ASES - Definitions Flashcards
AMPHIBIAN
A seaplane with retractable wheel-type landing gear that can be extended to allow landings to be made on land.
ANCHOR
A heavy hook connected to the seaplane by a line or cable, intended to dig into the bottom and keep the seaplane from drifting.
AUXILIARY FIN
An additional vertical stabilizer installed on some float planes to offset the increased surface area of the floats in front of the center of gravity.
BEACHING
Pulling a seaplane up onto a suitable shore so that its weight is supported by relatively dry ground rather than water.
BEAUFORT WIND SCALE
A standardized scale ranging from 0-12 correlating the velocity of the wind with predictable surface features of the water.
BILGE
The lowest point inside a float, hull, or watertight compartment.
BILGE PUMP
A pump used to extract water that has leaked into the bilge of a float or flying boat.
BULKHEAD
A structural partition that divides a float or a flying boat hull into separate compartments and provides additional strength.
BUOYANCY
The tendency of a body to float or to rise when submerged in a fluid.
BUOYS
Floating objects moored to the bottom to mark a channel, waterway, or obstruction.
CAN BUOYS
Cylindrical buoys marking the left side of a channel for an inbound vessel. They have odd numbers which increase from seaward.
CAPSIZE
To overturn.
CAST OFF
To release or untie a vessel from its mooring point.
CENTER OF BUOYANCY
The average point of buoyancy in floating objects. Weight added above this point will cause the floating object to sit deeper in the water in a level attitude.
CHINE
The longitudinal seam joining the sides to the bottom of the float. The chines serve a structural purpose, transmitting loads from the bottoms to the sides of the floats. They also serve a hydrodynamic purpose, guiding water away from the float, reducing spray, and contributing to hydrodynamic lift.
CHOP
A roughened condition of the sea surface caused by local winds. It is characterized by its irregularity, short distance between crests, and whitecaps.
CREST
The top of a wave.
CURRENT
The horizontal movement of a body of water.
DAYBEACONS
Unlighted beacons.
DAYMARKS
Conspicuous markings or shapes that aid in making navigational aids readily visible and easy to identify against daylight viewing backgrounds.
DECK
The top of the float, which can serve as a step or walkway. Bilge pump openings, hand hole covers, and mooring cleats are typically located along the deck.
DISPLACEMENT POSITION
The attitude of the seaplane when its entire weight is supported by the buoyancy of the floats, as it is when at rest or during a slow taxi. Also called the idling position.
DOCK
To secure a seaplane to a permanent structure fixed to the shore. As a noun, the platform or structure to which the seaplane is secured.
DOWNSWELL
Motion in the same direction the swell is moving.
FETCH
An area where wind is generating waves on the water surface. Also the distance the waves have been driven by the wind blowing in a constant direction without obstruction.
FLOATPLANE
A seaplane equipped with separate floats to support the fuselage well above the water surface.
FLOATS
The components of a floatplane?s landing gear that provide the buoyancy to keep the airplane afloat.
GLASSY WATER
A calm water surface with no distinguishable surface features, with a glassy or mirror like appearance. Glassy water can deceive a pilot?s depth perception.
HEIGHT-TO-LENGTH RATIO
The ratio between the height of a swell to the length between two successive crests (swell length).
HYDRODYNAMIC FORCES
Forces relating to the motion of fluids and the effects of fluids acting on solid bodies in motion relative to them.
HYDRODYNAMIC LIFT
For seaplanes, the upward force generated by the motion of the hull or floats through the water. When the seaplane is at rest on the surface, there is no hydrodynamic lift, but as the seaplane moves faster, hydrodynamic lift begins to support more and more of the seaplane?s weight.
IDLING POSITION
The attitude of the seaplane when its entire weight is supported by the buoyancy of the floats, as it is when at rest or during a slow taxi. Also called the displacement position.
KEEL
A strong longitudinal member at the bottom of a float or hull that helps guide the seaplane through the water, and, in the case of floats, supports the weight of the seaplane on land.
RAMPING
Using a ramp that extends under the water surface as a means of getting the seaplane out of the water and onto the shore. The seaplane is typically driven under power onto the ramp, and slides partway up the ramp due to inertia and engine thrust.
SAILING
Using the wind as the main motive force while on the water.
SEA
Waves generated by the existing winds in the area. These wind waves are typically a chaotic mix of heights, periods, and wavelengths. Sometimes the term refers to the condition of the surface resulting from both wind waves and swells.
SEA STATE CONDITION NUMBER
A standard scale ranging from 0-9 that indicates the height of waves.
SEAPLANE
An airplane designed to operate from water. Seaplanes are further divided into flying boats and floatplanes.
SEAPLANE LANDING AREA
Any water area designated for the landing of seaplanes.
SEAWARD
The direction away from shore.
SECONDARY SWELLS
Those swell systems of less height than the primary swell.
SISTER KEELSONS
Structural members in the front portion of floats lying parallel to the keel and midway between the keel and chines, adding structural rigidity and adding to directional stability when on the water.
SKEG
A robust extension of the keel behind the step which helps prevent the seaplane from tipping back onto the rear portion of the float.
LEEWARD
Downwind, or the downwind side of an object.
MOOR
To secure or tie the seaplane to a dock, buoy, or other stationary object on the surface.
NUN BUOYS
Conical buoys marking the left side of a channel for an inbound vessel. They often have even numbers that increase as the vessel progresses from seaward.
PLANING POSITION
The attitude of the seaplane when the entire weight of the aircraft is supported by hydrodynamic and aerodynamic lift, as it is during high-speed taxi or just prior to takeoff. This position produces the least amount of water drag. Also called the step position, or ?on the step.?
PLOWING POSITION
A nose high, powered taxi characterized by high water drag and an aftward shift of the center of buoyancy. The weight of the seaplane is supported primarily by buoyancy, and partially by hydrodynamic lift.
PORPOISING
Arhythmic pitching motion caused by an incorrect planing attitude during takeoff.
PORT
The left side or the direction to the left of a vessel.
PRIMARY SWELL
The swell system having the greatest height from trough to crest.
SKIPPING
Successive sharp bounces along the water surface caused by excessive speed or an improper planing attitude when the seaplane is on the step.
SPONSONS
Short, winglike projections from the sides of the hull near the waterline of a flying boat. Their purpose is to stabilize the hull from rolling motion when the flying boat is on the water, and they may also provide some aerodynamic lift in flight. Tip floats also are sometimes known as sponsons.
SPRAY RAILS
Metal flanges attached to the inboard forward portions of the chines to reduce the amount of water spray thrown into the propeller.
STARBOARD
The right side or the direction to the right of a vessel.
STEP
An abrupt break in the longitudinal lines of the float or hull, which reduces water drag and allows the pilot to vary the pitch attitude when running along the water?s surface.
STEP POSITION
The attitude of the seaplane when the entire weight of the aircraft is supported by hydrodynamic and aerodynamic lift, as it is during high-speed taxi or just prior to takeoff. This position produces the least amount of water drag. Also called the planing position.
SWELL
Waves that continue after the generating wind has ceased or changed direction. Swells also are generated by ships and boats in the form of wakes, and sometimes by underwater disturbances such as volcanoes or earthquakes. The waves have a uniform and orderly appearance characterized by smooth, rounded, regularly spaced wave crests. SWELL
DIRECTION
The direction from which a swell is moving. Once set in motion, swells tend to maintain their original direction for as long as they continue in deep water, regardless of wind direction. Swells may be moving into or across the local wind.
SWELL FACE
The side of the swell toward the observer. The back is the side away from the observer. These terms apply regardless of the direction of swell movement.
SWELL LENGTH
The horizontal distance between successive crests.
SWELL PERIOD
The time interval between the passage of two successive crests at the same spot in the water, measured in seconds.
SWELL VELOCITY
The velocity with which the swell advances with relation to a fixed reference point, measured in knots. There is little movement of water in the horizontal direction. Each water particle transmits energy to its neighbor, resulting primarily in a vertical motion, similar to the motion observed when shaking out a carpet.
TIDES
The alternate rising and falling of the surface of the ocean and other bodies of water connected with the ocean. They are caused by the gravitational attraction of the sun and moon occurring unequally on different parts of the earth. Tides typically rise and fall twice a day.
TIP FLOATS
Small floats near the wingtips of flying boats or floatplanes with a single main float. The tip floats help stabilize the airplane on the water and prevent the wingtips from contacting the water.
TRANSOM
As it applies to seaplanes, the rear bulkhead of a float.
TROUGH
The low area between two wave crests.
UPSWELL
Motion opposite the direction the swell is moving. If the swell is moving from north to south, a seaplane going from south to north is moving upswell.
VESSEL
Anything capable of being used for transportation on water, including seaplanes.
WATER RUDDERS
Retractable control surfaces on the back of each float that can be extended downward into the water to provide more directional control when taxiing on the surface. They are attached by cables and springs to the air rudder and operated by the rudder pedals in the cockpit.
WEATHERVANING
The tendency of an aircraft to turn until it points into the wind. WINDWARD
WING FLOATS
Stabilizer floats found near the wingtips of flying boats and single main float floatplanes to prevent the wingtips from contacting the water. Also called tip floats.
Calm
Less than 1 - Sea like a mirror. ***Check your glassy water technique before water flying under these conditions.
Light Air
1 to 3 - Ripples with the appearance of scales are formed but without foam crests.
Light Breeze
4 to 7 - Small wavelets, still short but more pronounced; crests have a glassy appearance and do not break.
Gentle Breeze
8 to 12 - Large wavelets; crests begin to break. Foam of glassy appearance. (Perhaps scattered whitecaps.) ***Ideal water flying characteristics in protected water.
Moderate Breeze
13 to 18 - Small waves, becoming longer; fairly frequent whitecaps.
Fresh Breeze
19 to 24 - Moderate waves; taking a more pronounced long form; many whitecaps are formed. (Chance of some spray.) ***This is considered rough water for seaplanes and small amphibians, especially in open water.
Strong Breeze
25 to 31 - Large waves begin to form; white foam crests are more extensive everywhere. (Probably some spray.)
Moderate Gate
32 to 38 - Sea heaps up and white foam from breaking waves begins to be blown in streaks along the direction of the wind. ***This type of water condition is for emergency only in small aircraft in inland waters and for the expert pilot.
