User manual

Part B Section Appendix A.4
For practice, select a 2-3 mile water run with wave conditions one foot or less. With the
controls hard back the power should be brought up to take-off settings (47 ins Manifold
Pressure and 2700 RPM) and the aircraft allowed to rise up over the "hump" and onto the
step. Elevator back pressure can then be relaxed a little and the aircraft will continue to
accelerate at the correct attitude. Once a speed of 45-50 knots has been reached power is
reduced to about 25 ins Manifold Pressure and if correct attitude is maintained speed will
be held steady.
Directional control is established early as airflow increases over the rudder and once up on
the step, rudder step turns can be used easily. There is a tendency for the wing on the
outside of any turn to drop due to the centrifugal effect but this is in part countered by the
faster airflow over the outside wing during the turn. Which effect predominates depends on
the wind and water conditions but at all times the pilot must keep the wings level. An
occasional quick glance at the floats is useful. During the step taxi the floats should be just
out of the water, so a float sitting high above suggests the other one will be dragging. A
float in the water requires corrective aileron input. The non-flying pilot can keep a watch on
float position during the manoeuvre as well.
05 PORPOISING
This is due to a low nose attitude and the oscillations must be overcome by prompt return
to the correct nose attitude before the oscillations reach the point that the nose gear doors
are taking load. The principles of porpoising recovery have been covered under Part 2 of
this supplement:
06 PORPOISING RECOVERY (FOR THE CATALINA)
1) Return to best trim angle by elevator back pressure and hold that attitude until the
porpoising ceases then confirm that acceleration is continuing and adjust attitude if
necessary. If unsuccessful,
2) Porpoising Abort. Close the throttles and draw back on the controls. Time this for
when the nose is rising. Abort the take off and let the aircraft come down off the step.
WARNING: Abort early before the oscillations get severe.Do not try to fly out of porpoising
by applying power.
07 TAXIING IN CURRENTS
When taxiing downstream the main problem is the sensation of speed relative to the shore
which often tempts the pilot to reduce power. This may reach the point that so little power
is left "on" that the aircraft is not really moving relative to the water and is essentially
drifting out of control. Regular checking that rudder control remains should occur as power
is reduced.
Taxiing up current is easier. The aircraft will have more power on for the same speed over
the ground and is more controllable. Small power adjustments make a controlled track
easier to maintain and in all cases the approach to a shore or a dock should be made up
current. The exception is where strong eddy currents run upstream close to the bank of a
major river.
Stichting Catalina PH-PBY Rev No: 02
01 April, 2006 Page: 3