Login
Register
Electrical Emergency
Occurs when all AC buses are lost. The emergency generator supplies 5.5 kVA, 3-phase, 115/200 V, 400 Hz power. When it is powered by the RAT, it supplies 3.5 kVA.
If AC buses 1.1 and 2.4 are lost, the emergency generator driven by the green hydraulic system feeds AC and DC essential buses. If engines 1 and 4 have also been lost, the RAT automatically deploys. Once the emergency generator is running, FMGEC 1 and 2 are lost, and only MCDU 1 is available in nav backup mode. The AP and A/THR are not available. Navaids must be tuned using the RMP. HF 1 and radar are also lost (different to the A330).
A330/A340 comparison
| A330 | A340 | |
| Instruments | PFD 1, E/WD-ECP, ND 1, standby instruments | PFD 1, E/WD-ECP, standby instruments |
| Autoflight | FMGEC 1, AP/FD 1 | MCDU on NAV BACK UP |
| Flight Controls | Alternate Law | Alternate Law |
| Navigation | 2 IRS, 2 ADR, ND 1, MCDU for navaid tuning | 2 IRS, 1 ADR, DDRMI, RMP for navaid tuning |
| After Land Recovery pb set to On | ||
| Autoflight | Manual | Manual |
| Flight Controls | Direct Law (when L/G down) | Direct Law (when L/G down) |
| Navigation | ILS 1 restored, radar lost | ILS 1 restored |
| Communication | HF 1 lost | - |
| L/G Extension | Gravity, BSCU 1 restored, Anti-Skid available | Gravity, LGCIU 1 |
Table: Electrical availability during electrical emergency
See also
Categories: Airbus A340 | Electrical System | Electrical Emergency