Go Back  PPRuNe Forums > Flight Deck Forums > Rumours & News
Reload this Page >

Southwest KLGA gear collapse.

Rumours & News Reporting Points that may affect our jobs or lives as professional pilots. Also, items that may be of interest to professional pilots.

Southwest KLGA gear collapse.

Old 23rd Aug 2013, 09:34
  #321 (permalink)  
 
Join Date: Mar 2002
Location: Seat 0A
Posts: 8,259
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Lord Spandex
Nope. Not as far as I know.
So in your "not all of them" the nose must stay in the same attitude??
Capn Bloggs is offline  
Old 23rd Aug 2013, 09:35
  #322 (permalink)  
 
Join Date: Jul 2013
Location: South East England
Age: 68
Posts: 39
Likes: 0
Received 0 Likes on 0 Posts
are there any examples where it rises?
There was mention in Another Thread that the 777's autotrim means that it doesn't change at all - others (Airbuses?) may be the same, but I'd guess that this 737 behaves "conventionally".
I'm sure someone will be along soon to confirm/deny that!
HDRW is offline  
Old 23rd Aug 2013, 09:51
  #323 (permalink)  
 
Join Date: Sep 2010
Location: England
Posts: 1,955
Likes: 0
Received 0 Likes on 0 Posts
Cap'n Bloggs, yes. At least two types that I've flown and I assume Airbii.
Lord Spandex Masher is offline  
Old 23rd Aug 2013, 11:42
  #324 (permalink)  
 
Join Date: Aug 2013
Location: South Alabama
Age: 72
Posts: 337
Likes: 0
Received 0 Likes on 0 Posts
flarepilot

You may not be far off with the tunnel vision idea.

The captain may have been focusing on their approach speeds and considering a floating possibility on a reasonably short runway.

But, from what I remember on this thread, the approach speeds did not seem overly high, especially for WN.

However, booth pilots had a lot of time in the 737, and would know the stopping capabilities of the plane.

The NTSB should have some really good data on this one.

Regards.
Old Boeing Driver is offline  
Old 23rd Aug 2013, 12:36
  #325 (permalink)  
 
Join Date: Sep 2003
Location: away from home
Age: 61
Posts: 835
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by flarepilot View Post
I agree with you old boeing driver...it isn't the cause

it is very odd that the NTSB would even mention the reduction in power...we normally reduce power as part of landing ( I know you know this OLD BOEING DRIVER).

and for lord spandex masher...I will revise my statement to only include the B737.


the runway is 7000' long followed by a dip into the water...if the landing occurred in the first third, adequate distance to stop remained...if landing was not to occur in this area, a go around should have been accomplished

this is a nutty one...I'm thinking that the words ''tunnel vision'' might be used at some point. only thinking how short the runway was instead of everything else in the duty of being a pilot.
A 7000' runway is not short for any current single-aisle airplane except the 737 Always felt it took an effort to stop them (-3/400s), I can only guess for the -900s.
oceancrosser is offline  
Old 23rd Aug 2013, 13:36
  #326 (permalink)  
 
Join Date: Aug 2013
Location: chicago
Posts: 359
Likes: 0
Received 0 Likes on 0 Posts
a 7000 foot runway and the737...flew em to DCA and MDW, and LGA...wasn't worried about stopping...but takeoff...hmmmm

however, planting the airplane firmly on the 1000' marker was always my goal.

wow spandex...thought you could do better than that...automatic trim tells me that the plane would act conventionally without the auto trim.


old boeing driver...did you ever hear the expression "bubba jet"?
flarepilot is offline  
Old 23rd Aug 2013, 14:25
  #327 (permalink)  
 
Join Date: Dec 2002
Location: UK
Posts: 2,294
Likes: 0
Received 0 Likes on 0 Posts
Nose drops with power

“Nose drops with power”
No, only if you let it. What is being (poorly) described is the change of pitching moment with power. In manual flight this can be detected by the pilot as a change in stick force – a change in the trimmed condition.
The stick position controls the nose attitude; changes in trim due to power, speed, or configuration, contribute to the ‘feel’ of the aircraft – that aspect which pilots should be familiar with and is necessary for maintaining control.
Poor descriptions might be lazy posting; alternatively poor understanding. If this is the way people think, then often what you think is what you do.
Rule 1 fly the aircraft; you determine the nose attitude, not the aircraft trim state or power setting.
safetypee is online now  
Old 23rd Aug 2013, 15:05
  #328 (permalink)  
Per Ardua ad Astraeus
 
Join Date: Mar 2000
Location: UK
Posts: 18,579
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by ocean crosser
A 7000' runway is not short for any current single-aisle airplane except the 737
- I think you might want tor re-evaluate your technique! 4800' is short, yes. It is a good 'stopper'.
BOAC is offline  
Old 23rd Aug 2013, 16:44
  #329 (permalink)  
 
Join Date: Sep 2003
Location: away from home
Age: 61
Posts: 835
Likes: 0
Received 0 Likes on 0 Posts
I am sure I can improve my technique for a lot of things BOAC. But out of 4 transport category jet types I have flown, the 737 classics were the worst "stoppers". Not to mention dismal runway performance/requirements at MTOW.
A quick search of the word "overrun" on Avherald produces 57 hits. 17 are
B737s.
Now I know there is a lot of them around, but this seems disproportionate. SWA has had some high profile runway excursions/overruns which included fatalities, probably most before they discovered that using the Autobrake (installed, but deactivated) might be a good idea.

Last edited by oceancrosser; 23rd Aug 2013 at 16:45.
oceancrosser is offline  
Old 23rd Aug 2013, 17:00
  #330 (permalink)  
Per Ardua ad Astraeus
 
Join Date: Mar 2000
Location: UK
Posts: 18,579
Likes: 0
Received 0 Likes on 0 Posts
737-300, 48T, F40, 2 reverse, good BA, unfactored is 3450' from 50' at threshold. (Half of 7000')
BOAC is offline  
Old 23rd Aug 2013, 17:47
  #331 (permalink)  
 
Join Date: Aug 2013
Location: South Alabama
Age: 72
Posts: 337
Likes: 0
Received 0 Likes on 0 Posts
@flarepilot

Seems like I have, but my memory isn't as good as it was yesterday.

What does it mean?

Regards.
Old Boeing Driver is offline  
Old 23rd Aug 2013, 19:33
  #332 (permalink)  
 
Join Date: Feb 2000
Location: Alaska, PNG, etc.
Age: 59
Posts: 1,550
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by safteypee
“Nose drops with power”
No, only if you let it. ........

I'm pretty sure everyone reading this thread understood that comment was intended in the context of; "if you don't move anything else"


Except you, obviously.
A Squared is offline  
Old 23rd Aug 2013, 21:35
  #333 (permalink)  
 
Join Date: Sep 2010
Location: England
Posts: 1,955
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by flarepilot View Post
wow spandex...thought you could do better than that...automatic trim tells me that the plane would act conventionally without the auto trim.
Who said auto trim?

Last edited by Lord Spandex Masher; 23rd Aug 2013 at 21:36.
Lord Spandex Masher is offline  
Old 24th Aug 2013, 01:37
  #334 (permalink)  
 
Join Date: Dec 2002
Location: UK
Posts: 2,294
Likes: 0
Received 0 Likes on 0 Posts
A Squared, “Never assume the obvious is true.” ― William Safire

The context arises from the suggestion that the crew sensed the aircraft pitch down; however the reported absence of a malfunction suggests that this was not 'airframe' induced. Thus if the pitch change came from thrust reduction, it suggests no or a late correcting control input, which might indicate deliberate intent or poor co-ordination.
The other scenario is that the pitch change was independent of power and thus it was deliberate, but the magnitude was greater than required for a ‘normal’ adjustment of the touch-down aiming point, resulting in a nose wheel first landing.
safetypee is online now  
Old 24th Aug 2013, 01:51
  #335 (permalink)  
 
Join Date: Jan 2008
Location: Denver
Posts: 1,123
Likes: 0
Received 0 Likes on 0 Posts
Since we got onto the subject......

1. Engine thrust will affect nose pitch - absent any corrective input from the pilot, auto-trim, or other sources - based on the engine location relative to vertical CG.

It has nothing to do with where the engine is relative to the wing, although it is obviously probable that an engine below the wing will usually also be below the CG.

E.G. - Twin Otter - engine thrust line essentially level with high wing. Power reduction (with no other corrective change in controls) will result in brief pitch UP because the engine is above the CG.

--------------------------

@oceancrosser: The 737-800/900 have been mentioned (specifically on this forum with regard to AA 331 in Kingston, 2009) as being a bit hotter on landing due to the stretch overhang behind the wing requiring a flatter flare to avoid a tail strike.

You might want to check your stats and make sure you've factored out the 800/900 accidents in analyzing the shorter versions. In addition, accidents like Mangalore, where the aircraft type was mostly irrelevant to an overrun primarily caused by a grossly unstable final approach.

You may be absolutely right - but I'd want to be sure the data is appropriately "filtered" for other factors before drawing a conclusion.
pattern_is_full is offline  
Old 24th Aug 2013, 10:56
  #336 (permalink)  
 
Join Date: Aug 2013
Location: South Alabama
Age: 72
Posts: 337
Likes: 0
Received 0 Likes on 0 Posts
Pure Speculation

It's been a long time since I flew the 737, and then it was only the classic model.

I don't remember any pitch problems when pulling the power off at landing. Other times it was noticeable and trim was immediately necessary.

I have heard that WN flies their approaches at less than full flaps (40) to save fuel and block time.

As I recall, if the flaps move from 25 or 30 to the 40 position, there was quite a "balloon" effect, and you had to push the nose over to counteract that.

Maybe the captain called for the extra flaps and pushed over at the same time.

Possibly some current 737 folks can comment on this wild speculation??

Regards.
Old Boeing Driver is offline  
Old 24th Aug 2013, 11:17
  #337 (permalink)  
 
Join Date: Jun 2009
Location: Australia
Posts: 2,162
Likes: 0
Received 0 Likes on 0 Posts
Called for extra flaps in the flare??????

Hardly likely....
nitpicker330 is offline  
Old 24th Aug 2013, 11:22
  #338 (permalink)  
 
Join Date: Aug 2013
Location: South Alabama
Age: 72
Posts: 337
Likes: 0
Received 0 Likes on 0 Posts
Have seen it done

Yes it has happened.
Old Boeing Driver is offline  
Old 24th Aug 2013, 12:34
  #339 (permalink)  
 
Join Date: Apr 2008
Location: US
Posts: 85
Likes: 0
Received 0 Likes on 0 Posts
OBD is correct. While it is certainly a bad idea, I have seen pilots both extend and retract flaps close to the ground in attempts to fix poor arrivals. It was probably even more prevalant in the days befor FOQA and QAR data. You see a lot of crazy stuff if you ride jumpseats for 25 years. Having said that, I have also witnessed aviators who we all should try to emulate. Somebody has to be on the good side of the bell curve.

Jet
sky jet is offline  
Old 26th Aug 2013, 14:29
  #340 (permalink)  
 
Join Date: Jan 2006
Location: US
Posts: 2,204
Likes: 0
Received 0 Likes on 0 Posts
737NG is approved for F15, 30, or 40 landings. F30 is typical. F40 is for shorter runways.

Less flaps always burns less fuel but offset by higher approach speeds.
misd-agin is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information

Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.