Start Faults — Hot / Hung / No Light-Up, ENG START FAULT, Auto Abort
Starting gave the normal sequence and the FADEC's detection. This article opens the spectrum of starts gone wrong: what triggers ENG START FAULT, what each fault is (hot / hung / no light-up), how the FADEC aborts and protects automatically, and how the crew handles it. It is the core of ground-start monitoring.
1. Detection
Per DSC-70-80-30, the FADEC runs the sequence and detects the anomalies:
It provides: ‐ Detection of hot start, hung start, surge, no light up or N1 rotor locked ‐ FAULT announcement with specific ECAM message ‐ Start abort on ground (high pressure valve closure, start valve closure, ignition stopped) and automatic engine dry crank after start abort.
2. ENG START FAULT — six trigger conditions
ENG 1(2) START FAULT — This alert triggers when one of the following conditions is detected: ‐ Starter time exceeded, or ‐ Stall, or ‐ EGT overlimit, or ‐ No light up, or ‐ Low N1, or ‐ THR levers not at idle.
Per PRO-ABN-ENG, ENG START FAULT triggers on any of: starter time exceeded / stall / EGT overlimit / no light-up / low N1 / THR levers not at idle.
3. Three typical faults
| Fault | Sign | START FAULT condition |
|---|---|---|
| hot start | EGT exceeds the start limit (700 °C, 10) | EGT overlimit |
| hung start | speed sticks low, won't accelerate to idle | low N1 |
| no light-up | fuel supplied but not lit (residual fuel → wet) | no light-up |
| starter time exceeded | starter runs past its limit | starter time exceeded |
| start surge | surge during start | stall (full → 22) |
[!note]- The hot-start EGT limit is the start-specific 700 °C (synthesis, from 10) The start EGT amber limit is 700 °C (DSC-70-90-40), below the in-flight 900 °C — start is the hot-start-prone phase, so the bar is stricter. EGT above it → the START FAULT "EGT overlimit" condition. Same hot-start chain as 06's "residual EGT > 100 °C cranks first."
4. Auto start abort + dry crank
On a ground-start failure the FADEC automatically (DSC-70-80-30) closes the HP fuel valve + closes the start valve + stops ignition (cuts combustion), then runs an automatic dry crank (ventilate residual fuel / cool, 06/07) — protection without prior crew action.
5. Handling and counterintuitive points
ENG START FAULT handling includes (PRO-ABN-ENG):
THR LEVERS NOT AT IDLE — THR LEVERS ... IDLE
(The full ENG START FAULT steps are in PRO-ABN-ENG; the spurious-second-start logic is in 17.)
| Watch | Fault sign |
|---|---|
| EGT (start limit 700 °C) | rapid rise / exceedance → hot start |
| N3/N1 spin-up | sticks low → hung start |
| AVAIL | absent → start not achieved |
| START VALVE symbol | failed open/closed (14) |
| starter inlet P | < 15 PSI (N3 > 8 %) abnormal (10) |
[!warning]- On a ground-start failure the FADEC aborts + dry-cranks automatically, no prior crew action Hot/hung/no light-up etc. → the FADEC closes the HP valve + start valve + stops ignition + automatic dry crank (DSC-70-80-30). The crew follows the ECAM (e.g. THR LEVERS → IDLE, MASTER → OFF).
[!warning]- The start EGT limit (700 °C) is below the in-flight one (900 °C) Start-specific amber limit 700 °C (10) — a stricter hot-start bar. And residual EGT > 100 °C cranks first (06).
Self-test
[!note]- Q1. The six ENG START FAULT conditions? starter time exceeded / stall / EGT overlimit / no light-up / low N1 / THR levers not at idle.
[!note]- Q2. Hot start / hung start — which condition each? hot start = EGT overlimit (start limit 700 °C); hung start = low N1.
[!note]- Q3. What does the FADEC do automatically on a ground-start failure? Close HP valve + close start valve + stop ignition (start abort) + automatic dry crank.
[!note]- Q4. The start EGT limit, and why below the in-flight one? 700 °C (in flight 900 °C); start is the hot-start-prone phase, a stricter bar.
Key takeaways
| Point | Detail |
|---|---|
| START FAULT | starter time / stall / EGT overlimit / no light-up / low N1 / THR not idle |
| Typical | hot = EGT overlimit (700 °C) / hung = low N1 / no light-up |
| Auto | FADEC abort (close HP + start valve + stop ignition) + dry crank |
| Handling | THR LEVERS → IDLE; spurious second-start logic in 17 |
References
- FCOM PRO-ABN-ENG — ENG START FAULT six conditions + THR LEVERS → IDLE.
- FCOM DSC-70-80-30 — FADEC detection (hot/hung/surge/no light-up/N1 locked) + ground start abort + automatic dry crank.
- FCOM DSC-70-90-40 (10) — start EGT limit 700 °C.
Independent study material, not an Airbus publication and not endorsed by the manufacturer. Always defer to the current operator FCOM, FCTM, and QRH for operational use.