Standard Rate Turn

[Jim Meade]

VFR pilots correctly look outside nearly all the time and turn following their eyes. If one has to turn on instruments it is useful to understand and use the standard rate turn, 3° per second.

The standard rate turn is not a constant bank angle. The bank to execute a standard rate turn depends on air speed. The radius of the turn is also a function of air speed.

For airplanes like those we discuss here, a rule of thumb recommended by the FAA in the Instrument Flying Handbook is 15% of the airspeed. If you are flying at 100 knots, that means a 15° bank. If you are flying at 80 knots, that is a 12° bank. For quick math, take 10% of your airspeed and add half that number to it. 10% of 100 is 10 plus half of ten is five for a total of 15%.

For the speed of planes we fly, a standard rate turn is nearly always a comfortable bank angle.

ATC understands standard rate turn and that is what they expect if you are maneuvering.

If you are maneuvering in IMC where precision is needed or if things are quite scary, you may choose a 1/2 standard rate turn.

One beautiful thing about a standard rate turn is that with a whiskey compass and a turn indicator and a second hand timer, you can be very precise about heading changes. Let's say you are headed 270° magnetic and want to turn to 180° magnetic. Let's say you are flying at 90 kias. You know that as you turn south the compass leads considerably, so it may read 120° for a moment when you are actually at 180°. If you time your turn, you will roll out on a good heading and in about 10 seconds or so the compass will settle down and admit that you are right.

You are turning 90° at 3° per second so 90/3=30 seconds. On a time mark of your choice, roll into a standard rate turn to the left. At 90 kias your bank angle is 13.5° Try for between 12-15 if you can. You lead a roll out by 1/2 bank angle, which is about 7° or just over 2 seconds which means that at 28 seconds you start a standard rate roll to the right back to straight and level. If you practice this just a few times you will be amazed at how accurately you roll out on the new heading.

If you are unfortunate enough to get caught IMC with a whiskey compass, turn coordinator and second hand timer, you can readily turn to any heading you desire.

FWIW, the whiskey compass has fewer errors on E and W, so if you are caught in the soup and have a choice, flying E or W will give you a more natural compass reading. If you fly N, then a left turn will show as a right turn and vice versa, and if you fly S, any turn will be exaggerated on the compass.

[FlyingMonkey]

Interesting. I know a "standard" bank turn is 30°, but unless I'm trying to look at something on the ground I rarely exceed 15° of bank for normal heading changes.

[Ed Cesnalis]

In my Skyhawk 30 degrees in the pattern and standard rate turns were the norm.

 

When my CT was delivered in 2006 the CFII that checked me out suggested that I do not limit my bank angle to 30° in the pattern. His thinking was that the CTSW could safely be banked more steeply to minimize the time when the wing blocks your view.

 

Ever since I have banked steeper than standard rate and steeper than 30 degrees and I find it works well for me. The CTSW does manuever quite differently than the Skyhawk.

 

[sandpiper]

I taught a max 30 degree bank downwind to base then to start a little early with a shallower bank turn base to final. Theory was less chance of an overshoot to final and less chance of a stall/spin.

[Jim Meade]

Don't confuse standard bank angle (whatever that is) and standard rate turn. A standard rate turn moves the nose of the airplane through 3° of angle (looking down form above) in each second. Tha angel of bank in a standard rate turn (and the turn radius) differ with air speed.

Charlie - no way is a 30° bank angle and a standard rate turn anywhere close for a CTSW at pattern speeds. At pattern speed of 60 kias the standard rate bank angle is 9°.

Some science guy can explain it, but a rate of turn has to do with the amount of change in the heading over time, not how far over the airplane is leaning.

Typically, standard rate turn is not done in a pattern as far as I know. It's done to change heading. Reread the OP for it's use and value.

If we want to talk angle of bank in the pattern, we should start a new thread.

 

[Ed Cesnalis]

Charlie - no way is a 30° bank angle and a standard rate turn anywhere close for a CTSW at pattern speeds. At pattern speed of 60 kias the standard rate bank angle is 9°.

 

Agreed, I was trying to say that both, 1) a 30° limitation in the pattern, and 2) a standard rate turn for heading changes are to shallow for me after John Schottenheimer showed me the benefit of steeper banks in a CTSW. John has over 10,000 hours in 747s and flies a Yak and a CTSW, or at least he did last time I saw him. I figure his advice was worth exploring and 6 years later I couldn't agree more, I prefer a 4 second turn and not being blinded longer than that.

 

I don't have a watch or anything with a second hand, If I needed a standard rate turn and my panel was dark I woudn't have an indicator of standard rate. If my panel is lit I have syn vision and little reason to turn standard rate.

[GlennM]

Many aircraft have little tick marks somewhere on the face of their turn coordinator gyro to indicate a standard rate turn. Analog they are the tick you put the representative aircraft wing on (turn coordinator) or the needle on the doghouse. Dynon has the turn rate indicator as the reddish pink bar just below the compass indication. I am not sure of any others.

[Ian]

As part of the PPL syllabus in the UK and tested in the GFT you have to learn turning onto a required heading solely using the turn coordinator, so divide the heading change by 3, roll into the turn, then count 1 thousand, 2 thousand, 3 thousand etc whilst maintaining rate 1, roll out and if you're lucky you are within a few degrees of what is required!!

[Ed Cesnalis]

I don't have a watch or anything with a second hand...

 

My transponder reads out flight time, in seconds, that works fine.

[Ian]

But that's the whole point, you don't need a watch - you count it!