EAS425 Flight Line & Hangar Management Tutor Marked Assignment | SUSS

Question 1

Arrow Airways is a small airline based in Singapore. It operates a fleet of eight Airbus A319 passenger aircraft to provide commercial passenger services within the Asia Pacific region. The flight data for the aircraft fleet, as at 31 May 2025, is shown in Table Q1a. With no in-house engineering and maintenance setup within the airline, Arrow Airways has outsourced all its maintenance requirements to a SAR-145 approved aircraft maintenance service company, Mission MRO Services.

Table Q1 – Arrow Airways – Aircraft Fleet Data (as at 31 May 2025)

Table Q1a – Maintenance frequency and turnaround time for A319 family aircraft

• Construct a 1-year scheduled maintenance plan from 1 Jun 2025 to 31 May 2026 using the maintenance guidelines shown in Table Q1a. Analyse the aircraft availability for the A319 aircraft fleet every week. (20 marks)
• Arrow Airways plans to maintain a minimum of seven (7) serviceable aircraft available to support flight operations. Analyse if this operational target can be achieved through the 1 year from 1 Jun 2025 to 31 May 2026. Design improvements that can be made to the maintenance plan in situations when the aircraft availability falls below seven serviceable aircraft per week. (10 marks)

Question 2

Arrow Airways has also appointed Mission MRO Services to manage the inventory of its aircraft fleet. One of the routine responsibilities is to review the adequacy of aircraft rotable spares to support the service level targets demanded by Arrow Airways.

Five aircraft rotables (see Table Q2) are flagged for routine spare review. These rotables were highlighted by the Line Maintenance in Mission MRO Services for review due to increased failure rate and/or non-fulfilment of the part demands in the recent weeks. These aircraft rotables have no established repair capabilities in Singapore and need to be shipped to the authorised repair centres located overseas for all repair and maintenance services.

Table Q2

MPN – The material part number (MPN) is the unique reference number used to identify an aircraft part and is used to track all its part procurement and repair/services activities.

QPERAC – This is the number of units of an aircraft rotable effective on the aircraft type in which it is installed.

Flight Tasking – This is the number of flight hours per day of revenue flights that each aircraft of an aircraft type is assigned by the airline to fly. This is the average figure derived for the respective aircraft type in the prevailing month.

Field MTBR – The Mean Time Between Removals (MTBR) indicates the frequency with which an aircraft rotable is expected to be removed from the aircraft and hence the need for a replacement spare unit. The field MTBR of a rotorable is the average figure derived from the removal data collected over the preceding 12 months from the effective aircraft fleets.

Repair TAT – This is the expected turnaround time (TAT) taken to send an unserviceable aircraft rotable to the repair workshop for repair and servicing, and be returned to the airline’s storage warehouse. TAT will include the lead-time to repair and service the part, the total transportation time to and from the repair workshop, including cross-border customs delay, where applicable. A set of standard TAT figures of 30 days, 45 days, 60 days or 90 days are pre-set in the rotable spare analysis, based on the geographical locations of the authorised repair centres for the respective aircraft rotables. These repair TAT figures are pre-set in the initial spare provisioning plan agreed between the airline and the OEMS. They are not indicative of the repair TAT performance of the existing overseas repair centres.

Essential Code (ESS) – The aircraft manufacturer will provide the airline the Master Maintenance Essential List (MMEL), which lists the aircraft parts that are critical to aircraft flight operations, including details regarding how the aircraft may or may not be operated with the part inoperative. The essentiality code (ESS) essentially represents the criticality level of an aircraft part to the airline’s operation.

Arrow Airways has categorised the criticality of the aircraft rotables into three categories and defined the target service level for the respective category as follows:

Target Service Levels

• Essentiality Code 1 = 95%
• Essentiality Code 2 = 90%
• Essentiality Code 3 = 85%

Using the data provided in Table 1, apply the spare provisioning methodology stated in the IATA Guidance Materials for Inventory Management to evaluate the annual demand and pipeline demand for the five components and hence analyse if their current stock holding is adequate to support the target service levels demanded by Arrow Airways. Design the follow-up actions to address and improve any stocking shortfall. (20 marks)

Question 3

Appraise the scope of the maintenance tasks in the RCM Methodology, stating an example for each as an illustration. (6 marks)

Question 4

Using a relevant example, analyse the issuing organisation for each of the following documents and the condition(s) that need to be met before each document can be issued.

• Aircraft Type Certificate (4 marks)
• Certificate of Airworthiness (4 marks)
• Certificate of Registration (4 marks)

Question 5

By stating the objective and organisation that issued an Airworthiness Directive (AD), evaluate how the information provided by the document is provided. (7 marks)

Question 6

Table Q6 summarises the accumulated flight hours of a fleet of six Airbus A319 aircraft operated by an airline and the respective number of hours that each aircraft is tasked to fly per month. Analyse the potential risks to the aircraft availability for the aircraft fleet 4 months from now and design a plan to mitigate the risks identified.

Table Q6

(10 marks)

Question 7

The annual demand for aircraft hardware is 38,820 units, and each unit is priced at $60. The minimum stock level equivalent to 2 months of demand is to be maintained at all times. The local hardware supplier typically delivers the goods 3 days after receiving the purchase order. Appraise the term Re-Order Point (ROP) and evaluate the ROP value for this aircraft hardware. (5 marks)

Question 8

Analyse the underlying assumptions and principles used for rotable spare review to identify THREE (3) potential scenarios that could affect the accuracy of the rotable review. (10 marks)