Aviation360 MEA

Airworthiness of air forces’ aircraft fleets around the globe have a direct dependency on the engineering teams. 

A flying base is equipped with flying squadrons to support operations. These operational bases are scattered in different locations of the country, depending upon establishing the right point of defense against the adversary.  Operational Readiness of flying squadrons is the top priority of a flying base, and “Time” is the biggest rival because availability of aircraft for a specific mission has a direct bearing on the efficiency of engineering teams. 

Aircraft fleet in squadrons are primarily maintained at two levels of aircraft maintenance ecosystem: Line Maintenance and Base Maintenance. The third level of maintenance which caters for overhaul of Air Forces’ aircraft fleet is the Depot Level Maintenance. While line maintenance focuses on immediate troubleshooting and minor repairs, base maintenance involves comprehensive inspections and repairs.

Line Maintenance: Line maintenance refers to routine maintenance tasks performed on aircraft at the flying squadrons. It typically occurs at the line station, which is an operational location where aircraft arrive and depart. Line maintenance activities are aimed at promptly resolving minor issues, conducting inspections, and ensuring that the aircraft is safe and airworthy for its next flight. These tasks include visual inspections, fluid replenishment, tire changes, minor repairs, and troubleshooting of defects highlighted by the aircrew.

Due to the frequently short turnaround of aircraft, certified line maintenance technicians must work under strict time constraints. Only type certified technicians are authorized to undertake a maintenance task. This condition holds good for both line, base and depot maintenance. Maintenance tasks are conducted in accordance with the standard technical publications issued by the OEM (Original Equipment Manufacturer) with specialized tools and equipment. Those, who are authorized to work, are trained through a comprehensive training process; followed by an on-job training. A line maintenance facility has a defined work scope.

All types of offensive and defensive missions are launched from an operational base. For that matter, the primary objective of line maintenance is to ensure the operational integrity of the fleet and address immediate issues to ensure availability of aircraft for next mission. In case of an unscheduled maintenance which is beyond the work scope of the line maintenance, the aircraft is dispatched to base maintenance.

Base Maintenance: Base maintenance refers to comprehensive inspections and repair activities that require more time and resources. Generally, it takes place in a hanger. Base maintenance is primarily meant for scheduled maintenance. These are also known as Cyclic or Periodic Inspections, and they are meant for inspecting aircraft structure, aircraft components and power plant. Typically, base maintenance takes place at a dedicated maintenance facility or hangar, where aircraft undergo extensive maintenance checks and modifications. However, at times, there are also complex unscheduled engineering tasks that require expertise and down time. All such maintenance activities are also conducted at base maintenance.

Base maintenance involves thorough examination of various aircraft systems, such as the airframe, power plants, avionics and armament where it requires removal of components or systems for inspection, repair or replacement. This type of maintenance often follows predetermined maintenance intervals recommended by aircraft manufacturers and regulatory authorities.

The Helm of Engineering: Easier to say a lot about maintenance but there is a whole lot that goes behind the scenes. It takes thousands of man hours to accomplish maintenance tasks. Day in and day out, these technicians are employed to recover and produce aircraft. But this entire mechanism is driven by planning.

Planning: There is a structured process of planning for scheduled maintenance at line and base maintenance facilities. Three, most critical factors under consideration, during the planning phase are,

1. Operational cycle of the airframe
2. Operational cycle of components and their remaining life
3. Operational cycle of the engine(s) and its remaining life

Maintenance planning is not only confined to a single aircraft. By virtue of different operational hours and cycles, a gap is maintained between each aircraft of the fleet so that all aircraft do not fall for maintenance at the same time. For scheduled maintenance, flying squadrons maintain their own maintenance plan and they share the same with the base maintenance team. Unscheduled aircraft requiring detailed repair are allocated to the base maintenance for recovery. However, its recovery is managed through comprehensive planning so as to bring it online as soon as possible.

Maintenance Managers are supported by the tech teams responsible for the upkeep and maintenance of tech logs for each aircraft. These tech logs contain technical data of components installed on the aircraft. 

The planning process also entails forecasting of components and engines to always maintain an acceptable level of inventory. This ensures effective asset management that helps in timely recovery of aircraft falling under scheduled or unscheduled inspection. To be honest, “serviceability of fleet is 90% spares availability and 10% human resource management.” If you have the spares available, it is just a matter of time to recover the aircraft. Though, man hours vary; depending upon the nature of maintenance task, but it is not a major hurdle.

The Automated Logistic Management System has all the data available to ascertain the availability of a specific component. In case of any requirement not being met at the base, a particular component is moved from the warehouse through air lift / train / road transport to the designated base in least possible time. The aim is to ensure availability of the component for the aircraft under maintenance to get online at the earliest since operational requirements change with very short or no notice. The idea is to always keep aircraft in a fly worthy state. There are no second chances in a real time operational theatre.

Production: Production part comes after planning.  The aircraft inducted for cyclic or periodic inspections are moved through different phases of inspection. Each phase has a different timeline. The technical human resource is distributed as such to manage multiple docks at the same time. 

Each aircraft progresses in its designated timeline as it must undergo different types of inspections. The designated timeline window constitutes of specific number of days, depending on the extent of inspection. It includes removal of components, their operational check at the test stations, and installation back on the aircraft followed by a ground Quality Control check of different systems e.g. Landing Gears. After clearing QC Check, aircraft goes for ground power run before it is cleared for a check sortie. Once check sortie is cleared, aircraft is handed over to the flying squadron. 

Depot Level Maintenance: As mentioned earlier, there is also a third level of maintenance i.e. Depot Level Maintenance. The scope of work and expertise is much higher than the base maintenance. It is an extensive level of inspection which covers extensive removal of aircraft structural parts and engine. The aim of this inspection is to give additional life to its airframe. Line and base level inspections are conducted in between the overhaul life cycles. One major inspection at a depot is considered as one overhaul. Subsequently, aircraft also undergo second and third overhaul cycles before their airframe life is expired. Depending upon the condition, OEM may extend and authorize additional life to the airframe, but it varies from case to case. 

Modifications: Many a times, aircraft need modifications which are conducted by depot level maintenance teams. These modifications could be external, like installation of a fuel probe, for air to air refueling or internal, like installation of a new radio inside the cockpit. All modifications are validated by Quality Assurance team to approve the authentication of technical task in accordance with the technical bulletin issued by the Original Equipment Manufacturer. Sometimes, aircraft are positioned at depot for major retrofits and modifications which takes months to complete on the entire fleet. Sometimes, tasks are not too long and complex therefore, modifications are conducted at the base level maintenance facility. Aerial trials are then followed by these modifications. Many a times, Depot level teams conduct the first few modifications, and in parallel, train the base level teams to continue serial modification on the entire fleet.

Maintenance: The Backbone of Air Force: Air Force operations are a blend of teamwork between operations and maintenance domains. Air operations are very high tempo during real time conflicts. Efficiency of missions has a larger dependency on the quality of maintenance. Logistics play a pivotal role on the maintenance outcomes during time compressed environment. Efficient logistics improve the maintenance efficiency, as a greater number of defected aircraft come on line in less time. The essence of operations lies in the integrity of maintenance, and quality of work exhibited by the technical manpower, to execute technical tasks effectively and efficiently during the need of hour. It is therefore, righty declared as the “Backbone of the Air Force”.

Author

FAISAL BASHIR BHURA

Manager (Safety Management System)

Serene Air Pvt Ltd