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Identifying 747 Aircraft Part

Posted: Sun Oct 20, 2019 1:42 pm
by AeroplaneFreak
Many years ago I bought a whole bunch of aircraft parts online including this air conditioning control panel taken from N474EV and when I did little research I discovered it was actually the 4th 747 built and was part of the test program before being delivered to Pan Am as N731PA.

I was wondering if anyone is able to confirm if this part is original and was in the aircraft when it was built.

Here are two photographs showing the panel front and back...

https://imgur.com/a/LYVps81
https://imgur.com/a/sKockdZ

Looking at the back there seems to be date below the part number which says 10-16-68 for which I take it as 16th October 1968, am I reading this right or is this not a date? Also of note on the front of the panel Zone 4 seems to be rubbed out and covered up which suggests that it was in the aircraft before being converted to a freighter in the 90s as there would be no need to air condition Zone 4 if it was only freight.

Any help would be much appreciated.

Re: Identifying 747 Aircraft Part

Posted: Sun Oct 20, 2019 2:03 pm
by Dalmd88
It would be hard to prove it was delivered on a particular aircraft with out the part records. Items like this could have been installed on various aircraft during service. Most airlines will swap out the panel if there is a problem with any of the components on the panel. The panel then goes to a shop and gets fixed. Put back in stock and installed on another aircraft.

It is an early build panel judging by the date stamp and was likely in service with Pan Am. I would guess the s/n would be a Pan Am assigned number. Likely assigned during the panel's first shop visit. The second panel of this part number to visit the shop I would guess.

Re: Identifying 747 Aircraft Part

Posted: Sun Oct 20, 2019 2:38 pm
by AeroplaneFreak
Dalmd88 wrote:
It would be hard to prove it was delivered on a particular aircraft with out the part records. Items like this could have been installed on various aircraft during service. Most airlines will swap out the panel if there is a problem with any of the components on the panel. The panel then goes to a shop and gets fixed. Put back in stock and installed on another aircraft.

It is an early build panel judging by the date stamp and was likely in service with Pan Am. I would guess the s/n would be a Pan Am assigned number. Likely assigned during the panel's first shop visit. The second panel of this part number to visit the shop I would guess.


Thanks for the quick reply, never noticed the serial numbers PA must be Pan Am it makes perfect sense. Well at least it looks like it's a very early build and was probably installed on one of early 747s. 16th October 1968 is the presumed production date which was only two weeks after the rollout of the first build 747 so it's looking like it was installed on an early build.

Re: Identifying 747 Aircraft Part

Posted: Sun Oct 20, 2019 3:31 pm
by DL_Mech
I was looking at a part from N633DL used to repair the Azores hard landing A/C and it had a date of Jan. 1987. That plane was delivered to DL in December 1987. So that October 1968 date does match up with an early build 747-121. I have only seen Boeing Variable Numbers on some parts which would trace it to a particular A/C.

Lockheed would frequently make the Serial Number of some large parts the same as the S/S (Ship Serial) Number. The Eastern Flight 401 Everglades crash A/C was S/S 1011 (11th L-1011 produced). I did find a couple of parts with S/S 1011 stamped on them on N308EA (S/S 1009). Whether it was swapped at the factory or at Eastern later will always be a mystery.

Re: Identifying 747 Aircraft Part

Posted: Sun Oct 20, 2019 4:57 pm
by 747classic
This panel is a modified 747-121SF airconditioning zone control panel.
At the lefthand side of the panel the push buttons of the old electric heaters for the upperdeck zone and below that the upperdeck temp controllers (L&R) are still present (but deactivated).
In the original configuaration, the upperdeck was heated by electric heaters and main deck zones 1,2,3 and 4 by adding hot trim air.
After -SF modification this panel was modified (very rude) to the new situation :
Zone 1 trim air valve indication and temp indication has been retained (FWD main cargo deck temp control)
Zone 2 trim air valve was modified to regulate the upperdeck and the original zone 2 temp indication is now used for the upperdeck.
Zone 3 and 4 trim air valve are now changed into zone 3 left and 3 right, and temp indicator zone 3 is now used for aft main cargo deck temperature indication.
Zone 4 temp indicator has been deactivated.

As mentioned in earlier replies : the actual first installation of this panel is very difficult to trace, but seen the date stamp it's an early example, but sadly very rude modified during the P-F conversion.

Note : I operated exactly the same airconditioning panel (in original configuration) on our early KLM 747-206B aircraft (PH-BUA-BUG).
After modification of the upperdeck (deletion of the lounge and installing seats + extra windows) the electric heaters were also deleted and one extra trim air valve was added for improved upperdeck temp control.

Re: Identifying 747 Aircraft Part

Posted: Sun Oct 20, 2019 9:11 pm
by fr8mech
Dalmd88 wrote:
Most airlines will swap out the panel if there is a problem with any of the components on the panel. The panel then goes to a shop and gets fixed.


I’m sure I’ve changed every LRU on a jumbo air conditioning panel, including the lightplate. In fact, I suspect I’ve changed a couple of parts on that exact panel, having worked for Evergreen back when that aircraft was in service, assuming the panel was the same...the dates are right.

Re: Identifying 747 Aircraft Part

Posted: Tue Nov 12, 2019 12:31 am
by TheWorm123
DL_Mech wrote:
I was looking at a part from N633DL used to repair the Azores hard landing A/C and it had a date of Jan. 1987. That plane was delivered to DL in December 1987. So that October 1968 date does match up with an early build 747-121. I have only seen Boeing Variable Numbers on some parts which would trace it to a particular A/C.

Lockheed would frequently make the Serial Number of some large parts the same as the S/S (Ship Serial) Number. The Eastern Flight 401 Everglades crash A/C was S/S 1011 (11th L-1011 produced). I did find a couple of parts with S/S 1011 stamped on them on N308EA (S/S 1009). Whether it was swapped at the factory or at Eastern later will always be a mystery.


Asking out of interest mostly, but did they actually remove every single part that came off 401 after the ghost stories started or were some (possibly including the parts you mentioned) still in rotation?

Re: Identifying 747 Aircraft Part

Posted: Tue Nov 12, 2019 2:05 am
by fr8mech
TheWorm123 wrote:
Asking out of interest mostly, but did they actually remove every single part that came off 401 after the ghost stories started or were some (possibly including the parts you mentioned) still in rotation?


Just listened to a podcast talking about Eastern 401, and they claim all the parts were removed...and the sightings stopped.

https://www.stitcher.com/podcast/plane-crash-podcast

Re: Identifying 747 Aircraft Part

Posted: Tue Nov 12, 2019 7:22 am
by CALTECH
Write to Boeing parts, they might help...

Re: Identifying 747 Aircraft Part

Posted: Tue Nov 12, 2019 3:41 pm
by TheWorm123
fr8mech wrote:
TheWorm123 wrote:
Asking out of interest mostly, but did they actually remove every single part that came off 401 after the ghost stories started or were some (possibly including the parts you mentioned) still in rotation?


Just listened to a podcast talking about Eastern 401, and they claim all the parts were removed...and the sightings stopped.

https://www.stitcher.com/podcast/plane-crash-podcast


Thank you and thanks for the link