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-   -   Bank angle and rate one turn. ques (https://www.pprune.org/professional-pilot-training-includes-ground-studies/501997-bank-angle-rate-one-turn-ques.html)

z.khalid 4th December 2012 10:09

Bank angle and rate one turn. ques
 
Just some confusion.
When you do a 10 degree climb, it is just the aircraft pitched up to 10 degrees, and the same on a bank.
20 degree bank is a 20 degree angle for the aircraft.

Now when calculating for a rate one turn, it says 3 degrees per second.
I'm just curious, when were doing a standard 20 degree right turn bank, how do we know how many degrees per second that is?

I seem confused, or missing something..:\

Lightning Mate 4th December 2012 10:15

Do you have a turn indicator fitted?

The pitch ATTITUDE shown on an attitude indicator is not the same as the FLIGHT PATH the aircraft is following.

The latter will be less.

sycamore 4th December 2012 10:35

Use the compass headings and a stopwatch; ie, turn thru` 60* in 15 secs=4*/sec..
Best approximation for a R1 turn ,at 120 kts = 12+7 =19* of bank. At 90kts =9+7 =16* bank.

Lightning Mate 4th December 2012 10:48

But if his aircraft is fitted with a turn indicator that is unneccessary.

Most are.

1Charlie 4th December 2012 11:02

Bank angle and rate one turn. ques
 
Depends on how fast you're going

Lightning Mate 4th December 2012 11:59

Should any of you be interested, the most accurate way of calculating rate of turn, which has absolutely no bearing whatsoever with regard to practical flying, is this:

(9.81 x tangent angle of bank) divided by TAS in metres per second.

This will give the answer in radians per second, so multiply by 57.3 and the answer will be in degrees per second. :)

BillieBob 4th December 2012 13:42


But if his aircraft is fitted with a turn indicator that is unneccessary.

Most are.
Actually, most are fitted with a turn co-ordinator, a subtly different beast. Turn indicators tend to be fitted mainly in aerobatic aircraft.

Lightning Mate 4th December 2012 14:43

Yes, but they both employ a rate gyro, the only difference is that of presentation and gyro gimbal inclination.

Both will show rate 1.

Believe me, I used to have to teach all this stuff. :)


Turn indicators tend to be fitted mainly in aerobatic aircraft.
Do you know why?

rob-d 4th December 2012 15:12

mental calculation ->

Bank angle for rate 1 turn == (TAS/10) + 7

i.e.

100kts / 10 = 10 + 7 == 17 degrees for rate one.

(rough guide, accurate up to about 25 degrees bank.)

BillieBob 4th December 2012 15:35


Do you know why?
Of course, and I expect most other FIEs do as well.

WhySoTough 4th December 2012 16:57

Never seen an aircraft with a Turn indicator.
Not flight school, not in the airbus.
Only info we get from our instrument is the bank angle.

Why would we need to know how many degrees we are doing per second? (just wondering).

lasseb 4th December 2012 17:24

Because all IFR procedures are based on the assumption that you do a rate-1 turn.
All IFR approved aircrafts must have a rate-of-turn indicator. Most small planes have the turn coordinator as previously mentioned.

WhySoTough 4th December 2012 17:39

Pardon me, but how exactly does the turn coordinator show rate of turn in degrees per second?
And jets don't usually have either from what I know. A normal roll scale on its attitude indicator is what's on most.

Also. I honestly never knew that IFR charts are based on a rate one turn.
Like the 45/180 turns inbound to intercept final course, etc.
All of these assume rate one turn?

FlyingStone 4th December 2012 18:15


Originally Posted by WhySoTough
Never seen an aircraft with a Turn indicator.
Not flight school, not in the airbus.
Only info we get from our instrument is the bank angle.

Let's hope you don't have an access to a real aircraft. You can't see rate of turn anywhere else rather than attitude indicator (bank)? Please inform your IRE to have yours and his licence revoked. Did you ever consider that the rate of turn is just what the phrase says: rate of turn - just look at the DG/HSI/ND/compass and note for how many degrees the heading changes in 3 seconds and then if you divide the heading change by 3 you get rate of turn. Yeah, I know, I should get a Nobel prize for this :ugh:


Originally Posted by WhySoTough
I honestly never knew that IFR charts are based on a rate one turn.

And what did you do during IR course studies? Walk around with shiny one-bar eppauletes instead of reading PANS OPS? Did you ever fly an IFR procedure (let's say base turn) designed for Cat D aircraft with a 100kt spamcan and adjust the turn accordingly? Or you just use "standard" bank and then wonder why those idiots create procedures, which lead you into severe undershoot every single time, even if you ace the turn?

All IFR procedures, designed according to PANS OPS require rate of turn 3°/s or 25° bank - whichever is less. The main reason why jets don't have a turn coordinator is because usually the speed during instrument procedures are so high that the 25° bank is limiting - for a 3°/s turn you would need a bank higher than 25°.

Lightning Mate 5th December 2012 06:19


Only info we get from our instrument is the bank angle.
I assume you are talking about the so-called turn coordinator.

This instrument contains a rate gyroscope and does not, repeat NOT, show any attitude whatsoever.

The display is totally misleading because to the ill-informed, it looks like bank angle.

edit: I can post an image, computer drawn by myself for instructional purposes, if you wish.

Lord Spandex Masher 5th December 2012 07:13

IIRC, I haven't seen one for years, the indications show rate 1, 2 and 3 turns and that's it. Plus slip and skid. That the one you're on about?

Lightning Mate 5th December 2012 07:17

I note that the OP has not returned.

z.khalid 5th December 2012 09:55

Thank you all for your very useful posts.
Did some of my own reading as well and it all makes sense.

Thanks lightning mate And also flying stone, appreciated.. :ok:

Lightning Mate 5th December 2012 10:06

My pleasure.

Would you like a diagram?


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