Wednesday, June 08, 2011

More on observing flight maneuvers

I want to continue where I left off last Friday when I reviewed aerodynamic stalls in preparation for writing about some flight maneuvers that I was observed during a scenic ride I took a few weeks ago.

Mike (pilot/CFI) flew to a practice area near the airport where we demonstrated these flight maneuvers.

 Mike told me what he was and doing and why, I took some notes on the flight. In addition, I had some notes from ground school and other scenic rides that I will refer to in this article.

Before starting each maneuver, it is important that one be at a safe altitude. There is also something called "clearing turns" that are done before each maneuver is started. The purpose of the clearing turns is to look for any other traffic before starting the maneuver. Depending on the maneuver, there will be additional items on "the checklist" that are completed prior to starting the maneuver. Unless otherwise noted, the maneuvers that I observed are required knowledge for those seeking a private pilot certificate.

Mike started with steep turns, a 360 degree turn (a complete circle) in a bank angle more than 45 degrees (but less than 60 degrees). As I understand it, constant altitude and airspeed is maintained during the steep turn. Mike demonstrated two steep turns, one at the Cessna 172P's normal cruise speed of about 99 knots and the second at about 85 knots. I was very interested to see that in the steep turn at the slower speed, Mike had to increase back pressure on the yoke in order to maintain constant altitude.

I have seen stalls demonstrated on earlier scen ic rides where the pilot comes to a near stall and then recovers. Recovering from stalls is an important skill for all pilots, and a life-saving skill.

I was especially interested in the two power-off stalls that Mike flew. If memory serves, power-on stalls are done in what is known in "take-off configuration" as the airplane is climbing to altitude (with power).  As I understand it, power-off stalls are done with power set at idle in what is known as the landing configuration. Mike did one power-off stall where he prolonged the stall enough that we lost 400 feet in altitude before he recovered by putting the nose down and increasing power.

The next to last maneuver was the chandelle. Chandelle's are required for CFI's and the commercial rating. Those seeking a private pilot certificate do not have to learn the chandelle. According to the Airplane Flying Handbook (FAA-H-8083-3A) (p. 9-4), the objective of the chandelle

is to develop the pilot's coordination, orientation, planning, and accuracy of control during maximum performance flight. A chandelle is a maximum performance climbing turn beginning from approximately straight-and-level flight, and ending at the completetion of a precise 180 degree turn in a wings-level, nose high altitude at the minimum controllable airspeed.

See this wikipedia article on chandelles for more information and some graphics.

I observed two chandelles, one entered from the left and the other entered from the right. In my notes from that flight, I noted that the bank angle on the chandelles that I experienced was no more than 30 degrees. Our altitude when the chandelles were completed was 5,500 ft.

After completing the chandelles, Mike flew a steep spiral (another maneuver required for CFIs and the commercial rating, but not for private pilots). As the name implies, Mike descended to about 2,500 ft in a spiral. For more on the steep spiral including a graphic, check out this link.

We were in the air for just over three-quarters of an hour. I was thrilled to observe these maneuvers and came away with renewed appreciation for the skills involved in flying an airplane. And just as thrilled that I did not get sick to my stomach.

All these maneuvers are discussed in detail in the Airplane Flying Handbook (FAA-H-8083-3A) with pictures. In addition, these maneuvers are covered in an excellent publication by ASA (Aviation Supplies and Academics, Inc.) called Visualized Flight Maneuvers Handbook. I have the edition for high winged aircraft. I understand that there is one for low winged aircraft as well. I have a hard copy that is small enough to fit in a flight bag, I do not know if you can purchase an electronic file.

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