Yak 18T Flight Operations Manual
Page 52 of 82
Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations
Manuals and has not been approved by the Yakovlev Design Bureau or any other authority.
• At the first 3-tum spins the angle of longitudinal inclination is gradually DECREASED and
angular rotational velocity rises at a constant speed and acceleration (n
y
=2). After 3-4
turns the aircraft spin becomes STABLE with slight rolling oscillations, constant speed
and acceleration
• At the first 3 turns there is no actual DIFFERENCE between the left and the right spins.
After 3-4 turns the RIGHT SPIN IS MORE sloping than the left. Rotation during both
spins is accompanied with some aircraft stalling VIBRATION or BUFFETING
• While spinning, direct a glance towards the spin direction by 25°-30° from the air
aircraft X-axis and by 20°-30° below horizon
9.2. Spin Recovery
To recover the aircraft from a spin, first –
• DEFLECT the rudder pedal towards the side opposite to the spin direction and after this
in 2 seconds move the yoke forward beyond a NEUTRAL position by ¼-1/5
th
of motion
• NOTE: moving the yoke fully forward is not advisable, as this can result in dive angle
increase, appearance of a negative load factor, rising of the indicated airspeeds and a
LOSS OF HEIGHT during recovery
• As soon as the aircraft stops its rotation, immediately place the rudder pedals in the
NEUTRAL position, increase the IAS to 160-170km/hr and then by SMOOTHLY
pulling the yoke backwards, recover the aircraft from the dive at such a rate that the IAS
reading at the end of recovery is 220-240km/h
• When the aircraft APPROACHES the horizon, increase the engine boost
• During three turns of the spin the aircraft's HEIGHT LOSS in recovery is 740m
(approx. 2,400ft)
• The aircraft recovers from a spin (up to three turns) with a LAG not exceeding ONE
TURN
• When recovering from a spin, always DEFLECT the rudder pedal AGAINST the spin
EARLIER than the elevator. In case of the REVERSE sequence the aircraft can FAIL to
recover
• DEFLECTION of ailerons within up to ½ pro-spin motion does NOT affect the spin
nature. At a full pro-spin deflection the spin gets less stable and steeper; DEFLECTION
of the ailerons by ½ of motion and fully against the spin, the latter becomes more FLAT
in its nature
• Influence of the AILERONS on the spin nature is felt MORE at the RIGHT spin than at
the left one
• While spinning, if the ailerons are DEFLECTED against the spin by MISTAKE and the
aircraft FAILS to recover in two turns of lagging (after pulling the controls for recovery),
proceed as follows -
• apply pro-spin controls (at the right spin the rudder is fully to the right side, the yoke
is pulled fully backwards, ailerons in the NEUTRAL
position) check to insure that
they are in NEUTRAL
• make one turn with the pro-spin controls
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