Independent variables in the regression analysis
| Name | Type of variable | Description | Measuring | Source |
|---|---|---|---|---|
| Platform | Binary | There are 30 individual aircraft platforms, as delineated in Table I. The base case is the A-10 | Technology, complexity, etc. | LIMS-EV |
| Aircraft age | Continuous | Average age of all aircraft in the corresponding platform | Effects of age | LIMS-EV |
| Hours flown per aircraft | Continuous | Average hours flown per aircraft | Usage | LIMS-EV |
| Breaks per aircraft | Continuous | Average breaks incurred per aircraft | Reliability | LIMS-EV |
| Sorties per aircraft | Continuous | Average sorties flown per aircraft | Usage | LIMS-EV |
| Aborts per aircraft | Continuous | Average missions aborted on the ground or in the air per aircraft | Reliability | LIMS-EV |
| Cannibalization | Continuous | Average removals of a serviceable part from an aircraft or engine to replace an unserviceable part on another aircraft or engine | Maintenance practice | LIMS-EV |
| Repeat/recur per aircraft | Continuous | Average times a repeat discrepancy occurs on the same system or subsystem on the first through fourth sorties attempt after originally reported | Maintenance quality, test equipment, etc. | LIMS-EV |
| Mean Time Between maintenance (hours) | Continuous | Represents the average time between all maintenance actions, both corrective and preventive in hours | Reliability | LIMS-EV |
| Year | Binary | Includes years 1998-2017 | Fluctuations in requirements | LIMS-EV |
| Fleet size | Continuous | Number of aircraft in the inventory by platform type | Scale effects | LIMS-EV |
| Pilot reported discrepancy (PRD) per aircraft | Continuous | Average number of times a pilot reported a discrepancy per aircraft | Pilot assessment | LIMS-EV |
| Name | Type of variable | Description | Measuring | Source |
|---|---|---|---|---|
| Platform | Binary | There are 30 individual aircraft platforms, as delineated in | Technology, complexity, etc. | LIMS-EV |
| Aircraft age | Continuous | Average age of all aircraft in the corresponding platform | Effects of age | LIMS-EV |
| Hours flown per aircraft | Continuous | Average hours flown per aircraft | Usage | LIMS-EV |
| Breaks per aircraft | Continuous | Average breaks incurred per aircraft | Reliability | LIMS-EV |
| Sorties per aircraft | Continuous | Average sorties flown per aircraft | Usage | LIMS-EV |
| Aborts per aircraft | Continuous | Average missions aborted on the ground or in the air per aircraft | Reliability | LIMS-EV |
| Cannibalization | Continuous | Average removals of a serviceable part from an aircraft or engine to replace an unserviceable part on another aircraft or engine | Maintenance practice | LIMS-EV |
| Repeat/recur per aircraft | Continuous | Average times a repeat discrepancy occurs on the same system or subsystem on the first through fourth sorties attempt after originally reported | Maintenance quality, test equipment, etc. | LIMS-EV |
| Mean Time Between maintenance (hours) | Continuous | Represents the average time between all maintenance actions, both corrective and preventive in hours | Reliability | LIMS-EV |
| Year | Binary | Includes years 1998-2017 | Fluctuations in requirements | LIMS-EV |
| Fleet size | Continuous | Number of aircraft in the inventory by platform type | Scale effects | LIMS-EV |
| Pilot reported discrepancy (PRD) per aircraft | Continuous | Average number of times a pilot reported a discrepancy per aircraft | Pilot assessment | LIMS-EV |