Section 2

Wiring Overview 07/2001 Pre Restoration

Key:

PD – Problem diagnosis

MEB- Master Equipment Bay

MRG-Master Reference Gyro

RF- Radio

All wiring to the rear fuselage runs through exterior cable ducting. Wiring is bunched with cable ties and guided along the ducting on glass fibre stays. Currently the ducting covers are present up to frame no 32, thereafter have been removed, facilitating airframe disassembly at the transportation joint. All sections of wiring are generally joined using inline connectors and crimps. Wiring sections are labeled at their extremities and crimp breaks, denoting individual circuit as well as overall bunch or bung ids’. This normally allows for individual cables and bungs to be identified and traced back to their respective circuits and functions for pd purposes or for re-joining upon re-build, after transportation.

ZF579 was broken at the transport joint upon retirement ready for sale. All cables and bungs traversing the transport joint were broken at the crimp and inline connector points, as per AP101…….

ZF579 was subsequently sold to a private party. All wiring emanating from the nose section conduits was cut inboard of the identity tags, and the 2-3 feet of wiring necessary to traverse the transport joint disposed of. (see plates????)

Currently, the wiring is in the condition described. Much of the wiring idents in the rear cable ducts have been allowed to weather from exposure over long periods (though most id tags are just about readable to record and re-tag). Nose section cable bungs have been cut parallel to the internal vertical conduits and are for the most part not identifiable.

This will make restoration difficult, since identifying the wiring will require removal of ejection seat and much equipment in the MEB bays, in order to find id tags at internal extremities, also within the cockpit section and respective fuse panels. Many circuits can be restored via continuity measures.

Wiring bungs to the main planes are good and have already been re-joined at the crimp and inline connector points, at regions JB7 and JB8 during fuselage re-assembly. All electrical services in the gear bays and main planes will be simple to restore. To this end the DC ground supply point and relay are already re-connected and the ground supply relay is functioning correctly thus restoring 28V DC supply (see plate below). AC ground supply has not been re-connected, this will require pre-function checks to make sure that the 200volt 3 phase supply bus is safe. All AC fuse and relay panel fuses have been removed, as well as various DC feeder fuse panel fuses, for safety, until circuits can be tested one at a time. The 115V AC inverter is functioning upon switching over the Master Instrument selector, indicating that the relevant under voltage phase sequence module is also functioning correctly. The condition of the stand by air emergency generator is unknown, requiring detailed inspection. The main generator supply cable runs along the s/b cable duct, joining forward of the transport joint. This cable is currently missing a 2-foot section and will require re-connecting. The internal condition of the main generator in the rear fuselage is good, though the drive turbine blades are rotten due to water ingress via the exhaust duct. It is advisable to remove it, preventing any further damage or corrosion. Fuses to sensitive equipment, e.g. MRG, RF etc have been removed to prevent damage. Generally wiring is in good condition due to the thick sheath protection. Most should be re-usable, and replacement Efglass and Tersil is still available. All electrical modules and components in the MEB’s are in good order, though some corrosion has taken place where dissimilar metals are in contact with one another i.e. multi-pole connectors.

Above and below plates show how all of the wiring looms have been cut inboard of the crucial identity tags.

Cockpit lighting services are restored after re-connection of the 28v DC bus.

Similarly below plate shows cockpit lighting again.