A320
What is a Post Flight Report?

Let's break it down ↓

The Post Flight Report (PFR) Mystery

I understand that many of you may have questions about its purpose and how to utilize it effectively. Even experienced mechanics can find it challenging to comprehend the significance of this report. However, fear not, as my goal today is to demystify the PFR and provide clarity on its role. This report holds great importance as it offers crucial information such as warnings, maintenance status updates, and failure messages from the last flight leg. So, without further ado, let's delve into the details!

The PFR, also known as the Post Flight Report, is a document that becomes available after a flight when the aircraft is on the ground. There are two ways to access it: either through the onboard printer or via ACARS (Aircraft Communications Addressing and Reporting System) using manual or automatic transmission methods. This report is generated automatically after touchdown, specifically 2 minutes and 30 seconds after the aircraft speed decreases below 80 knots.

An example of a typical PFR from A320 CFDS Trainer

It's important to note that if the aircraft hasn't flown, the report will be printed on the last engine shutdown, provided that a flight number has been entered on the MCDU (Multipurpose Control and Display Unit) INIT page. In case the crew has written up a discrepancy in the logbook, it is recommended to manually print the report if it hasn't already been generated. The logbook serves as the entry point for troubleshooting, and obtaining the PFR is the next step in the process.

No FLT NBR = no PFR until >80 knots.

Printing of the Post Flight Report

To manually print the PFR, you should follow these steps: Press the MCDU MENU button on the MCDU, then select CFDS. On the CFDS page, locate and press the line select key located on the bottom right of the screen, labeled "Print". After a few seconds, you will receive a printed Post Flight Report similar to the example provided.

Remember, the PFR contains valuable information regarding warnings, maintenance status, and failure messages from the last flight, which will aid in the troubleshooting process and determining the necessary maintenance actions.

A320 CFDS Trainer

Integrating Data into the Comprehensive Post-Flight Report

The importance of the PFR stems from its role as the main source of information for initiating troubleshooting procedures and determining the required maintenance actions. It brings together data from two key sources: the Last Leg Report and the Last Leg ECAM Report.

The Last Leg Report is responsible for displaying fault messages, also known as Built-In Test Equipment (BITE) messages, which are received from the Line Replaceable Units (LRUs). These messages provide valuable insights into any malfunctions or abnormalities detected by the LRUs during the last flight leg.

On the other hand, the Last Leg ECAM Report focuses on presenting warning messages and maintenance status information from the ECAM system, with a specific emphasis on the Flight Warning Computer (FWC). These warnings and status updates can shed light on potential issues or areas that require attention.

Here we see the correlation between the MCDU Report and PFR.

By consolidating information from these two sources, the PFR offers a comprehensive overview of the aircraft's operational condition and any anomalies encountered during the previous flight. It serves as a critical tool for maintenance personnel to identify potential problems, prioritize maintenance actions, and effectively troubleshoot and resolve issues to ensure the aircraft's continued airworthiness and safety.

Let's take a closer look

At the very top of the report, you will find the "Print Header" row, which includes the following details:

Aircraft Identification: This is the unique Aircraft ID received by the Flight Data Interface Unit (FDIU). It corresponds to the tail number of the specific aircraft.
Date: The UTC date when the report was printed.
GMT: The UTC time when the report was printed.
Flight Number: The Flight number received by the Flight Augmentation Computer (FAC).
City Pair: This refers to the origin and destination airports for the corresponding flight leg, also received by the FAC.

Following the Print Header, you will encounter the "Report Header" section. Here, you will find the following information:

Aircraft Identification: Similar to the Print Header, this is the Aircraft ID received by the Flight Data Interface Unit (FDIU) and represents the tail number of the aircraft.
Date: The UTC date when the report was generated.
GMT: The UTC time indicating the start and end times of the report. It provides the time period covered by the information presented in the report.
Flight Number: The Flight number received by the Flight Augmentation Computer (FAC) specifically for this report.
City Pair: This denotes the origin and destination airports for the corresponding flight leg, also received by the FAC for the report.

These header sections provide essential contextual information about the aircraft, the date and time of the report, and the specific flight leg to which the report pertains. This information helps maintenance personnel identify and correlate the report data with the corresponding flight operation.

ECAM and BITES Messages explained

After the Headers we have the next item is WARNING MAINTENANCE AND STATUS MESSAGES.
The PFR includes warning messages that are displayed on the upper ECAM (Electronic Centralized Aircraft Monitor) display unit and maintenance status messages on the lower ECAM. These warning messages are categorized as Class 1 faults and are shown on the upper ECAM. Additionally, the PFR presents maintenance status messages, classified as Class 2 faults, which can be found on the lower ECAM's STS (Status) page. These messages are associated with ATA (Air Transport Association) references, which are four-digit codes.

Let's break down the contents of these messages:

GMT: The UTC time when the ECAM message was triggered.
Phase Number: A number ranging from 02 to 09, representing the phase of flight during which the message occurred. Further details on these phases will be explained shortly.
ATA: The four-digit ATA code corresponding to this ECAM message.
Fault Event: The ECAM message displayed to the flight crew on both the upper and lower ECAM displays. These messages are categorized as either Class 1 or Class 2.
Fault Event Occurrence: A parenthetical occurrence counter indicating how many times the fault has appeared. In this case, the fault occurred twice.

Next we have FAILURE MESSAGES.
This section of the PFR is dedicated to listing BITE (Built-In Test Equipment) messages, which provide information about faults detected by the Centralized Fault Display System (CFDS). These messages are identified by six-digit ATA codes.

Let's explore the components of the Failure Messages section:

GMT: The UTC time when the BITE message was received by the Centralized Fault Display Interface Unit (CFDIU).
Phase: A number ranging from 02 to 09, representing the phase of flight during which the message occurred.
ATA: The six-digit ATA code associated with the specific fault. This ATA code can be used as a reference for the removal and installation procedures, including cross-references to the Illustrated Parts Catalog (IPC). This simplifies the process of locating relevant information without the need for manual searching.
Fault Message: The BITE message itself, which includes the Functional Item Number (FIN). The FIN provides further details about the specific component or system affected by the fault.
Source: The Source field indicates the menu or system report from which the BITE message originated. It assists in identifying the specific location or system associated with the fault. In some cases, the Source field may match the name of the Line Replaceable Unit (LRU) involved. This field is Mandatory.
Identifiers: The Identifiers field denotes secondary sources that report an external failure related to the identified Source. This provides additional context and helps in understanding the root cause of the reported fault. This field is Optional.

Phases (PH) explained

Now, to help you understand the context of these messages, the PFR provides additional details such as flight phase and GMT (Greenwich Mean Time) for each message.

The flight phases are encoded as numeric values, such as:

01 Aircraft at gate
02 for Engine start + 3 minutes up to takeoff power
03 for Take-off
04 Lift-off (no weight on wheels)
05 for Climb
06 Cruise
07 for Descent
08 for Landing
09 Taxi in, and
10 Post Flight (5 Mins after phase 10 the cycle restarts to phase 01 which is when the aircraft is at the gate with engines off)

Using ATA's for Manuals

Another important piece of information in the PFR is the ATA code. ATA represents the ATA chapter of the first suspected component associated with the fault or warning. This code serves as an entry point to the technical documentation, specifically the AMM (Aircraft Maintenance Manual) and IPC (illistrated Parts Catalog) for that particular component. It helps in identifying the removal and installation procedures or provides additional guidance related to the warning or fault message and the GMT timestamp.

Additionally, the PFR provides details about the source of the fault message. The source refers to the system or computer that generated the maintenance message recorded by the CFDIU (Centralized Fault Data Interface Unit) for that particular event. Moreover, the PFR may indicate one or more identifiers, which are computers that have also reacted to the fault by generating external maintenance messages or cockpit effects.

Now, let's talk about correlation

The CFDIU performs correlation between fault messages to limit the number of printed fault messages and provide line mechanics with the root cause of a fault. This correlation is based on the GMT timestamp and the ATA chapter of the received fault messages. Similarly, correlation can be performed between fault messages and ECAM warnings or Maintenance Status, but this task falls under the responsibility of the line mechanic.

In some cases, a fault may appear and disappear multiple times during the same flight leg. In such situations, the corresponding fault message is transmitted only at the first detection, while the ECAM warning (for a Class 1 fault) or the Maintenance Status (for a Class 2 fault) is displayed every time in the cockpit and transmitted to the CFDIU. This means that you may find several instances of the same ECAM warning or Maintenance Status in the PFR, but only one fault message.

For better illustration, let's consider this example:

In this example, the fault message for "NAV ILS 1 FAULT(2)" appears several times during the flight. The number in parentheses (2) displayed after the Maintenance Status "NAV ILS 1 FAULT" indicates that this Maintenance Status was sent two consecutive times to the CFDIU for PFR recording

In addition, the PFR mentions that an ECAM warning or Maintenance Status can be associated with a system that is only shown as an identifier in the PFR. This indicates that the system is not the root cause of the fault.

To summarize the correlation process, it involves comparing the time/occurrence and ATA number of warning/maintenance status messages with those of fauilure messages and identifiers. Airbus allows 2 minutes plus or minus to group them together. The goal is to establish associations between them by selecting an entry point and identifying the associated fault message(s) or identifier(s). This process is repeated until all warning/maintenance status messages are correlated or when no further correlation is possible.

MCDU Correlation

Now, it's important to note that the correlation results are only available on the MCDU (Multipurpose Control and Display Unit) through the CFDS main page. Unfortunately, these results cannot be printed or sent to the ground station, and they are not memorized. If a correlation exists between a warning/maintenance status and a fault message, a prompt called the chevron pointing to the right line select keys is displayed next to the corresponding fault message or warning maintenance status on the MCDU. By pressing the corresponding MCDU line key, you can access the associated correlated effect or fault message.

In Conclusion

To conclude, the Post Flight Report (PFR) is a crucial document for maintenance personnel. It provides valuable information about warnings, maintenance status, and fault messages from the last flight leg. By understanding the PFR's content and the correlation principles, you can effectively troubleshoot issues and take appropriate maintenance actions based on the data provided. On the next video we will dive in and plug these corrolations into AirnavX so we can retreive the procedure in the Troubleshooting Mnauals for these faults.

-ERMSims