jalbert
Consider the following scenario.
Norm Ops - TAS 400, HWC 50 kts
Asy Ops - TAS 330, HWC 50 kts
Sector - 1000 nm.
Therefore:
NGSO - 350 kts
NGSH - 450 kts
AGSO - 280 kts
AGSH - 380 kts
Normal Ops CP > 1000/800 [TAS x2 or GSO + GSH] = a factor of 1.25.
Asy Ops CP > 1000/660 [TAS x2 or GSO + GSH] = a factor of 1.515
- Time from CP to Home or Dest = 1.25 (or 1.515) x 60
- Dist from CP to Dest = 1.25 )or 1.515) x GSO
- Dist from CP to Home = 1.25 (or 1.515) x GSH
Now just plug in the the appropriate values and you will find that:
- Norm Ops CP is 437.5 nm from Dest
- Norm Ops CP is 562.5 nm from Home
- Norm Ops CP is 75 mins from either Home or Dest
However:
- Assy CP is 424.2 nm from Dest
- Assy CP is 575.8 nm from Home
- Assy CP is 90.9 mins from both Home and Dest
So if blogs the pax has a heart attack and thus a quick landing is required, at normal ops anything further from Home than
562.5 nm means it is quicker to continue than return.
However should bloggs have his heart attack whilst Asymmetric, the CP moves to
575.8 nm of Home, some 13 nm further along track.
This example doesn't consider the possibility of having to chose a lower level due Asy situation.
Stronger winds or a greater diff between Norm & Asy ops will cause the CP to move more.
(ETE @ Norm CP = 96.4 mins. ETE @ Asy CP = 98.7 mins)
[ 07 August 2001: Message edited by: Capt Claret ]