Maintenance - PDMs and Emergency Repair

The number of PDM tabs has been expanded with some that have a frequency specified in flying hours and other in months.

The frequency of Emergency Repair actions is now specified in terms of Flying Hours rather than the Actions/1000 Flying Hours used in OSCAM Air v3. This makes it consistent with the specification for flying hours based PDMs.

There is no longer the ability to specify a capacity constraint for PDMs and Emergency Repair. Aircraft will start the PDM or Emergency Repair as soon as it is required.

Aircraft and Engine PDMs

The Maintenance sector has Aircraft PDM and Engine PDM sub-tabs. These contain inputs relating to maintenance that is scheduled to occur at intervals that make the aircraft unavailable to fly for a significant period (generally a month or more).

Option switches allow the choice of Simplified and Detailed PDMs. These switches can be set independently for Aircraft and Engine PDMs.

The Simplified representation allows Government and Contractor PDM costs to be specified in a dollars per aircraft per year basis. The PDM Downtime % input can be set that ensures that the appropriate proportion of the aircraft program is unavailable to squadrons each month due to PDMs.

Maintenance - PDM Simplified option

Simplified PDM option inputs

The Detailed representation allows a number of PDM programs to be defined. These allow an interval to be defined between PDMs with the amount of aircraft downtime each time an aircraft goes into the PDM and associated costs.

Maintenance - PDM Detailed

Detailed PDM inputs

Up to eight Aircraft PDM types can be defined; four types are flying hours based, and four types are months based. Up to eight Engine PDM types can be defined of which two are for whole engine PDMs (one is flying hours based and one is months based), and six are for engine modules (all flying hours based frequencies).

The structure of the inputs on all of the tabs is the same, except that the flying hours based PDMs have a PDM frequency in flying hours, while the months based PDMs have inputs for Time of First PDM and Frequency of PDM which are both specified as months. The Engine Module PDMs have an additional text input box that allows the module to be named.

Maintenance - flying hours-based PDM inputs

PDM frequency inputs based on flying hours

Maintenance - months-based PDM inputs

PDM frequency inputs based on elapsed time in months

All inputs on a tab are grayed out and the tab header is grayed until a non-zero PDM frequency is entered. A downtime can be specified for a PDM which represents the amount of time that an aircraft is grounded (a zero value can be used if there is no significant downtime). A cut-off time before retirement can be expressed. This will prevent any aircraft from going into a PDM once it is within a specified number of months away from retirement; instead the aircraft will continue flying until they retire. The OSCAM simulation will look at both the aircraft age and how close the aircraft is to its flying hours retirement ceiling when applying this retirement cut-off.

The percentage of repairs carried out at government depot and the percentage carried out at contractor depot is defined, as well as the associated government and contractor costs.

A Contractor Logistics Support (CLS) period can be defined that allows a more complex charging structure to be defined for carrying out the PDMs. A start month (after the introduction of the first aircraft) and duration in months defines the CLS period. During this time all cost inputs entered for CLS will override any information entered for government or contractor PDMs during the CLS period. CLS costs can be specified using any combination of cost per action, fixed annual cost, cost per aircraft and cost per flying hour.

Aircraft and Engine Emergency Repair

The Emergency Repair sub-tab contains inputs relating to failures that make the aircraft unable to fly for a significant period (usually a month or more). Emergency Repairs can be represented at either a Simplified level or a Detailed level for aircraft and engine failures. Check the box next to the Simplified inputs to use the Simplified representation and uncheck the box for the Detailed representation.

Maintenance - Emergency Repair

Emegency Repair with Detailed option selected

The Simplified level tracks the Emergency Repair cost per aircraft per year and the percentage downtime.

The Detailed level allows Emergency Repair frequency to be expressed in flying hours, and downtimes to be expressed in months (a zero value can be used if there is no significant aircraft downtime). All inputs are grayed out until a non-zero frequency is specified. A cut-off time before retirement can be expressed. This will prevent any aircraft from going into Emergency repair once it is a specified number of months away from retirement; instead aircraft will retire early. The OSCAM simulation will look at both the aircraft age and how close the aircraft is to its flying hours retirement ceiling when applying this retirement cut-off.

The percentage of repairs carried out at government depot and the percentage carried out at contractor depot is defined, as well as the associated government and contractor costs.

A Contractor Logistics Support (CLS) period can be defined. A start month (after the introduction of the first aircraft) and duration in months defines the CLS period. During this time all cost inputs entered for CLS will override any information entered for government or contractor Emergency Repair. CLS costs can be specified using any combination of cost per action, fixed annual cost, cost per aircraft and cost per flying hour.