Is there a general rule of thumb of correcting outbound timing when flying rawdata in big jets?

I was inspired by Nick Collets videopreview of the 777.. That got me wondering. What do you do when flying a holding at 200 kts? How do you correct the timing for known wind?

 

 

Hope this makes sence!

You time the inbound portion and correct the outbound to get the time you want (0´-14000´ - 1min, 14001´ and up - 1.5min).

 

I.e:

You get 50sec inbound, then you have to fly 1min 10sec outbound to get the 1min inbound. Pretty easy

Speed does not matter for the timing portion.

 

 

 

- Gert A. Barring

Or look at your head/tail wind component on the outbound leg and add/subtract to a minute.

 

So in the above example the aircraft would have a 10kt headwind component on the outbound leg.

In most real world situations you just approximate what you need to do to the outbound leg to fix the inbound leg. If I knew the inbound leg had a headwind then I knew my outbound leg would need to be shorter than 1 minute and vise versa for a tailwind on inbound. I'm sure there is a formula somewhere to get the exact timing but it would be very difficult because of all the variables, i.e. crosswinds and shifting wings. Just guess what how much you need to extend or shorten the leg and make adjustments for what happens on the leg. Sometimes extending your outbound leg by 10 seconds might only extend your inbound leg by 3 or 4 seconds.

I fly IFR in real world in small airplanes. I fly holdings procedures etc at 90 kts.

Then I use the rule to add the wind headwind comp pr min.. IE: if I have 30 kts headwind I add 30 seconds pr minute. If its a tailwind I use half the wind componen.. If 30 kts tailwind i subtract 15 seconds pr minute.. But that only works at 90 kts, not 200..

 

So was just curious if anyone knew a rule of thumb like the abobe