Time differences

[Barthandelus 1]

The calculation is obviously not difficult, but today my brain refuses to work; the more i think about this, the more tangled im getting...

 

Lets say im taking off from KORD (GMT -6), flying to KSFO (GMT -8).

 

Assuming the flight is 8 hours, what time should i take off to land at KSFO 13:00 local time?

 

How would i work this out for any flight, such as to land at EGLL (GMT 0) at 0930 from HECA (GMT +2).

[kowgli 2]

I would simply unify it into UTC (you should use UTC in aviation)

 

You want to land at 13:00 local (UTC-6) = 13+6 UTC = 19:00 UTC

 

Flight takes 8 hours so you need to take off at 19:00 - 8 = 11:00UTC

 

local KORD (UTC-6) = 11:00 - 6 = 05:00 local

[Barthandelus 1]

Thank you, sir!

Thats pretty much what i had, but the more i thought about it, the more wrong it seemed!

Thanks again.

[Barthandelus 1]

Does the '-8' in "Flight takes 8 hours so you need to take off at 19:00 - 8 = 11:00UTC" mean flight time, or the time difference at KSFO?

 

Sorry, iv found something that im not sure is right:

KJFK (-5 UTC) to EGLL (UTC 0), flight time 3 hours (concorde!)

 

From your example, to land in London at 14:00

14:00 + 5 hours (UTC difference) = 19:00

Minus 3 hour flight time = 16:00

Minus difference at KJFK (5) = 1100

[TheDanger 182]

Get a flux capacitor installed in your aircraft and you need never worry about time again

[Barthandelus 1]

Get a flux capacitor installed in your aircraft and you need never worry about time again

 

http://i60.photobucket.com/albums/h39/careree26/tumblr_inline_mgameqEyLZ1r261l0_zps9958623f.gif

:-)

[LHookins 3,113]

From your example, to land in London at 14:00

14:00 + 5 hours (UTC difference) = 19:00

Minus 3 hour flight time = 16:00

Minus difference at KJFK (5) = 1100

 

You're adding when you should be subtracting.

 

When it's 1400 in London, it's 0900 at JFK. You'll need to take off at 0600 at JFK to arrive three hours later in London at 1400 London time. Or just set your watch to London time, which is UTC. Take off at 1100 UTC (which will be 0600 local JFK time).

 

The same flight in reverse, to land at 1400 JFK time, that's 1900 London time, you'd take off 3 hours earlier, 1600 London time. Take off at 4 PM, land at 2 PM the same day? There's your flux capacitor right there.

 

If you're crossing the international date line, you're on your own.

 

Hook

[mtrunz 3]

Why don't you just add 8 hours to the local time of the departure airport..and then do the conversions to the arrival airport? (you just did it yourself when you wrote the thread)