We're taught (in fact, it's hammered into us) to recover immediately
from the insipient phase of any stall. Hanging in there to allow the
condition to fully develop is an exercise that takes practice, and
probably one that you don't want to get too used to.

Given the confusion of your asi, the next best way to differentiate is
by g load. In a spin, the loading quickly stabilizes to 1.5 to 2g. In
a spiral dive it builds quickly beyond this. Visually, the yaw string
goes right over in a spin, but since a spiral dive needn't be
coordinated, this too can be confusing.

Spinning or spiral diving are both unusual maneuvers. Because of that,
each of us will perceive them a little differently, based on our
personal idiosyncracies. For most of us, a canopy full of mother earth
screams acceleration, overpowering any other cues.

I am reminded of an experience I relive at least once every winter:
the first application of brakes on ice. When I step on the brakes, I
expect the reassurance of weight into my shoulder belt. When that
doesn't happen, I get the oddest feeling that instead of decelerating
I am accelerating, which, of course, makes me want to mash the brake
pedal down even harder. It takes a second or two to break through the
misperception and get my foot back up off the brake. I suspect that we
are all subject to varying degrees of a similar effect when we explore
parts of the envelope we don't often visit. Practice makes perfect,
but why do we need to be perfect unless we're aerobatic pilots.

We should focus instead on the insipient phase. Much more subtle, but
much more valuable in gleaning out every last ounce of performance
when it counts most.




(Mark James Boyd) wrote in message news:3fac007b$1@darkstar...
Most pilots instinctively recover long before they can
tell the difference between a stall -- recovery -- spiral dive
scenario and a stall -- spin. This often causes confusion about which
is which.

I personally intentionally tried a spin entry once in a glass
glider and got a surprise and made an immediate spin recovery.

It seems the airspeed indicator rotates all the way around, so
80 knots indicated is the same as 20 knots indicated.

Imagine my surprise when the glider stalls, the nose drops,
and the ASI wobbles and then indicates ???
I tried it a few more times and by god could never
tell the difference, so I was too scared to do
anything but recover immediately (release the cross-controlled
inputs). Whichever it was, the glider sure picked up
speed like lightning when nose down.

I still wonder if this killed the Nimbus4DM pilots in Reno.
Imagine looking at the ASI and not knowing if
you should be doing a spin recovery or a spiral recovery
(two very different things).