9 Steep Spirals ( Instructing the Commercial Student )

[@skylarcaldwell7208]

Just a heads up for those watching this video to learn steep spirals, the new ACS says you should enter this maneuver on the upwind, not the downwind like this video says and most ground reference maneuvers say. The reason for this change is because when you complete a 360° turn you need to "clear" your engine by pumping the throttle forward to prevent rapidly cooling the engine or fowling the spark plugs, and you want to do this while in the upwind to reduce the amount of forward movement caused by increasing the throttle. 👌🏻

[@yamacat4010]

I think you are wrong about this. The ACS does not specify whether you have to enter this maneuver upwind or downwind. Also, you don’t “pump” the throttle. That’s very hard on the engine. You increase power to cruise power and then back to idle every time you are upwind.

[@skinnyfixed]

While the ACS may not specify this, the AFH does.

[@flcircus2009]

Steep Spiral The objective of the steep spiral is to provide a flight maneuver for rapidly dissipating substantial amounts of altitude while remaining over a selected spot. This maneuver may be useful during an emergency landing. A steep spiral is a gliding turn wherein the pilot maintains a constant radius around a surface-based reference point-similar to the turns around a point maneuver, but in this case the airplane is rapidly descending. The maneuver consists of the completion of at least three 360° turns [Figure 10-2], and should begin at sufficient altitude such that the maneuver concludes no lower than 1,500 feet above ground level (AGL). Note that while there are similarities between a steep spiral and an emergency descent, the reasons for using the two maneuvers may differ, and the airspeed and configuration are usually different. Figure 10-2. Steep spiral. 10-3 The steep spiral is initiated by properly clearing the airspace for air traffic and hazards. In general, the throttle is closed to idle, carburetor heat is applied if equipped, and gliding speed is established. Once the proper airspeed is attained, the pitch should be lowered and the airplane rolled to the desired bank angle as the reference point is reached. The pilot should consider the distance from the reference point since that establishes the turning radius, and the steepest bank should not exceed 60°. The gliding spiral should be a turn of constant radius while maintaining the airplane’s position relative to the reference. This can only be accomplished by proper correction for wind drift by steepening the bank on downwind headings and shallowing the bank on upwind headings. During the steep spiral, the pilot should continually correct for any changes in wind direction and velocity to maintain a constant radius. Operating the engine at idle speed for any prolonged period during the glide may result in excessive engine cooling, spark plug fouling, or carburetor ice. To assist in avoiding these issues, the throttle should be periodically advanced and sustained for a few seconds. Monitoring cylinder head temperature gauges, if available, provides a pilot with additional information on engine cooling. When advancing the throttle, the pitch attitude should be adjusted to maintain a constant airspeed and, preferably, this should be done when headed into the wind. Maintaining a constant airspeed throughout the maneuver is an important skill for a pilot to develop. This is necessary because the airspeed tends to fluctuate as the bank angle is changed throughout the maneuver. The pilot should anticipate pitch corrections as the bank angle is varied throughout the maneuver. During practice of the maneuver, the pilot should execute at least three turns and roll out toward a definite object or on a specific heading. To make the exercise more challenging, the pilot rolls out on a heading perpendicular to or directly into the wind rather toward a specific object. This ability would be a particularly useful skill in the event of an actual emergency. In addition, noting the altitude lost during each revolution would help the pilot determine when to roll out in an actual emergency so as not to be too high or too low to make a safe approach. During rollout, the smooth and accurate application of the flight controls allow the airplane to recover to a wings-level glide with no change in airspeed. Recovering to normal cruise flight would proceed after the establishment of a wings-level glide. Common errors when performing steep spirals are: 1. Not clearing the area 2. Inadequate pitch control on entry or rollout 3. Not correcting the bank angle to compensate for wind 4. Poor flight control coordination 5. Ineffective use of trim 6. Inadequate airspeed control 7. Becoming disoriented 8. Performing by reference to the flight instruments rather than visual references 9. Not scanning for other traffic during the maneuver 10. Not completing the turn on the designated heading or reference