23/08 during upgrade or tear down has been in storage since. It is in good condition without damage to the housing or connectors. The display is not cracked BUT has some delamination on bottom edge and all controls are in place. The data plate reads CONTROL DISPLAY UNIT, PART NO. 160080000-021, POWER 115V 400 HZ 0.8A, 5V 400 HZ 1.5A, CUST. NO. 60B40150, DELCO ELECTRONICS, FAA PMA 747 SERIES. It is not tagged and I have no way to test it so it is being listed AS IS. Thank you for looking and please see our many other aviation auctions.
 
RetiredWeasel
Posts: 779
Joined: Sat Jul 05, 2014 8:16 pm

Re: Details on a 747-200 CDU (retro!)

Mon Jun 12, 2017 4:14 am

This is the CDU for the Performance Management System that NW had several on their newer 200's. I'll just quote what the purpose of that system is straight from the manual:

Performance Management System (PMS)
Introduction The PMS is an interface between the autopilot and the autothrottle. It calculates aircraft
performance by using pilot inputs, stored data, and real time information from several
aircraft systems.
The purpose of the system is to provide fuel conservation and optimize aircraft
performance.
The CADC and INS provide vertical climb rate and acceleration information to the PMS
to determine if the aircraft is in climb, cruise, or descent. The PMS selects the applicable
control mode to become active when engaged.
When engaged, the PMS provides outputs to the A/P, F/D and A/T to control the aircraft
during climb, cruise, and descent.
The components of the PMS include:
• control display unit (CDU)
• performance management computer unit (PMCU)
• switching unit (SU)
• engine interface unit (EIU)

To learn more you'll have to locate either a Boeing Manual on it or NW Aircraft Operation Manual Vol II for the 747-200. I'll certainly not provide it as it was proprietary but you may find one on Ebay.
 
jgilbert20
Topic Author
Posts: 4
Joined: Sun Jun 11, 2017 11:19 pm

Re: Details on a 747-200 CDU (retro!)

Mon Jun 12, 2017 1:09 pm

Thanks for the assistance! I managed to find a CDROM manual on ebay. Is this definitely the one? Will it have screen shots of the CDU?

http://www.ebay.com/itm/NWA-Boeing-747-aircraft-operating-manual-cd-rom-Volume-1-II-AOM-/311803266237?hash=item4898ec44bd:g:3JYAAOSw8w1X~m~M&vxp=mtr

I'm way over budget on this "just for fun" project so I'm a but hesitant to throw more money at it. Its hard to believe in this age of the internet this material isn't just available online.
 
RetiredWeasel
Posts: 779
Joined: Sat Jul 05, 2014 8:16 pm

Re: Details on a 747-200 CDU (retro!)

Mon Jun 12, 2017 3:36 pm

jgilbert20 wrote:
Thanks for the assistance! I managed to find a CDROM manual on ebay. Is this definitely the one? Will it have screen shots of the CDU?

http://www.ebay.com/itm/NWA-Boeing-747-aircraft-operating-manual-cd-rom-Volume-1-II-AOM-/311803266237?hash=item4898ec44bd:g:3JYAAOSw8w1X~m~M&vxp=mtr

I'm way over budget on this "just for fun" project so I'm a but hesitant to throw more money at it. Its hard to believe in this age of the internet this material isn't just available online.


That's definitely the one. There are no photos or color diagrams but there are many B&W diagrams showing what the screen displays and their purpose. But I will say that some of the PMS's were deactivated so I can't guarantee that by 2007 (the manuals you're referring to) show everything I have. My manuals are circa 2000. All the PMS info is in the 'autoflight' section. Good luck.
 
BravoOne
Posts: 4062
Joined: Fri Apr 12, 2013 2:27 pm

Re: Details on a 747-200 CDU (retro!)

Mon Jun 12, 2017 4:07 pm

One thing you can be sure of is when that thing was new, it cost a small fortune.
 
jgilbert20
Topic Author
Posts: 4
Joined: Sun Jun 11, 2017 11:19 pm

Re: Details on a 747-200 CDU (retro!)

Mon Jun 12, 2017 5:42 pm

BravoOne wrote:
One thing you can be sure of is when that thing was new, it cost a small fortune.


I can imagine. The build quality of this is incredible. It was clearly hand assembled. Each PCB has a hand-written serial number. Tons of manually threaded wire bundles. Lots of custom machined components. Has all sorts of tech stuff that I suspect was incredibly esoteric in the late 1970s - kapton tape, flex PCBs, chip-scale LED assemblies. I'm not sure how expensive SN74x logic was back then but it couldn't have been cheap.

I got it <$100 on ebay largely because the front panel is slightly delaminated. The better maintained head-ends go for >$200.
 
BravoOne
Posts: 4062
Joined: Fri Apr 12, 2013 2:27 pm

Re: Details on a 747-200 CDU (retro!)

Mon Jun 12, 2017 6:42 pm

Wonder how many operators used this in their 747 Classic ops? I have seen similar stuff for the 737 and 727s of that era.
 
SAAFNAV
Posts: 598
Joined: Wed Mar 17, 2010 5:41 pm

Re: Details on a 747-200 CDU (retro!)

Tue Jun 13, 2017 2:49 pm

jgilbert20 wrote:
BravoOne wrote:
One thing you can be sure of is when that thing was new, it cost a small fortune.


I can imagine. The build quality of this is incredible. It was clearly hand assembled. Each PCB has a hand-written serial number. Tons of manually threaded wire bundles. Lots of custom machined components. Has all sorts of tech stuff that I suspect was incredibly esoteric in the late 1970s - kapton tape, flex PCBs, chip-scale LED assemblies. I'm not sure how expensive SN74x logic was back then but it couldn't have been cheap.

I got it <$100 on ebay largely because the front panel is slightly delaminated. The better maintained head-ends go for >$200.



Would you mind sharing some pictures of the insides?
L-382 Loadmaster; ex C-130B Navigator
 
jgilbert20
Topic Author
Posts: 4
Joined: Sun Jun 11, 2017 11:19 pm

Re: Details on a 747-200 CDU (retro!)

Wed Jun 14, 2017 5:02 pm

Hi there. I've started a project page on Hackaday with photos.

https://hackaday.io/project/25458-boeing-747-200-pmscdu-restoration
 
RetiredWeasel
Posts: 779
Joined: Sat Jul 05, 2014 8:16 pm

Re: Details on a 747-200 CDU (retro!)

Wed Jun 14, 2017 5:36 pm

jgilbert20 wrote:
Hi there. I've started a project page on Hackaday with photos.

https://hackaday.io/project/25458-boeing-747-200-pmscdu-restoration


Nice presentation. My only nitpicking comment would be that the cockpit photo of the PMS and associated systems is not a NW 747-200. We always had 3 INS's (one where the PMS is pictured) and the PMS CDU head was just in front of the thrust levers. Also we had no 'glass' ADI.

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