A PDA, also called “Things Falling-Off Aircraft” (TFOA) is any piece of equipment falling from an aircraft, ranging in size from a simple rivet up to a fan cowl.

A PDA may lead to damage vital parts of the aircraft and/or cause serious or fatal injuries to passengers or people on ground. A part detached during take-off or landing may also represent a danger to following aircraft, if the part falls on the runway and is ingested by an engine or projected against a control surface for example.

(fig.1 and 2) Example of a lost potable water service panel that damaged the horizontal tail plane

In the vast majority of reported PDA events, they happened just after, or a few flights after, a maintenance task during which the affected part was opened, removed, re-installed or repaired.

Some reported events highlight the contribution of other factors independent of aircraft maintenance that can lead to parts detaching from the aircraft.

The parts which are usually reported as lost, or partially lost, include items such as:

• Wing leading/trailing edge access panels
• On-wing landing light lenses
• Hydraulic servicing panels
• Water servicing panels
• Wing shroud box panels
• Detached parts due to composite surface delamination
• Engine oil servicing panels
• Engine cowl doors
• Fuel servicing panels
• Antennas
• Wheel tie bolt.

The Airbus database shows in particular that the most affected parts are the servicing panels and antennas. These are parts which are frequently operated and particular attention should be paid to them.

Airbus data show that in 2025 more than 200 PDA events were reported. Although the trend shows that the number of reported PDA events is decreasing, today one PDA event is reported every 175 000 FH.

For more information on PDA, you can refer to:

• Maintenance Briefing Note 2025-MBN-00-0006-03-“Parts Departing from Aircraft (PDA)” available on the AirbusWorld portal
• “Preventing Fan Cowl Door Loss” Safety first article published in April 2018.

Preventing PDAs starts with a PDA-proof aircraft design, but it also requires a permanent vigilance of all the actors of the aircraft operations.

Mechanics may reduce the number of occurrences by accurately complying with the AMM/MP/AMP procedures, making sure they properly close all access panels and cowls after maintenance operations.

During the aircraft inspection, maintenance personnel should detect any elements that could lead to a PDA such as:

• improperly closed access panels,
• improperly latched engine cowls
• paint cracks or corrosion at the root of antennas,
• composite surface delamination,
• missing fasteners.

Flight crew should perform a thorough exterior walkaround before each flight, as per Standard Operating Procedures (SOP) and report any finding to the maintenance.

In the turn around of the aircraft many activities take place around the aircraft, notably servicing and refueling. Adding the variable of time, one might feel the pressure of time due to delays and or other factors, and be prone to forget to close the servicing panels.

As shown in the example mentioned above, such panels that are left unlocked could become PDA and cause damage to the aircraft itself, to the next aircraft departing or even people on ground.

This is why it is crucial that the ground handling team also ensure they remain vigilant by accurately following the procedures to the end, down to closing the panels correctly and clearing the area of any FOD.

By reporting all PDA events to Airbus, the engineering department contributes to the identification of areas where a design/procedure/training modification would reduce the risk.

The recurrence of similar PDAs across the whole Airbus aircraft fleet may highlight the need to modify the design of an aircraft component, amend a maintenance procedure or training.

The reporting of PDA is facili­­tated by the standardized PDA Reporting Sheet available in the Maintenance Documentation (fig.4) and the creation of a generic reporting e-mail address: pda.reporting@airbus.com.

(fig.4) Extract of a PDA Reporting Sheet

The PDA reporting sheet can be found in:

• A220 Aircraft Maintenance Publication J05-51-00-02 “Process for reporting a part departure from aircraft - Safety items and parts”
• A300, A310 Trouble Shooting Manual (TSM) chapter 05-50-00 “Part Found Missing during Walk Around Inspection or Maintenance Action or Servicing”
• A320 family, A330, A340, A380 Trouble Shooting Manual (TSM) chapter 05-50-00-810 “Part found missing during walk around inspection / maintenance action / servicing”
• A350 MP 05-51-45 “Part Found Missing during Walk Around Inspection/Maintenance Action/Servicing”

Additional information on PDA reporting to Airbus can be found on the AirbusWorld portal:

• ISI 05.50.00003 - How to report to Airbus a part found missing after a flight (PDA)
• OIT 999.0018/17 - ATA 05 - Reporting of Parts Departing from Aircraft (PDA)

Operators can regularly check the list of available solutions (Airbus Service Bulletins Technical Follow-up (TFU) or In-Service-Information (ISI) articles) to prevent PDA events, in the ISI 00.00.00184 “Part Departing From Aircraft (PDA) - Available Solutions To Avoid Pda Events” article available on the AirbusWorld portal.