Timed turns
 

Hi all,

Does anyone have a good rule of thumb for timed turns? Just in the beginnings of the IR and finding them difficult.( crap at maths gives me zero capacity!) I have made myself a whizz wheel type thing but not tested it yet!!

Any help gratefully appreciated

Cheers :ok:

Hi there, i used to take every 30deg as 10 seconds give or take.
Also i used to start the timer just before starting the turn.

The OBS Can be very useful to count on and give you reference.

And it best to first calibrate the TC by turning at 'standard rate' on the instrument for a convenient time interval and divide number of degrees by number of seconds---might not actually indicate a true standard rate turn


PA

totally agree with sgwkvfr.
However, just before you roll in ........check to see that no one has "stolen " the original heading you made all the calculations on!!!!

And don't forget to turn the right way !!. The way the compass works makes you want to turn the wrong way !! (even those LOT 737 pilots in the recent AAIB report did exactly that when all their primary instruments failed)

Using the OBS method will show you which way to turn too.

:ok:

if the heading you want to fly to is less than what you are currently at, you turn left. if the heading you want to turn to is more, you turn right.

more=right
less= left.

i have a good way of remembering it but too rude to put up here.

swawkvfr is absolutely totally correct in everything he says............

Damn life sucks sometimes! I'll just go back to chasing pu55y!

jees

Nashers, Your "more=right, less= left" rule does not work on all occasions. Assuming that I am flying a heading of 350° and wish to turn onto a heading of 020° then applying your rule since 020° is (mathematically) less than 350° I should turn left! This won't impress any instructor or examiner.

Anyone knows how to calculate bank angle so as to get standard rate turn apart from looking at the turn coordinator?

Just wing it !!

Sorry couldn't resist !! :E

If memory serves correct it's

(TAS/10) + 7 = Degrees to turn using A.I.

E.g. travelling at 120kts TAS; turn to 19 deg on AI.

Someone will correct me if I'm wrong !!

AR.

IAS/10 + 7.

eg. 90kts/10 + 7 = 16 degrees.

A reasonable rule of thumb.

Edited (can't remember whether it is IAS or TAS but frankly, it doesn't really matter at low levels/speeds.)

Yes - it is TAS but like you say - there's pence in it. Most certainly can't hand fly an AOB to 1 degree of accuracy anyway.

Worth noting that this equation is an approximation itself. The 'proper one' is deemed only good enough for the ATPL's. TAS/10 + 7 does not work for high TAS.

Some good advice so far - set OBS to M HDG from the compass and then count the big divisions (every 30 degrees) to your required heading. Multiply by 10 and that is your time. Only look at the compass before and after the turn.

I'm sure there are lots of other ways of doing it though. Have a chat with your instructor.

EK

Set your current compass HDG on the OBS box, then you can easily see which way to turn. Divide the number of degrees to turn by three, and that is how many seconds you need to turn for.

Further, the OBS should hopefully have segments of 30 degrees on it, representing ten seconds per segment, so that you can simply count 10, 20, 30 seconds and so on. Add 3 seconds for an extra 10 degrees beyond the segment and there's very little in the way of maths to it at all. That's what I was taught anyway. Fly and do maths at the same time? No chance!

timed turns
 

And if you want to turn at the standard rate of turn (3°/sec) you can calculate the AOB for different speeds . Take 15% of the TAS .

Ex: You fly 120 kt TAS , AOB is 18° :8

For angles of turn you multiply by 0,3 .

Ex: if you want to turn by 50° , it will take 15'' .

Also, don't forget that a lot of training aircraft have fairly inaccurate turn gauges. If you roll out of the turn and (once the compass has settled down) find you're 30deg out, simply correct with another 10sec turn. They won't fail you for the inaccuracy of the instruments!

Using the OBI is a good tip. Put your current heading at the top, and just memorise the numbers for quick calculation: 360/2mins, 180/1min, 90/30secs, 30/10secs etc..

Third time this year this has come up - did you use the search function?

http://www.pprune.org/professional-p...med-turns.html