In the aviation industry, safety and reliability are paramount, complex system of maintenance operations ensures that aircraft are airworthy, and passengers reach their destinations safely. At the heart of this system are two key components: the AMP (Aircraft Maintenance Program) and the LDND (Last Done Next Due) tracker.

The AMP is the roadmap for aircraft maintenance, detailing every task required to keep the aircraft airworthy along with its interval (when to repeat it) and threshold (when to initially carry it out). From routine inspections to major overhauls, the AMP specifies what needs to be done and when and managing the AMP is no simple task. It involves tracking countless components with varying lifespans and maintenance requirements – this is where the Last Done and Next Due (LDND) comes in.

Read More

Aircraft lease returns represent a complex intersection of Aircraft Maintenance Programs (AMPs), lease return conditions, and the preservation of asset value for subsequent leases which often use MPD (Maintenance Planning Data) information. Understanding the interplay between these factors is imperative for both lessors and operators to facilitate a seamless transition at the conclusion of a lease term and it is a good example of where airworthiness which is based around the AMP meets commercial lease obligations often built around the MPD which is essentially a more generic document.

Traditionally, operators relied on a phased or block maintenance approach, where standardized checks (A-checks, C-checks, etc.) were performed at fixed intervals. While this system offers predictability, it can lead to calling tasks before they have reached their full potential and required longer blocks of ground times for scheduled maintenance inputs at A and C checks for example.

In an attempt to optimize aircraft availability during a lease period the operator might use equalized maintenance which breaks down larger phased or block maintenance events and distribute tasks over time when the aircraft has operational ground time.

Read More

The Boeing Maintenance Planning Document (MPD) is an essential tool in planning aircraft maintenance, providing a comprehensive guide to managing the maintenance programs for various Boeing aircraft models. This document outlines the procedures and recommendations for maintaining aircraft airworthiness and safety, focusing on long-term efficiency and reliability.

Overview of the Boeing MPD

The MPD is structured to offer a systematic approach to maintenance, applicable to different Boeing models, such as the 737 and 777. It details the necessary tasks, divided into specific sections and appendices, that guide maintenance teams on routine checks, repairs, and replacements. The MPD is a generic document, which means it must be adapted into a tailored Aircraft Maintenance Program (AMP) that addresses the specific needs and configurations of individual aircraft.

Read More

Aircraft Maintenance Programs (AMPs) provide a structured framework for ensuring the continued airworthiness of aircraft.  A critical element within these AMPs is the management of Hard Time (HT) components. These components have strict lifespans measured in flight hours, cycles, or calendar time, requiring work such as an overhaul at designated intervals.

Last Done Next Due and Hard Time Tracking

The Last Done Next Due (LDND) is integral to effective maintenance planning, it is the heart of the planning and used to schedule long and short-term planning. It involves meticulously tracking when maintenance tasks were last performed and when they are next scheduled. For HT components, this means knowing the date or flight hours/cycles (FH/FC) of the last time the required task was carried out such as an overhaul and comparing this to the component’s specified lifespan.

Read More