Can you depart and spin from coordinated flight? Specifically a coordinated
climbing turn?

Several weeks ago I chimed in on an otherwise awful thread suggesting that
if the ball was in the center
the airplane would not spin. One of the posters
) responded that the difference
in relative wind between the inside/outside wing during a climbing turn
would result in an assymetrical stall
and wing drop even in coordinated flight. He had several
Canadian/Australian citations to back it up.

He posted summaries of them originally and my apologies for re-constructing
them:

Full power stalls in a balanced climbing turn tend to result in the outer
wing stalling first, because of the higher aoa of the outer wing, with a
fairly fast wing and nose drop (particularly so if the propeller torque
effect is such that it reinforces the roll away from the original direction
of turn and the aircraft is a high wing configuration) and likely to result
in a stall/spin situation that any pilot lacking spin recovery experience
may find difficult to deal with. If the climbing turn is being made with
excessive bottom rudder then the lower wing might stall first with the
consequent roll into the turn flicking the aircraft over. Recovery from a
stall in a climbing turn is much the same as any other stall - ease the
control column forward to about the neutral position, stop any yaw, level
the wings and keep the power on.

http://www.auf.asn.au/groundschool/u...ml#climb_turns

When the aircraft stalls in a climbing turn, the high wing is at a greater
angle of attack than the low wing and therefore stalls first, which results
in a rolling motion toward the high wing, creating asymmetric lift and drag.
The down-going wing will stall further as a result of less lift and more
drag than the up-going wing. A deeper stall, generated by aft C of G, will
aggravate these asymmetries, increasing aircraft rolling and yawing moments
into the down-going wing. In addition, the aft C of G reduces the distance
from the C of G to the centre of pressure of the vertical fin, thus reducing
directional control authority, making recovery more difficult

http://www.tsb.gc.ca/en/reports/air/...p?print_view=1

In a climbing turn, the outside or upgoing wing is meeting the relative wind
at a slightly higher angle of attack than the lower wing. If we pull on
the column to the stalling bite, then the upgoing wing will reach it
first...The upgoing wing suddenly drops and the wing falls away from the
original direction of turn.

http://www.casa.gov.au/fsa/2000/sep/FSA34-35.pdf

The Transport Canada Guidelines on Stall Training and Spin Awareness
specifically requires demonstrations in coordinated climbing turns:
http://www.tc.gc.ca/civilaviation/ge...stalltrain.htm


I would have thought that the hamfisted chandelles I perform would have
flirted with disaster if this were the case. However while I have had to
demonstrate accellerated stalls from 20 degree banks, I cannot recall having
to deliberately stall the airplane from a climbing turn.

My question to uunet is; can you spin from coordinated flight? Regardless
the previous dialog did get me thinking:

The convergence of insufficient right rudder and a slipping turn, the left
turning tendencies and the
assymetrical stall could gang up on our hapless pilot resulting in a quick
snap and
spin during a climbing right turn away from obstacles in the departure path.

Regards
Todd

--
"Instrument flying, I had concluded, is an unnatural act, probably
punishable by God."
--Gordon Baxter