When the Tornado was designed much thought was given to maintaining the airframe and systems. Many components and system do not have hard time limits, instead they are maintained 'on condition'. This means items are only replaced when a failure or lack of performance warrants it.
To achieve this extensive use is made of self checking fault detection facilities. Where items are safety critical or very expensive to repair a more traditional maintenance regime is followed and this items are checked at regular intervals and replaced when the limit is reached. The number of components that full in to this category have been minimised to reduce scheduled maintenance.
The airframe and systems contain extensive electronic systems to monitor the real time health of the numerous subsystems. Panavia estimated the that scheduled maintenance should be in the region of 4.5 direct maintenance man hours per flying hour. Original estimates were as follows,
Periodic inspections were scheduled for 300, 600, 900 Flying Hours.
To ensure high maintainability Panavia built the following features into the airframe and systems,
- Airframe mounted Auxiliary Power Unit
- Skin mounted Hydraulic Gauges
- Central Warning Panels/OCAM System Check
- Folding Radome and hinged Radar Mounting Ring
- Hinged Wind Shield(Forward Canopy)
- Ground Test Program for Main Computer
- LOX Converter changeable in 2 minutes
- Central Maintenance Panel
- 40% of the airframe surface is removable for maintenance
- Sub systems are built using Line Replaceable Units( LRUs) with no harmonisation required when replacing most LRUs
- On board Checkout and Monitoring (OCAM)
- Test access points on the few LRUs without built in test functions
- Stringent reliability specifications on all equipment
- Minimum Aerospace Ground Equipment (AGE) requirement
- Automatic Test Systems (ATS) at Base Second Level.