PPRuNe Forums - View Single Post - Bell 412 start and performance questions
View Single Post
Old 25th Sep 2010, 10:06
  #50 (permalink)  
JimL
 
Join Date: May 2003
Location: Europe
Posts: 900
Received 14 Likes on 8 Posts
If you are talking about an offshore procedure, target/delta Tq is associated with the deck-edge clearance (as discussed in the thread shown) - this target/deltaTq will provide the vertical acceleration (ROC) that results in the energy for the rotation/deck-edge clearance manoeuvre.

In the limited winds and high temperatures associated with India, deck-edge clearance is unlikely to be the limiting condition, it is more likely to be the drop-down (which is associated with single-engine power).

As the wind increases (for a given engine setting) drop down decreases until the limiting condition becomes the second segment climb. None of this is entirely predictable because the helicopter/engine combinations are configured to favour one or another of the power setting.

The engine manufacturer can also 'make available' an additional power mode - this has already been discussed on this thread because the PT6 can come with a 30 minute power setting (or it can be limited just to the max continuous). Not all manufacturers provide the '30 second'/'2 minute' power modes - staying instead with a single 2.5 minute power setting.

So, in answer to your question; not necessarily!

Jim
JimL is offline