Part 3 — Water Handling

Objective

To facilitate the student learning:

  • displacement taxiing
  • plowing taxiing
  • step taxiing
  • docking
  • ramping
  • sailing
  • beaching
  • mooring
  • abnormal water handling situations

Motivation

Handling a seaplane on the water requires a great deal of skill and judgment. What might one day be a simple beaching or docking could change greatly the next day depending on wind, water condition, available space, and the like. Because of the great variety of possible situations that can be encountered, mastery of water handling skills is essential.

Displacement Taxiing

Essential Background Knowledge

Explain the term displacement taxi. Should be able to sketch the float in the water and know the power required.

Point out local hazards to taxiing and docking such as rocks or shallows.

Explain the maximum RPM for displacement taxi and the risk of water damage to the propeller and the risk of engine overheating.

Explain how the water rudders affect the centre of resistance to lateral movement.

Explain the importance of good lookout for shallows or logs, and for other aircraft or for boats, swimmers, water-skiers, etc.

Explain the procedure for turns out of and into wind and associated hazards.

Review engine controls, ancillary controls and performance data.

Explain local traffic procedures, including prohibited, danger and practice areas.

Explain the use of aileron drag to assist turning.

Have the student explain the effect of wind on the aircraft, including the tendency to weathercock, how to prevent it, and how to use it.

Advice to Instructors

  • The objective is to TEACH the student how to handle the seaplane on the water. Do not assume that a new student knows anything about a seaplane. In an effort to assist the learning process, take time on the ground to explain carefully the exercises that you are about to do. High technology or a lengthy process is not required, a piece of paper with hand drawn diagrams and hand written notes will really help. The student will keep your notes for reference and sometimes, even copy them to a more permanent record for future use. Use a parked aircraft as a teaching aid.
  • Repetitive practise of each exercise is a must. Return to previously completed exercises for short periods.
  • If possible, have the student view a spray-damaged propeller.
  • While in displacement taxi in restricted areas, it is often handy to raise the water rudders to let the aircraft "pivot" into wind rather than follow an arc.
  • Work with the wind, not against it. Skilful float pilots use the wind to their advantage.
  • Have the student try taxiing with the water rudders up. This can lead to a sailing exercise even in very light winds. Present challenging docking problems but ones that can be successfully completed.
  • To avoid a possible accident have the student practise exiting the aircraft while it is secured to the dock.
  • Do not overlook taxiing downwind. With aircraft that are 'under floated' or nose heavy, demonstrate how excess speed can submerge the floats.
  • While practising displacement taxiing, have the students make approaches to the dock but avoid actual docking until the displacement taxi is mastered. Have them use as slow a speed as possible that just maintains steerage.

Instruction and Student Practice

Demonstrate and have the student practise displacement taxiing, including

  • use of water rudders
  • lookout
  • turns into and out of wind
  • engine handling
  • use of ailerons
  • weather cocking

Plowing Taxiing

Essential Background Knowledge

Explain the term plowing taxi and point out that it is normally used only for engine run-up or turning downwind if the wind is strong. Ask the student to sketch the float in the water and give the power required.

Explain how the plowing attitude causes the centre of buoyancy and the resistance to lateral motion to move aft, and why this is advantageous.

Review the effect of torque and slipstream so the student can appreciate why plowing turns are usually made to the left and not to the right.

Explain that, when turning from into wind to downwind, a turn can be started in the opposite direction to gain momentum.

Advice to Instructors

  • When applying power for take-off, step taxi and plowing turns the power should be applied briskly and without hesitating at the point where spray damage to the propeller may occur. Students will often hesitate at about 1500 RPM.
  • In windy conditions, when using a plowing turn to turn out of wind, the windward wing will rise and the aircraft may only turn 90° to the wind. Surprisingly, the aircraft may not turn back into wind because the windward wing is now high enough that it is offsetting the fin and rudder! Power must be reduced to idle to regain control and avoid being blown over.
  • Torque and slipstream make an aircraft turn left easier than right. Trying to follow a sharp bend to the right in a river while using full power to get up on the step, could lead to disaster. Some aircraft will barely turn to the right.
  • Visibility is reduced when the nose is high so a good lookout should be made prior to commencing.
  • If plowing taxi is prolonged the engine can overheat to the point of causing damage.

Instruction and Student Practice

Demonstrate and have the student practise plowing taxiing for run-up and for turning downwind.

Step Taxiing

Essential Background Knowledge

Explain the meaning of and uses for step taxiing. Ask the student to sketch the float position in the water and to explain the power required.

Explain the importance of lookout and space to do the exercise.

Explain that the pre-take-off check should be performed before commencing the high-speed taxi.

Explain the necessity to retract water rudders to prevent damage.

Explain the use of power and elevator to put the aircraft on the step.

Effect of power on direction, especially during the plowing phase and as the nose is lowered.

Explain that it is sometimes necessary to point aircraft out of wind prior to raising water rudders to maintain desired direction.

Explain the use of elevator to control attitude and power setting to maintain step speed.

Explain the importance of lookout for floating objects, boats that cannot hear the aircraft and may not be looking.

Explain that fairly high power and slow speed make it necessary to monitor engine temperatures.

Explain the use of ailerons and rudder to control effect of crosswind.

Explain the use of elevator and rudder to control the aircraft when the power is reduced.

Explain the aft movement of the centre of buoyancy and resistance to lateral motion in the plowing attitude.

Explain how to maintain speed below take-off speed.

Advice to Instructors

  • Be prepared for over controlling of the elevator.
  • Have the student make small adjustments of the elevator to find the attitude giving least drag.
  • Monitor the student's lookout carefully.
  • DEMONSTRATE the exercise before having the student do it.
  • Check the student's judgment of distance and speed. Watch for a "tunnel vision" approach to the exercise.

Instruction and Student Practice

Demonstrate and have the student practise step taxiing, including

  • use of power and elevator to put aircraft on the step
  • controlling attitude and power to maintain speed
  • lookout
  • control of aircraft when power is reduced

Sailing

Essential Background Knowledge

Define sailing and explain when it is used.

Explain the effect of wind and current.

Explain how the controls behave and respond when sailing.

Explain the effect of opening the aircraft doors.

Explain the effect of wing flaps on sailing.

Explain when and how the engine is used when sailing.

Advice to Instructors

  • Sailing is the procedure used for moving the aircraft into a location where normal manoeuvres are not possible because of room, wind or other conditions. Sailing is done with the help of wind, current, engine or even paddle power. In a light wind with the engine stopped, the floatplane moves backward in the direction of the wind. In a stronger wind with the engine idling, the aircraft moves directly backwards or at an angle towards the side the nose is pointed.
  • Demonstrate how the nose of the aircraft can be moved by COARSE application of rudder and by using full application of ailerons.
  • The downward deflection of the aileron is greater than the upward hence more drag on the downward aileron which will cause it's wing to move back.
  • When sailing use the air rudder and aileron drag to steer the aircraft.
  • Opening doors increases surface area exposed to wind and therefore a faster speed is obtained. The same results can be obtained by lowering the wing flaps.
  • Explain that too fast a backward speed can cause water to ride up on the rear of the floats and tend to "pull" the back of the float under or fill up the pump out ports with water.
  • Water rudders work in reverse to the air rudder and should be pulled up during this exercise.
  • Show that with the engine idling, its forward thrust can further be reduced by the application of carburettor heat or by running on one magneto. Point out that this mode should only be of short duration as spark plug fouling will occur.

Instruction and Student Practice

Demonstrate and have the student practise sailing, including

  • engine handling
  • use of flaps and doors
  • use of rudder and ailerons
  • controlling speed and direction

Docking

Essential Background Knowledge

Explain the location and use of ropes for docking.

Explain how to tie at least a double half hitch.

Explain how to approach the dock for parallel docking.

Explain the possibility of bow damage if the aircraft is nosed into the dock and the importance of using a very slow speed and shutting down early, if necessary, to nose in.

Explain the importance of allowing for the delay in engine stopping after idle cut-off is pulled.

Explain the danger of propeller strikes — passengers should not exit until the aircraft is tied to the dock. Risk of passengers waiting on the dock trying to help. Human nature to want to help should be discouraged.

Explain the problem of hazardous footing on some docks due to slime, bird droppings, ice, or debris.

Use caution and brief passengers.

Explain the tie down procedure for overnight. Four rope minimum. More if wind expected.

Explain the use of wing ropes (not available on many aircraft).

Explain "back eddies" that can happen near a dock, causing the aircraft to be pushed into the dock instead of slowing down.

Review the importance of being ready to exit the aircraft quickly, i.e. headset off, harness released, door open for docking and to not secure the belt until clear of the dock when departing.

Advice to Instructors

  • Have the students actually paddle the aircraft, making a 180-degree turn (in calm conditions) and paddling it to the dock or beach. Warn them to kneel and brace themselves to avoid falling in the water and to check pockets for items that may do the same.
  • Allow plenty of practice docking. This exercise can be done even on days not suitable for flying. Use different docks if possible. When a lesson is finished dock three times instead of just once.
  • Have the students turn the master and magnetos off on each docking and insist on a double check that they are off before leaving.
  • Have the students cut the engine too early so steerage is lost before reaching the dock. Have them get out and attempt to paddle in. The instructor must ensure there is no danger to other aircraft during the exercise.
  • In crowded areas, ensure that the student plans an exit route in case the docking doesn't work.
  • Impress on the student just how fragile an aircraft is, and the cost of repairs.
  • Docking in rough water conditions is not normally a problem but if the aircraft is not tied tightly to the dock, the floats can be damaged and ropes broken. There should be no slack in the ropes securing the aircraft to the dock. During a storm, all the ropes should be checked and tightened again, if necessary.
  • If possible, cut the engine so that the propeller is not turning as the dock is approached, especially if people unfamiliar with floatplanes are on the dock.
  • Try to present various docking situations to the student and consider having the student do 2 or 3 dockings when returning from each lesson.
  • Allow the student to do solo docking early in the training. This is a good confidence-builder.
  • Caution the student that passengers waiting on a dock sometimes try to help stop a seaplane by grabbing the wingtip. Although well intended, this only causes the aircraft to pivot.

Instruction and Student Practice

Demonstrate and have the student practise docking, including

  • assessing the docking situation
  • planning arrival
  • engine handling
  • moving aircraft by hand
  • paddling the aircraft
  • tie down procedures

Beaching

Essential Background Knowledge

Explain how to select a suitable area.

Explain how to assess surface condition, depth of water, rocks.

Explain how to determine what the wind, current and/or tide are doing.

Explain how to determine whether it is necessary to sail or paddle the aircraft to the beach.

Explain how to secure the aircraft after beaching and to consider turning the aircraft around in preparation for departure.

Review the shape of the float profile, i.e. deeper from step forward and shallow at the heel.

Advice to Instructors

  • When docking an aircraft on a natural beach, ascertain the nature of the shore BEFORE contact is made. If it is rocky there is danger of damaging the floats, especially if the wave action causes the aircraft to bob up and down. Sandy beaches are the best but even these will wear off paint and protective coatings if there is wave action. A sheltered area is best.
  • With an onshore wind the best approach is to sail the aircraft backwards with the water rudders up (to prevent damage to them when contact with the bottom is made). This enables the pilot to walk of the rear of the floats without having to wade in the water. Also the aircraft is already positioned for departure.
  • If the wind is off shore, approach slowly, checking for obstructions. The use of the paddle is sometimes indicated depending on the direction and strength of the wind.
  • When the wind is parallel to the shore, taxi close until opposite desired area then use the engine to turn the nose into the shore and beach as soon as possible.

Instruction and Student Practice

Demonstrate and have the student practise beaching, including

  • assessing the beaching situation
  • approaching and departing the beach
  • tie down procedures

Mooring

Essential Background Knowledge

Have the student explain how to determine what the wind, tide and current are doing.

Explain how to secure the aircraft to a buoy:

  • importance of a passenger briefing on what you are about to do and what the passenger is to do
  • what type of tie-down is available on the buoy
  • ropes available in the aircraft
  • use of a bridle

Explain how to depart a buoy:

  • importance of where buoy is in relation to aircraft
  • deciding which direction is desirable for departure

Advice to Instructors

  • Success in this only comes with practice. Always approach the buoy into wind and current at minimal speed. Shut down the engine and exit the aircraft WITH ROPE IN HAND.
  • Once the aircraft is secured to the buoy, a bridle should be incorporated. A bridle is simply a rope from the front of each float in a "Y" configuration to the buoy. The longer the rope that forms the bottom of the "Y", the more effective it will be. Remember: a moored floatplane has a great deal of surface exposed to the breeze. This, and high waves and will exert considerable drag force on the mooring line. Under these conditions, an anchorage which has proven satisfactory for large pleasure craft may be found to be quite unsatisfactory for even a small floatplane.
  • Brief the passenger on what you are about to do and, if they are knowledgeable, what you want the passenger to do. Warn about the danger of the propeller. Sometimes it is better to come alongside a buoy as if it were a dock and secure one line first before arranging a bridle.
  • When departing a buoy in shallow water the buoy anchor could damage the float bottoms as the aircraft moves away, so always use caution in shallow water, position the buoy for departure so that it is off to one side. If necessary, bring out the paddle.

Instruction and Student Practice

Demonstrate and have the student practise mooring, including

  • assessing the mooring situation
  • approaching a buoy
  • departing a buoy
  • using a bridle

Abnormal Water Handling Situations

Essential Background Knowledge

Explain how to recognize, prevent, and recover from porpoising.

Explain how to recognize an improper float attitude.

Explain how to recognize, prevent, and recover from submerging float.

Explain how to repair minor float component damage.

Explain that damaged struts or fuselage skin areas may mean more serious structural problems exist so "field" repairs should only be done under extreme emergency situations.

Explain that if a flight plan or flight itinerary is always filed, pressure to make emergency field repairs will be greatly reduced if it is known that help will soon be on the way.

Explain how to egress under water.

Explain that doors should not be expected to open until the cockpit has filled with water and the pressure on the doors has equalized.

Advice to Instructors

  • Familiarity with the aircraft is very important for egress. Practise opening doors and windows with your eyes closed. It is extremely easy to become disorientated under water, especially if the water is muddy. The aircraft can be inverted on the bottom of a lake but since you can only see or feel the parts of the aircraft near you, you relate only to them and think you are upright. If that is the case, you will probably leave the aircraft and try to swim down into the mud!
  • In the event of an upset, keep the left hand on the doorframe or handle and use the right hand to undo the seat belt. Open the door or window with the left hand and without letting go, follow that hand out of the aircraft.
  • A thorough passenger briefing should be given on all flights.

Instruction and Student Practice

Demonstrate how to recognize, prevent, and recover from

  • porpoising
  • submerging float

Demonstrate how to carry out minor float repairs.

Completion Standards

Taxiing (displacement, plowing, step)

The student shall be able to:

  • plan and follow the most favourable taxi route, considering existing winds, water currents, water conditions, and hazards
  • control taxi speed
  • position the controls for the existing wind conditions
  • use water rudders effectively
  • avoid excessive water spray on propellers
  • taxi straight in displacement, plowing, and step positions
  • perform 180 degree and 360 degree turns in displacement and plowing positions
  • take proper action to prevent and correct porpoising or skipping

Sailing

The student shall be able to:

  • recognize the conditions and situations in which sailing would be used
  • plan and follow the most favourable route toward a point, considering the effect of wind, water currents, water conditions, and hazards
  • use flight controls, flaps, doors, water rudders, and power to change the desired course
  • change direction from downwind to crosswind
  • control seaplane speed as required for the conditions

Docking

The student shall be able to:

  • assess the docking situation, considering wind, water currents, obstructions, other aircraft, boats, and people on the dock
  • depart the dock
  • approach the dock in the proper direction and at a suitable speed
  • plan an exit route
  • dock the seaplane and ensure it is secure

Beaching

The student shall be able to:

  • select a suitable area for beaching, considering water depth, currents, tides, wind, and weather changes
  • approach the beach in the proper direction and at a suitable speed, considering the beach condition
  • beach the seaplane and ensure it is secure

Mooring

The student shall be able to:

  • depart a buoy
  • assess a mooring situation, including wind, water currents, obstructions, other aircraft, and boats
  • approach a buoy in the proper direction and at a suitable speed
  • moor the seaplane and secure it using a bridle
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