october2021 - 12

INDUSTRY EXPERT
COLUMN
Proper Methods for PCA Maintenance
A well maintained pre-conditioned air unit supplies adequate air volume and
temperature while aircraft are on the ground.
By Tim Fox
T
PCA hoses should be
visually inspected for
internal and external
tears, bad connection
cuffs and exposed
reinforcement rods.
o maintain comfortable temperatures in a
parked aircraft, a pre-conditioned air (PCA)
unit is connected to the aircraft while at a
boarding gate or maintenance location. The
passenger boarding experience is enhanced with good
cabin air quality, and modern aircraft contain sensitive
electrical components that require a temperate
environment.
Maintenance functions may require " normal " room
temperatures for successful results. On-board systems
require protection against freezing or excessive heat.
There are electrically powered fixed mounted PCAs
and engine-generator powered mobile units. This
column will cover the topics of refrigeration, airflow
and electrical aspects of PCAs.
Preventive maintenance is an essential part of
ownership and/or maintenance of pre-conditioned air
units. Maintenance tasks and intervals are specified
by the equipment manufacturers and published in
their maintenance manuals. Some airlines' and airport's
maintenance departments and maintenance
contractors write their own preventive maintenance
tasks and intervals. However, the manufacturer's suggestions
should be considered the minimum standard.
It's OK to perform additional steps but never fewer.
Let's take a look at some common PCA maintenance
tasks and the purposes of the procedures.
Lock Out Tag Out (LOTO)
The Occupational Safety and Health Administration
(OSHA) standards for control of hazardous energy
sources should be followed as part of preventive maintenance
activity. The first maintenance task should
advise to lock and tag the (switched off) disconnect
source. The main power will need to be " on " for operational
testing purposes later. However, all panels and
doors should be in place for that activity. It's a good idea
to quickly run equipment prior to preventive maintenance
procedures to verify the machine works correctly.
Filters
The airport ramp can be a dirty environment. Cleaning
or changing filters is an elementary task, but it
remains an important one. In order to heat or cool air
efficiently, the mass air flow needs to be as specified
by the equipment's design engineers. Dirty filters can
affect the amount of air getting to the cooling and
heating components, and ultimately, the aircraft cabin.
Intervals for cleaning or changing filters will be
according to manufacturer recommendations. Filter
types, sizes and efficiencies vary among brands.
PCA filters are generally washable or replaceable.
Washable filters will get cleaned at quarterly intervals,
unless local environmental conditions dictate otherwise.
A good way to clean washable filters is to fill
12 GROUND SUPPORT WORLDWIDE OCTOBER 2021
Photo courtesy of ITW GSE
october2021

Table of Contents for the Digital Edition of october2021
