Questions If you are a professional pilot or your work involves professional aviation please use this forum for questions. Enthusiasts, please use the 'Spectators Balcony' forum.

737NG Nav system

Old 30th Mar 2014, 16:50
  #1 (permalink)  
Thread Starter
 
Join Date: Oct 2013
Location: Britain
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
Red face 737NG Nav system

Hi,
so here's a post which is probably going to receive a few sarcastic answers but I'm struggling to make sense of this.

The following is a question supposedly asked during an interview for Ryanair:
"What type of navigation system is used on the 737NG?"

I'm not really even sure where to start with this question. But so far this is what I've come up with, and if any of this is incorrect I would greatly appreciate being put straight.

ALL 737s (NG and CLassic) have INS. Exact coordinates are entered into the FMS on stand to give the aircrafts 'start-point'. In flight the IRS measures data regarding attitude, speed, heading, acceleration. This data is fed into the FMC which delivers navigation information to the CDUs.

However the NGs use GPS as the primary source of navigation which is more accurate but availability not always guaranteed since it uses military satellites.

now my questions:
1. INS is a required backup system for GPS on the 737?
2. Do the INS and GPS systems use the same CDUs to display nav guidance?
3. Was the initial question a lot more simple than I am making it, by which I mean does the nav system on the 737 simply have a 'brand name' i.e. G1000, Avidyne?

I know this post is a bit of a mishmash and a struggle to read but any pointers would really be appreciated.
ccjbrown is offline  
Old 30th Mar 2014, 17:21
  #2 (permalink)  
 
Join Date: Dec 2012
Location: On SBY next to my phone
Posts: 286
Likes: 0
Received 0 Likes on 0 Posts
They have IRSs not INSs

Very simplified: you have IRS, GPS and then the conventional VHF/HF-systems all "reporting" to the FMC that tries to make out where the airplane is, displaying it on a map on the EFIS.

You also have the conventional presentation displayed via the EFIS or on the standby instrument, such as ILS, VOR, ADF.

The "ADIRU" collects information from the static/dynamic ports and the IRS to supply Heading, altitude, V/S, airspeed
TypeIV is offline  
Old 31st Mar 2014, 12:27
  #3 (permalink)  
Thread Starter
 
Join Date: Oct 2013
Location: Britain
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
Thanks a lot, makes much more sense

cheers
ccjbrown is offline  
Old 31st Mar 2014, 13:41
  #4 (permalink)  
 
Join Date: Jul 2001
Location: East of West and North of South
Posts: 549
Likes: 0
Received 0 Likes on 0 Posts
4) The cheapest possible?
cosmo kramer is offline  
Old 31st Mar 2014, 13:46
  #5 (permalink)  
 
Join Date: Jul 2001
Location: East of West and North of South
Posts: 549
Likes: 0
Received 0 Likes on 0 Posts
I'll be serious. This is what Boeing says:
Flight Management System The flight management system (FMS) is comprised of the following components:
• flight management computer system (FMCS)
• autopilot/flight director system (AFDS)
• autothrottle (A/T)
• inertial reference systems (IRS)
• global positioning system (GPS).
So since IRS and GPS are subcomponents of the FMS, I would say the answer is: FMS
cosmo kramer is offline  
Old 3rd Apr 2014, 12:54
  #6 (permalink)  
 
Join Date: May 2001
Location: A few degrees South
Posts: 809
Likes: 0
Received 0 Likes on 0 Posts
Was that a question from a Flight Simulator X simmer?
latetonite is offline  
Old 9th Apr 2014, 11:48
  #7 (permalink)  
 
Join Date: Mar 2007
Location: Another Planet.
Posts: 559
Likes: 0
Received 0 Likes on 0 Posts
So far, nobody has mentioned "looking out of the big window in front".

Or is that no longer/not yet EASA approved?
BARKINGMAD is offline  
Old 9th Apr 2014, 13:15
  #8 (permalink)  
Per Ardua ad Astraeus
 
Join Date: Mar 2000
Location: UK
Posts: 18,579
Likes: 0
Received 0 Likes on 0 Posts
Heavens, Barking - what ARE you suggesting?
BOAC is offline  
Old 9th Apr 2014, 14:04
  #9 (permalink)  
 
Join Date: Mar 2007
Location: Another Planet.
Posts: 559
Likes: 0
Received 0 Likes on 0 Posts
"Heavens, Barking - what ARE you suggesting?"

Hi BOAC, only a little common sense, fact, logic & reasoning, but as we all know, there is a disconnect between these approaches and modern aviation!

However, I'm sure Ryrs flight management would encourage the method if it shortened flight times, saved fuel and reduced the risk of inadvertent ground contact?! Note the order in which these are listed!

What say you, M O'L??!!
BARKINGMAD is offline  
Old 9th Apr 2014, 14:23
  #10 (permalink)  
 
Join Date: Mar 2001
Location: I wouldn't know.
Posts: 4,497
Likes: 0
Received 0 Likes on 0 Posts
Dunno, doesn't seem to be a particular EASA problems given the recent excursions to unplanned landing fields in other regions of the world, including the almighty us of a.

Visual approaches of course do fulfill the list of requirements, don't know about ryr, but other carriers still so encourage their pilots to fly them, even if they are MPL cadets. Not a problem given proper training.
Denti is offline  

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


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.