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

T/O 2nd segment vs. APP clb

Wikiposts
Search

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

T/O 2nd segment vs. APP clb

Thread Tools
 
Search this Thread
 
Old 24th December 2016 | 07:11
  #1 (permalink)  
Thread Starter
10 Anniversary
 
Joined: Jun 2014
Posts: 346
Likes: 1
From: Mordor
T/O 2nd segment vs. APP clb

That got me thinking when reading on fuel dumping. Current rules require fuel jettison system to be installed on an a/c if it is not able to meet app/ldg climb requirements during turn back 15 minutes after t/o.

Now, since the a/c is fulfilling all the takeoff performance requirements at MTOW (including 2nd segment), under what circumstances the app/ldg clb criteria would be more penalizing?

2nd segment is 2.4% at MTOW
App clb is 2.1% at MTOW-15mins of fuel

I know there are differences between those two:

2nd segment is at TOGA, possibly optimum flap config and optimized V2
App Clb is at thrust level 8s after accept from idle, g/a flap setting and speed close to Vref

Would that account for a major difference?

Last edited by Sidestick_n_Rudder; 24th December 2016 at 07:39.
Sidestick_n_Rudder is offline  
Reply
Old 24th December 2016 | 07:34
  #2 (permalink)  
 
Joined: Jul 2002
Posts: 371
Likes: 0
From: guess where
If you have a specifically designed Engine Out Procedure for the TO calculation. That means you are not able to meet the gradient requirement on straight out departure and, potentially, the required climb gradient (which can be higher than the 2.1%) on the designed Missed Approach.
One could argue, that you then fly the EO SID for a Missed Approach, which could be your out of jail card.
Other problem could be that the departure Runway hasn't got the required Approach Aid for the Landing and the Landing Runway has a higher Missed Approach Climb Gradient requirement.
what_goes_up is offline  
Reply
Old 24th December 2016 | 09:11
  #3 (permalink)  
50 Countries Visited
15 Anniversary
 
Joined: Nov 2007
Aviation Qualifications: ATPL
Posts: 1,954
Likes: 30
From: Texas
Boeing in their Aero magazine in 2007 said if you meet all the requirements to take off from a runway you meet all the requirements to land on it. The approach climb and landing climb limits come into play when you are landing on a different runway than you departed on.
MarkerInbound is offline  
Reply
Old 24th December 2016 | 10:08
  #4 (permalink)  
 
Joined: Jul 2002
Posts: 371
Likes: 0
From: guess where
@Marker
This is, according my understanding, certainly true for the brake performance and, most likely, for "standard" 2.1% (2 ENG) App Climb requirement. However, this might not be true if you depart VHHH and have a 7.1% requirement for the approach. That is, why you would have an Engine Out SID for a TO from this runway.
On the B777 there is an MEL for inop Fuel Jettison where you have to calculate the Missed Approach Gradient at your TO weight minus 2'450kgs for a quick return.

BTW the link for said article is here:http://www.boeing.com/commercial/aer...icle_03_1.html
what_goes_up is offline  
Reply
Old 24th December 2016 | 15:38
  #5 (permalink)  
50 Countries Visited
15 Anniversary
 
Joined: Nov 2007
Aviation Qualifications: ATPL
Posts: 1,954
Likes: 30
From: Texas
We have engine out procedures for the 7s in VHHH in order to meet the obstacle clearance requirements. It's separate from meeting 2nd stage climb. Both of them go NE about 6 miles and turn to a 185 heading through the Ma Wan channel, almost an overlay of the Logan 3 departures. If I lost an engine leaving VHHH and had to shoot the ILS 07L to come back I would tell ATC we are unable the published missed approach and if we miss we'll go to Rover and then turn heading 185. The same thing that made us legal to depart in the first place. If they don't like that they can give us 07R.
MarkerInbound is offline  
Reply
Old 24th December 2016 | 15:53
  #6 (permalink)  
 
Joined: Jul 2002
Posts: 371
Likes: 0
From: guess where
Agree Marker. That is what I meant with:
One could argue, that you then fly the EO SID for a Missed Approach, which could be your out of jail card.
That is what aviators would do in case of an emergency. However, the regulator says you have to meet the Missed Approach Gradient for the published procedure.
what_goes_up is offline  
Reply
Old 26th December 2016 | 21:12
  #7 (permalink)  
 
Joined: May 2007
Posts: 224
Likes: 0
From: FL390
How the regulator says this? The regulator doesnt account single engine ops, PANS OPS are crystal clear about this, they talk about regulations during normal ops.

Single engine ops are operators responsibility.
Lantirn is offline  
Reply

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 © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.