Commercial airliners have evolved over the years to offer passengers a more enjoyable and comfortable experience. In addition to upgraded seats and free in-flight meals, many of them feature Passenger Service Units (PSUs). What are PSUs exactly, and why do so many commercial airliners have them?
The Basics of PSUs
PSUs are control mechanisms that allow passengers to control various aspects of their flight experience, such as their comfort and lighting. There’s typically a single PSU above each seat. Passengers can use their respective PSU to adjust their comfort, lighting, etc. according to their own preference.
Common Features of PSUs
While there are many different types of PSUs, they typically share some common features. As previously mentioned, most PSUs offer lighting. They feature one or more small, adjustable light-emitting diode (LED) lights that passengers can use for reading.
Air vents are a common feature of PSUs. Most commercial airliners maintain a relatively cool cabin temperature of 71 to 75 degrees Fahrenheit. While some passengers prefer this cool air, others may find it to be too cool. Fortunately, passengers can control the air vents over their seats. They can close or open their air vents, or they can redirect their air vents.
Many PSUs have a flight attendant call button. Pressing this button will illuminate a colored light above the seat. As flight attendants walk up and down the aisles, they will look for these lights. Upon seeing this illuminated light, a flight attendant will check on the passenger to see what he or she needs.
Informational displays are often a part of PSUs. These displays provide passengers with essential information, such as the “Fasten Seatbelt” sign. The “Fasten Seatbelt” sign will illuminate during takeoffs and landings, and it will typically turn off once the airliner has reached cruising altitude.
Some PSUs contain drop-down masks for oxygen. If the airliner experiences a loss of cabin pressure, the oxygen masks will be activated, They will drop down automatically from an overhead compartment while providing passengers with a source of breathable air.
The Importance of PSUs
Most passengers today expect commercial airliners to offer PSUs. These control mechanisms contribute to a more comfortable and enjoyable flight experience Passengers can use them to control the lighting and air vents, call for a flight attendant and much more. Some components of PSUs are even essential for passenger safety, such as informational displays and drop-down oxygen masks.
