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-   -   equipment cooling (https://www.pprune.org/tech-log/343062-equipment-cooling.html)

goksunkurkcu 13th Sep 2008 16:36

equipment cooling
 
in 737 aircraft all switches are in "normal" or "on" position when the switch is moved downward. but why are the equipment cooling switches normal position when switched upwards.

Mr.Buzzy 14th Sep 2008 11:07

Have pondered this myself but soon found unwrapping my small cheese portion more interesting. Let us know if you find out.:ok:

Old Fella 14th Sep 2008 13:03

Switch positions
 
Whilst it may be useful to have switch positions all "up" or "down" when a system is in the "normal" or "on" configuration it is always good practice to check that a system does what you expect it to be doing whenever a switch is actuated.

IFixPlanes 15th Sep 2008 08:02


Originally Posted by goksunkurkcu
in 737 aircraft all switches are in "normal" or "on" position when the switch is moved downward...

Not in all 737.
Check cockpit layout of LH.

framer 15th Sep 2008 11:02


it is always good practice to check that a system does what you expect it to be doing whenever a switch is actuated
.
so how do you check that the equipment cooling is operational when you make the selection?

Old Fella 15th Sep 2008 12:53

B737 Equipment Cooling
 
Framer, since the B737 does not carry a F/E, and therefore I have not operated on that type, I can only rely on Boeing providing an "Equipment Cooling Failure" annunciator to alert the crew to such a failure, so it follows that if the applicable control switch was moved to the "Normal" or "On" position and the cooling fan did not operate the annunciator would illuminate. My point is that that it is inappropriate to be "flicking" switches without noting that the appropriate reaction takes place when a switch position is changed.

tcas1 15th Sep 2008 18:20

Interesting photo but if you look closer all other switches are also opposite from equipment cooling switch. ie equipment cooling on selected downwards, packs on selected upwards ,seatbels on upwards etc etc....

Navigator33 15th Sep 2008 20:20

zey did it becauze zey are zgerman!

mr.newfy 15th Sep 2008 22:42

off isn't an option with equipment cooling. cooling air is supplied by normal supply and exhaust fans whenever main elec power is on. in the event of a 'normal' fan failure the crew can select the failed cooling duct to the alternate fan. hence the orientation of the switches.

BAM_dk 16th Sep 2008 10:05

Did they put in the yoke upside down as well??

Very funky layout when you are used to the 'normal' one.:confused:

BelArgUSA 16th Sep 2008 14:23

Different strokes for different folks...
 
Remember...
xxx
You got airplanes (most USA airlines) which have overhead panel switches ON/OPERATING when they are DOWN or FORWARD... and rest of the world airlines generally ask Mr. Boeing (and former Mr. Douglas and Mr. Lockheed) to have overhead panel switches ON/OPERATING to the UP or AFT position...
xxx
The only USA airline that was doing like the rest of the world was TWA. When they merged into AA a few years ago, I am sure that AA and ex-TWA pilots were insulting each other every time they switched their landing lights ON or OFF...
xxx
What makes me laugh, are these airlines that acquire airplanes "second hand" from other airlines, with completely different "switchology" and instrument types and location, a headache when you have a fleet of "same type aircraft" which have a dozen different cockpit set-ups. On top of that, you do your initial or recurrent training in a simulator of (yet) another airline.
xxx
With PanAm, we had our original 747s... Then we had some 747s acquired second hand from American, United or Singapore. When we first sat in the cockpit, it was our joke to first say "where are the switches", and "what do we have and do not have on this bird"... before doing our cockpit set-up.
xxx
And then I had contracts with other airlines...
THEY want pilots to be STANDARDIZED...?
Why don't they standardize their airplanes as well...?
We already have to study a zillion different limitations for the same type.
xxx
:ugh:
Happy contrails

Flight Detent 18th Sep 2008 11:35

Yeah...

Cathay Pacific was notorious for opting for 'reverse' direction switches in it's fleet of classic '74s.

What a hassle they were to operate!!

Cheers...FD...:ugh:

...but I guess that was inline with most other things at Cathay...


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