John T,
Ah yes, I did miss that!
putting the colourful use of "slam" to one side, the technique should be to use rudder to the extent necessary to maintain a constant heading. All part of the desirable aim to minimise the likelihood of a departure.
I understand the philosophy behind keeping a constant heading to be that it will significantly lessen the likelihood of entering a spin - do you agree? Shouldn't the main focus of stall recover be just that - stall recovery? The primary pitch control is the elevator and should be used to decrease the pitch of the airplane so that it begins flying again.
It seems that instructors (with good intentions) end up putting so much emphasis on using the rudders in the stall instead of ailerons that the student ends up coming out of the lesson with the idea stuck in his/her head that for a stall "use the rudder and not ailerons!", instead of, "decrease pitch to recover!".
For example, lets say the airplane enters a stall and gets a wing drop of 45 degrees bank to the left. What happens when the pilot pitches down to reduce the angle of attack? The elevator, now acting 50% as pitch control and 50% as directional control, will cause the airplane to decrease its angle of attack AND decrease the directional deviation (yawing moment) from its heading. What happens when the pilot decides to instinctively fight the wing drop by adding rudder? It's also at 45 degrees and so it acts like the elevator does - in this case, it does help reduce the yawing moment but it also pitches the nose of the airplane up! Pitching up in a stall is definitely not a good idea.
Then there are the instructors who don't just say to use rudder to control the heading deviation but say to "pick up the wing" using the rudder. That puts the airplane into a slip initially (hardly the maneuver you'd like to do when you're trying to get maximum performance out of your wing), which slowly transitions to a skid as the airplane rolls towards level which is, again, not a good idea when you're at such a low speed.
Here are some quotes from an article I wrote:
During this training, the student will need to be taught a recovery procedure that will produce a combined high rate of success and a minimum loss of altitude, if it is initiated at the point of stall. “In arriving at an optimum procedure for use by the operational pilot, the test pilot must not only consider the effectiveness of the technique (in terms of altitude loss or manoeuvrability regained) but must also consider the simplicity of the technique.” [2] That quote is from the U.S. Naval Test Pilot School Flight Test Manual for Fixed Wing Stability and Control. Keeping a simple recovery procedure is important to keep the pilot focused on reducing the angle of attack, the only reaction that will unstall the wings. That is especially important when flying during a critical phase of flight, i.e.: take-off or landing, where it is easier to become distracted and where, unfortunately, most of the stall/spin accidents occur. I believe that the four-step procedure listed above will produce a combined high rate of success and a minimum loss of altitude.
The four-step procedure:
1. Reduce pitch
2. Power full
3. Coordinated roll to wings level
4. Pitch for VY
In summary, applying opposite rudder is not conducive to carrying out an effective and safe recovery from a stall. Here are a couple quotes from FAA documents on the stall recovery procedure: “Straight and level flight should be established with full coordinated use of the controls.” [3], “...straight-and-level flight should be regained with coordinated use of all controls.” [4] These two paragraphs from the FAA Airplane Flying Handbook, under the heading “Use of Aileron/Rudder in Stall Recovery”, summarize it well: “When the airplane is in a stalled condition, the wingtips continue to provide some degree of lift, and the ailerons still have some control effect. During recovery from a stall, the return of lift begins at the tips and progresses toward the roots. Thus, the ailerons can be used to level the wings.”, “Even though excessive aileron pressure may have been applied, a spin will not occur if directional (yaw) control is maintained by timely application of coordinated rudder pressure. Therefore, it is important that the rudder be used properly during both the entry and the recovery from a stall. The primary use of the rudder in stall recoveries is to counteract any tendency of the aircraft to yaw or slip. The correct recovery technique would be to decrease the pitch attitude by applying forward-elevator pressure to break the stall, advancing the throttle to increase airspeed, and simultaneously maintaining directional control with coordinated use of the aileron and rudder.” [4]
If the FAA, and others, support teaching stall recovery using the elevator first in the stall recovery to reduce the angle of attack and then use coordinated aileron and rudder to roll level, where are these instructors getting the idea that you should use uncoordinated rudder in the stall recovery?
Here is a Transport Canada AC regarding stall training and checking:
Advisory Circulars - Transport Canada
It's a bit off topic but I encountered pilots who believed that an "approach to stall" exercise should be done with zero altitude loss because, in their words, "you weren't stalled". Nowhere in the flight test guide, or anywhere else, does it say that one of the aims of the exercise is zero altitude loss. Some (read: most) DFTEs were/are also under the impression that zero altitude loss was/is required to get a mark of 4 on the flight test. That's clearly not what Transport Canada wants but showing the document to these pilots didn't change their minds.