Originally Posted by
jonkster
Problem is the definition of an incipient spin is not clearly stated as far as I can see in the Australian documentation.
Getting there with CASA’s AC 61-16, Spin avoidance and stall recovery training, earlier this year.
Originally Posted by
Clare Prop
The POH extract above is for the fully developed spin recovery. Applying full opposite rudder at the incipient stage has already been discussed.
Nope, nowhere does it say in the POH that the extract is for a fully developed spin. The particular example is for a type approved for spinning when loaded in Utility Category. That spin recovery procedure in the Emergency Procedures section of the POH is also applicable to Normal Category where we’re expected to recover (from an unintentional spin) by about one turn. When loaded in Normal Category it was flight tested only up to one turn (so still in the incipient phase).
The flight test crew who do that testing are the same people who write the words for the POH. They follow what it says in the FAR 23 Flight Test Guide which defines a spin as “A sustained autorotation at angles-of-attack above the stall.” So, if in a spin per that definition then use the spin recovery procedure in the POH.
Incidentally, the term “incipient spin” is not used in the FAR 23 Flight Test Guide however it does state that "Most airplanes will not attain a fully developed spin in one turn."
It goes on to state: “Normal category airplanes must recover from a spin in no more than one turn after the initiation of the first control action for recovery. For example, if you are spinning left with ailerons neutral, recover by reducing power to idle, if not already at idle, apply full right rudder followed by forward elevator.” That would be from an incipient spin.
Originally Posted by
Icarus2001
How about we actually READ what the manufacturer says rather than regurgitating opinions...
Good advice. That example was for a Cessna A152 so let’s read on from Cessna’s document D5014-2-13, Spin Characteristics of Cessna Models … A152 ….
“For the purpose of this discussion, we will divide the spin into three distinct phases. These are the entry, incipient, and steady phases. ……. in the entry phase, recovery from or prevention of the spin is as simple as normal stall recovery since, in fact, at this point that's all we are really faced with. Coordinated use of rudder and aileron to oppose any tendency to roll should be applied with emphasis on the rudder due to its generally more powerful influence at this point. This should be accompanied by relaxation of elevator back pressure to reduce the angle of attack below that of the stall. Coordinated use of all controls should then be applied to return to normal level flight.
……..
During this incipient phase, spin recoveries in those airplanes approved for intentional spins are usually rapid, and, in some airplanes, may occur merely by relaxing the pro-spin rudder and elevator deflections. However, positive spin recovery control inputs should be used regardless of the phase of the spin during which recovery is initiated.
Briefly, these control inputs should be 1) neutral ailerons and power off, 2) full rudder opposite to the direction of rotation, 3) just after the rudder reaches the stop, elevator briskly forward to break the stall, and 4) as rotation stops, neutralize the controls and recover from the resulting dive.
……..
The final phase is the fully developed ''steady" phase. Here a more-or-less steady state spin results where the autorotational aerodynamic forces (yaw due to rudder deflection, lift and drag differences across stalled wing) are balanced by the centrifugal and gyroscopic forces on the airframe produced by the rotating motion.
……
Finally, it is important, particularly in this steady spin phase, in addition to using the correct control application and proper sequence of control application, to HOLD THIS APPLICATION UNTIL THE RECOVERIES OCCUR. In extreme cases, this may require a full turn or more with full down elevator deflection.”
Pretty clear to me.