it has no tendency to oppose sideways rolling.

=Stabilizer=--A surface, such as fin or tail-plane, designed to give an
aeroplane inherent stability.

=Stall, to=--To give or allow an aeroplane an angle of incidence greater
than the "maximum" angle, the result being a fall in the lift-drift
ratio, the lift consequently becoming less than the weight of the
aeroplane, which must then fall, _i.e._, "stall" or "pancake."

=Stress=--Burden or load.

=Strain=--Deformation produced by stress.

=Side-Slip, to=--To fall as a result of an excessive "bank" or "roll."

=Skid, to=--To be carried sideways by centrifugal force when turning to
left or right.

=Skid, Undercarriage=--A spar, mounted in a fore and aft direction, and
to which the wheels of the undercarriage are sometimes attached. Should
a wheel give way the skid is then supposed to act like the runner of a
sleigh and to support the aeroplane. [28]

=Skid, Tail=--A piece of wood or other material, orientable, and fitted
with shock absorbers, situated under the tail of an aeroplane in order
to support it upon the ground and to absorb the shock of alighting.
[28_a_]

=Section=--Any separate part of the top surface, that part of the bottom
surface immediately underneath it, with their struts and wires.

=Spar=--Any long piece of wood or other material.

=Spar, Main=--A spar within a surface and to which all the ribs are
attached, such spar being the one situated nearest to the centre of
pressure. It transfers more than half the lift from the ribs to the
bracing. [29]

=Spar, Rear=--A spar within a surface, and to which all the ribs are
attached, such spar being situated at the rear of the centre of pressure
and at a greater distance from it than is the main spar. It transfers
less than half of the lift from the ribs to the bracing. [30]

=Strut=--Any wooden member intended to take merely the stress of direct
compression.

=Strut, Interplane=--A strut holding the top and bottom surfaces
apart. [31]

=Strut, Fuselage=--A strut holding the _fuselage longerons_ apart. It
should be stated whether top, bottom, or side. If side, then it should
be stated whether right or left hand. _Montant_. [32]

=Strut, Extension=--A strut supporting an "extension" when not in
flight. It may also prevent the extension from collapsing upwards during
flight. [33]

=Strut, undercarriage=-- [33_a_]

=Strut, Dope=--A strut within a surface, so placed as to prevent the
tension of