Dubious "clearing turns"

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Jim Logajan

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When I first started training and first came across the term "clearing turn" it seemed only natural, and I mentally thought "that must be a 180 or even 360 to check for nearby traffic."

That is, until I got to the point where it was described as often being a 90 degree (left or right) turn, followed by a 90 degree (right or left) turn. Basically back to the original heading. How one can see 360 degrees in most planes without also doing an imitation of the kid's head in the movie "The Exorcist" is difficult to understand. Realistically, the 90/90 turns would cover 270 to 300 degrees - and that's assuming you do a lot of head swivel in addition to airplane turning.

To add to the dubious clarity, I found this instructional video on the subject on Youtube:

http://www.youtube.com/watch?v=ADllZzoSG-s

Beginning about 1:30 into it, he draws a 180 arc showing the area scanned. He doesn't draw an arc for the area scanned after the 90 degree turn, probably because he realizes it'll leave a 90 degree un-scanned gap. Not his fault, I guess, its a common "clearing turn" technique so I guess he has to cover it.
 
In most planes you can do a full view clearing turn by turning 60* right, 120* left and 60* right back to heading. If you have a bubble canopy you can get away with 30*R-60*L-30*R. Remember, you can turn your head and look over your shoulder....
 
From the FAA-H-8083-3A, Airplane Flying Handbook - Chapters 1-3
There are many different types of clearing procedures.
Most are centered around the use of clearing turns. The
essential idea of the clearing turn is to be certain that
the next maneuver is not going to proceed into another
airplane’s flightpath. Some pilot training programs
have hard and fast rules, such as requiring two 90°
turns in opposite directions before executing any
training maneuver. Other types of clearing procedures
may be developed by individual flight instructors.
Whatever the preferred method, the flight instructor
should teach the beginning student an effective clearing
procedure and insist on its use. The student pilot
should execute the appropriate clearing procedure
before all turns and before executing any training
maneuver. Proper clearing procedures, combined
with proper visual scanning techniques, are the most
effective strategy for collision avoidance.
Click to expand...
 
I think what you're describing is from laziness and misinterpretations. The clearing turn should be 90* one direction, then 180* the other direction, which is the same as 2 90* turns away from the heading of origin.

I suspect some people took the 2 90* turns part too literally. I know I've had CFIs do that, and when I draw them a picture and ask about the other quarter of the sky, they can't give a good answer.

If you start at heading 360, your first turn would be to heading 270, where you'll have checked the sky from 180 to 360. Then, you can turn to heading 090, where you see from 180 to 360.

Using the common "lazy" method, you start at 360, turn left to 270, having the ability to see 180 to 360. Then you turn back to 360, where you can see 090 to 360. But you'll never get to see 180 to 090.
 
I've had different CFIs with different turns - either 360s or multiple 90s.

The DPE I had on my PP checkride said, "It doesn't matter HOW you do them, it matters THAT you do them."
 
SkyHog said:
I think what you're describing is from laziness and misinterpretations. The clearing turn should be 90* one direction, then 180* the other direction, which is the same as 2 90* turns away from the heading of origin.

I suspect some people took the 2 90* turns part too literally. I know I've had CFIs do that, and when I draw them a picture and ask about the other quarter of the sky, they can't give a good answer.

If you start at heading 360, your first turn would be to heading 270, where you'll have checked the sky from 180 to 360. Then, you can turn to heading 090, where you see from 180 to 360.

Using the common "lazy" method, you start at 360, turn left to 270, having the ability to see 180 to 360. Then you turn back to 360, where you can see 090 to 360. But you'll never get to see 180 to 090.
Click to expand...

Depends on the Airplane and the ability of the pilots spine to twist, assuming you can only see 180° from one headding tells me you don't look over you shoulder. Technically in a 172 I can see almost 360 without turning the plane, what I really need to check is the sky above the wing. In the Archer I need to check my 6 and below the wing that can be accomplished by two 90° turns and some approrate pilot swivles.

Everyone's clearing turns will be different depending on aircraft and pilot felxability.
 
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In an Ag turn, as you pull out of the field, you start with a turn downwind before you cut back around to re-enter. I'll be looking at my entry point while it's still well behind my wing, actually as it is coming out from next to my tail before I am even back to the heading I departed the field on as I'm turning into the wind.
 
Matthew said:
The DPE I had on my PP checkride said, "It doesn't matter HOW you do them, it matters THAT you do them."
Click to expand...
The FAA examiner on my CFI checkride reminded me that there is no PTS standard for them, and told me whatever was effective would be satisfactory as long as I was sure I had a good look around. I personally do a lot more head swiveling if the cockpit view allows it. I'm also not very keen on prolonged banks in high-wings where I have a significant blind spot in the direction I'm turning.

Ryan
 
it matters THAT you do them
Click to expand...
Does it?

How many here have personally made a clearing turn where they believe that they have actually avoided a mid-air ?
 
I thought that clearing turns have 2 objectives:
1. Allow you to see in areas that airframe usually obscures
2. Make yourself visible to other pilots by banking

All the talk about 180 degrees is bogus, I already have scanned more than 180 degrees while flying level. Turning 180 or even 360 does zilch. What is important is to see behind wings, and the right rear. If I were flying P-51D or Spitfire, I would not even need much of that, just do a bit of snake maneuver like what combat pilots did. But the second reason means you should make turns steep even in fighter-like visibility airplane.

There was a number of cases when I could not see the airplane in the vicinity until it turned. Sometimes there was a large altitude differential too. You'd think that looking down would show its wings clearly but umm no. Well, I know I would make a poor fighter pilot, but then you never know if I am flying around. So bank those wings good, and both ways.
 
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Here's a point that is often lost during clearing turns: When an aircraft is on a collision path with yours, it will appear stationary (constant bearing, closing range). By varying your airplane's heading, conflicting targets start to move in the windshield thus making them easier to spot (we are better at seeing moving specks than picking out stationary specks).
 
airdale said:
How many here have personally made a clearing turn where they believe that they have actually avoided a mid-air ?
Click to expand...

I sure have - maybe not specifically avoided a mid-air, but in the busy practice areas around San Diego, I have indeed spotted traffic on multiple occasions while doing clearing turns that made me adjust my intended maneuvers.

It's not just about performing the turns - ya gotta actually look outside. I've seen alot of people just do the turns and not be serious about actually looking. I've also flown with the occasional CFI who will tell ya - you don't need to do a turn - I cleared ya.

Like Henning said - you CAN turn your head and look over your shoulder - there is no need to limit yourself to a 90 deg field over view. As long as you are serious about looking, I do believe you can be just as effective with 2 90 deg turns as with any other combination.
 
aghoras said:
Here's a point that is often lost during clearing turns: When an aircraft is on a collision path with yours, it will appear stationary (constant bearing, closing range). By varying your airplane's heading, conflicting targets start to move in the windshield thus making them easier to spot (we are better at seeing moving specks than picking out stationary specks).
Click to expand...

Keep in mind, in terms of relative motion - the aircraft on a collision course will ONLY appear stationary if you are in straight non-accelerated flight.

Clearing turns are to help you identify the traffic, not determine relative motion.
 
Jim Logajan said:
How one can see 360 degrees in most planes without also doing an imitation of the kid's head in the movie "The Exorcist" is difficult to understand. Realistically, the 90/90 turns would cover 270 to 300 degrees - and that's assuming you do a lot of head swivel in addition to airplane turning.
Click to expand...

In your typical Piper or Cessna, you can easily see an arc of 135 degrees (and arguably more) off the side you sit. If you are flying with an instructor in the other seat, they have the same coverage on their side. If you start at 360 and turn left to 270 you would be able to scan from 360 to 135. If you then turn right back to 360, you with the assistance of the CFI, can see the other side to 135 degrees. You have scanned the entire arc. If you are doing the manuevers by yourself, then you may have to turn more in one direction to make sure you have the coverage, but even on the off side, unless you have some musculoskeletal issues, you can see more than 90 degrees in most planes.
 
airdale said:
Does it?

How many here have personally made a clearing turn where they believe that they have actually avoided a mid-air ?
Click to expand...
Yeah. While in the semi-official South Practice Area here in San Antonio, I was guiding a student through some stall practice. We were talking to approach under flight following and had an area to work in. Another training aircraft in the area made some rather poor and lengthy radio calls, and things started going south on the radio quickly. Controller switched us over to another frequency and we made the call, but no-one was on the freq. I'm trying to regain contact while the student Finished a couple of stalls and did a few shallow turns to check we were still clear. About this time I see another of the competition's aircraft just in time to have us stop what we're doing. I think he passed about 2-300 feet below us within 6-800 feet. With the unpredictable nature of some power on stall practice, and student reactions, it could've been worse. I still don't know if he ever saw us, but the significant radio confusion was a major contributing factor.
I can think of a few other times when it's been not real close, but enough to make me cautious.

Ryan
 
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We've seen conflicting traffic many times and had we just gone ahead without having looked first, certainly could have bent metal or worse. We are a low wing AC; so, if doing things like stalls, we try to look below also.

Best,

Dave
 
airdale said:
Does it?

How many here have personally made a clearing turn where they believe that they have actually avoided a mid-air ?
Click to expand...

I did on my Commercial ride - we knew there was a helo operating in our area and he was SUPPOSED to be at 6000 (we were at 3000). So as I'm getting ready for the chandelle which would take us up to maybe 5000 at most, we do clearing turns, and there he was at what would have been my 7 oclock at 4000-ish. We called up ATC who we thought was working him, and requested they relay to him to give us a call onthe air-to-air. He did and we were able to work out some parameters so we wouldn't interfere with each other. Worked out good (and made me look good to the DPE which probably came in handy if some of my other things were not so outstanding).

On my CFI ride I always verbalized them before doing them, and said something like "I like to make at least two 90 degree changes" so he'd have an opportunity to let me know if he wanted something different.
 
I once did some training with a person who had been told he had to make clearing turns before he could practice a turn. :dunno:

My philosophy is that before conducting maneuvers which may result in unpredictable trajectories (especially in the vertical plane, like with stalls), you do whatever is needed to make sure you're not going to run (or fall) into anyone else. The exact maneuver needed will depend on what you're planning to do as well as what you're flying. For example, in a 172, it's a good idea to lift the wing before starting a steep turn so you get a good look up as well as laterally. In a low wing plane, that's not as critical, as you'll have good visbility into the turn both up and down as soon as you roll. So, I think the AFH is right -- do what is "appropriate" to the situation.
 
Matthew said:
I've had different CFIs with different turns - either 360s or multiple 90s.

The DPE I had on my PP checkride said, "It doesn't matter HOW you do them, it matters THAT you do them."
Click to expand...


Students: Take note of this. If your heading drifts too far during checkride, just call out "clearing turn" :thumbsup:
 
I worked in a helicopter at 7,000 AGL over the Las Vegas area on an aerial photography job... that was in an EC130. Strange feeling in a helo being that high up, doors off, holding position.
 
A lot of the clearing procedures talked about over the years have been covered above. The basic reason for clearing turns, however you want to do them, is to clear the area where you will be maneuvering. As an instructor you should know the local flow of traffic in the area you are using and explain that to the student and as a student be aware of what others do in "your" airspace. Remember, most mid air collisions happen in severe clear VFR conditions in the neighborhood of an airport. Transitioning traffic, traffic descending into the airport area and other maneuvering traffic populate "our" training areas. In my area near Tucson, add in Boarder Patrol helicopters at 20 feet to several thousand feet depending on their mission.
I try to stay out of where I expect other pilots to be. There are a couple of abandoned air fields in the local practice area. When I first moved here I found them comforting to maneuver above - insurance you might say. That was until on one flight I saw three other aircraft in that general area. Each apparently unaware of the others. The bottom line is clearing the area no mater how you do it must be complete and not just a rote pre-maneuver activity. I also use ATC whenever possible. Give them a good idea where and between what altitudes you will be. Although, we ultimately retain the responsibility of 'see and avoid' and the safe conduct of the flight, it is smart to use all of the resources available.

JMHO
 
Fearless Tower said:
Where on earth did you find a helo operating that high up???

What type?
Click to expand...

Ours regularly operates above 14k and occasionally can be found at FL200.

I jumped a cross country ride on it last summer where we climbed to 12500 for three hours. Just like airplanes...burns less fuel up there.

Have to admit it felt weird, having spent a lot of time in fling wings at about 300agl.
 
With regard to clearing turns, it was drilled in to me that the first clearing turn is always to the LEFT, since aircraft overtake one another on the right. While there may be no PTS for clearing turns, I always followed 90 to the left, then 90 back to the right... but never to the right first.
 
Mike I said:
With regard to clearing turns, it was drilled in to me that the first clearing turn is always to the LEFT, since aircraft overtake one another on the right.
Click to expand...
Does this mean if you're headed north and need to head east, you make a 270 to the left rather than a 90 right?
 
Ron-

Just talking about clearing the area before practicing maneuvers... but I do see your point about a 90deg turn when changing course. With clearing turns, though, it's arbitrary which way you turn since you may be returning to your original course, so why not turn in the direction of less chance of conflict?
 
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