Aircraft maintenance
Aircraft maintenance is carried out by a maintenance organization - in compliance with the Ordinance on Testing Aviation Equipment (LuftGerPV) - on the aircraft and its components in order to keep the aircraft safe and ready for daily flight operations. The work includes various penetration depths from short-term repairs on the ramp (airport apron) during flight operations to complete dismantling and reassembly of the entire aircraft in the so-called D-Check . The term is not limited to the entire aircraft, but is also used for subsystems such as B. the engines or attachments, such as generators, etc. out.
Definition of aircraft maintenance
The term maintenance is used as a generic term in aircraft maintenance. Aircraft maintenance includes the following four terms:
- maintenance
- Preservation of the target state
- inspection
- Establishing and assessing the current situation
- Repair
- Restoration of the target state
- improvement
- Installation of the modifications required by the authority ,
- if necessary, the modifications recommended by the manufacturer.
For example, the following measures are carried out during the maintenance of an aircraft: cleaning, preservation, lubrication, supplementation of operating materials, replacement and readjustment or adjustment.
Branch
To these complex logistics processes to own industry has developed with over $ 36 billion in annual revenue, which in Germany through the maintenance subsidiary of Deutsche Lufthansa that Lufthansa Technik AG is headed. Other European companies are MTU Maintenance , Air France Industries, KLM Engineering & Maintenance, Iberia, TAP Air Portugal, Finnair Technical Services and a number of independent companies (Avcon Jet AG, Jetalliance Technical Services GmbH, SR Technics Group , Jet Aviation , EIS Aircraft GmbH, Atlas Air Service AG ). Another well-known company in this area up to its business end was Air Berlin Technik GmbH .
Maintenance of commercial aircraft
The maintenance of commercially used aircraft, especially commercial aircraft , is regulated even more strictly in accordance with Annex II of EU Regulation 1321/2014 (Part 145) and includes time-dependent or flight-hour-dependent events for each important component, which can be summarized in blocks. The work is divided into routine, nonroutine and modification work.
The maintenance and repair concept for a commercial aircraft consists of maintenance and repair events, so-called letter checks (A, B, C and D checks). A-checks are carried out most frequently, the B-check, for example, every six months, a C-check is carried out about every two years and takes a few days. The D-Check is the longest event and occurs every 6-10 years. The standstill of the aircraft during maintenance means unproductive time for airlines. The shortest maintenance work is therefore carried out in night shifts . The re-provision of aircraft arriving, including short-term repairs to the aircraft on the airport apron, is called line maintenance.
Routine work can be planned in advance and must be repeated at certain intervals in accordance with the MPD ( maintenance planning document ) (examples: various filter changes / filter cleaning, replacement of wearing parts, also: hangaring / dehangaring, carrying out inspections and controls).
Non-routine work includes the elimination of the findings recorded by the inspections and controls (finding: deviation of the actual condition of the aircraft) compared to the target condition (Structure Repair Manual, Aircraft Maintenance Manual, construction drawings, ...). Non-routine work is difficult or impossible to plan.
The work package modification includes the implementation of conversions, checks, modifications or improvements prescribed by the aircraft manufacturer or the aviation authority.
Approved maintenance
All checks are carried out according to an officially approved maintenance program. Every operator is obliged to have such a maintenance program approved by his responsible aviation authority. Such a maintenance program is always related to a specific aircraft type. It can be created by the operator himself or a service provider, or it can be purchased from the aircraft manufacturer. The framework for this is the maintenance manual , which is supplied by the aircraft manufacturer. It is a recommendation, but various other requirements must be taken into account.
The intervals between the checks therefore differ considerably from aircraft type to aircraft type and sometimes from airline to airline, depending on the maintenance program being used. The intervals specified in the maintenance program must be adhered to; if exceeded, measures by the aviation authority are imminent.
A-check (minor check)
The A-Check is a maintenance event with routine checks of technical systems that are important for flight operations , as well as thorough maintenance of the cabin. An A-check is due every 250 to 650 flight hours, depending on the type of aircraft, i.e. about every two months.
A-checks are the most common. Due to the limited scope of the work to be carried out and the low “penetration depth”, they can be carried out within one night (in the hangar); the aircraft need not be taken out of flight operations.
B-check
The B-Check is a supplement to the A-Check and usually takes place every three to four months, i.e. about every 1000 flight hours. However, this check is now only available for the aircraft types Boeing 737-200 and Boeing 747-200.
Work will be carried out that will dig deeper into the airframe and systems. The duration of this check is approx. 150 working hours, so the aircraft is taken out of flight for at least twelve hours.
C-Check (Major Check)
A C-Check is the detailed inspection of the aircraft structure and a thorough test of the systems, for the most part the fairing is removed and all seats are removed. A C-Check takes place every 15 to 18 months, depending on the type of aircraft; the aircraft remains in the hangar for around one to two weeks. A C-check of this kind comprises approx. 5000 working hours.
IL check (intermediate layover)
In-depth control of all components of the structure, fuselage and wings. Checking and, if necessary, repairing the devices (electronics, hydraulics). Installation of product improvements by the manufacturer, complete overhaul of the cabin. An IL check usually takes place every 48 months.
D-check
The D-Check is equivalent to a major overhaul and is the most intensive, longest and most expensive maintenance event. It takes place roughly every six to ten years (after 55,000 flight hours on a Boeing 747-400). The aircraft is exposed down to the basic structure and may have to be repainted afterwards. In the course of the D-Check, 30,000 to 50,000 working hours are required. A D-Check takes about four to six weeks and can cost several million euros.
MRO Consultants
There are companies that specialize in advising airlines on this matter. These are known as MRO Consultants . MRO stands for Maintenance, Repair, Overhaul .
Smaller airlines in particular often use these services to check their interests in the overhaul of the aircraft or its components. Some of these consulting firms operate worldwide, e. B. Bureau Veritas , others are smaller in comparison, but specialized in the aviation sector, such as B. AeroStrategy.net, based in London (UK), Ann Arbor (US), as well as the boutique aviation strategy consultancy ADAVCO in Germany.
See also
- Aircraft On Ground (AOG)
Individual evidence
- ^ Company presentation ( memento of July 1, 2012 in the Internet Archive ), accessed on April 28, 2019
- ↑ One day at Line Maintenance , Swiss Blog, December 8, 2014
- ↑ aircraft maintenance. In: The fear of flying portal. Archived from the original on February 10, 2013 ; accessed on October 14, 2018 .