Landing Gear for Water and Snow
Besides landing gear for land, there are landing gear systems for water (Weight-Shift Control Sea) and snow (ski-equipped). If ski-equipped, skis are added to the bottom of the wheels or replace the wheels. If sea-equipped, a complete system provides aircraft flotation and steering using rudders similar to a boat. The water rudders are foot controlled, similar to WSCL steering on the ground. Two types of sea equipped systems are the flying boat and pontoon.
The flying boat is a solid or inflatable boat that the WSC aircraft fits into, and its fuselage is secured to as well. [Figure 3-39] This is generally used for rougher seas in the ocean and, with the extra drag of the boat itself, this typically uses a larger wing and is therefore a slower flying WSC aircraft. The boat design is known to be more stable in rough seas and assists in keeping less water from splashing up so pilot and passenger stay dryer.
The pontoon system is used for calmer water, has less drag while flying, and therefore can accommodate faster, smaller wings. [Figure 3-40] Both the flying boat and the pontoon system need more horsepower than land operations for two reasons: first, to provide enough thrust to accelerate to takeoff speed with the extra drag of the boat or pontoons on the water, and second, to provide enough extra thrust to overcome the additional drag of the boat or pontoons in the air for flight.
WSC aircraft are typically equipped with a 12-volt direct current (DC) electrical system. A basic WSC aircraft electrical system consists of a magneto/generator, voltage regulator, battery, master/battery switch, and associated electrical wiring. Electrical energy stored in a battery provides a source of electrical power for starting the engine and other electrical loads for the WSC aircraft.
The electrical system is typically turned on or off with a master switch. Turning the master switch to the on position provides electrical energy from the battery to all the electrical equipment circuits with the exception of the ignition system. Equipment that commonly uses the electrical system energy includes:
- Position lights
- Anticollision lights
- Instrument lights
- Radio equipment
- Navigation equipment
- Electronic instrumentation
- Electric fuel pump
- Starting motor
- Electric heating systems (gloves, socks, pants, vests, jackets, etc.)
Fuses or circuit breakers are used in the electrical system to protect the circuits and equipment from electrical overload. Spare fuses of the proper amperage should be carried in the WSC aircraft to replace defective or blown fuses. Circuit breakers have the same function as a fuse but can be manually reset, rather than replaced, if an overload condition occurs in the electrical system. Placards at the fuse or circuit breaker panel identify the circuit by name and show the amperage limit.
An ammeter may be used to monitor the performance of the electrical system. The ammeter shows if the magneto/ generator is producing an adequate supply of electrical power. It also indicates whether or not the battery is receiving an electrical charge. A voltage meter also provides electrical information about battery voltage, an additional status of the electrical system.
An additional safety system available is a ballistic parachute system. In the case of a structural failure because of a mid-air collision or an engine out over hostile terrain such as a forest, the ballistic parachute provides an added safety system. The parachute is sized so that when used, the complete aircraft comes down under canopy. Details of ballistic parachute system use are covered in more detail in Chapter 13, Abnormal and Emergency Operations.
When the system is activated, a rocket shoots out, pulling the parachute system to full line stretch, and forcing the parachute out and away from the carriage and wing.
The preferred point of attachment for the parachute is on top of the wing at the hang point. This allows the WSC aircraft to descend level and land on the wheels, helping to absorb the shock. This requires routing from the chute to the top of the wing with “O” rings to be able to remove this routing to easily take the wing off the carriage. Alternate attach points where there is no routing to the top of the wing are the mast and engine attachment points; however, this has the WSC aircraft descending nose down when activated.
The ballistic parachute canister can be mounted in a number of locations on the WSC, typically on the carriage pointed sideways to avoid entanglement with the propeller. The actuation handle is mounted in the flight deck for pilot use when needed. [Figures 3-41 and 3-42]