Rate Of Turn
 

Hey.....

I was a bit confused regarding the Rate Of Turn(Rate Two Turn specifically!!)

A rate 1 turn is 3dgrees per second..a rate two turn is 6 degrees per second..so while flying a rate two turn,a 360 degree tun should be completed in 1 minute..

But according to this article,

http://www.airdorrin.com/Resources/i...imedturns.html

a rate two turn is defined as 1 and a half degree per second:ugh:

so this ways,the aircraft would take 4 minutes to complete a 360 degree turn.

so what should be the correct value?? :confused:

thnx

flyer_by_the_wire


...A rate 1 turn is 3dgrees (sic) per second

Correct.


... rate two turn is 6 degrees per sec...

Correct.


...a rate two turn is defined as 1 and a half degree per second...

Not correct.

As stated earlier in the article a turn rate of one and a half degrees per second is ... a Half Standard Rate Turn .... 1 1/2 degrees per second rate of turn ... and it will take you 4 minutes to turn 360-degrees....


Best Regards

Bellerophon

@ Bellerophon

thank you so much for the reply..

But the article mentions that the HSRT is sometimes known as a RATE TWO TURN..

So have they quoted it wrong?? :confused:

Yegads! I'm lucky I didn't crash without knowing about Rate 1 and Rate 2 turns.

I was always taught (and then taught) standard rate turns. (3 degrees per second or two minute turns).

And, the U.S. military used to use 1/2 standard rate turns.

Memory is a little fuzzy, but my recollection from the 60s was that in precision radar controlled approaches, 1/2 rate turns were expected once on final approach.

Another use for 1/2 rate turns were holding for a jet penetration at FL200: a standard rate turn would give an excessive angle of bank, particularly in a century series fighter.

BTW, a good GCA would give accuracy as good or better than Cat 1 ILS - a good thing, as sometimes in Europe an F86 pilot needed to get to the equivalent of Cat 2.5 by GCA, with no fuel for other options.

And to fly it, try an angle of bank equal to 10% of the airspeed +7
ie !20kts, bank angle would be 12+7 =19deg to achieve a rate one turn.

(That's if I have remembered correctly)

plt_aeroeng

Yes, indeed.

For example, to have performed a rate 1 turn, in level flight in the cruise, in one passenger aircraft in the BA fleet not so long ago, would have required a bank angle of 73°, and pulling 3.23g.

Even a half-standard rate turn would have involved a bank angle of 58°, and pulling 1.89g.

Probably why we didn’t ever attempt them in the cruise!

In fact, most jet passenger aircraft will not attempt a rate 1 turn, in level flight in the cruise, as anything cruising around M0.85 and FL350 would need to use a bank angle of about 53° and pull around 1.66g.


bingofuel

Well remembered; a formula still being used, which works well for any aircraft when flying at more modest speeds.


Best Regards

Bellerophon

Re 10% of airspeed+7:

It may be accurate enough, but it's still not very accurate, particularly at low speed. The correct expression should, I think, be arctan(v/364), where v is the speed in knots.

At 50 knots, the approximation gives 12 degrees where the right answer is 8 degrees. At 80 knots, 15, where the right answer is 12. By 130 knots the error is less than a degree. The two agree exactly at only one speed, which is about 160.5 knots.

then the rule of thumb is really good

three degree error at the typical 80 kt TAS is very good

and Who wants to fly at 50 kt? ;)

what i am not going to do is to get my calculator out of my flight bag and start dividing by 364 :8

although I like to use it for other stuff quite often