HARD LANDING AND ABNORMAL RUNWAY CONTACT
AMM IMPROVEMENTS
ATR recently updated the Maintenance Procedure to be performed following Abnormal Runway Contact at landing, including Hard Landing events. It is the opportunity to provide the highlights of these changes.
Aircraft at landing
ATR highlights the flight operational advice to always target a firm landing. Therefore, we make a distinction between this & an abnormal runway contact, which may require maintenance action to safely return the aircraft to service.
What is the difference between a “Hard Landing” and an “Abnormal Runway Contact”?
The “Hard Landing” is one type of “Abnormal Runway Contact” at landing. “Abnormal Runway Contacts” at landing include but are not limited to hard landings, heavy landings, tail strikes, nose wheel first touchdowns. Each aircraft manufacturer provides its own definition of a hard landing. ATR’s definition was updated as follows:
A hard landing is a touchdown at landing with a high level of vertical ground loads and accelerations.
A hard landing can occur on one or both main landing gears first or on the nose landing gear first. It can also be combined with for example a tail strike or a landing with high lateral accelerations.
How to detect a hard landing (or other high loads abnormal runway contacts)?
Currently, the detection of a high loads event at landing relies upon the flight crew report. Some events are easily identifiable without doubt. However, in some cases, the distinction between an abnormal and a normal landing may be more subtle and difficult to identify in terms of flight crew’s perception (AIA Best Practices Guide).
We recommend to pay particular attention to the following cases:
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- Touchdown on the nose landing gear first;
- Touchdown with drift angle and/or lateral accelerations;
- Bounced landing often results in high acceleration events including touchdown on the nose landing gear.
For airlines practicing Flight Data Monitoring, an abnormal runway contact can be identified in the flight data. It represents a valid entry point for the Maintenance Procedure. We encourage the use of Flight Data Monitoring:
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- As a complement to the flight crew reports;
- For the development of SOPs and standardization.
Maintenance improvements
The purpose of the new procedure following hard landing events is to further enhance safety and at the same time improve the efficiency of returning an aircraft to service after an abnormal runway contact event. The main changes are:
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- The updated definition of “hard landing”;
- The addition of a flowchart defining the different steps of the maintenance procedure;
- A clarification of the applicability of the graph provided to determine a hard or overweight landing;
- Inclusion of the data collection sheet, which reflects priority of requested data;
- Inclusion of additional illustrations;
- Inclusion of the inspections previously provided upon request. These are divided into four levels depending on the severity of the event.
In summary the four levels are:
Level 1: inspections and checks of the airframe, landing gears and flight controls not requiring specific tools, or requiring tools that are available in any station.
Level 2: inspections requiring accesses or specific tools to be performed in case of damage found or landing gear(s) confirmed overloaded.
Level 3: inspections mainly of the nacelles and wing to fuselage junctions, requested by ATR for some specific events or in case of findings.
Level 4: further inspections of airframe and systems for the most severe events.
In addition, a procedure was created as an entry point for all the abnormal runway contact events (including hard landing).
Our AMM and associated recommendations will continue to evolve with in-service experience. We welcome your feedback on the updated procedure.
Should you have any question, please contact ATR’s technical support or flight operations support teams via “Request ATR” on the ATRactive portal (click here).
