Single Engine Sea Oral Exam Review (copy)

How do atmospheric conditions affect the performance of a seaplane?

A: The higher the temperature, the less dense the air, which results in a higher density altitude. This has a great influence on seaplane performance. The primary reason is the that at higher density altitudes the aircraft needs increased ground speed for takeoff. With increased ground speed there is a significant increase in water drag during takeoff.

How much weight do the floats add to the airplane?

258 lbs floats only— 305 lbs. total including rigging as per website (probably because of updates since 1991). Handbook specifies 300 lbs. on affidavit.

FAA regulations require that each float be capable of supporting what percentage of the allowable gross weight?

90%

How do the the floats change the performance of an airplane?

• Due to the increased surface area in front of the center of gravity (CG), a seaplane will exhibit more adverse yaw in flight than it’s landplane counterpart. The increased adverse yaw requires the pilot to stay more vigilant to keep the aircraft coordinated in flight. Some aircraft have auxiliary fin(s) added to the empennage to assist with longitudinal stability.

• Cruise speed will be much slower due to the increased drag from the floats.

• The floats add weight to the aircraft, which can reduce the useful load. For amphibians, the additional weight of the landing gear significantly reduces the useful load. The float design provides additional lift to counteract the added weight from the floats. In some planes, this additional lift may increase the gross takeoff weight, but is not likely to exceed the weight of the floats so the useful load would likely still be reduced.

• The additional lift created by the floats can lower the stall speed.

How do the floats affect the stability of the airplane?

The floats affect the stability of the airplane by potentially decreasing directional stability due to the length of the floats and their vertical surface area located ahead of the airplane's CG. This can lead to increased yaw or sideslip. To counteract this effect, an auxiliary fin is often added to the tail to help restore directional stability.

What’s the aircraft’s max gross weight?

2350 lbs.

Licenced empty weight?

1643.85 lbs.

Useful load?

706.15

Vso

50 - Vso is the stall speed of the aircraft in landing configuration, meaning the landing gear and flaps are down (sometimes referred to as dirty configuration).

Vs1

59 - VS1 is often referred to as the "clean" stall speed, which is when the aircraft's flaps and gear are up. 

Vx

64 - (61 with 10 degrees flaps to clear 50ft obstacle) (gaining the most altitude in the shortest horizontal distance)

Vy

71 - Speed for best rate of climb.(fastest way to gain altitude over a short period of time)

Vfe

100 - Maximum flap extended speed.

Va

122 - Design maneuvering speed. (the maximum speed an aircraft can fly at while still allowing full deflection of the flight controls without damaging the aircraft's structure)

Vno

140 - Maximum structural cruising speed. (As the Green Arc is the Normal Operating Range, the top of the green arc is the Velocity (V) of Normal (n) Operations (o) or Vno. This is the maximum structural cruising speed. Operation of the Aircraft at the Vno speed, and lower, is within the certified range for operations within gusts. The aircraft is certified to withstand substantial wind gusts without experiencing structural damage. Operations above Vno move into the Yellow Arc on the Airspeed Indicator. Do not exceed Vno, except in Smooth Air, and only with caution.)

Vne

174 - Never-exceed speed.

What’s the best glide speed for the airplane?

71 MPH @ 2200 lbs

What type of engine is installed and how much horsepower does it produce?

Avco-Lycoming O-360-A1A 180 HP @2700 RPM

Are there any RPM limitations on the propeller?

Takeoff - 5 minutes Full Throttle @2700 RPM / Maximum Continuous - Full Throttle @2550 RPM

What is the purpose of the spring where the water rudder steering cable connects to the air rudder?

It allows the rudder to continue to function if the water rudders become stuck. (ASK INSTRUCTOR)

Are there any hydraulic systems installed on the airplane?

NO - Removed by not having landing gear — Ask instructor

How much fuel does this aircraft hold and what minimum fuel grade will it use?

42 Gal — 91/96 red AVGAS — 1.5 gal each tank unusable (1.0 gal available each tank in level flight. 0.5 gal each tank unusable) — 39 gal total usable

What type of floats are installed?

Aqua model 2200

What effect does the size of a lake have on the water?

1. The size of a lake can affect the characteristics of water. In larger lakes, due to the expanse of water, winds can create larger waves compared to smaller lakes. The size of the lake influences how wind interacts with the water surface, impacting wave size and surface conditions for seaplanes.

2. The size of a lake can influence wind direction and create variations in wind direction from one area to another. Larger lakes can have significant variations in wind direction due to the shape of shorelines and hills surrounding them. This can lead to differences in wind direction on different sides of the lake. Additionally, the size of a lake can impact wave patterns, with larger lakes potentially experiencing more complex wave interactions, such as wave reinforcement and cancellation, affecting the smoothness of the water surface.

Why is it important to find protected areas on the water?

It is important to find protected areas on the water to ensure the safety of the seaplane during landing and taxiing. Protected areas can help avoid hazards such as boat traffic, wakes, swimmers, and debris that could pose risks to the seaplane's operation. Identifying these areas allows the pilot to plan a safe landing and taxi route, minimizing the chances of accidents or damage to the aircraft. Additionally, recognizing protected zones like no-wake areas or swimming beaches helps in complying with regulations and respecting designated spaces for other water activities.

How can we determine wind direction on the water and in the air?

1. In the air, pilots at towered airports receive wind information from the control tower. Seaplane pilots, on the other hand, must assess wind direction by observing the movement of objects on the water's surface, such as ripples or waves. Additionally, they can look for indications like smoke or flags on nearby boats or structures.

2. On the water, wind direction can be determined by observing the water's surface. In lakes and sheltered waters, wind direction can be deduced by looking at the water's surface - a strip of calm water along the upwind shore of a lake indicates wind direction, while waves are perpendicular to the wind direction.

3. In the air, noticing drift and wind correction angle can be a clue

What does glassy water look like?

Calm water surface with no distinguishable features. Like a mirror or also a clear window

What does rough water look like?

Rough water appears chaotic with a mix of heights, periods, and wavelengths. Due to wind, waves have steep, pointed crests and rounded troughs. At 12 knots, waves break, creating foam. The roughness of water depends on factors like wind speed, duration, and distance it acts upon.

When we take-off and land between boats, how close can we get to them?

When taking off and landing between boats, it is important to maintain a safe distance. The exact distance can vary depending on the specific regulations of the state or city where the seaplane operation is taking place. Some states and cities may have stringent restrictions on the proximity of seaplanes to boats, while others may be more liberal. It is advisable to consult the local regulations and guidelines provided by authorities such as the Parks and Wildlife Department of the state or the State Aeronautics Department to ensure compliance and safety.

If you must taxi across a large boat wake, how is it done?

When taxiing across a large boat wake, it is best to approach the wake at a 45-degree angle to minimize the impact of the waves on the seaplane. This technique helps reduce the chance of the waves causing instability or damage to the aircraft. By crossing the wake at an angle, the seaplane can ride over the waves more smoothly, ensuring a safer taxiing experience.

What causes porpoising, and how do we correct for it?

Sometimes when on the step, during a step taxi or takeoff run, the seaplane may start to porpoise. A porpoise is caused when the nose is either too high or too low. This undesired condition usually relates to incorrect pilot input on the elevator. This commonly occurs when the seaplane completes its second rise during the takeoff run and the pilot either does not release pressure or pushes the nose over too much. The following are the pilot’s control actions for the various conditions.:

• If the nose is too low, correct by pulling back slightly.

• If the nose is too high, correct by releasing back pressure slightly.

Should the porpoising not stop quickly, cut power and return to a displacement taxi.

What causes skipping and how do we correct for it?

Skipping is caused by landing at excessive speed with the nose at too high a pitch angle, placing the seaplane at the upper trim limit of stability. This results in a cyclic oscillation when touching the water, causing the seaplane to skip across the surface. To correct skipping, pilots should reduce the power to idle and hold the elevator control back firmly so the seaplane settles onto the water with no further instability. It's important to maintain the correct pitch attitudes for landing maneuvers.

What does a seaplane base look like on a sectional chart?

A boat Anchor

How can you find out about the operating restrictions at various bases or bodies of water?

Pilots can find out about operating restrictions at various bases or bodies of water by noting the position of buoys marking preferred channels, hidden dangers, or off-limits areas such as no-wake zones or swimming beaches. Additionally, they can gather information from local authorities, nautical charts, or NOTAMs (Notices to Air Missions) which provide important information about restrictions or hazards in the area.

Explain right-of-way rules pertaining to seaplane taxiing on the water.

Seaplanes taxiing on water must give way to vessels and avoid impeding their navigation. When seaplanes and vessels are on crossing courses, the one to the right has the right-of-way. If they are approaching head-on, both should alter course to the right. Each aircraft or vessel that is being overtaken has the right-of-way, and the one overtaking shall alter course to keep well clear. These rules are outlined in 14 CFR Part 91, Section 91.115.

Who has the right-of-way when one seaplane is taking off and another is landing?

1. In general, the seaplane that is landing has the right-of-way over a seaplane that is taking off.

2. Landing. Aircraft, while on final approach to land or while landing, have the right-of-way over other aircraft in flight or operating on the surface, except that they shall not take advantage of this rule to force an aircraft off the runway surface which has already landed and is attempting to make way for an aircraft on final approach. When two or more aircraft are approaching an airport for the purpose of landing, the aircraft at the lower altitude has the right-of-way, but it shall not take advantage of this rule to cut in front of another which is on final approach to land or to overtake that aircraft.

3. 91.115 (e) Special circumstances. When aircraft, or an aircraft and a vessel, approach so as to involve risk of collision, each aircraft or vessel shall proceed with careful regard to existing circumstances, including the limitations of the respective craft.

When taxiing into a harbor, on which side of the red buoy should we go?

When taxiing into a harbor, you should keep the red buoy on your right side. This is based on the mnemonic "red, right, returning," which reminds mariners to keep the red buoys to their right when proceeding toward the shore, which is known as "returning" to their home port.

What is the color of a seaplane base rotating beacon?

Yellow and white

Define the three types of water taxi.

1. Idling position or displacement position — Idling taxi involves using the idling or displacement position for taxiing operations at speeds below 6-7 knots to minimize spray reaching the propeller. It is crucial in congested areas to prevent coasting accidents. This method minimizes the risk of damage from collisions and ensures safe maneuvering in confined spaces.

2. PLOWING POSITION — The plowing position taxi involves applying power, shifting the center of buoyancy back, and holding the elevator full up. This causes the seaplane's weight to shift behind the step, with the sterns sinking farther into the water. It creates high drag, requiring more power for a modest speed gain. The propeller may pick up spray, risking heat buildup in the engine due to higher power and low cooling airflow. It is not recommended for taxiing and is usually a transitional phase between idle taxi and planing.

3. PLANING OR STEP POSITION — In the planing or step position taxi, most of the seaplane's weight is supported by hydrodynamic lift rather than the buoyancy of the floats. This position allows the seaplane to accelerate to lift-off speed by reducing water drag as the rear portions of the floats are raised clear of the water. Aerodynamic lift may also support some of the seaplane's weight. This position is achieved by moving the float faster through the water, enabling a change in pitch attitude.

Why is plow taxi used so infrequently?

Plow taxi is used infrequently because it creates high drag, requires a large amount of power for a modest speed gain, and can lead to engine overheating due to higher RPMs and low cooling airflow. The plowing position shifts the center of buoyancy back, causing the floats to sink farther into the water, increasing drag and power demand. Additionally, the propeller may pick up spray, and the engine can overheat due to the combination of higher power and low cooling airflow. Therefore, plow taxi is not recommended and is usually just a transitional phase between idle taxi and planing.

Explain the control inputs for sailing.

When sailing a seaplane, the pilot can control the direction by using the air rudder to swing the tail a few degrees. This action allows the seaplane to sail backward in the direction the tail is pointed. It is important to lift the water rudders in this situation, as their action is counterproductive. Additionally, if the wind is strong and speed increases, the pilot should use full forward elevator to prevent the sterns of the floats from submerging and keep the seaplane's nose down. Adding power can also help prevent the floats from submerging. These control inputs are crucial to maintain stability and prevent potential accidents while sailing a seaplane.

Explain the beaching process.

Beaching a seaplane involves approaching the shoreline at an oblique angle to allow for turning out into deeper water. Success depends on the type and firmness of the shoreline, so it's important to inspect it beforehand. If unable to inspect, the shore should be approached at an angle that allows for turning back into deeper water. To protect them from damage, water rudders should be up before entering the shallow water near a beach.

Except when necessary for takeoffs and landing, what are the minimum safe altitudes when flying over congested areas, other than congested areas, and open water or sparsely populated areas?

§ 91.119 Minimum safe altitudes: General.Except when necessary for takeoff or landing, no person may operate an aircraft below the following altitudes:(a) Anywhere. An altitude allowing, if a power unit fails, an emergency landing without undue hazard to persons or property on the surface.(b) Over congested areas. Over any congested area of a city, town, or settlement, or over any open air assembly of persons, an altitude of 1,000 feet above the highest obstacle within a horizontal radius of 2,000 feet of the aircraft.(c) Over other than congested areas. An altitude of 500 feet above the surface, except over open water or sparsely populated areas. In those cases, the aircraft may not be operated closer than 500 feet to any person, vessel, vehicle, or structure.

Describe the emergency procedure for an engine failure.

In the event of an engine failure in a seaplane, the pilot should immediately lower the nose to maintain airspeed and establish the best glide attitude and airspeed (71mph in this case). The pilot should then identify a suitable landing area on the water, plan the approach, and prepare for a water landing. Once in the water, the pilot should secure the aircraft and evacuate if necessary, following proper safety procedures.

When picking up a buoy, on which side of the floats should it be?

Mooring

1. Mooring is the process of securing the seaplane to a buoy. This task is similar to docking but approaching a buoy instead of a dock. Approach a buoy on the outside of the floats. Do not ever straddle a buoy. Whenever possible, make the final positioning into the wind.

Explain how to ramp a seaplane.

1. To ensure a successful landing and taxi onto a ramp with a seaplane:

   • Approach: Approach the ramp downwind to leverage the seaplane’s weathervaning tendencies.

   • Power and Speed: Add power and maintain enough speed to create a cushioning bow wave when contacting the ramp.

   • Safety: Be cautious of slippery ramps, avoid concrete ramps with straight floats, and extend landing gear on amphibians.

   • Alignment: Line up straight with the ramp, use full flaps and forward elevator, and do not stop while ascending.

   • Taxiing: Taxi amphibians slowly, be mindful of ramp angle changes, and watch for spectators.

   For departure:

   • Weathervaning: Utilize wind direction to counteract weathervaning when pushing off the dock/ramp.

   • Direction: Push off in a direction that avoids problems caused by weathervaning.

   • Alternative: Consider turning the aircraft around on the ramp to taxi straight into the wind.