point-of-no-return

Always remain in a position where you can turn toward lowering terrain.
Never fly beyond the point of no return.

the point of no return

The "point of no return" is defined as the point on the ground of rising terrain where the terrain out climbs the aircraft. The turn-around point is determined as the position where, if the throttle is reduced to idle, the aircraft can be turned around during a glide without impacting the terrain.

(It is not proper technique to reduce the throttle for the turnaround. This merely denotes the point where the turnaround must be initiated.)

turn around point

More important than the "point of no return" is the "turn around point." What or where exactly is this position where, if the throttle is reduced to idle, the aircraft can be turned around during a glide without impacting the terrain?

The reason it is an elusive value is because of the variables that may be encountered. If the airplane is flying upslope terrain at a high speed, the turn around point will be further up the upslope than it would be if the airplane is flying at minimum airspeed.

Usually, if a pilot gets into trouble while flying upslope terrain, he has experienced a phenomena known as "short arm" effect. The self-preservation instinct causes a pilot to unconsciously pull back on the control wheel to avoid the rising terrain. The airplane slows down and this reduction in airspeed is usually imperceptible to the pilot, who is probably directing his attention outside the airplane.

As the pilot, flying at or near the minimum controllable airspeed, realizes he needs to turn around, the density altitude may preclude a level flight turn around. It becomes necessary to trade altitude for airspeed during the turn. This is the main reason for the definition of the "turn around point."

One of the manoeuvres that should be demonstrated by a good mountain flight school is the "turn around point."

demonstration - turn around point

NOTE: This demonstration is not required to safely fly in the mountains. Search pilots operate close to the terrain (500 feet vertically and 500 feet laterally) on a continuous basis. It is felt this demonstration, with the required steep nose-down attitude, will help prevent complacency and cause the search pilot to continually be aware of his position and altitude.

While flying upslope terrain in a canyon, the "student" (actually, the participants are all experienced pilots) is asked to determine the turn around point. The Cessna 182 or T-41 is used for the backcountry flying in this course.

The instructor must monitor the position diligently in order not to fly beyond the turn-around point. This is definitely a place where complacency will "get you."

This picture shows flying up a canyon after completing the last pass of a contour search The contour search began at the top of the ridge and moved back and forth with step-downs in 500-foot intervals
The airspeed is 80 knots indicated, the speed used for the contour search technique. When the student determines the turn around point, the throttle is reduced to idle and the turn around is commenced. Because of the slow speed it is necessary to lower the nose to a position most students consider excessive; however, to maintain a constant airspeed, it is required.
 
This is the last pass of the contour. In this case it results in the airplane flying upslope terrain at low altitude The student continues up the canyon until reaching the "turn around point"

If the student has judged the position properly, the airplane will complete the 180-degree turn just over the tree tops at 80 knots indicated airspeed.
 
At the "turn around point" the throttle is reduced to idle and a gliding turn is begun Because of the slow speed the nose must be lowered to maintain 80 KIAS. Operation in a confined area may also require a steep turn. Lowering the nose further is necessary to maintain the constant 80-KIAS airspeed.

 


It is in this area of the turn that the 'student's' heart rate increases. The nose is pointed downward and the airplane is approaching the trees.

 

Most students find this demonstration quite exuberating ... and most of the time the instructor does too. This demonstration is made with the power at idle. If the student misjudges the turn-around point, power is used to get out of the situation, so it is not as dangerous as it may appear.

Required Altitude

What altitude is required for the Cessna 182 to complete the 80-KIAS turn around? It's going to be about 400-500 feet above ground level, probably closer to 500 feet.