PPRuNe Forums - View Single Post - TAM A320 crash at Congonhas, Brazil
View Single Post
Old 7th Sep 2007, 21:15
  #2135 (permalink)  
bsieker
 
Join Date: Jul 2007
Location: Germany
Posts: 556
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by flyingnewbie10
It leaves approach thrust and surpasses climb EPR (apparently).
I think I see another reason for your misunderstanding here.

There is no such thing as "approach thrust" as a fixed value, which can be "left".

Unlike "maximum climb thrust" ("CLIMB", the highest thrust used after thrust reduction on a normal flight), "maximum continuous thrust" ("MCT", the highest thrust used during single-engine operation after thrust reduction) and "maximum take-off-thrust ("TOGA"), which are more or less constant.

Approach thrust is whatever is necessary to maintain approach speed.

Obviously, with both engines operating that is a lot less than if a single engine has to achieve that, so consequently EPR rises.

As you can see, during the approach, the EPR value fluctuated between 1.1 and 1.06.


Bernd
bsieker is offline