PPRuNe Forums


Engineers & Technicians In this day and age of increased CRM and safety awareness, a forum for the guys and girls who keep our a/c serviceable.

Reply
 
Thread Tools Search this Thread
Old 22nd May 2017, 13:27   #1 (permalink)


Probationary PPRuNer
Thread Starter
 
Join Date: May 2017
Location: Cardiff
Posts: 1
WoW system

I am looking into how the undercarriage WoW system functions when based on proximity switches and not contact switches and i'm struggling to find any content online, wondering if any of you guys could shed some light,

Thanks!
Frostywing is offline   Reply With Quote
Old 22nd May 2017, 16:42   #2 (permalink)
Thought police antagonist
 
Join Date: Jul 2003
Location: Where I always have been...firmly in the real world
Posts: 830
You didn't look very hard....

This should help.

https://www.faa.gov/regulations_poli...a/ama_Ch13.pdf
Krystal n chips is offline   Reply With Quote
Old 22nd May 2017, 19:57   #3 (permalink)
 
Join Date: May 2009
Location: England
Posts: 37
Functional Description - Nose Sensing
The nose air safety sensor sends target position signals to the nose air sensing proximity switch card. The proximity switch card operates nose ground sense relays.
This is the sequence for the nose air sensing when the airplane is on the ground:
- Target moves far from the nose air safety sensor - Nose air sensing proximity switch card sends
electrical ground to nose ground sense relays - Nose ground sense relays energize.
The opposite of the above happens when the airplane is in the air. The nose sensing in air red light comes on when the nose air sensing is in the air mode.

Functional Description - Air Sensing
The air safety sensor sends target position signals to the air sensing proximity switch card. The proximity switch card operates air sense relays.

- Target moves far from the air safety sensor
- Air sensing proximity switch card sends electrical
ground to air sense relays
- Air sense relays energize
- Air sensing in air red comes on.
The opposite of the above happens when the airplane is on the ground.

Functional Description - Ground Sensing

The ground safety sensor sends target position signals to the ground sensing proximity switch card. The proximity switch card operates ground sense relays.
This is the sequence for the ground sensing when the airplane is on the ground:
- Target moves near the ground safety sensor - Ground sensing proximity switch card sends
electrical ground to ground sense relays - Ground sense relays energize.

The opposite of the above happens when the airplane is in the air. The ground sensing in air red light comes on when the ground sensing is in the air mode.
YOUNGBUCK is offline   Reply With Quote
Old 8th Jun 2017, 18:47   #4 (permalink)
 
Join Date: Dec 2009
Location: Moo moo land
Posts: 241
737 has prox switches on its gear
lowfat is offline   Reply With Quote
Old 11th Jun 2017, 14:45   #5 (permalink)
 
Join Date: Sep 2004
Location: Yorkshire
Posts: 344
Hello Frostywing. I'm very familiar with the Bombardier Global undercarriage. This uses a plethora of proximity switches to monitor door, leg and oleo extension. Each proximity switch had a steel 'target' that was sensed when in close proximity to the sensor. In effect it was like a microswitch but didn't need to physically move the switch. The target had to be very close to the proximity sensor - probably no more than 3-8mm for it to be sensed.

Of all the undercarriage malfunctions I was aware of (10 or so) all but one was caused by the steel target falling off. This meant, say, when the nose doors did close, the sensor couldn't see the target and so wrongly reported the doors as still being open!

Last edited by H Peacock; 11th Jun 2017 at 16:39.
H Peacock is offline   Reply With Quote
Reply


Tags
weight on wheels

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT. The time now is 22:59.


1996-2012 The Professional Pilots Rumour Network

SEO by vBSEO 3.6.1