AIRCRAFT SYSTEMS LIGHTS SA227‐ SERIES/FCOM/VTM 6.33.1 AIRPLANE LIGHTING SYSTEMS The lighting system is divided generally into three groups; exterior lighting, interior cabin lighting, and cockpit lighting. The cockpit lighting is divided further into those lights powered from the essential buses and those powered from the nonessential bus. All exterior lighting is powered from the nonessential DC bus. The exterior lighting consists of a standard set of navigation lights, a rotating beacon, two ice detection lights, two landing lights, two recognition lights, and a taxi light. Strobe lights are optional and when installed, are powered from the left essential bus.
LIGHTING SYSTEM – INTERIOR All interior cabin lighting is powered from the nonessential DC bus with the exception of the entrance lights, which are powered from the battery side of the left battery relay. The edge lighted panel lights in the cockpit are powered by 5 VDC which is obtained from four 5 VDC power supplies connected to the essential buses. The pilot’s flight instrument lights and panels are powered from the left essential bus. The copilot’s flight instrument lights and panels are powered from the right essential bus. The remaining cockpit lights are powered from the nonessential bus. Spare bulbs are stored behind the pilot’s seat. The 327 bulbs are used in press‐to‐test lights, the 334 bulbs are used in glareshield lights, the 328 bulbs are used in post lights and the standby magnetic compass, and the 6839 bulbs are used in the landing gear position indicator, crossflow valve switch position light, oil cooler duct heat lights, and the fuel, hydraulic, and crossflow valve position lights. NOTE Bulbs must be verified for the correct type prior to replacement of burned out bulbs. ENGINE AND AUXILIARY INSTRUMENT LIGHTS
Figure 6.33‐1
Revision: Original Aug 1,2013
GO/FCOM/SA227‐SERIES/VTM
AIRCRAFT SYSTEMS LIGHTS SA227‐ SERIES/FCOM/VTM PILOT COPILOT INSTRUMENT LIGHTS
6.33.2
Figure 6.33‐2
CARGO COMPARTMENT LIGHTING Compartment lighting is available in the forward baggage compartment and the rear cargo compartment by activation of light switches in the respective compartments. If the airplane primary electrical system is on, lighting is available in these two compartments by selecting the compartment lights switches on. A time delay relay is incorporated in the light circuits to provide electrical power from the right battery for five minutes after primary electrical system is turned off. If more than five minutes time is needed, the auxiliary light system can be recycled for additional use of lights. Momentarily turning on either battery switch, or activating the system by use of the button in the left side of the nose baggage compartment, will reset the auxiliary light system
Revision: Original Aug 1,2013
GO/FCOM/SA227‐SERIES/VTM
AIRCRAFT SYSTEMS LIGHTS
SA227‐ SERIES/FCOM/VTM
6.33.3
LIGHTING SYSTEM – EXTERIOR NAVIGATION LIGHTS The navigation light circuitry consists of two right wingtip lights (green), two left wingtip lights (red), and one or two tailcone lights (white). These lights are powered from the nonessential bus through a switch located on the pilot’s switch panel. Any time the navigation lights are turned on, all green lights on the annunciator panel and the duct heat cycle lights are dimmed automatically. TAXI LIGHT The taxi light circuitry consists of a 250 watt lamp assembly mounted on the nose landing gear, a relay located in the nose baggage compartment, and a microswitch in the nose wheelwell. The taxi light operates on 28.5 VDC supplied by the nonessential bus through a 15 amp circuit breaker. Any time the taxi light switch located on the pilot’s switch panel is selected to the ON position, ground will be provided to the relay. Energizing the relay causes current to flow from the nonessential bus, across the relay contacts to the taxi light. The nose landing gear must not be in the up position for the relay to close and the light to illuminate. NOTE • It is good practice to ensure the taxi light switch is in the OFF position except when in actual use. Should a malfunction occur and the light be ON when the nose landing gear is retracted, the light is powerful enough to cause heat damage within the nose landing gear wheelwell. However, the microswitch in the nose wheelwell will turn the light out when the landing gear is fully retracted. • If the taxi light is used during takeoff in hazy or foggy weather, it may produce a disconcerting beam of light as the nose gear retracts after takeoff. LANDING AND RECOGNITION LIGHTS A landing/recognition light assembly is mounted in the leading edge of each wing outboard of the fuel cells. Each of these light assemblies contains one landing light and one recognition light. These four lights are controlled by a three position switch located on the pilot’s switch panel. The three switch positions are identified as LDG & RECOG, OFF, or RECOG. If the LDG & RECOG position of the switch is selected, both landing lights and both recognition lights are illuminated. The selection of RECOG switch position illuminates only the two recognition lights. The landing/recognition light assemblies receive 28.5 VDC power through the nonessential bus and are protected by four 15 amp circuit breakers.
Revision: Original Aug 1,2013
GO/FCOM/SA227‐SERIES/VTM
AIRCRAFT SYSTEMS LIGHTS SA227‐ SERIES/FCOM/VTM 6.33.4 WING ICE LIGHTS The wing ice detection light circuitry consists of a 50 watt sealed beam light assembly located in the outboard side of each engine nacelle at the wing leading edge and the light control switch located on the pilot’s switch panel. The wing ice lights receive power from the nonessential DC bus through a five amp circuit breaker. ROTATING BEACON The rotating beacon is a lightweight, oscillating anti‐collision light mounted on top of the vertical stabilizer. It has an aerodynamic shape to reduce drag and is shielded to prevent radio interference. The light is a dual lamp unit with the lamps oscillating 180 degrees out of phase. The beacon flashes at a rate of 60 to 100 flashes per minute. The forward, ROT BCN, position of the switch allows the light to operate and the center, OFF, position turns the beacon off. The aft, ROT BCN and LOGO, position will cause the beacon as well as four optionally installed logo lights to illuminate. The rotating beacon is energized from the nonessential bus through a five amp circuit breaker. It is controlled by a switch located on the pilot’s switch panel (logo lights are not installed/operational on TSM aircraft).
Revision: Original Aug 1,2013
GO/FCOM/SA227‐SERIES/VTM