Engine Indicating — Full Parameter Scales and Red Lines
The parameters scattered through earlier articles (EGT, N1/N2/N3, oil, starter inlet…) are gathered here into one table of scales, red lines and amber limits, with the split between the E/WD (primary) and the ENG SD (system page). This is the yardstick every fault article (21–30) reads against.
1. The display split
- E/WD (Engine/Warning Display): thrust rating mode + thrust limit, EPR, N1, N3, EGT — the thrust and core parameters watched continuously.
- ENG SD (System Display) page: N2, F.USED, OIL (QTY/PRESS/TEMP), VIB (N1/N2/N3), IGN, START VALVE, starter inlet pressure, NACELLE TEMP — the system-monitoring parameters.
(Echoing the overview: N1·N3 on the E/WD, N2 on the ENG SD.)
2. E/WD primary parameters
CURRENT EGT — Green: normal range. The scale goes from 0 °C to 1 200 °C. Amber: exceeds the EGT limit. Red: above the EGT red limit — between 900 °C and 920 °C for more than 20 s, or exceeds 920 °C. EGT LIMIT — The maximum EGT is: 700 °C during the engine start sequence on ground, or 900 °C in all other cases. EGT RED LINE — The EGT red limit is 920 °C.
CURRENT N1 — Red: exceeds the N1 red limit. N1 red limit is 99 %. / N3 — Green: normal. Red: exceeds the N3 red limit. In a grey box: start sequence or crank in progress.
CURRENT EPR — Green: valid and engine in EPR mode. XX in amber: EPR not valid, or engine operates in N1 mode.
Per DSC-70-90-40: EGT scale 0–1200 °C, red line 920 °C; N1 red line 99 %; N3 in a grey box during start/crank; EPR shows XX in amber when EPR is invalid or in N1 mode (echoing the 03 EPR→N1 reversion).
3. ENG SD parameters
N2 — Red: exceeds the N2 red limit. N2 red limit is 103.3 %. / OIL QUANTITY — scale 0 to 22 QT. advisory limit is 4 QT. / OIL PRESSURE — scale 0 to 250 PSI. / OIL TEMPERATURE — Amber: above 190 °C.
STARTER INLET PRESSURE — Amber: Abnormally high, or Abnormally low (below 15 PSI, when N3 is above 8 % and the starter valve is not closed). / NACELLE TEMPERATURE — Pulses green: above the advisory limit. The advisory limit is 260 °C.
Per DSC-70-90-40: N2 red line 103.3 %; OIL QTY 0–22 QT (advisory 4 QT); OIL PRESS 0–250 PSI; OIL TEMP amber > 190 °C; starter inlet pressure amber if abnormally high or < 15 PSI (N3 > 8 %, start valve not closed); NACELLE TEMP advisory 260 °C.
4. The full scale / red-line table
The yardstick for the fault articles (shaft red lines confirmed against FCOM LIM-ENG):
| Parameter | Display | Scale | Amber / advisory | Red line |
|---|---|---|---|---|
| EGT | E/WD | 0–1200 °C | limit: start 700 °C / other 900 °C | 920 °C (or 900–920 °C > 20 s) |
| N1 | E/WD | — | limit (TOGA / MAX REV) | 99 % |
| N2 | ENG SD | — | — | 103.3 % |
| N3 | E/WD | — | grey box during start/crank | 100 % |
| OIL QTY | ENG SD | 0–22 QT | advisory 4 QT | — |
| OIL PRESS | ENG SD | 0–250 PSI | — | red (low) |
| OIL TEMP | ENG SD | — | > 190 °C amber | — |
| starter inlet P | ENG SD | — | < 15 PSI (N3 > 8 %, valve not closed) | — |
| NACELLE TEMP | ENG SD | 0–350 °C | advisory 260 °C | — |
[!note]- The three shaft red lines (LIM-ENG) The shaft-speed red lines come from FCOM LIM-ENG SHAFT SPEEDS: Maximum N1 = 99 %, N2 = 103.3 %, N3 = 100 %. (DSC-70-90-40 gives N1 and N2 in the display section but not N3; N3 is read from LIM-ENG.)
5. EGT — two lines
[!note]- EGT has two lines (integrative synthesis across verbatim) Two lines: an amber EGT limit (start 700 °C / other 900 °C — amber above it) and a red EGT red line of 920 °C (red above it, or 900–920 °C for more than 20 s). The ground-start amber line (700 °C) sits below the in-flight 900 °C — start is the hot-start-prone phase, so the bar is stricter. Directly relevant to Start Faults and EGT Overlimit.
6. Colour grading and counterintuitive points
| Colour | Meaning |
|---|---|
| Green | normal range |
| Pulsing green | advisory (OIL QTY 4 QT, NACELLE 260 °C) |
| Amber | exceeds limit (EGT limit, OIL TEMP > 190 °C, starter inlet abnormal, CLOG) |
| Red | exceeds red line (EGT 920 °C, N1 99 %, N2 103.3 %, N3 100 %) |
| Grey box | N3 start / crank in progress |
[!warning]- The EGT start amber line (700 °C) is below the in-flight one (900 °C) Start-sequence EGT limit 700 °C, in flight 900 °C (DSC-70-90-40) — start is hot-start-prone, the bar is stricter. The red line is 920 °C throughout.
[!warning]- An advisory (pulsing green) is not a warning OIL QTY 4 QT and NACELLE 260 °C are pulsing-green advisories, not amber/red warnings — mind the colour grading.
Self-test
[!note]- Q1. The N1 / N2 / N3 red lines? N1 99 %, N2 103.3 %, N3 100 % (LIM-ENG).
[!note]- Q2. EGT scale, red line, and start vs in-flight amber limits? The two red conditions? Scale 0–1200 °C, red line 920 °C; amber limit start 700 °C / in-flight 900 °C; red = 900–920 °C > 20 s, or > 920 °C.
[!note]- Q3. OIL QTY / PRESS scales, OIL TEMP amber? OIL QTY 0–22 QT (advisory 4 QT); OIL PRESS 0–250 PSI; OIL TEMP amber > 190 °C.
[!note]- Q4. When does starter inlet pressure go amber? Abnormally high, or < 15 PSI when N3 > 8 % and the start valve is not closed.
[!note]- Q5. Where are N1/N3 shown, where N2, and what does the N3 grey box mean? N1/N3 on the E/WD, N2 on the ENG SD; N3 grey box = start/crank in progress.
Key takeaways
| Point | Detail |
|---|---|
| Red lines | EGT 920 °C / N1 99 % / N2 103.3 % / N3 100 % |
| EGT two lines | amber limit start 700 / in-flight 900; red 920 (or 900–920 > 20 s) |
| OIL | QTY 0–22 QT (adv 4) / PRESS 0–250 PSI / TEMP amber > 190 °C |
| Starter inlet / nacelle | amber < 15 PSI (N3 > 8 %); NACELLE advisory 260 °C |
| Split | E/WD = EPR/N1/N3/EGT; ENG SD = N2/OIL/VIB/F.USED/IGN/START/starter/NACELLE |
References
- FCOM DSC-70-90-40 — E/WD + ENG SD parameter scales and limits (EGT, N1, N2, EPR, OIL, starter inlet, nacelle).
- FCOM LIM-ENG — shaft-speed red lines: Maximum N1 99 %, N2 103.3 %, N3 100 %.
- ENG SD page diagram — layout of N2 / F.USED / OIL / VIB / IGN / starter inlet / nacelle.
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.