PBS-1

General lighting function of the PBS-1

The PBS-1 provides white light for onboard spaces where reliable general illumination is needed. In helicopters, it may be used in the cockpit, cargo cabin, passenger area, radio compartment, rear technical compartment and entrance zones. The light helps crew members and technicians work safely in dark conditions, during night preparation, loading, unloading or service checks. It is not an external navigation light or signal beacon. The PBS-1 belongs to the internal lighting system of the aircraft.

PBS-1 and PBS-1B on Mi-8 family helicopters

The PBS-1 and PBS-1B are widely associated with Mi-8 family helicopters, including Mi-8, Mi-9, Mi-17, Mi-171 and Mi-172, depending on configuration. They are also mentioned for heavier and later helicopter types such as Mi-26 and Mi-38. On Mi-8-type helicopters, the lights may be installed in rows along the cargo / passenger cabin ceiling panels, above crew workplaces, in technical compartments and near entrance areas. Exact quantity and location depend on the helicopter modification and interior layout.

PBS-1 installation in cockpit and cargo areas

In the cockpit, the PBS-1 may be installed on ceiling panels above pilot, navigator or crew work areas. In the cargo or passenger cabin, the lights are mounted in ceiling panels to provide general illumination along the cabin. In radio and technical compartments, they are installed near equipment zones where maintenance personnel need access to avionics or electrical units. Near entrances and vestibules, the light supports safe boarding, disembarkation and movement inside the aircraft at night.

Construction of the PBS-1 aircraft light

The PBS-1 has an oval rounded housing with a mounting flange, built-in reflector and protective glass diffuser. The diffuser and reflector shape provide directed white light with even illumination over the required area. The housing is designed for installation into ceiling or wall panels of aircraft interiors. During maintenance, the diffuser, lamp holder, reflector, housing, contacts and mounting holes should be inspected. Damage to the diffuser, weak contacts or incorrect lamp type can reduce light output or cause unreliable operation.

Electrical operation of the PBS-1

The PBS-1 operates from the aircraft 27 V DC power system and uses a two-wire electrical connection. The unit is normally fitted with a small aircraft incandescent lamp, often from the SMZ series, such as SMZ 28-23 or similar approved lamp versions. The light consumes limited power and is intended for repeated use in aircraft cabin lighting circuits. Electrical checks should include lamp operation, voltage supply, contact condition, wiring integrity and current draw.

Operating reliability of the PBS-1 light

The PBS-1 is designed for aircraft operating conditions, including vibration, pressure changes and temperature variation. Its robust housing and simple electrical layout make it suitable for long-term use in cabin and service lighting systems. Even so, the light should not be judged only by external appearance. Before installation or return to service, the condition of the glass, lamp holder, contacts, body, mounting flange and wiring connection should be checked.

Supply and inspection of PBS-1 / PBS-1B

For procurement, the unit should be specified as PBS-1 or PBS-1B, with the required version, lamp type and documentation confirmed in advance. The product may be supplied new, from storage, repaired or serviceable depending on availability. If the unit is intended for a specific Mi-8, Mi-17, Mi-171, Mi-26 or aircraft interior, the installation side, mounting pattern, lighting circuit and aircraft parts catalog should be checked before shipment.