Aircraft Maintenance Management Aircraft Maintenance

Aircraft Maintenance Management

Aircraft Maintenance

There is only one reason to spend as much time, energy and money on aircraft maintenance as we do, to make sure you get to your destination safely and efficiently.

Modern maintenance enables the aircraft to remain at the highest possible levels of reliability, performance and safety, and the various studies and techniques used improve efficiency levels of technical intervention and maintenance.

Two functional models are used in a coordinated manner, preventive maintenance according to a set schedule, and requirement-based maintenance. This way, every part of every aircraft is regularly and thoroughly checked according to a maintenance cycle that takes place on a regular, progressive basis.

Testing procedures are repetitive, complex and meticulous, and are carried out using special test beds that allow our technicians to find the tiniest degree of wear or breakdown. The operations vary according to the type of aircraft, and are labeled a, B, C or D. Each letter represents a different testing phase, for which the engineer must check-off, sign and hand in a detailed checklist.

Under normal conditions, an aircraft is inspected after every flight and subsequently after every 500 flying hours (level a), after every 1,500 flying hours (level B), and after every 15-18 months (level C). Level D is assigned when a plane has been flying for several years and is sent for a complete overhaul. This takes over a month and every part of the aircraft is checked and replaced if necessary.

No part escapes in the testing process. The wings, fuselage and tail plane are stripped of paint using special products in carefully controlled environmental conditions. The same is done to all equipment and systems on board, including pumps, valves, regulators, radios and other instrumentation.

Set tests are carried out before every takeoff and after every landing and other repairs are made as needed to make sure the aircraft is fully prepared for its next flight.

Procedures:

Daily Inspection

The daily inspection ensures continuing safe operation of aircraft through visual and operational checks. It is made by the crew chief after the last flight of the day or before the next day's first flight. Because of the importance of keeping aircraft in a fully mission-ready status, it is preferable that the daily inspection be performed as soon as possible after the post flight inspection of the flight crew.

A daily inspection must be performed after a specified number of days if an aircraft has not flown during that period. The number of days specified varies with different aircraft. The exact interval for such inspections is found in the applicable aircraft technical manuals.

The removal of cowling and inspection plates is kept to a minimum. Disassembly of components is not required or desirable, unless faults found during the inspection make it necessary. The daily inspection includes checking for obvious damage, security of equipment installation and mountings, leaks, compliance with LO requirements, completeness of equipment, engine and equipment operation, and availability of current forms. Aircraft are not considered airworthy until this inspection is completed and noted on the DA Form 2408-13, Section 16 and Section 7 (Condition Status).

Special Inspection special inspection is one that is not tied to a set airframe inspection or operating time. This type of inspection includes inspections required by specific incidents, such as hard landings, over speed, or sudden stops; inspection on a calendar basis of details, such as safety belts, first-aid kits, weight and balance, and aircraft inventory; and specific inspections on aircraft engines based solely on operating time. These special inspections are made at the time specified in the applicable aircraft technical manuals.

Acceptance Inspection

An acceptance inspection is made on all newly assigned aircraft. Receiving organizations inspect the aircraft thoroughly to determine mechanical fitness for flight and completeness of equipment, forms, and records.

Transfer Inspection

The transferring unit according to TM1-1500-328-23 makes transfer inspections. If a command has jurisdiction over both the transferring and receiving organizations, it may, at its discretion, authorize transfer without completing the inspection. However, the aircraft is inspected to ensure that it is complete, and forms and records are examined to ensure that they are accurate and complete.

One-Time Inspection

The one-time inspection is made at the level of maintenance specified in the safety-of-flight message or technical bulletin. A technical examination is an inspection to check possible damage to an aircraft or to verify a condition that could affect safety of flight. The one-time inspection for aircraft is recorded on DA Form 2408-13-1 and DA Form 2408-15 (Historical Record for Aircraft). One-time inspections for installed components are recorded on DA Form 2408-13 and DA Form 2408-5-1 (Equipment Modification Record).

Flight Readiness Inspection

The aircraft crew prior to each flight makes a flight readiness inspection. Using the appropriate aircraft checklist ensures that the aircraft has been serviced, is airworthy, and has all necessary forms and records required for flight. The flight readiness inspection is often referred to as the preflight inspection.

Maintenance Test Flight Inspection maintenance test flight inspection is a flight for which the primary objective is to determine airworthiness of the aircraft. There are two categories of maintenance test flight inspections, the general test flight and the limited test flight. A general test flight is a detailed inspection intended to evaluate the airworthiness of the entire aircraft and prove all systems/components are functioning as prescribed in applicable aircraft maintenance manuals. The limited test flight evaluates whether a specific item/component of a system is functioning, using only the applicable portions of the Maintenance Test Flight Manual. Requirements for maintenance test flight inspections are contained in applicable aircraft maintenance manuals and TM 1-1500-328-23.

Post-Test Flight Inspection post-test flight inspection is required after each test flight. The flight crew and required maintenance personnel inspect the aircraft for any faults, which may have developed during the test flight.

Maintenance Operational Check (MOC)

An MOC consists of checks accomplished on the ground, through engine run-up, use of auxiliary power or test equipment, in such a manner as to simulate conditions under which the system is to operate. The purpose of an MOC is to ensure that aircraft systems, installed aviation associated equipment, and/or components that have been disturbed during an inspection or maintenance action have been repaired, reassembled, or adjusted satisfactorily.

Organizational Structures

The company will be organized into five major operational areas:

Flight Operations

Maintenance

Financial

Marketing

Customer Service

Methods of Performing Maintenance

A. Crew Chief

This is the primary method of performing maintenance on Army aircraft. It is accomplished by a crew chief assigned to the aircraft, which becomes the primary maintenance person for that aircraft. If the aircraft should require extensive maintenance, the crew chief will request and receive assistance from AVUM maintenance personnel.

B. Dock

This method is for aircraft undergoing extensive repairs or lengthy inspections. It uses a fixed maintenance dock or bay. The dock could be a location in a hangar or shop, a parking spot on the flight line, or any prearranged location. The aircraft normally remains in the maintenance dock until all maintenance is complete. Maintenance crews or teams rotate to and from the aircraft. The dock method is normally used at AVUM units, AVIM units, and depots.

C. Production line

This method is routinely used for aircraft undergoing extensive modifications or complete overhaul such as at an Army depot or contractor facility. It is similar to an automobile production line, except that the aircraft or components can be disassembled or assembled using this system. Examples of the production line method can be seen at any airline overhaul facility. The basic characteristic of this method is that the aircraft moves through the disassembly or assembly area as maintenance crews or teams perform their respective tasks at a fixed location.

Maintenance Levels

There are three levels at which maintenance is performed on aircraft that the United States Navy has in inventory at any given time: organizational, intermediate and depot. Each performs a specific function or serves a purpose such that anything required for the aircraft to be maintained in a fully operational status 365 days a year is immediately attended to with the utmost regard to quality and safety. Some repairs being either too time consuming or requiring expertise outside of the level is one of the primary reasons why maintenance is broken down into this three-part system.

A. Organizational

Maintenance of this type is defined by the efforts necessary required by a specific unit on a day-to-day basis to keep an airframe in an operational condition. In addition to the requirement of maintaining assigned aircraft and aeronautical equipment in a full mission capable status, O-level is also responsible for the continual improvement of the local maintenance process.

B. Intermediate

Maintenance required in support of operational activities. This includes the repair of specific parts unable to be refurbished at the organizational level and detailed maintenance of electronic components requiring specific equipment not peculiar to O-level. I-level is also responsible for maintaining a constant flow of necessary materials to operational assets with the lowest possible cost expenditure in order to maximize efficiency.

C. Depot

Occasionally in depth maintenance or complex repairs on an airframe is required to maintain equipment in an operational status. Depot level repairs would include major alterations or refurbishing of an asset due to age or upgrade far beyond the capabilities of the organizational level requiring industrial facilities not available elsewhere. Special Depot Level Maintenance (SDLM) commonly performs overhaul operations on airframes in need of such attention.

Aircraft Maintenance Elements

The aircraft maintenance elements of AVIM (Aviation Intermediate Maintenance) and AVUM (Aviation Unit Maintenance) units are responsible for unit-level maintenance of aircraft that is beyond the capability or responsibility of the crew chief.

A. Scheduled Maintenance

To effectively perform its mission, the aircraft maintenance section must perform the following scheduled maintenance tasks:

Perform scheduled phase/periodic maintenance inspections assisted by the crew chief and aircraft component repair section personnel.

Comply with SOF or unit-level TBs requiring onetime or recurring inspections of aircraft in coordination with the quality control element.

Perform operator maintenance on GSE assigned to the section.

B. Unscheduled Maintenance

The aircraft maintenance section will often have to perform unscheduled maintenance. This requirement normally results from the replacement of a component; for example, the crew chief needs help with replacement of a UH-60 main module. The crew chief or other personnel will handle the majority of unscheduled maintenance actions, as determined by the maintenance officer, in coordination with the appropriate company commander/platoon leader.

C. Deferred Maintenance

Minor faults noted during daily inspections that do not affect mission readiness or the safe operation of the aircraft might be deferred until the next scheduled inspection. The more faults deferred, however, the more delays when the aircraft receives scheduled maintenance. Minor faults deferred due to shop backlog or awaiting replacement parts will be reentered from DA Form 2408-13-1 (Aircraft Maintenance and Inspection Record) or DA Form 2408-13-3 (Aircraft Technical Inspection Worksheet) to DA Form 2408-14-1 (Uncorrected Fault Record Aircraft) only after a valid requisition document number or work order number has been received. The entries will be reentered back to DA Form 2408-13-1 and signed off when corrected. To ensure flight safety, the following factors must be considered before classifying a deficiency for deferred maintenance:

No flight safety faults are considered for deferred maintenance.

Aircraft must be grounded for maintenance if there is a reasonable doubt about flight safety.

A large number of deferred faults that do not present SOF problems on an individual basis may degrade aircraft reliability when considered collectively.

D. Other Duties

Aircraft maintenance element personnel may also provide maintenance support teams as required and assistance in maintaining GSE.

Aircraft Maintenance Reporting Requirements

Occurrences of the following events are required to be reported: