Go Back  PPRuNe Forums > Flight Deck Forums > Tech Log
Reload this Page >

737-800 Pitch bar show 10 degrees nose down

Wikiposts
Search
Tech Log The very best in practical technical discussion on the web

737-800 Pitch bar show 10 degrees nose down

Thread Tools
 
Search this Thread
 
Old 5th Oct 2018, 00:49
  #1 (permalink)  
Thread Starter
 
Join Date: Oct 2018
Location: Tokyo
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
737-800 Pitch bar show 10 degrees nose down

Hello,

The pitch bar is at 10 degrees down because I am rolling at less than 60 KIAS.
But why does the pitch bar show nose down?
I think that it is easier to understand if the pitch bar show nose up from the beginning.

Thank you for your answers.
ANAJASJAL008 is offline  
Old 5th Oct 2018, 15:27
  #2 (permalink)  
 
Join Date: Apr 2005
Location: Australia
Posts: 1,414
Likes: 0
Received 0 Likes on 0 Posts
But why does the pitch bar show nose down?
Encourages the FD addicted pilot to keep light forward pressure on the control column as per FCTM advice...
A37575 is offline  
Old 6th Oct 2018, 13:57
  #3 (permalink)  
Thread Starter
 
Join Date: Oct 2018
Location: Tokyo
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
Thank you very much A37575.

Is this behavior the same for 737-400 and 737-200 too?
Nobody knows?
ANAJASJAL008 is offline  
Old 7th Oct 2018, 11:10
  #4 (permalink)  
 
Join Date: Jan 2018
Location: Amantido
Posts: 866
Likes: 0
Received 0 Likes on 0 Posts
Yes on the Classic. Can't speak for the -200.
Banana Joe is offline  
Old 7th Oct 2018, 14:42
  #5 (permalink)  
 
Join Date: Feb 2003
Location: Brighton
Posts: 973
Received 6 Likes on 6 Posts
Is this behavior the same for 737-400 and 737-200 too?
Not on -200. Very different instruments, all analogue, the attitude display driven by a vertical gyro.
kenparry is offline  
Old 7th Oct 2018, 15:15
  #6 (permalink)  
Moderator
 
Join Date: Apr 2004
Location: Rome
Posts: 792
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by ANAJASJAL008
Thank you very much A37575.

Is this behavior the same for 737-400 and 737-200 too?
Nobody knows?
As far as I can remember (that was a long time ago), on the -200 You needed to manually select the FD pitch attitude that You wanted to maintain and therefore it was rarely used as it induced more workload than anything. The -230 advanced on the other hand had an AFDS similar to the classics and I think it used the same principle but I should definitely check in the FCOMs that I do not have anywhere handy at this time. Maybe somebody can contribute a little more to this nostalgic moment ;-)
I-2021 is offline  
Old 7th Oct 2018, 23:06
  #7 (permalink)  
 
Join Date: Jul 1999
Location: UK
Posts: 166
Likes: 0
Received 0 Likes on 0 Posts
On the -200s that I flew (basic and advanced aircraft), the pitch bar was set manually to wherever you wanted it except when on the ILS when it gave commands to follow the glideslope. The only autopilot pitch mode available was CWS from both Captain and First Officers sides except when following a glideslope. Heading Select only available from the Captains HSI so the First Officer flew in CWS and asked the Captain to update the heading bug. The standard call was “match me heading and modes.” Happy days,great aircraft to fly. The Classic flight director gives the same commands as the NG for take off
Matey is offline  
Old 7th Oct 2018, 23:40
  #8 (permalink)  
 
Join Date: Sep 2016
Location: USA
Posts: 803
Likes: 0
Received 0 Likes on 0 Posts
So... no altitude hold?
Vessbot is offline  
Old 8th Oct 2018, 11:41
  #9 (permalink)  
Thread Starter
 
Join Date: Oct 2018
Location: Tokyo
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
Hello Gents,

Thank you for the detailed explanation. 737 family have a long history, so these change a lot.

Warm regards,
ANAJASJAL008 is offline  
Old 8th Oct 2018, 17:19
  #10 (permalink)  
Moderator
 
Join Date: Apr 2004
Location: Rome
Posts: 792
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Matey
On the -200s that I flew (basic and advanced aircraft), the pitch bar was set manually to wherever you wanted it except when on the ILS when it gave commands to follow the glideslope. The only autopilot pitch mode available was CWS from both Captain and First Officers sides except when following a glideslope. Heading Select only available from the Captains HSI so the First Officer flew in CWS and asked the Captain to update the heading bug. The standard call was “match me heading and modes.” Happy days,great aircraft to fly. The Classic flight director gives the same commands as the NG for take off
Thanks for the revival Matey, now I have a few distant memories coming back to my mind. We used the same procedures, I also remember we had the ALT HOLD and ALT ACQ function on the MCP selector, basically You need to select Your cleared altitude in a small panel in front of the thrust levers (or somewhere in that area, just above the Wx Radar box I think) and then pitch to maintain 1000 ft/min for the last 1000 ft below the cleared level and the AP would gently level off at that altitude. You would then need to select ALT HOLD on the MCP. That is what I vaguely remember from these days, it was a lot of fun and those JTD would burn tons and tons of gas !
I-2021 is offline  
Old 8th Oct 2018, 22:06
  #11 (permalink)  
 
Join Date: Jul 1999
Location: UK
Posts: 166
Likes: 0
Received 0 Likes on 0 Posts
Thread creep I know. Alt Hold yes, but no posh Alt Acq in Britannia aircraft! We did, in later years, have an Omega navigation system which used VLF radio signals originally designed for submarine navigation. You entered the Lat/Long of a waypoint and it basically told you whether you were left or right of a desired track. Went “walkabout” quite a lot though. A bit of a step up from the dead reckoning we had to use between Santiago VOR and Porto Santo NDB when radio signal ran out on the way to the Canaries. Unlike today, often the only time you saw other aircraft on your route was overhead radio aids before meandering off again.
Matey is offline  
Old 8th Oct 2018, 22:12
  #12 (permalink)  
Moderator
 
Join Date: Apr 2004
Location: Rome
Posts: 792
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Matey
Alt Hold yes, but no posh Alt Acq in Britannia aircraft! We did, in later years, have an Omega navigation system which used VLF radio signals originally designed for submarine navigation. You entered the Lat/Long of a waypoint and it basically told you whether you were left or right of a desired track. Went “walkabout” quite a lot though.
Wow the Omega that was some serious stuff eheh. We were lucky enough to have a Marconi GPS that You could even slave to the CM1 HSI and fly RNAV5 airspace... even more posh !
Sorry for the off topic folks !
I-2021 is offline  
Old 8th Oct 2018, 22:48
  #13 (permalink)  
 
Join Date: Jul 1999
Location: UK
Posts: 166
Likes: 0
Received 0 Likes on 0 Posts
Britannia originally bought the -200 to be able to fly from Luton to Palma (around 2hrs 20) with a full load of 130 passengers and normal reserves. By the time they were phased out, with all the engine and weight upgrades we were regularly flying 5 hour sectors. Great performance too as we could get back to the UK from most performance limited airfields without tech stopping enroute, unlike competitors flying other types. JT8D fuel flow if I recall rightly was around 2400kg per hour to carry those 130 passengers at Mach .72.. The NG has a similar fuel flow but carries 189 pax at typically Mach .78. The MAX-8 similar fuel flow again, but over 200 passengers. OK...back to the NG flight director!
Matey 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



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.