Part 4 — Take-Off

Objective

To facilitate the student learning:

  • normal take-off
  • glassy water take-off
  • crosswind take-off
  • engine failure after take-off

Motivation

Seaplanes do have one clear advantage over landplanes when taking off. They almost always take off into wind. But no two bodies of water are alike and the effect of changes in wind and water conditions mean a seaplane pilot must develop a high level of situational awareness to make good decisions about taking off. Then they need the skill to carry out what they have planned.

Normal Take-off

Essential Background Knowledge

Discuss the float design, theory and terminology of

  • on the step
  • minimum drag attitude or best planing attitude
  • stages of take-off
  • abnormal flight situations caused by improper float attitudes
  • directional control dynamics — cause and effect
  • review pitch/yaw relationships — anticipate

Explain the hydrodynamics of a float aircraft.

Review procedures to establish rejected take-off points.

Explain the difficulty of estimating the distance ahead, depending on the surrounding terrain.

Explain that one should anticipate the reduction of float drag at the point of lift off and expect a possible pitch up tendency depending on aircraft type and technique used.

Ask the student to review the use of Vx and Vy; introduce speeds used for improved cooling as required.

Explain the procedures for power management.

Explain the normal practice of following the water until a safe altitude has been reached — to take advantage of good air for lift — to avoid unnecessary turns until 500' or more — to respect noise abatement procedures where appropriate — to always have an "out" in the event that engine problems develop.

Explain that there can be more debris on the water when the wind blows in a direction opposite to the prevailing wind, especially in areas where there is logging activity.

Explain that in mountainous or hilly terrain, the pilot's perception of the correct climb attitude may be altered.

Review how to read the water for wind direction, intensity and gustiness.

Review how the air will flow and where the best lift can be found, where downdrafts are likely. Explain that the dark areas or "cat's paws" can be a sign of severe descending air.

Advice to Instructors

  • An introduction to, and closely supervised practise of attitude/drag relationships can be helpful. One method is to reduce power once on the step and first demonstrate, then allow the students to experiment with the range of attitudes. This will develop a feel for the aircraft and this will allow them to relate the feel and the visual clues to proper and improper float attitudes.
  • The students' experience with proper float attitudes leads directly to many other exercises and may help avoid having the student inadvertently digging a float.
  • On an aircraft with marginal directional control — and even for those with positive control — a review of the pitch/yaw relationship and the techniques used to enhance directional control is time well spent. (Slow pitch over, restricted use of flap etc). This will become important especially on take-off with a crosswind component or in confined areas.
  • The point to transition from back pressure to the step phase can be recognized in a number of ways. When the nose has reached its maximum nose up attitude is likely the universal method. The float spray position can be used early in the training and can be helpful although this technique will not work in all aircraft types and it hampers the ability to ensure that a safe obstruction free path is maintained.
  • When transitioning onto the step a variety of methods are employed depending on type, the environment and many other variables. "Rocking" the seaplane should be done with care.
  • The ability to read the water, anticipate and handle the effects of the wind is an integral part of any complete float training program. The first few hours may be best spent under conditions of light steady wind but be sure to provide exposure to as many different conditions as practicable. In order to accomplish this, the training will have to take place at different times of the day.
  • Water take-offs involve many variables, many not found on wheels. One should plan to use maximum take-off space. If it involves back tracking, do so over your proposed take-off path — this will help confirm that your take-off path is obstruction free.
  • Lift-off may be as simple as maintaining the minimum drag angle until enough lift is produced and/or applying increased back pressure at the appropriate time.
  • The far shoreline should be used as an attitude reference until climb speed is attained.
  • A common rule-of-thumb is to double the distance you think is sufficient for take-off, especially when taking off toward a shore.

Air Instruction and Student Practice

Demonstrate and have the student practise normal take-offs, including

  • assessing the take-off situation
  • before take-off check
  • apply take-off power
  • transition to the step
  • attitude control
  • lift-off
  • climb
  • after take-off check

Glassy Water Take-off

Essential Background Knowledge

Have the student review normal take-off items.

Discuss depth perception problems on take-off and after lift off.

Describe the difference in float drag compared to a normal water surface — the suction and stickiness associated.

Emphasize that the take-off distance required can be greatly extended and will not be reflected on most take-off performance charts. Therefore, select a take-off path that provides extra distance.

Discuss climb out path considerations — to keep a suitable reference nearby and to avoid a climb out over a large open stretch of water just in case you have an engine problem.

Emphasize how to establish, maintain and confirm a positive rate of climb after lift off

Explain that, when reducing power after take-off, it is important to wait until well clear of the surface.

Advice to Instructors

  • Every effort should be made to do glassy water training in real glassy water conditions, otherwise the exercise will have to be simulated. Real glassy water conditions are most often found in the early morning or late evening.

Air Instruction and Student Practice

Demonstrate and have the student practise glassy water take-offs, including assessing the glassy water situation.

Crosswind Take-off

Essential Background Knowledge

Have the student review normal take-off items.

Have the student review determination of crosswind limitations.

Review reading the water and methods to determine wind intensity, direction and gustiness.

Explain how to minimize the effect of crosswind and how to select the best area for take off and climb out.

Point out similarities to a land plane and the differences. The control limitation on floats is easily reached, especially with a left hand cross wind.

Recognize that the left cross wind component added to the aircraft's natural tendency to yaw left on take off is a substantially greater problem than on a wheel aircraft. This may lead to directional control problems that may exceed the pilot and the aircraft's ability.

Review the aerodynamics and pitch/yaw relationships and methods of enhancing direction control.

Explain how to "roll" a float on take-off, including the timing and technique to be used and compensating for the yaw tendency resulting from the imbalance in float drag.

Explain that the downwind float should be lifted first.

Advice to Instructors

  • Plan to retract water rudders on a heading that will result in the desired track by the time the throttle is advanced.
  • This exercise can be worked into gradually by altering subsequent take off paths to increase the cross wind angle. Start with a small crosswind.
  • Cross winds should be practised with both left and right hand components.
  • As with most exercises, if possible, start with a steady light wind.

Air Instruction and Student Practice

Demonstrate and have the student practise crosswind take-offs including assessing the crosswind take-off situation.

Engine Failure After Take-off

Essential Background Knowledge

Review the procedure for an engine failure after take-off.

Explain the importance of choosing a take-off lane that is clear of any obstacles for some distance beyond the intended lift-off point.

Explain that, unless the take-off area is very restricted, more options for landing are normally available straight ahead for the seaplane.

Explain the importance of flying the seaplane first rather than doing checks.

Explain that some seaplanes, such as those with radial engines, require an alert reaction to put the nose down immediately to preserve sufficient speed for a flare.

Advice to Instructors

  • Assume that the engine will fail at the worst possible moment and mentally prepare for this occurrence.

Air Instruction and Student Practice

Demonstrate and have the student practise engine failures after take-off.

Completion Standards

The applicant for the rating must be able to safely take off using the correct procedures for the actual conditions of water surface, wind, and available take-off distance.

The student shall be able to:

  • complete the before take-off check
  • select the recommended wing flap setting
  • clear the area before take-off
  • align the aircraft with the desired take-off path
  • raise the water rudders
  • advance the throttle smoothly to maximum allowable power
  • avoid excessive water spray into the propeller
  • establish and maintain the most efficient planing attitude and correct for any porpoising or skipping
  • maintain directional control
  • lift off correctly and accelerate to the appropriate climb speed
  • retract the wing flaps as recommended or at a safe altitude
  • maintain take-off power to a safe manoeuvring altitude
  • maintain a straight track over the extended take-off path or remain over the water until at a safe altitude
  • complete after take-off checklist
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