Timed turns to magnetic compass

Robyn1993

Robyn1993

Well-Known Member
I'm trying to prepare for my instrument rating, and I'm having a very hard time understanding timed turns. Can someone explain them for me please.

1. When should the time be started when rolling into a timed turn?

2. If a standard rate is 3 degrees per second, how many seconds will it take me to turn left from a heading of 050 to 300?

3. How many seconds will it take me to turn right from a heading of 360 to 180?

4. How can I fly a standard rate turn with only an attitude indicator?

If you can also refer me to any useful articles besides the confusing instrument handbook, I'll be great! Thanks
 
A full turn is 2 minutes, so every 90 degrees is 30 seconds. 30 degrees is 10 seconds, etc. Just remember those numbers, and it's easier to interpolate for odd headings. 50 -> 300 is 110 degrees (turn left), so it's a 90 degree turn (30 seconds) plus 20 degrees (~7 seconds), so 37 seconds in the left turn.
 
Robyn1993 said:
I'm trying to prepare for my instrument rating, and I'm having a very hard time understanding timed turns. Can someone explain them for me please.

1. When should the time be started when rolling into a timed turn?
Click to expand...

Start time and roll into the turn. Stop time and roll out of the turn. The lag from roll in and roll out will mostly cancel each other out.

For word problems you need to do math. If you're not great at quick mental math, in the real world you could look at a VOR head to quickly see how many 10 degree increments there are between your current and desired heading. On smaller heading changes (up to about 90 degrees of change) just multiple the number of 10* changes by 3 (or literally count by threes while pointing at the increments)

Robyn1993 said:
2. If a standard rate is 3 degrees per second, how many seconds will it take me to turn left from a heading of 050 to 300?
Click to expand...

050 to 0 is 50 degrees of change
0 to 300 is 60 degrees of change
50+60 = 110
110/3 = 36 seconds

You can ball park with 3 seconds per 10 degrees for easier math or as a sanity check (11 * 3 = 33.. pretty close)

Even simpler, realize 360 of change is 2 minutes, 180 of changes is 1 minute, 90 of change is 30 seconds... fairly easy to roughly interpret from there.

Try not to over think it.

Robyn1993 said:
3. How many seconds will it take me to turn right from a heading of 360 to 180?
Click to expand...

360 (aka 0) to 180 is 180 degrees of change
180/3 = 60 seconds (but this is obvious since a standard rate turn is 360 degrees in 2 minutes and you're turning 1/2 way around a full circle...again, easier to look at the big picture than the details sometimes)

Robyn1993 said:
4. How can I fly a standard rate turn with only an attitude indicator?
Click to expand...

Know how many degrees of bank you require for a standard rate turn at a few true airspeeds. A rough but good estimate is 15% of TAS (or for easier mental math - 10% of TAS + 5). We're not answering a physics test so use a simple rule of thumb like this and call it good enough.

100 knots = 15 degrees bank
150 knots = 22 degrees bank
200 knots = 30 degrees bank

So know what the bank angle should be at approach speeds and cruise speeds for your airplane and the turn coordinator just reinforces what you already know. You can interpolate at other speeds as needed and be close enough.
 
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Murdoughnut said:
Do not worry too much about how. Engineers designed your airplane to be aerodynamic and manufacturers built it to fly. It is a big chunk of aluminum sitting there. You cannot change that. You just deal with it. If started and turned loose, it could fly by itself, so what is all the fuss about?
Click to expand...

I have two words for you: Space Flight
 
I think the concept of timed turns is fine as another exercise to improve and develop your scan. However, if you ever get to the point of needing to do it in real life, declare an emergency and tell ATC you need no gyro vectors.
 
rframe said:
Start time and roll into the turn. Stop time and roll out of the turn. The lag from roll in and roll out will mostly cancel each other out.

For word problems you need to do math. If you're not great at quick mental math, in the real world you could look at a VOR head to quickly see how many 10 degree increments there are between your current and desired heading. On smaller heading changes (up to about 90 degrees of change) just multiple the number of 10* changes by 3 (or literally count by threes while pointing at the increments)



050 to 0 is 50 degrees of change
0 to 300 is 60 degrees of change
50+60 = 110
110/3 = 36 seconds

You can ball park with 3 seconds per 10 degrees for easier math or as a sanity check (11 * 3 = 33.. pretty close)

Even simpler, realize 360 of change is 2 minutes, 180 of changes is 1 minute, 90 of change is 30 seconds... fairly easy to roughly interpret from there.

Try not to over think it.



360 (aka 0) to 180 is 180 degrees of change
180/3 = 60 seconds (but this is obvious since a standard rate turn is 360 degrees in 2 minutes and you're turning 1/2 way around a full circle...again, easier to look at the big picture than the details sometimes)



Know how many degrees of bank you require for a standard rate turn at a few true airspeeds. A rough but good estimate is 15% of TAS (or for easier mental math - 10% of TAS + 5). We're not answering a physics test so use a simple rule of thumb like this and call it good enough.

100 knots = 15 degrees bank
150 knots = 22 degrees bank
200 knots = 30 degrees bank

So know what the bank angle should be at approach speeds and cruise speeds for your airplane and the turn coordinator just reinforces what you already know. You can interpolate at other speeds as needed and be close enough.
Click to expand...


Rframe, THANK YOU SO MUCH! It's clear now!

I wish that they explained it in a better way in the Instrument handbook.
 
DE727UPS said:
I think the concept of timed turns is fine as another exercise to improve and develop your scan. However, if you ever get to the point of needing to do it in real life, declare an emergency and tell ATC you need no gyro vectors.
Click to expand...

What's a no gyro vectors?

The only thing I can imagine is that ATC would tell you to make left or right turns, and to stop the turn. Is that what it is?
 
DE727UPS said:
Yeah, and you may need to explain it to the controllers that way, too...hehe.
Click to expand...

If controllers would actually do the yearly refresher it might be easier to remember when needed. Instead most sit there on their phone while clicking next.

Sent from my SAMSUNG-SGH-I747 using Tapatalk 2
 
Step One - Start turn.
Step Two - Magic occurs.
Step Three - Roll out on heading.
If you fly jets...
Skip Steps One thru Three...
Step Four - Turn autopilot heading knob to desired heading
Step Five - Ask FA for more coffee.
 
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