Complex Math (NAV) Problem
07-15-2014, 01:52 AM
#31
Line Holder
Joined APC: Jan 2008
Position: B747 FO
Posts: 45
Actually not that difficult, for the 45 divide by ten and subtract 3 times the answer, for 60 subtract 1 from the answer( in other words subtract 3/10th or 1/10th from the wind).
For example 30 knot wind@45, divide by 10 = 3, subtract 3*3=9 from 30=21
For 60 degrees 30 divided by 10 is 3, subtract 3 from 30 is 27.
Seems like a lot of work but practice it a few times and it becomes second nature. A lot easier than using the graph on the C/L to calculate if you exceed or don't exceed the max crosswind component on TO or LDG, even if the wind is not a nice round figure like 30.
In your example, I think you meant 45 iso 60 because 35 at 60 would be around 31.5 where 35@45 degrees would be 24.5!
Happy flying!!
For example 30 knot wind@45, divide by 10 = 3, subtract 3*3=9 from 30=21
For 60 degrees 30 divided by 10 is 3, subtract 3 from 30 is 27.
Seems like a lot of work but practice it a few times and it becomes second nature. A lot easier than using the graph on the C/L to calculate if you exceed or don't exceed the max crosswind component on TO or LDG, even if the wind is not a nice round figure like 30.
In your example, I think you meant 45 iso 60 because 35 at 60 would be around 31.5 where 35@45 degrees would be 24.5!
Happy flying!!
Last edited by KLM pilot; 07-15-2014 at 02:25 AM.
07-15-2014, 05:45 PM
#33
Gets Weekends Off
Joined APC: Sep 2013
Position: PA-18, Front
Posts: 187
True. The safest flights are those that never leave the gate. But that's control of operations - a different ball of wax. Here, the question relates to operational control, namely choosing a runway. That's what I chimed in on.
07-19-2014, 04:16 PM
#34
Otto
Joined APC: Jul 2013
Position: Turkish Pile Driver
Posts: 1,806
So this thread has been helpful, maybe I can get another rule of thumb answered. The mighty Talon typically does a 5 degree descent profile which makes starting down calculations easy -- just double the altitude to lose + 5-10 nm slop to slow below 300 before we get <10k and we're good.
I've been studying a lot of techniques from interview gouge and it seems the most common descent gradient rule of thumb is multiply the altitude to lose by 3, which gives a 3.33 degree descent gradient. Is that a pretty standard airliner descent profile?
Thanks!
I've been studying a lot of techniques from interview gouge and it seems the most common descent gradient rule of thumb is multiply the altitude to lose by 3, which gives a 3.33 degree descent gradient. Is that a pretty standard airliner descent profile?
Thanks!
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